Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
City of SLO Final WRRF Facilities Plan_20150629
Water Resource Recovery Facility Facilities Plan City of San Luis Obispo San Luis Obispo, CA June2015 Water Resource Recovery Facility Facilities Plan Prepared for: City of San Luis Obispo June 2015 Prepared under the responsible charge of: Holly Kennedy, P.E. 2121 North California Blvd., Suite 475 Walnut Creek, CA 94596 Holly Kennedy NO. 74682 Page i Contents 1. Executive Summary ............................................................................................................... 1-1 1.1.Background .......................................................................................................................... 1-1 1.2.Project Overview .................................................................................................................. 1-1 1.3.Project Vision and Objectives .............................................................................................. 1-3 1.4.Water Resource Recovery ................................................................................................... 1-3 1.5.Flow and Load Projections ................................................................................................... 1-4 1.6.Capacity Assessment Recommendations ............................................................................ 1-4 1.7.Treatment Plant Upgrades ................................................................................................... 1-5 1.8.Site Plan ............................................................................................................................... 1-6 1.9.Construction Sequencing ..................................................................................................... 1-6 1.10.Implementation Schedule ................................................................................................. 1-15 1.11.Opinion of Probable Cost ................................................................................................. 1-15 1.12.Next Steps ....................................................................................................................... 1-16 2. Introduction ............................................................................................................................. 2-1 2.1.Background .......................................................................................................................... 2-1 2.2.Project Overview .................................................................................................................. 2-1 2.3.Project Vision and Objectives .............................................................................................. 2-2 2.4.Report Organization ............................................................................................................. 2-5 2.5.Abbreviations and Acronyms ............................................................................................... 2-6 3. Existing Facility ...................................................................................................................... 3-1 3.1.Existing Treatment Facilities ................................................................................................ 3-1 3.1.1. Preliminary Treatment ............................................................................................ 3-3 3.1.2. Primary Clarification ............................................................................................... 3-7 3.1.3. Flow Equalization ................................................................................................... 3-8 3.1.4. Biofilters ................................................................................................................. 3-9 3.1.5. Activated Sludge Process .................................................................................... 3-12 3.1.6. Filter Feed Flow Equalization and Pumping Station ............................................. 3-15 3.1.7. Cooling Towers .................................................................................................... 3-15 3.1.8. Filtration ............................................................................................................... 3-16 3.1.9. Disinfection ........................................................................................................... 3-17 3.1.10. Recycled Water .................................................................................................... 3-18 3.1.11. Plant Water .......................................................................................................... 3-19 3.1.12. Dissolved Air Flotation Thickener ......................................................................... 3-19 3.1.13. Anaerobic Digesters ............................................................................................. 3-21 3.1.14. Dewatering and Storage ...................................................................................... 3-22 3.1.15. Supernatant Lagoon ............................................................................................. 3-23 3.2.Existing Plant Operation ..................................................................................................... 3-24 3.2.1. Wet Weather Operation ....................................................................................... 3-24 3.2.2. Discharge Permit Compliance .............................................................................. 3-25 3.2.3. Operations ............................................................................................................ 3-27 WRRF Project Contents Page ii 3.2.4. Water Quality Laboratory ..................................................................................... 3-27 3.2.5. Operational Issues ............................................................................................... 3-28 3.3.Condition Assessment of Existing Treatment Plant ............................................................ 3-29 3.4.Existing Site and Surroundings .......................................................................................... 3-32 3.5.Existing Traffic and Access around Site and Site Security ................................................. 3-32 3.6.Existing Site Topography ................................................................................................... 3-33 4. Regulatory Compliance ......................................................................................................... 4-1 4.1.Renewed Permit Conditions ................................................................................................. 4-1 4.1.1. Nutrients ................................................................................................................. 4-1 4.1.2. Disinfection Byproducts .......................................................................................... 4-3 4.1.3. Nitrosamines .......................................................................................................... 4-3 4.1.4. Dissolved Oxygen .................................................................................................. 4-3 4.1.5. Temperature ........................................................................................................... 4-3 4.2.Future Limits ........................................................................................................................ 4-3 4.2.1. Role of Water Conservation ................................................................................... 4-3 4.2.2. Role of Recycled Water ......................................................................................... 4-4 4.2.3. Nutrients ................................................................................................................. 4-5 4.2.4. Contaminants of Emerging Concern ...................................................................... 4-5 4.2.5. Human Health Criteria ............................................................................................ 4-6 4.2.6. Disinfection Indicators ............................................................................................ 4-6 4.2.7. Biosolids ................................................................................................................. 4-6 4.2.8. Air Emissions ......................................................................................................... 4-6 5. Flow and Load Projections .................................................................................................... 5-1 5.1.Existing Conditions ............................................................................................................... 5-1 5.1.1. Existing Flow and Loads ........................................................................................ 5-1 5.1.2. Peaking Factors ..................................................................................................... 5-1 5.2.Projections ........................................................................................................................... 5-2 5.2.1. Population Projection ............................................................................................. 5-2 5.2.2. Land Use/Development Projection ......................................................................... 5-3 5.2.3. Flow Projections ..................................................................................................... 5-3 5.2.4. Load Projections .................................................................................................... 5-4 5.2.5. Summary of Flow and Load Projections ................................................................. 5-4 6. Capacity Assessment ............................................................................................................ 6-1 6.1.Flow Equalization ................................................................................................................. 6-1 6.1.1. Diurnal Equalization ............................................................................................... 6-1 6.1.2. PWWF Equalization ............................................................................................... 6-2 6.2.Approach .............................................................................................................................. 6-5 6.3.Liquid Unit Processes .......................................................................................................... 6-7 6.4.Solid Unit Processes ............................................................................................................ 6-9 6.5.Capacity Assessment Recommendations ............................................................................ 6-9 7. Treatment Plant Upgrades ..................................................................................................... 7-1 7.1.Flow Equalization ................................................................................................................. 7-1 7.1.1. Diurnal Equalization ............................................................................................... 7-1 7.1.2. Wet Weather Equalization ...................................................................................... 7-1 7.1.3. Filter Feed Equalization ......................................................................................... 7-2 7.2.Headworks ........................................................................................................................... 7-2 7.3.Primary Clarifiers and Sludge Pumping ............................................................................... 7-2 WRRF Project Contents Page iii 7.4.Secondary Treatment ........................................................................................................... 7-3 7.4.1. Secondary Treatment Alternatives ......................................................................... 7-3 7.4.2. Recommended Secondary Treatment Technology ................................................ 7-5 7.4.3. High Rate A/B ........................................................................................................ 7-9 7.5.Tertiary Filtration ................................................................................................................ 7-10 7.5.1. Filtration Alternatives ............................................................................................ 7-10 7.5.2. Evaluation of Filtration Alternatives ...................................................................... 7-11 7.5.3. Recommendation ................................................................................................. 7-14 7.6.Cooling ............................................................................................................................... 7-14 7.6.1. Cooling Alternatives ............................................................................................. 7-16 7.6.2. Evaluation of Cooling Alternatives ........................................................................ 7-16 7.6.3. Recommendation ................................................................................................. 7-18 7.7.Disinfection ........................................................................................................................ 7-18 7.7.1. Technology Evaluation ......................................................................................... 7-18 7.7.2. UV Disinfection Recommendations ...................................................................... 7-20 7.8.Solids Thickening ............................................................................................................... 7-22 7.8.1. Technology Evaluation ......................................................................................... 7-22 7.8.2. Solids Thickening Recommendations .................................................................. 7-25 7.9.Anaerobic Digesters ........................................................................................................... 7-26 7.10.Biosolids Dewatering ........................................................................................................ 7-26 7.11.Sidestream Treatment / Return Stream Management ...................................................... 7-27 7.11.1. Sidestream Treatment / Return Stream Management Comparison ..................... 7-27 7.11.2. Recommended Sidestream Treatment Technology ............................................. 7-33 7.12.Odor Control..................................................................................................................... 7-34 7.13.Summary of Recommended Treatment Upgrades ........................................................... 7-35 8. Hydraulics ............................................................................................................................... 8-1 8.1.Existing Hydraulic Profile ..................................................................................................... 8-1 8.2.Proposed Hydraulic Profile ................................................................................................... 8-1 8.2.1. Wet Weather Equalization Hydraulics .................................................................... 8-1 9. Operational and Control Strategies ...................................................................................... 9-1 9.1.Operational Strategy ............................................................................................................ 9-1 9.1.1. Dry Weather Operation .......................................................................................... 9-1 9.1.2. Wet Weather Operation ......................................................................................... 9-2 9.2.Preliminary Control Strategy ................................................................................................ 9-2 9.2.1. Wet Weather Flow Equalization ............................................................................. 9-2 9.2.2. Influent Flow Measurement .................................................................................... 9-3 9.2.3. Diurnal Flow Equalization ....................................................................................... 9-3 9.2.4. Grit Removal .......................................................................................................... 9-3 9.2.5. Aeration Basins/Secondary Treatment ................................................................... 9-3 9.2.6. Final Clarification .................................................................................................... 9-5 9.2.7. Effluent Cooling ...................................................................................................... 9-5 9.2.8. UV Disinfection ....................................................................................................... 9-5 9.2.9. Solids Thickening ................................................................................................... 9-6 9.2.10. Anaerobic Digestion ............................................................................................... 9-6 9.2.11. Sidestream Treatment ............................................................................................ 9-6 10. Additional Upgrades ............................................................................................................ 10-1 10.1.Electrical System Upgrades ............................................................................................. 10-1 WRRF Project Contents Page iv 10.1.1. Existing Facilities .................................................................................................. 10-1 10.1.2. Electrical Loads .................................................................................................... 10-3 10.1.3. Major Electrical Equipment Condition Assessment .............................................. 10-4 10.1.4. Electrical System Recommendations ................................................................... 10-6 10.2.Instrumentation and Control Upgrades .......................................................................... 10-10 10.2.1. Existing SCADA and PLC System ..................................................................... 10-10 10.2.2. Existing SCADA Equipment ............................................................................... 10-10 10.3.WRRF Controls .............................................................................................................. 10-11 10.4.SCADA System Improvements ...................................................................................... 10-12 10.5.Stormwater Management ............................................................................................... 10-13 10.5.1. Existing Conditions ............................................................................................. 10-14 10.5.2. Site Drainage Recommendations ....................................................................... 10-14 10.5.3. Recommended Flood Protection Improvements ................................................ 10-19 10.5.4. Other Stormwater Management Considerations ................................................ 10-20 10.6.Renewable Energy ......................................................................................................... 10-20 11. Building Programming ......................................................................................................... 11-1 12. Site Planning ......................................................................................................................... 12-1 12.1.Facilities to be Demolished .............................................................................................. 12-1 12.2.Locations for New Treatment Facilities ............................................................................ 12-1 12.3.Access and Security ......................................................................................................... 12-2 12.3.1. Perimeter Access ................................................................................................. 12-2 12.3.2. Vehicle Access ..................................................................................................... 12-2 12.3.3. Intrusion Detection ............................................................................................. 12-11 12.3.4. Building Access .................................................................................................. 12-11 12.3.5. Interior Sensitive Areas ...................................................................................... 12-11 12.3.6. Remote Buildings ............................................................................................... 12-11 12.3.7. Security System Integration ............................................................................... 12-12 13. Project Implementation ........................................................................................................ 13-1 13.1.Permitting Considerations ................................................................................................ 13-1 13.1.1. Environmental Permit Strategy ............................................................................. 13-1 13.1.2. Project Permits ..................................................................................................... 13-2 13.2.Construction Sequencing Considerations ........................................................................ 13-2 13.3.Implementation Schedule ................................................................................................. 13-5 13.4.Opinion of Probable Cost ................................................................................................. 13-6 13.5.O&M Costs ....................................................................................................................... 13-7 13.6.Next Steps ....................................................................................................................... 13-9 14. References ............................................................................................................................ 14-1 List of Tables Table 1 1. Renewed NPDES Discharge Limits for Selected Pollutants (R3-2014-0043) ................. 1-2 Table 1 2. Summary of Projected Flows and Loads ......................................................................... 1-4 Table 1 3. Opinion of Probable Construction Costs ....................................................................... 1-16 Table 3 1. Existing Preliminary Treatment Facilities ......................................................................... 3-3 Table 3 2. Existing Primary Clarification Facilities ............................................................................ 3-7 WRRF Project Contents Page v Table 3 3. Existing Flow Equalization Facilities ................................................................................ 3-8 Table 3 4. Existing Biofilter Facilities ................................................................................................ 3-9 Table 3 5. Existing Activated Sludge Facilities at the WRRF ......................................................... 3-12 Table 3 6. Existing Cooling Tower Facilities at the WRRF ............................................................. 3-15 Table 3 7. Existing Filtration Complex Facilities at the WRRF ....................................................... 3-17 Table 3 8. Existing Disinfection Facilities at the WRRF .................................................................. 3-17 Table 3 9. Existing Plant Water (3W) Facilities at the WRRF ......................................................... 3-19 Table 3 10. Existing Thickening Facilities at the WRRF ................................................................. 3-20 Table 3 11. Existing Digestion Facilities at the WRRF ................................................................... 3-21 Table 3 12. Existing Dewatering Facilities at the WRRF ................................................................ 3-22 Table 3 13. Existing Supernatant Lagoon Facilities at the WRRF .................................................. 3-23 Table 3 14. Summary of Previous Discharge Limits for Selected Pollutants (R3-2002-0043) ........ 3-25 Table 3 15. Historical Plant Performance Data .............................................................................. 3-25 Table 3 16. WRRF Operations Staffing .......................................................................................... 3-27 Table 3 17. Sampling Locations at the WRRF ............................................................................... 3-27 Table 3 18. Analytical Sampling Distribution by the WRRF and Outside Laboratories ................... 3-28 Table 3 19. Summary of Condition Assessment Recommendations by Process Area .................. 3-30 Table 4 1. Renewed NPDES Discharge Limits for Selected Pollutants (R3-2014-0043) ................. 4-2 Table 5 1. Peaking Factors for Historical Flows ............................................................................... 5-2 Table 5 2. Peaking Factors for Historical TSS and Ammonia Loads ................................................ 5-2 Table 5 3. Projected Flows and Loads of Selected Constituents ..................................................... 5-3 Table 5 4. Summary of Projected Buildout Flows and Loads ........................................................... 5-4 Table 6 1. Existing Liquid Stream Treatment Unit Capacity Criteria ................................................. 6-6 Table 6 2. Existing Solids Stream Treatment Unit Capacity Criteria ................................................ 6-6 Table 6 3. Summary of Capital Needs ........................................................................................... 6-10 Table 7 1. List of Alternative Technologies for Screening ................................................................ 7-3 Table 7 2. Compressible Media Filter Installations in CA ............................................................... 7-13 Table 7 3. Cooling Technologies Comparison Matrix ..................................................................... 7-17 Table 7 4. Disinfection Technology Screening Results .................................................................. 7-20 Table 7 5. UV Disinfection Performance Criteria ............................................................................ 7-21 Table 7 6. Evaluation of Sludge Thickening Technologies ............................................................. 7-25 Table 7 7. Nitrifying Sequencing Batch Reactor Technology Advantages and Disadvantages ...... 7-29 Table 7 8. Deammonification Technology Advantages and Disadvantages ................................... 7-30 Table 7 9. Zeolite/Anammox Technology Advantages and Disadvantages ................................... 7-32 Table 7 10. Sidestream Treatment Deammonification Facility Needs ............................................ 7-33 Table 7 11. Summary of Odor Control Assumptions ...................................................................... 7-34 Table 7 12. Design Criteria for Upgrades Required for Permit Compliance ................................... 7-39 Table 7 13. Design Criteria for Additional Upgrades ...................................................................... 7-41 Table 10 1. Existing Electrical Loads ............................................................................................. 10-3 Table 10 2 Projected Electrical Loads ............................................................................................ 10-4 Table 10 3. Summary of Electrical Equipment Condition Assessment ........................................... 10-4 Table 10 4. LID Storage Volumes ................................................................................................ 10-14 Table 10 5. Recommended Flood Control Improvements ............................................................ 10-19 Table 11 1. Summary of Building Programming Needs ................................................................. 11-2 WRRF Project Contents Page vi List of Figures Figure 1 1. Proposed Peak Hour Flow Schematic ............................................................................ 1-5 Figure 1 2. Process Flow Diagram ................................................................................................... 1-7 Figure 1 3. Proposed Site Plan ........................................................................................................ 1-9 Figure 1 4. Public Amenities Concepts .......................................................................................... 1-11 Figure 1 5. Construction Sequencing Plan ..................................................................................... 1-13 Figure 1 6. Implementation Schedule ............................................................................................. 1-15 Figure 2 1. Location Map .................................................................................................................. 2-3 Figure 3 1. Existing Process Schematic (includes WRRF Energy Efficiency Project Upgrades) ...... 3-2 Figure 3 2. Picture of the Existing Influent Pumping Station............................................................. 3-4 Figure 3 3. Picture of the Existing Aerated Grit Channels ................................................................ 3-5 Figure 3 4. Picture of an Existing Parshall Flume ............................................................................. 3-6 Figure 3 5. Picture of an Existing Primary Clarifier ........................................................................... 3-7 Figure 3 6. Picture of the Existing Flow Equalization Basin.............................................................. 3-8 Figure 3 7. Aerial of the Recirculation Pump Station ...................................................................... 3-10 Figure 3 8. Picture of Biofilter 3 ...................................................................................................... 3-11 Figure 3 9. Picture of the Secondary Clarifier ................................................................................. 3-11 Figure 3 10. Picture of the Existing Aeration Basins ...................................................................... 3-13 Figure 3 11. Picture of the Existing Blowers ................................................................................... 3-13 Figure 3 12. Picture of the Existing Final Clarifiers ......................................................................... 3-14 Figure 3 13. Picture of an Existing RAS Pumping Station .............................................................. 3-14 Figure 3 14. Picture of the Filter Feed Pumping Station ................................................................. 3-15 Figure 3 15. Picture of the Existing Cooling Towers ....................................................................... 3-16 Figure 3 16. Pictures of the Existing Filter Complex ....................................................................... 3-17 Figure 3 17. Picture of an Existing Chlorine Contact Tanks ........................................................... 3-18 Figure 3 18. Picture of the Existing DAFT Facilities ....................................................................... 3-20 Figure 3 19. Picture of Existing Digesters 1 and 2 ......................................................................... 3-21 Figure 3 20. Rendering of a Dewatering Screw Press ................................................................... 3-22 Figure 3 21. Picture of the Existing Belt Filter Press ...................................................................... 3-23 Figure 3 22. Picture of the Supernatant Lagoon ............................................................................. 3-24 Figure 3 23. Historical Effluent TSS and BOD Concentrations ....................................................... 3-26 Figure 3 24. Historic Effluent Total Ammonia Concentrations ........................................................ 3-26 Figure 3 25. Treatment Plant Site .................................................................................................. 3-35 Figure 3 26. Site Availability ........................................................................................................... 3-37 Figure 3 27. Topography ................................................................................................................ 3-39 Figure 4 1. Historical Raw Influent Ammonia Concentrations .......................................................... 4-4 Figure 4 2. Historical Recycled Water Volume ................................................................................. 4-5 Figure 4 3. GHG Emissions Distribution per Treatment Level for a 10 mgd Nominal Plant (Falk et al., 2013) ........................................................................................................................................ 4-7 Figure 6 1. Hydrographs for Diurnal Flow Equalization Analysis (April 7, 2014 – ADWFCP contribution) .............................................................................................................................. 6-2 Figure 6 2. Influent Hydrograph for 10-Year, 24-Hour Design Storm at Buildout (2035) .................. 6-3 Figure 6 3. Equalized Influent Flow using the Expanded 5.4 MG Flow Equalization Pond in a 10- year 24-hr Storm ....................................................................................................................... 6-4 Figure 6 4. Layout of improved Wet-Weather Equalization Pond .................................................... 6-5 Figure 6 5. Liquid Stream Plant Capacity per Unit Process .............................................................. 6-8 WRRF Project Contents Page vii Figure 6 6. Solids Stream Plant Capacity per Unit Process ............................................................. 6-9 Figure 7 1. Secondary Treatment Technology Screening and Evaluation Approach ....................... 7-3 Figure 7 2. BioWin® Screen Capture for the Recommended Secondary Treatment Alternative, MLE, with (Top) and without (Bottom) Sidestream Treatment ........................................................... 7-6 Figure 7 3. BioWin® Final Clarifier Ammonia and Nitrate Effluent Levels for Maximum Month and Maximum Day Scenarios (includes Sidestream Treatment) ..................................................... 7-7 Figure 7 4. BioWin® Final Clarifier Ammonia and Nitrate Effluent Levels for Maximum Month and Maximum Day Scenarios (excludes Sidestream Treatment) .................................................... 7-7 Figure 7 5. Methanol Chemical Feed Facility at the Scotts Valley, CA Water Reclamation Facility . 7-8 Figure 7 6. Number of Cooling Towers On-Line over Time ............................................................ 7-15 Figure 7 7. Temperature over Time ................................................................................................ 7-15 Figure 7 8. Recommended Cooling Configuration for the (A) Cooling Towers and (B) Heat Exchanger/Chillers ................................................................................................................. 7-19 Figure 7 9. Gravity Belt Thickener Photograph (Courtesy of Ashbrook) ......................................... 7-23 Figure 7 10. RDT Rendering and Schematic (Courtesy of FKC) .................................................... 7-24 Figure 7 11. Centrifuge Photograph (Courtesy of Centrisys) .......................................................... 7-24 Figure 7 12. Nitrifying Sequencing Batch Reactor Operational Steps ............................................ 7-28 Figure 7 13. Zeolite Media on Left and Zeolite/Anammox Pilot Plant on Right ............................... 7-31 Figure 7 14. Zeolite/Anammox Pilot Beds at Union Sanitary District in 2012. ................................ 7-32 Figure 7 15. Proposed Process Flow Diagram ............................................................................... 7-37 Figure 8 1. Proposed Peak Hour Flow Schematic ............................................................................ 8-2 Figure 8 2. Proposed Hydraulic Profile ............................................................................................. 8-3 Figure 9 1. Contact Stabilization Mode ............................................................................................ 9-4 Figure 9 2. Normal Operational Mode .............................................................................................. 9-4 Figure 10 1. Existing Plant Electrical Facilities ............................................................................... 10-2 Figure 10 2. Plant Upgrade Electrical System ................................................................................ 10-8 Figure 10 3. Reuse Upgrade Electrical System .............................................................................. 10-9 Figure 10 4. Typical SCADA Block Diagram ................................................................................ 10-15 Figure 10 5. Proposed Site Drainage ........................................................................................... 10-17 Figure 11 1. Rendering of Water Resource Center ........................................................................ 11-3 Figure 11 2. Water Resource Center Site Plan .............................................................................. 11-5 Figure 12 1. Demolition Plan .......................................................................................................... 12-3 Figure 12 2. Proposed Site Plan .................................................................................................... 12-5 Figure 12 3. Landscape Concepts ................................................................................................. 12-7 Figure 12 4. Public Amenities Concepts......................................................................................... 12-9 WRRF Project Contents Page viii List of Appendices (Provided Electronically) A. TM No.1 – Wastewater Characterization B. TM No.2 – System-Wide Conceptual Alternatives C. TM No.3 – Site Planning D. TM No.4 – Disinfection Study E. TM No.5 – Asset Planning and Rehabilitation F. TM No.6 – Renewable Energy Generation Study G. TM No.8 – Regulatory Compliance H. TM No.9 – Capacity Consideration I. TM No.9.1 – Influent and Effluent Flow Monitoring J. TM No.9.2 – Influent Hydrograph Simulation for the WRRF K. TM No. 9.3 – Wet Weather Flow Equalization L. TM No.10.1 – Infrastructure Planning, Stormwater M. TM No.10.2 – Infrastructure Planning, Electrical and I&C N. TM No 10.3 – Infrastructure Planning, Site Access and Security O. TM No 12 – Process Alternatives Analysis P. TM No. 13 – Filter Technology Evaluation Q. TM No. 14 – Cooling Technology Evaluation R. TM No. 15 – Additional Sampling S. TM No. 16 – High Rate A/B Bench Testing Protocol T. Building Program U. Community Workshop Summary V. Cost Estimates W. Value Engineering Comments and Responses Note: Some information presented in the technical memoranda included in the appendix may have been updated during the finalization of the Facilities Plan. Where there are discrepancies, the reader should rely on the information presented in the Final Facilities Plan 1. Executive Summary Page 1-1 1. Executive Summary This Facilities Plan for the City of San Luis Obispo’s (City) Water Resource Recovery Facility (WRRF) was developed to identify improvements needed at the WRRF to enable the plant to treat future flows and loads, meet new waste discharge requirements, replace aging equipment, maximize the production of recycled water, and incorporate interpretive features and public amenities to create a valued community asset. 1.1. Background The City owns and operates the WRRF located on Prado Road in San Luis Obispo, California. The WRRF treats municipal wastewater collected from the City, California Polytechnic State University (Cal Poly), and the San Luis Obispo County Airport under Waste Discharge Requirements (WDR) R3-2014-0033 and National Pollutant Discharge Elimination System (NPDES) No. CA0049224. The WRRF is currently rated for 5.1 million gallons per day (mgd) for average dry weather flow (ADWF) conditions and currently treats an average of approximately 3.1 mgd under ADWF conditions. After being treated, the water is either recycled or discharged to San Luis Obispo Creek. The plant was originally constructed in 1923 and upgraded or expanded in 1942, 1962, 1982, and 1994, and in 2006 the water reuse facilities were added. In partnership with Pacific Gas and Electric (PG&E), the plant is currently undergoing an upgrade to incorporate energy efficiency projects, referred to as the WRRF Energy Efficiency Project. This upgrade includes improvements to the cogeneration system, headworks, solids dewatering, filter towers, aeration, outdoor lighting, and the supervisory control and data acquisition system (SCADA). 1.2. Project Overview The City is beginning a program to upgrade the WRRF to update treatment processes to meet the City’s new National Pollutant Discharge Elimination System (NPDES) permit, treat future flows and loading, replace aging equipment, maximize the production of recycled water, and incorporate interpretive features and public amenities. The program is expected to be completed in 2020. A key driver of the WRRF Project is the new NPDES permit adopted in September 2014 (effective December 1, 2014). The new permit includes discharge limitations that will require significant process upgrades. Specifically, the new permit includes strict disinfection byproduct limits which will require a new disinfection technology, as well as nitrate limits which will require a significant upgrade of the secondary treatment processes. A new Time Schedule Order (TSO) was also adopted in September 2014 which requires the City to achieve the disinfection byproduct limits and nitrate limits by November 30, 2019. Refer to Table 1-1 for a summary of the new permit requirements. In addition to the regulatory driven process upgrades, this Facilities Plan includes recommended upgrades for primary clarifiers, flow equalization, filtration, effluent cooling, and solids handling to address condition, capacity, and operational concerns. Finally, this Facilities Plan includes recommendations for new operation and maintenance spaces, as well as a learning center and associated public amenities to create a valued community asset. WR R F P r o j e c t Ex e c u t i v e S u m m a r y Pa g e 1 - 2 Ta b l e 1 - 1 . R e n e w e d N P D E S D i s c h a r g e L i m i t s f o r S e l e c te d P o l l u t a n t s ( R 3 - 2 0 1 4 - 0 0 4 3 ) Pa r a m e t e r U n i t Av e r a g e D r y We a t h e r F l o w Av e r a g e An n u a l Av e r a g e Mo n t h l y Av e r a g e We e k l y Ma x i m u m Da i l y Instantaneous Minimum Instantaneous Maximum Ma x i m u m E f f l u e n t D i s c h a r g e F l o w m g d 5 . 1 - - - - - - - - - - - - Bi o l o g i c a l O x y g e n D e m a n d , 5 - d a y (B O D ) mg / L - - - - 1 0 3 0 5 0 - - - - lb / d - - - - 4 2 5 1 , 2 7 5 2 , 1 2 5 - - - - To t a l S u s p e n d e d S o l i d s ( T S S ) m g / L - - - - 1 0 3 0 7 5 - - -- lb / d - - - - 4 2 5 1 , 2 7 5 3 , 1 9 0 - - - - Un - i o n i z e d A m m o n i a m g N / L - - - - - - - - 0 . 0 2 5 (a ) - - - - In t e r i m N i t r a t e (c ) m g N / L - - - - 4 2 . 6 - - - - - - - - Ni t r a t e m g N / L - - - - 1 0 - - - - - - - - Co l i f o r m (b ) M P N / 1 0 0 m L - - - - 2 3 2 . 2 - - - - 2 4 0 Di s s o l v e d O x y g e n m g / L - - - - - - - - - - 4 . 0 - - pH s . u . - - - - - - - - - - 6 . 5 8 . 3 In t e r i m C h l o r o d i b r o m o m e t h a n e (c ) g / L - - - - - - - - - - - - 4 2 In t e r i m D i c h l o r o b r o m o m e t h a n e (c ) g / L - - - - - - - - - - - - 3 6 Fi n a l C h l o r o d i b r o m o m e t h a n e (d ) g / L - - - - 0 . 4 0 - - 1 . 0 - - - - Fi n a l D i c h l o r o b r o m o m e t h a n e (d ) g / L - - - - 0 . 5 6 - - 1 . 0 - - - - N- N i t r o s o d i m e t h y l a m i n e ( N D M A ) g / L - - - - 0 . 0 0 0 6 9 - - 0 . 0 0 1 4 - - - - (a ) I n - s t r e a m c r i t e r i a ( i . e . , n o n - d i s c h a r g e l i m i t ) . (b ) T h e f e c a l c o l i f o r m c o n c e n t r a t i o n s s h a l l n o t e x c ee d a m e d i a n o f 2 . 2 M P N / 1 0 0 m L a s d e t e r m i n e d f r o m t he l a s t 7 d a y s o f s a m p l i n g r e s u l t s f o r w h i c h a n a l y s es have been co m p l e t e d ; n o m o r e t h a n o n e s a m p l e s h a l l e x c e e d 2 3 MP N / 1 0 0 m L t o t a l c o l i f o r m i n a n y 3 0 - d a y p e r i o d ; n o sa m p l e s h a l l e x c e e d 2 4 0 M P N / 1 0 0 m L t o t a l c o l i f o r m . (c ) I n t e r i m l i m i t s l i s t e d i n r e n e w e d T S O R 3 - 2 0 1 4 - 0 0 36 a r e v a l i d t h r o u g h N o v e m b e r 3 0 , 2 0 1 9 . (d ) F i n a l l i m i t s c o m p l i a n c e b y N o v e m b e r 3 0 , 2 0 1 9 . WRRF Project Executive Summary Page 1-3 1.3. Project Vision and Objectives The vision of this Facilities Plan is to present recommended improvements to create a community asset that is recognized as supporting health, well-being and quality of life. The Program Charter identified the following objectives aimed at delivering the WRRF Project such that it provides economic, social, and environmental value for the community: Economic Optimize capital investment and life cycle cost Maximize value for ratepayers’ investment Incorporate flexibility and scalability to adapt to future conditions Simplify process flow and make treatment more robust Optimize application of appropriate technology Social Create and sustain diverse partnerships that add value to the community Provide an interpretive center and dedicated features to engage and educate the community Be a good neighbor Engender the trust of project stakeholders Support the development and empowerment of City employees Environmental Develop and implement a holistic strategy to maximize sustainable resource recovery and manage salts, nutrients and environmental pollutants in the Basin Incorporate sustainability practices in planning, design, construction, and operation Maintain compliance and minimize impacts to operations and the community during construction Sustain reliable compliance post-construction 1.4. Water Resource Recovery The WRRF currently produces Title 22 Unrestricted Use Recycled Water which is used to irrigate parks, medians, and landscape features in the City. Although all the treated effluent the WRRF produces is compliant with Title 22 recycled water requirements (except during peak wet weather events), only a portion of the recycled water produced is currently used for irrigation purposes, while the remainder is discharged to San Luis Obispo Creek. That is because the demand for recycled water is typically limited to the dry, late spring, summer, and early fall months. In addition, the recycled water distribution system is not yet built out (i.e., additional customers could be added). As described in the preceding subsection, a key environmental objective of the WRRF Project is to maximize sustainable resource recovery. An opportunity exists as part of the WRRF Project to increase the volume of recycled water distributed for beneficial use. Several opportunities to expand the recycled water system have been identified. The expansion of the recycled water system could WRRF Project Executive Summary Page 1-4 provide multiple benefits to the City, and region, including enhanced management of regional water resources as well as reduced life cycle costs for the WRRF project. Additional work is required to determine the feasibility of delivering recycled water to new potential users, including evaluation of regulatory compliance strategies, identification of customers, quantification and timing of demands, and evaluation of the infrastructure and costs needed to convey water from the WRRF to the end users, including pumping facilities, pipelines, and storage. Therefore, the City is pursuing grant funding to conduct a Recycled Water Facilities Planning Study. As described in later subsections, the TSO deadline is a major schedule driver for the project. As a result, the recommendations for the WRRF upgrade presented in this report are based on the assumption that discharge to San Luis Obispo Creek will continue such that the project can proceed on schedule; however, these recommendations will be reevaluated following the conclusion of the Recycled Water Facilities Planning Study. 1.5. Flow and Load Projections The projected flows and loads through buildout of the WRRF’s service area are presented in Table 1-2. These values are based on an analysis of historical WRRF data for the five year period from January 2009 through January 2014, and consider both population growth and land use in the service area as described in the 2035 Land Use and Circulation Element (LUCE) adopted in 2014. Table 1-2 presents the design flows and loads that the facility plan was based on. Table 1-2. Summary of Projected Flows and Loads Parameter Units ADWFCP AA MM MW MD PH Flow mgd 5.4 (b) 6.1 8.4 11.4 17.3 33.5 (c) TSS lb/d 12,300 12,900 18,300 24,700 33,400 - BOD (a) lb/d 9,900 10,400 14,800 20,000 27,100 - Ammonia lb N/d 13,400 14,100 19,900 26,900 36,400 - TKN lb N/d 1,500 1,600 2,200 2,600 3,200 - TSS mg/L 2,300 2,400 3,300 3,800 4,800 - BOD (high)(a) mg/L 272 253 261 260 231 - Ammonia mg N/L 221 205 211 210 187 - TKN mg N/L 297 276 284 283 252 - (a) BOD:TSS ratio assumed at 1.09. (b) ADWFCP is the average dry weather flow calculated for the three driest months of the year plus projected Cal Poly contributions. (c) Peak hour flow is based on the results of collection system monitoring (V&A 2012), and the Influent Hydrograph Simulation Technical Memorandum (WSC, 2014). 1.6. Capacity Assessment Recommendations The plant-wide treatment capacity analysis for the WRRF considered flow equalization and recycled water production, as well as equipment replacement and the upgrades being implemented as part of the WRRF Energy Efficiency Project. After the upgrades are complete, all influent flows will receive secondary treatment, filtration, UV disinfection, and effluent cooling (as needed) prior to being discharged to San Luis Obispo Creek or WRRF Project Executive Summary Page 1-5 delivered as recycled water. Flow equalization was considered for both dry weather diurnal and peak wet weather flows. Equalization of peak wet weather flows can be achieved with the equalization pond for storage until influent flows subside. In order to prevent inundation during the 100-yr storm event, the existing pond will be surrounded with a perimeter berm that will prevent inflow during flooding. This additional elevation has the added benefit of increasing the available storage volume in the pond from 4.0 MG to approximately 5.4 MG. The downstream facilities (i.e., aeration basins, filtration, cooling and disinfection) will be sized for 16 mgd. Although diurnal equalization of the dry weather flows was considered, it is not essential to the overall performance of the plant, and is not included in the recommended upgrades. The schematic in Figure 1-1 provides an illustration of peak hour flows that will be routed to each area of the plant. Figure 1-1. Proposed Peak Hour Flow Schematic 1.7. Treatment Plant Upgrades In addition to meeting the new discharge permit requirements, treatment plant upgrades are needed to address capacity, redundancy, condition, O&M, energy efficiency, and odor concerns, as well as provide new building spaces and public amenities. The recommended improvements are summarized below and a process flow diagram of the improvements is provided in Figure 1-2. Flow equalization, including relining and reconstruction of the perimeter berm for the existing wet weather equalization pond. Improvements at the headworks, including new influent flow monitoring and odor control. Rehabilitation of the primary clarifiers, including new weirs, new sweeps and arms, new sludge and scum pumps, new primary sludge pump pit. Primary effluent diversion box retrofits. Three new aeration basins, as well as new blowers and blower building, diffusers, mixed liquor pumps and mixers, and chemical feed. Influent PH = 33.5 mgd Headworks Aeration Basins Filters Cooling UV PCs FCs Tertiary + Cooling + Disinfection PH = 16 mgd PCs PH = 22 mgd Secondary Treatment PH = 16 mgd Peak Cooling Flows > 16 mgd Flows > 22 mgd Flows > 16 mgd Wet Weather EQ Pond Filter Feed EQ Basin WRRF Project Executive Summary Page 1-6 Two new final clarifiers and new RAS and WAS pumps per new clarifier. Expansion of the filter feed pumping station. Expansion of the tertiary filter complex, including two new mono-media filters, new backwash pumps and air scour blowers. Additional cooling towers, new effluent chillers, and pumps. UV disinfection. Solids treatment upgrades, including new thickening and conversion of the DAFT to a blend tank, a new screw press, odor control, and a new anaerobic digester. Sidestream treatment using a deammonification technology, including one new tank to replace Digester 3 as a biological reactor, aeration blowers, and a diffused air system and conversion of Digester 2 to a sidestream treatment feed flow equalization tank. Solar energy generation. New Water Resource Center, including operations and laboratory facilities. Learning Center and associated amenities. New maintenance facility. 1.8. Site Plan Figure 1-3 presents the proposed site plan for the WRRF upgrades. Siting of the process units was developed to minimize relocation of existing pipelines and utilities and to locate facilities in close proximity to upstream and downstream processes, where feasible. Traffic circulation through the plant was also considered to provide adequate and safe access for truck deliveries, as well as the buses which must access the City’s Bus Yard. The operations center as well as the public spaces, research space and the maintenance building were sited after treatment structures were sited, and with input from the community and Utilities Department staff (including WRRF and laboratory staff). Figure 1-4 presents the plan for public amenities, including concepts for the demonstration gardens and wetlands, landscaping concepts, the learning center including a walking tour of the plant, a future BMX park, and patio spaces for the staff and public As the City moves forward with design of the upgrades, consideration will be given to reserve land within the plant site for future upgrades that may be needed to address future regulations. 1.9. Construction Sequencing A conceptual level construction sequencing plan was developed for the recommended upgrades that addresses priorities with respect to meeting the schedule requirements in the TSO and to address facilities that need to be brought online prior to demolition of other facilities. The sequencing plan includes four construction stages as shown in Figure 1-5. The construction staging places an early emphasis on completing the facilities essential to compliance with the TSO deadline of November 30, 2019. WR R F P r o j e c t Ex e c u t i v e S u m m a r y Pa g e 1 - 8 Pa g e i n t e n t i o n a l l y b l a n k . WR R F P r o j e c t Ex e c u t i v e S u m m a r y Pa g e 1 - 1 0 Pa g e i n t e n t i o n a l l y b l a n k . CITY OF SAN LUIS OBISPO | WATER RESOURCE RECOVERY FACILITY SITE PLAN JUNE 5, 2015 0’80’160’240’40’320’ FLOOD PROTECTION BERM AND NEW EQ POND LINER EQ POND EQ RETURN FLOW PUMP STATION WATER RESOURCE CENTER WITH SOLAR PANELS STAFF ENTRY GATE FUTURE BMX BIKE PARK RESERVE FOR FUTURE UPGRADES/CAL POLY RESEARCH CENTER POSSIBLE FUTURE RV WASTE RECEIVING FACILITY NEW CITY CORP YARD ENTRANCE SOLAR PANELS OVER PARKING PLANT ENTRY GATE ABANDONED CLARIFIER (FUTURE DIURNAL FLOW EQ BASIN IF NEEDED) NEW MAINTENANCE SHOP WITH SOLAR PANELS AERATION BLOWER BUILDING WITH SOLAR PANELS AERATION BASIN EFFLUENT FLOW SPLIT STRUCTURE FINAL CLARIFIER 4 AERATION BASINS 1&2 AERATION BASIN 3 AERATION BASIN 4 AERATION BASIN 5 RELOCATED MCC’S MgOH2STORAGE METHANOL STORAGE SLUDGE DRYING BEDS FILTERS 5 & 6 FILTERS 1,2,3 & 4 LEARNING CENTER WITH SOLAR PANELS ELECTRICAL BUILDING WITH SOLAR PANELS COOLING TOWERS FLOW EQUALIZATION BASINS EFFLUENT CHILLER PLANT THICKENING 1,000 KW STANDBY GENERATOR 2,000 KW STANDBY GENERATOR SOLIDS BLEND TANK PRIMARY SLUDGE PUMP STATION NEW DIGESTER 2 COGENERATION SIDESTREAM TREATMENT FUTURE FOG RECEIVING STATION SIDESTREAM TREATMENT EQUALIZATION EXISTING BIOSWALE FERROUS CHLORIDE STORAGE SOLAR PANELS ON DEWATERING BUILDING INFLUENT PUMP STATION, SCREENING, AND NEW FLOW METERING RECYCLED WATER TANK WITH SOLAR PANELS NEW GRAVEL ACCESS ROAD AND GATE BIKE STORAGE VACUUM TRUCK CLEANOUT FACILITY FACILITY VEHICLE PARKING STAFF PATIO CONFERENCE ROOM PATIO STAFF PARKING WITH SOLAR PANELS CAMPUS ENTRY DIRECTIONAL SIGNAGE WETLAND WETLAND & BOARDWALK/ EDUCATIONAL DEMONSTRATION GARDEN BOB JONES TRAIL PR A D O R O A D VISITOR PARKING HWY 101 CITY TRANSIT FACILITY ODOR CONTROL BIOFILTER FINAL CLARIFIER 5 FINAL CLARIFIER 6 FINAL CLARIFIER 7 RAS PUMPING PRIMARY CLARIFIER 2 PRIMARY CLARIFIER 1 UV DISINFECTION PUBLIC TOUR ROUTE/STOPS1 1 2 3 4 5 6 7 POTENTIAL BIKE TOUR TO OUTFALL 7-POINT WALKING TOUR LEARNING CENTER AREA The outdoor space connected to the Interpretive Center will provide a group picnic area and intimate amphitheater amongst the trees. This space will allow for community groups of all sorts to gather, learn and lunch in association with a WRRF tour, as well as a great space to congregate on select Open House education days, during which the public can access the Interpretive Center via the Bob Jones Trail. 1 2 2 3 WETLAND DEMONSTRATION GARDENS As part of the public space surrounding the Operations Building/Welcome Center, a wetland demonstration garden with a circulating boardwalk and educational signage will provide opportunities for the public to learn about the WRRF systems and it’s relationship to the natural surrounding habitat. These gardens will also be the public face of the WRRF, being clearly visible from Prado Road. STAFF & PUBLIC PATIO SPACES The main conference room inside the Operations building will open up directly onto an outdoor patio, providing a flexible gathering space for talks and events, immediately adjacent to the boardwalk and wetland. The WRRF staff will also have a dedicated private patio space, sectioned off from the public patio by a divider that can be open in the event the WRRF staff should want to expand the space for a larger gathering. 3 2 1 WR R F P r o j e c t Ex e c u t i v e S u m m a r y Pa g e 1 - 1 2 Pa g e i n t e n t i o n a l l y b l a n k . WR R F P r o j e c t Ex e c u t i v e S u m m a r y Pa g e 1 - 1 4 Pa g e i n t e n t i o n a l l y b l a n k . WRRF Project Executive Summary Page 1-15 1.10. Implementation Schedule A preliminary implementation schedule is presented in Figure 1-6. The schedule assumes that the construction contract is awarded in October 2017. The construction duration is estimated to be just over three years and assumes that equipment is not pre-purchased by the City. As the City proceeds with the SRF loan application and design procurement, the implementation schedule will be revisited and refined accordingly. An alternative for the secondary treatment process is being contemplated (High Rate Adsorption / Bio-Oxidation). If initial bench scale testing indicates the process is feasible and could result in significant energy savings, pilot testing would be needed and the schedule for completion of the secondary treatment facilities (as shown in Figure 1-5), could be extended. Figure 1-6. Implementation Schedule 1.11. Opinion of Probable Cost Table 1-3 presents a summary of the opinion of probable costs for the WRRF upgrades. The construction costs are presented in 2014 dollars and were then escalated to the midpoint of construction (2019) using a three percent annual escalation rate. Detailed construction cost estimates by process are included in Appendix V – Cost Estimates. Major assumptions associated with the development of the opinion of probable costs include: A 30 percent construction contingency was applied on Divisions 2 through 16. Division 1 costs were applied at 15 percent of Divisions 2 through 16. Specialty foundations (e.g., pile foundations) are not included in the estimate. WRRF Project Executive Summary Page 1-16 Tertiary filtration costs assume GMF and use of the existing backwash facilities with the new filters. Costs do not include relocation of the Cal Poly Research Area or the Prado Day Center. Demolition of these facilities is included. Table 1-3. Opinion of Probable Construction Costs Component Opinion of Probable Costs Flow Equalization $1,501,000 Headworks Odor Control $788,000 Primary Clarifiers $2,879,000 Aeration Basins $14,121,000 Final Clarifiers $4,272,000 Tertiary Filtration and Cooling $6,163,000 UV Disinfection $7,485,000 Renewable Energy Generation $1,066,000 Solids (Digestion, Thickening, Dewatering) $6,759,000 Sidestream Treatment $3,642,000 Flood Protection $1,500,000 General Site $11,090,000 Water Resource Center $4,800,000 Learning Center and Public Amenities $1,505,000 Maintenance Building $1,953,000 Total Construction Costs in 2014 Dollars(a) $69,524,000 Allowance for Design, Environmental, Permitting, and Construction Management(b) $20,857,000 Total Project Cost in 2014 Dollars $90,381,000 Total Project Cost in 2019 Dollars(c) $104,777,000 (a) Total construction costs include 30 percent construction contingency. (b) Estimated at 30 percent of construction. (c) Escalated using three percent per year. 1.12. Next Steps The next steps in the implementation of the WRRF upgrade include the following: Continue additional sampling to determine raw influent flows and loads, as well as information required to design the nutrient removal technologies: MLE or High Rate A/B and sidestream treatment. Once the designer is selected, the additional sampling request can be augmented to provide any necessary supplemental information for designing the facilities. Conduct UVT testing to support development of design criteria for the UV disinfection system. The WRRF has collected UVT data from mid January to mid May 2015. Additional UVT monitoring is recommended to cover the entire wet weather season, typically from October to April, in accordance with the industry accepted National Water Research Institute (NWRI) UV guidelines. WRRF Project Executive Summary Page 1-17 Evaluate alternative disinfectants to sodium hypochlorite (e.g., peracetic acid, etc.) for maintaining unit processes throughout the plant, such as the filter towers, nitrified effluent box, and cooling towers. Complete bench testing evaluation for the High Rate A/B process for secondary treatment as an alternative to MLE. If the outcome is positive, conduct additional research (e.g., visit a full scale plant, conduct pilot testing, etc.) and consider adjusting recommended facilities to include in predesign and design. Conduct structural analysis of concrete tanks constructed before 1985, including the existing primaries. Conduct study to re-rate the existing filters and confirm recommended filtration technology for expansion, if an alternate media is desired. Continue flow monitoring analysis to support hydrograph simulation and refinement of flow projections. Conduct sidestream treatment evaluation to select preferred deammonification technology. Conduct temperature monitoring to support development of design criteria for the cooling towers and chiller. Conduct site visits of operational facilities and talk with staff to assist with technology and equipment selection. Procure an environmental consultant and initiate environmental review. Procure a design consultant and initiate predesign. Complete the Recycled Water Facilities Planning Study and confirm recommended WRRF upgrades and associated recycled water infrastructure needs. WRRF Project Executive Summary Page 1-18 Page intentionally blank. 2. Introduction Page 2-1 2. Introduction This Facilities Plan for the City of San Luis Obispo’s (City) Water Resource Recovery Facility (WRRF) was developed to identify improvements needed at the WRRF to enable the plant to treat future flows and loading, meet new waste discharge requirements, replace aging equipment, and incorporate interpretive features and public amenities to create a valued community asset. 2.1. Background The City owns and operates the WRRF located on Prado Road in San Luis Obispo, California (see Figure 2-1). The WRRF treats municipal wastewater collected from the City, California Polytechnic State University (Cal Poly), and the San Luis Obispo County Airport under Waste Discharge Requirements (WDR) R3-2014-0033 and National Pollutant Discharge Elimination System (NPDES) No. CA0049224. The WRRF is currently rated for 5.1 million gallons per day (mgd) for average dry weather flow (ADWF) conditions and currently treats an average of approximately 3.1 mgd under ADWF conditions. After being treated, the water is either discharged to San Luis Obispo Creek or recycled. The NPDES permit identifies several beneficial uses for flow discharged to San Luis Obispo Creek: municipal and domestic (MUN); agricultural supply (AGR); ground water recharge (GWR); water contact recreation (REC1); non-contact water recreation (REC2); wildlife habitat (WILD); cold fresh water habitat (COLD); warm fresh water habitat (WARM); migration of aquatic organisms (MIGR); fish spawning, reproduction, and/or early development (SPWN); freshwater replenishment (FRESH); commercial and sport fishing (COMM). In order to satisfy the listed beneficial uses, the WRRF must maintain a minimum 1.6 mgd flow discharged to San Luis Obispo Creek. The plant was originally constructed in 1923 and upgraded or expanded in 1962, 1982, 1994, and 2006. In partnership with Pacific Gas and Electric (PG&E), the plant is currently undergoing an upgrade to incorporate energy efficiency projects, referred to as the WRRF Energy Efficiency Project. This upgrade includes improvements to the cogeneration system, headworks, return activated sludge pumps, solids dewatering, filter towers, aeration, outdoor lighting, and the supervisory control and data acquisition system (SCADA). 2.2. Project Overview The City is beginning a program to upgrade the WRRF to update treatment processes to meet the City’s new National Pollutant Discharge Elimination System (NPDES) permit, treat future flows and loads, replace aging equipment, and incorporate interpretive features and public amenities. The program is expected to be completed in 2020. A key driver of the WRRF Project is the new NPDES permit adopted in September 2014. As described in Section 4 of this Facilities Plan, the new permit includes discharge limitations that will require significant process upgrades. Specifically, the new permit includes strict disinfection byproduct limits which will require a new disinfection technology, as well as nitrate limits which will require a significant upgrade of the secondary treatment processes. WRRF Project Introduction Page 2-2 In addition to the regulatory driven process upgrades, this Facilities Plan includes recommended upgrades for the primary clarifiers, flow equalization, filtration, and solids handling to address condition, capacity, and operational concerns. Finally, this Facilities Plan includes recommendations for onsite storm water management, new operation and maintenance spaces, and a learning center and public amenities to create a valued community asset. 2.3. Project Vision and Objectives The vision of this Facilities Plan is to present recommended improvements to create a community asset that is recognized as supporting health, well-being and quality of life. In early 2014, the Project Team developed a Program Charter, which identified the following objectives aimed at delivering the WRRF Project such that it provides economic, social, and environmental value for the community: Economic Optimize capital investment and life cycle cost Maximize value for ratepayers’ investment Incorporate flexibility and scalability to adapt to future conditions Simplify process flow and make treatment more robust Optimize application of appropriate technology Social Create and sustain diverse partnerships that add value to the community Provide an interpretive center and dedicated features to engage and educate the community Be a good neighbor Engender the trust of project stakeholders Support the development and empowerment of City employees Environmental Develop and implement a holistic strategy to maximize sustainable resource recovery and manage salts, nutrients and environmental pollutants in the Basin Incorporate sustainability practices in planning, design, construction, and operation Maintain compliance and minimize impacts to operations and the community during construction Sustain reliable compliance post-construction W R R F P r o j e c t In t r o d u c t i o n Pa g e 2 - 3 Fi g u r e 2 - 1 . L o c a t i o n M a p WR R F P r o j e c t In t r o d u c t i o n Pa g e 2 - 4 Pa g e i n t e n t i o n a l l y b l a n k . WRRF Project Introduction Page 2-5 2.4. Report Organization This Facility Plan is divided into the following sections: Section 1.0 Executive Summary. This section presents a high level summary of the recommended facility upgrades including the site plan, the implementation schedule, and the opinion of probable cost. Section 2.0 Introduction. This section introduces the plan. Section 3.0 Existing Facility. This section includes a discussion of the existing WRRF facility, including the existing site and its constraints, the existing topography, and the existing treatment facilities including their condition, the new facilities being constructed under the WRRF Energy Efficiency Project, and existing plant operation. Section 4.0 Regulatory Compliance. This section presents the new regulatory requirements in the City’s renewed NPDES permit as well as future regulatory considerations. Section 5.0 Flow and Loading Projections. This section describes a summary of existing flow and load conditions as well as projections for future flows and loads. Section 6.0 Capacity Assessment. This section includes the capacity analysis for the WRRF, including an analysis of flow equalization. Section 7.0 Treatment Plant Upgrades. This section presents the recommended process upgrades for the WRRF, including influent flow meters, primary clarifiers, secondary treatment, tertiary filtration, cooling, and disinfection, as well as solids thickening, anaerobic digesters, biosolids dewatering, and sidestream treatment. Section 8.0 Hydraulics. This section presents the hydraulic profile for the plant upgrades. Section 9.0 Operational Strategy. This section includes a discussion of the operational considerations for the plant upgrades. Section 10.0 Additional Upgrades. This section includes recommendations for electrical and instrumentation upgrades, as well as management of stormwater on the site and upgrades necessary for flood management. Section 11.0 Building Programming. This section provides an overview of the building programming for the new Water Resource Center, including the operation and laboratory facilities. Also included in this section is the building programming for the learning center, public amenities, and maintenance facilities. Section 12.0 Site Planning. This section presents the site plan for the upgraded facility and identifies facilities to be demolished, locations for new treatment facilities, and describes access and security. Section 13.0 Project Implementation. This section presents project implementation considerations, including permitting requirements, construction sequencing, the implementation schedule, the opinion of probable cost for the upgrades as well as life cycle costs, and next steps. WRRF Project Introduction Page 2-6 2.5. Abbreviations and Acronyms To conserve space and improve text readability, the following abbreviations have been used in this document: AA average annual A/B Adsorption / Bio-oxidation AD anaerobic digestion ADA Americans with Disabilities Act ADC alternative daily cover ADWF average dry weather flow ADWFCP average dry weather flow with Cal Poly AOO ammonia oxidizing organism BFP belt filter press BOD biological oxygen demand CAA Clean Air Act Cal Poly California Polytechnic State University CBOD Carbonaceous Biological Oxygen Demand CCRWQCB Central Coast Regional Water Quality Control Board CCT chlorine contact tank CDBM chlorodibromomethane CEC contaminants of emerging concern CExC cation exchange capacity CEQA California Environmental Quality Act City City of San Luis Obispo cf cubic feet CMF compressible media filtration CTR California Toxins Rule CWA Clean Water Act d day DAFT Dissolved Air Floatation Thickener DBP disinfection byproduct DCBM dichlorobromomethane DO dissolved oxygen EFF effluent WRRF Project Introduction Page 2-7 EIR Environmental Impact Report ENR CCI Engineering News Record Construction Cost Index ESA Endangered Species Act FCL final clarification ft foot GHG greenhouse gas GSHP Ground Source Heat Pump GIS geospatial information system GMF granular media filtration gpcd gallons per capita per day gph gallons per hour hp horsepower HVAC heating, ventilation and air conditioning I&C instrumentation and controls I/I inflow and infiltration I/O input / output IS Initial Study KWh kilowatt-hour lb pound lb/d pound per day LPHO low pressure high output LUCE Land Use and Circulation Elements Update MAP magnesium ammonium phosphate MBR membrane bioreactor MCC motor control center MD maximum day MG million gallons mgd million gallons per day mg/L milligram per liter mL milliliter MLE Modified Ludzack-Ettinger MLSS mixed liquor suspended solids MM maximum month WRRF Project Introduction Page 2-8 MND Mitigated Negative Declaration MPN most probable number MSL mean sea level MW maximum week N Nitrogen NAHC Native American Heritage Commission NDMA N-nitrosodimethylamine NEDB Nitrified Effluent Diversion Box NHPA National Historic Preservation Act NPDES National Pollution Discharge Elimination System NSBR nitrifying sequencing batch reactor O&M operation and maintenance OUR Oxygen uptake rate PCL primary clarification PEDB Primary Effluent Distribution Box PH peak hour POTW Publicly Owned Treatment Works PLC programmable logic controller PM Team Program Management Team PG&E Pacific Gas and Electric ppb parts per billion ppt parts per trillion PWWF Peak Wet Weather Flow RAS return activated sludge SCADA supervisory control and data acquisition scfm Standard Cubic Feet per Minute SCL secondary clarification SEBD Secondary Effluent Distribution Box sf square foot SLO San Luis Obispo SRF State Revolving Fund SRT solids residence time SWD side water depth WRRF Project Introduction Page 2-9 SWRCB State Water Resources Control Board TDS total dissolved solids THM trihalomethane TKN Total Kjeldahl Nitrogen TM technical memorandum TMDL total maximum daily loads TMWRF Truckee Meadows Water Reclamation Facility TSO Time Schedule Order TSS total suspended solids USEPA U.S. Environmental Protection Agency SWD side water depth UV ultraviolet VFD variable frequency drive WAS waste activated sludge WDR Waste Discharge Requirements WRRF Water Resource Recovery Facility WSEL Water Surface Elevation µg/L micrograms per liter WRRF Project Introduction Page 2-10 Page intentionally blank. 3. Existing Facility Page 3-1 3. Existing Facility This section describes the existing treatment facilities at the WRRF and operation thereof, condition of the existing facility, the site and its surroundings, and the plant topography and implications for flood control. 3.1. Existing Treatment Facilities As described in Section 2, the WRRF treats municipal wastewater flow from the City, Cal Poly, and the San Luis Obispo County Airport. The WRRF has a permitted ADWF capacity of 5.1 mgd and currently treats an ADWF of 3.1 mgd, and when Cal Poly is in session that increases to approximately 3.5 mgd. A process schematic of the existing treatment plant, including upgrades implemented under the WRRF Energy Efficiency Project, is shown in Figure 3-1. Additional schematics of existing wet weather flow diversions are included in Appendix H, TM No. 9 – Capacity Consideration. The plant consists of the following processes: Liquid Stream Wet weather and diurnal flow equalization Preliminary treatment Primary clarification Biofilter trickling filters (biofilter) with clarification (secondary clarifiers) Air activated sludge and final clarifiers Evaporative cooling towers Filtration Disinfection including chlorination and dechlorination Recycled water storage and pumping Solids Stream Dissolved air flotation thickener (DAFT) Anaerobic digesters Digested solids storage Belt filter press and screw press (sludge dewatering) Drying beds Supernatant lagoon WR R F F a c i l i t y Ex i s t i n g F a c i l i t y Pa g e 3 - 2 Fi g u r e 3 - 1 . E x i s t i n g P r o c e s s S c h e m a t i c ( i n c l u d e s W R RF E n e r g y E f f i c i e n c y P r o j e c t U p g r a d e s ) He a d w o r k s (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) Ae r a t i o n Ba s i n Mo n o M e d i a Fi l t e r ( W R R F En e r g y E f f i c i e n c y Pr o j e c t ) CC T SLO Creek Emergency Storage3W Water System Recycled Water PC L SC L Bi o t o w e r FC L Co o l i n g To w e r DA F T AD AD AD St o r a g e Vo r t e x Cl a s s i f i e r Dr y i n g B e d Su p e r n a t a n t St o r a g e La g o o n Di s p o s a l Fe r r o u s Ch l o r i d e Po l y m e r Ra w In f l u e n t So d i u m Hy p o c h l o r i t e Ma g n e s i u m Hy d r o x i d e Fi l t e r B a c k w a s h Li q u i d S t r e a m s Sl u d g e S t r e a m s Re t u r n S t r e a m s Ch e m i c a l S t r e a m s Pr i m a r y C l a r i f i c a t i o n PC L Se c o n d a r y C l a r i f i c a t i o n SC L Fi n a l C l a r i f i c a t i o n FC L Ch l o r i n e C o n t a c t T a n k CC T Di s s o l v e d A i r F l o a t a t i o n T h i c k e n e r DA F T An a e r o b i c D i g e s t i o n AD Be l t F i l t e r P r e s s BF P DA F T S u p e r n a t a n t La g o o n R e t u r n Sodium Bisulfite Sc r e w P r e s s (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) RA S (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) WA S Fl o w s > 3 2 m g d to F l o w E Q Fl o w s > 2 2 m g d to F l o w E Q Bi o t o w e r B y p a s s Ad v a n c e d T r e a t m e n t B y p a s s ( F l o w s > 5 . 1 m g d ) Fl o w s C u r r e n t l y >1 6 m g d t o F l o w E Q WRRF Facility Existing Facility Page 3-3 Sidestreams at the WRRF include DAFT subnatant, filter backwash, dewatering filtrate, and drying bed supernatant. As indicated in Figure 3-1, the DAFT subnatant is returned upstream of the aeration basins. The dewatering filtrate and drying bed supernatant are equalized in the supernatant lagoon and returned with filter backwash downstream of the headworks. The following subsections describe each of the major unit processes. 3.1.1. Preliminary Treatment A summary of the existing preliminary treatment facilities is provided in Table 3-1 followed by a discussion of each. Table 3-1. Existing Preliminary Treatment Facilities Equipment Description Units Value Comment Bar Screens Two mechanically cleaned screens (chain and rake) One manual bar screen (in bypass channel) mgd 16 per screen Two mechanically cleaned screens installed under the WRRF Energy Efficiency Project. The new screens have 0.25” spacing Screenings Washer and Compacter One screw washer compactor cf/hr hp 140 5 Installed under the WRRF Energy Efficiency Project Screenings Washwater Pump One medium pressure pump to wash the washer and compactor gpm psi 50 40 Installed under the WRRF Energy Efficiency Project Influent Pumps Two horizontal, dry fit centrifugal pumps (5 mgd) Two vertical turbine, solids handling pumps (22 mgd) mounted in wet well for storm flows mgd mgd mgd mgd 5 5 22 22 All four pumps are variable speed Both 5 mgd pumps will be replaced as part of Capital Improvement Project Aerated Grit Two rectangular tanks with coarse bubble diffused aerators ft ft ft 34 long 17 wide 12 SWD Grit Pumps Four grit handling pumps gpm 250 per pump Grit Washer Tank Two vortex grit separators using fluidized grit beds ton/hr gpm 1.5 per unit 400 per unit Installed under the WRRF Energy Efficiency Project Grit Screw One screw per grit washer tank (two in total) rpm hp 1680 per unit 1.5 per unit Installed under the WRRF Energy Efficiency Project Aeration Air Blower Two blowers with coarse bubble diffusers in grit tank scfm 240 per blower Agitation Air Blower One blower with coarse bubble diffusers in influent channel scfm 500 per blower WRRF Project Existing Facility Page 3-4 SCREENS Raw wastewater flows into the plant and is screened with two mechanically cleaned screens. The previous mechanically cleaned bar screens were replaced as part of the WRRF Energy Efficiency Project with two new mechanically cleaned screens (0.25-inch spacing) that have a rated peak flow capacity of 16 mgd each. As peak flows exceed 32 mgd, the WRRF has the ability to bypass the mechanical screens with a diversion box. The diversion structure has a manual barscreen that requires an operator to lower the barscreen manually. The screened material is washed and compacted using a screw washer compactor installed as part of the WRRF Energy Efficiency Project. A screw (1405 cf/hr) that operates on a 5-hp motor is cleaned with a washwater pump (50 gpm at 40 psi). The compacted screenings are discharged into a collection hopper before being hauled to Cold Canyon Landfill. INFLUENT PUMPING STATION The influent pumping station consists of four pumps that convey screened wastewater to the aerated grit chambers. A picture of the influent pumping station is provided in Figure 3-2. Two of the pumps are horizontal, dry pit centrifugal pumps (5 mgd capacity each) and two pumps are vertical turbine, solids handling pumps (22 mgd capacity each). The WRRF staff is planning to replace the two smaller pumps with new pumps as part of a capital improvement project. Both smaller pumps are near the end of their useful life. As peak flows exceed 32 mgd, the WRRF has the ability to divert influent flows upstream of the influent pumping station to the equalization basin. Figure 3-2. Picture of the Existing Influent Pumping Station WRRF Project Existing Facility Page 3-5 GRIT REMOVAL The wastewater is lifted from the influent pumping station to the two parallel aerated grit units. A picture of the existing aerated grit tanks is provided in Error! Reference source not found.. Each grit unit is 34 feet long by 17 feet wide by 12 feet side water depth. Two air agitation blowers (240 scfm each) impart air on the tanks and a blower (500 scfm) is used to aerate the influent channel. The aerated grit effluent is combined into a single channel prior to the Parshall flumes. Figure 3-3. Picture of the Existing Aerated Grit Channels Four grit pumps pump grit to a grit washing and compacting facility that was installed as part of the WRRF Energy Efficiency Project. The grit washing system has two vortex-type grit washer tanks (1.5 ton/hr per unit and 400 gpm per unit), followed by a dedicated grit screw per washer tank (1680 rpm per unit and 1.5 hp per unit). Each screw lifts the washed and compacted grit into a dedicated hopper. INFLUENT FLOW METERS Two Parshall flumes are located downstream of the grit chambers and are used to measure influent flow. A picture of one of the two Parshall flumes is provided in Figure 3-4. The feed channel splits into two channels for each Parshall flume. The two flumes are rated for approximately 16 mgd each, however due to hydraulic constraints downstream of the flumes, flow measurements can only be measured up to 22 mgd (total). For additional information related to the existing flow meters, refer to Appendix I, TM No. 9.1 – Influent and Effluent Flow Monitoring. WRRF Project Existing Facility Page 3-6 Figure 3-4. Picture of an Existing Parshall Flume WRRF Project Existing Facility Page 3-7 During significant peak wet weather events, influent flows to the WRRF can be higher than 22 mgd. To provide more accurate influent flow measurements during peak events, these influent flow meters will be replaced as part of the WRRF Project with mag meters on each influent pumping station pumps. 3.1.2. Primary Clarification A summary of the existing primary clarification facilities is provided in Table 3-2. There are two primaries [80-foot diameter each at 10-foot side water depth (SWD)]. Solids that settle/float and scum are removed by a rotating collector mechanism and a surface scum trough, respectively, into a sludge hopper. A picture of one of the two existing primary clarifiers is provided in Figure 3-5. The separated solids are continuously pumped (2-125 gpm per pump) and scum intermittently pumped (2-75 gpm per pump). The pumped solids and scum are pumped to the DAFT. Table 3-2. Existing Primary Clarification Facilities Equipment Description Units Value Comment Primary Clarifiers Two circular clarifiers with scum trough and center sludge hopper for solids removal ft ft 80 diameter 10 side water depth Primary effluent collects in a channel between the two primary clarifiers Sludge Pumps Two continuously pumping primary sludge pumps gpm 125 per pump Scum Pumps Two scum pumps gpm 75 per pump Figure 3-5. Picture of an Existing Primary Clarifier WRRF Project Existing Facility Page 3-8 3.1.3. Flow Equalization The existing facilities for flow equalization are summarized in Table 3-3. A single, 4 MG basin covering 2.5 acres provides temporary storage of diurnal and emergency peak flows. A picture of the flow equalization basin is provided in Figure 3-6. The diversion locations where liquid stream flow has the ability to divert to flow equalization are screening (flows >32 mgd), the aerated grit effluent channel (flows >22 mgd), primary effluent diversion box (PEDB) (flows >16 mgd), and the secondary effluent diversion box (SEDB) (flows > 5 mgd). Table 3-3. Existing Flow Equalization Facilities Equipment Description Units Value Comment Equalization Basin One, 2.5 acre basin MG 4 Flow Diversion Structures Three flow diversion structures send flow to the equalization basin: influent, grit tank effluent and primary effluent mgd mgd mgd 32 22 16 The primary effluent flow diversion structure also ensures adequate wastewater flows are available to the biofilter. Values shown indicate flows at which flows must be diverted at each structure, respectively Figure 3-6. Picture of the Existing Flow Equalization Basin WRRF Project Existing Facility Page 3-9 For diurnal flow equalization, the diurnal peaks are diverted at the primary effluent diversion box. For emergency peak flow equalization, any flows diverted at the screening and aerated grit effluent channel are conveyed to the primary effluent diversion box prior to the flow equalization basin. A variable speed pump located at the flow equalization inlet structure returns flow from flow equalization. 3.1.4. Biofilters A summary of the existing biofilter facilities is provided in Table 3-4. The biofilters remove BOD prior to the aeration basins. Table 3-4. Existing Biofilter Facilities Equipment Description Units Value Comment Biofilter Pumping Station Two recirculation pumps (one duty, one standby) dose Biofilter 3 mgd 8.6 per pump Biofilter 1 and 2 Two biofilters are no longer in service ft ft 200 diameter 3 side water depth De-commissioned Received 3.2 mgd each when in service Biofilter 3 One rock media biofilter ft ft 200 diameter 3 side water depth Receives 8.6 mgd flow Secondary Clarifier 3 One round secondary clarifier ft ft 140 diameter 7.5 side water depth Originally designed to receive effluent from all three biofilters but now services Biofilter 3 only Sludge/Scum Pumps One pump (1,200 gpm) continuously pumps sludge One pump (75 pgm) pumps scum twice a day gpm gpm 75 1,200 RECIRCULATION PUMP STATION There are two biofilter pumping stations, one for Biofilters 1 and 2 (decommissioned) and one for Biofilter 3 (on-line), which is referred to as the Recirculation Pump Station in this document. The Recirculation Pump Station has two pumps (8.6 mgd per pump) that feed Biofilter 3, and is part of the Recirculation Chamber structure. Primary effluent is routed through the Primary Effluent Diversion Box to the Recirculation Pump Station. An aerial of the Recirculation Pump Station is provided in Figure 3-7. Secondary effluent is also routed to the Recirculation Chamber and serves as a recycle stream to Biofilter 3. WRRF Project Existing Facility Page 3-10 Figure 3-7. Aerial of the Recirculation Pump Station BIOFILTERS SECONDARY CLARIFIER There are three rock media biofilters (1, 2, and 3). Biofilters 1 and 2 have been decommissioned and Biofilter 3 is active and on-line. Biofilter 3 uses a rotary distribution arm to feed the rock media. Biofilter 3 will be decommissioned as part of the W RRF upgrades. A picture of Biofilter 3 is shown in Figure 3-8. WRRF Project Existing Facility Page 3-11 Figure 3-8. Picture of Biofilter 3 SECONDARY CLARIFIER Secondary Clarifier 3 used to receive flow from all three biofilters and now only receives flow from Biofilter 3. A picture of the secondary clarifier is shown in Figure 3-9. Sludge and scum from the secondary clarifier pass through a vortex style grit removal chamber upstream of the DAFT to remove snails that live on the biofilter media. Figure 3-9. Picture of the Secondary Clarifier WRRF Project Existing Facility Page 3-12 3.1.5. Activated Sludge Process A summary of the existing activated sludge facilities is provided in Table 3-5. The activated sludge process removes any BOD not removed in the biofilter, ammonia (oxidized to nitrate), and TSS. A description for each component of the activated sludge is provided below. Table 3-5. Existing Activated Sludge Facilities at the WRRF Equipment Description Units Value Comment Aeration Tanks Two aeration tanks containing fine bubble diffusers MG ft ft ft 0.41 per tank 184 long 20 wide 15.5 side water depth Blowers Two multistage blowers (250 hp) One variable vane Turblex blower scfm 4,100 per blower The Lamson multi-stage blowers are both on-line. The turbo blower is not currently operational. Two new Neuros blowers (sizing still undecided) will be installed as part of the WRRF Capital Improvement Project. Following their installation, the Lamsons will be taken off-line. Diffusers Fine-bubble disc diffusers inch 9 diameter Final Clarifiers Two round clarifiers ft ft 80 diameter 16 side water depth Return Activated Sludge Pumps Four total, two dedicated dual-speed RAS pumps per clarifier mgd 2.5 per pump Waste Activated Sludge Pumps Two centrifugal flooded suction WAS pumps gpm 100 per pump Waste from the mixed liquor channel or RAS pipe AERATION BASINS The WRRF has two aeration basins (each 20 feet wide by 184 feet long by 15.5 feet deep; 0.41 MG each). A picture of the aeration basins is shown in Figure 3-10. Each aeration basin is equipped with a fine-bubble diffuser aeration system. There are two multi-stage blowers (250 hp each; both on-line and functional) and one Turblex blower (variable vane; off-line and not functional). These blowers are being replaced with two new Neuros blowers as part of the WRRF Capital Improvement Projects. A picture of the existing blowers is shown in Figure 3-11. The process controls include dissolved oxygen (DO) meters to control air delivery. Alkalinity is added manually based on lab tests. Historically, the WRRF used sodium hydroxide (caustic) for alkalinity. In the last two years, the WRRF replaced caustic with magnesium hydroxide. The switch to magnesium hydroxide was based on pH and alkalinity stability issues with caustic, as well as safety concerns. WRRF Project Existing Facility Page 3-13 Figure 3-10. Picture of the Existing Aeration Basins Figure 3-11. Picture of the Existing Blowers WRRF Project Existing Facility Page 3-14 FINAL CLARIFIERS The WRRF has two final clarifiers each with an 80-foot diameter and 16-foot side water depth. A picture of the final clarifier launders and flocculating feed well is presented in Figure 3-12. Figure 3-12. Picture of the Existing Final Clarifiers RETURN ACTIVATED SLUDGE Each final clarifier has two dedicated return activated sludge (RAS) pumps (2.5 mgd per pump). A picture of an existing RAS pumping station is shown in Figure 3-13. RAS is pumped to the influent channel of the aeration basins. As part of the WRRF Energy Efficiency Project, VFDs will be installed on each RAS pump to enable RAS flow-pacing. Magmeters will be installed on the pump discharge side of the RAS pumps for measuring flow. Figure 3-13. Picture of an Existing RAS Pumping Station WRRF Project Existing Facility Page 3-15 WASTE ACTIVATED SLUDGE The waste activated sludge (WAS) pumps have the ability to draw suction either from the RAS pipe or from the mixed liquor channel at the end of the aeration tanks. Wasting is typically performed from the mixed liquor channel and pumped to the DAFT for thickening. 3.1.6. Filter Feed Flow Equalization and Pumping Station There are two 0.5 MG flow equalization tanks located downstream of the nitrified effluent diversion box and a spiral energy dissipater. The equalization tanks are referred to as the filter feed equalization tanks. Nitrified effluent is pumped from the equalization tanks to the cooling tower/filter complex with three pumps (2.6 mgd per pump). A picture of the filter feed pumping station is provided in Figure 3-14. The pumps can be operated automatically, semi-automatically, or manually. Figure 3-14. Picture of the Filter Feed Pumping Station 3.1.7. Cooling Towers There are three cooling towers each at 12 feet wide by 21 feet long by 14 feet tall. A picture of the existing cooling towers is presented in Figure 3-15. A summary of the existing cooling tower facilities is provided in Table 3-6. Table 3-6. Existing Cooling Tower Facilities at the WRRF Equipment Description Units Value Comment Cooling Towers Three independently operated cooling towers ft ft ft 12 wide 21 long 14 tall Effluent Pumps Three constant speed pumps, each dedicated to a single tower gpm 1,200 per pump Cooling Media Brentwood Industries Accu-Pac XF-75 Herringbone Film Fill Media The media was replaced during the summer of 2014. WRRF Project Existing Facility Page 3-16 A sidestream flow of nitrified effluent is currently diverted to the cooling towers from the filter feed distribution box. The cooling tower effluent is then pumped back to the filter complex. The cooling tower media was replaced during the summer of 2014 with Brentwood Industries Accu-Pac XF-75 Herringbone Film Fill Media. The media has integrated inlet louvers (XF75 IL) and drift eliminators (XF75 ID). The benefits of the new cooling tower media is improved cooling efficiencies coupled with the ability to maintain and clean biological growth/scaling on the media. Each cooling tower has a dedicated pump that is rated at 1,200 gpm. The pump is used to return the flow to the filter feed complex, but can also be used to recycle flow to the inlet of the cooling tower (i.e., multiple pass cooling). Single pass cooling is typically the mode of operation. The cooling towers are operated to meet the receiving water temperature requirements in the WRRF’s discharge permit. Currently, a grab sample of the receiving water, at the point of discharge, is collected routinely and used to operate the cooling towers. Figure 3-15. Picture of the Existing Cooling Towers 3.1.8. Filtration A summary of the existing filtration complex facilities is provided in Table 3-7. The filter complex removes residual TSS, meets the Title 22 recycled water requirements, and conditions the water for disinfection. The filtration complex contains four granular media filters each at 15 feet wide by 16 feet long (240 sf per filter). Pictures of the filter complex are shown in Figure 3-16. The filters provide tertiary treatment for recycled water production and to comply with permit limitations for creek discharge. The filter media was recently replaced (2014) from dual media to mono media. Additionally, the WRRF is installing a new underdrain system as part of the WRRF Energy Efficiency Project. The filter loading rate after completion of the WRRF Energy Efficiency Project upgrades is anticipated to be approximately 8 gpm/sf. WRRF Project Existing Facility Page 3-17 Table 3-7. Existing Filtration Complex Facilities at the WRRF Equipment Description Units Value Comment Filter Cells Four rectangular filter cells Number of Cells ft ft 4 15 wide 16 long Media Mono-Media -- -- Dual-media has been replaced with sand mono-media Backwash Water Tank One tank stores filtered nitrified effluent via two feed gates from the backwash water diversion box to the backwash tank. MG ft ft ft 0.18 110 long 16 wide 14 SWD Backwash Pumps Two pumps draw from the backwash water tank gpm gpm/sf 2,760 23 Backwash Air Blowers Two multi-stage blowers scfm scfm/sf 1,200 5 Waste Backwash Water Pumps Two vertical turbine pumps (one duty, one standby) operated periodically gpm 300 per pump Tank Drainage Pumps Two flooded suction pumps operated for filter maintenance only gpm 250 per pump Figure 3-16. Pictures of the Existing Filter Complex 3.1.9. Disinfection A summary of the existing disinfection facilities is provided in Table 3-8. The disinfection conditions the water to meet coliform limits and any related disinfection requirements. Table 3-8. Existing Disinfection Facilities at the WRRF Equipment Description Units Value Comment Chlorine Contact Tanks Two concrete tanks, two basins per tank MG 0.16 per tank Sodium Hypochlorite Tanks Three polyethylene tanks gal 5,500 per tank Sodium Hypochlorite Feed Pumps Eight peristaltic metering pumps gph 2.8 - 120 Sodium Bisulfite Tanks Two polyethylene tanks gal 5,500 per tank Sodium Bisulfite Mixing Pump One in-line mixer gpm 100 per pump WRRF Project Existing Facility Page 3-18 Equipment Description Units Value Comment Sodium Bisulfite Feed Pumps Two disk diaphragm metering pumps gph 30 Filtered water is fed into a common box, after which there are gates to feed each chlorine contact tank. There are four chlorine contact basins (0.32 MG per tank, two basins per tank). A picture of the existing chlorine contact tank is shown in Figure 3-17. Three of the chlorine contact tanks are typically used for discharge to the creek and the other tank is dedicated to producing recycled water. Sodium hypochlorite is currently used as the disinfectant at WRRF. Figure 3-17. Picture of an Existing Chlorine Contact Tanks Sodium hypochlorite is stored in three polyethylene tanks (5,500 gal per tank) and fed by peristaltic metering pumps to various locations at the WRRF. Two pumps are used to disinfect the chlorine contact tanks, two pumps are used to dose the filter towers or nitrified effluent box, two remaining are dedicated for reuse, and two pumps to transfer from chemical storage to the 3W pipe. Each set of dosing pumps has a different flow metering capacity. The chlorinated water is subsequently dechlorinated at the end of the chlorine contact tanks with sodium bisulfite. The sodium bisulfite is stored in two polyethylene tanks (5,500 gal per tank) and fed by disk diaphragm type metering pumps (2 – 30 gph per pump). 3.1.10. Recycled Water The City is currently updating its Recycled Water Master Plan. The WRRF currently produces an average annual recycled water flow of 0.15 mgd. Demand is greatest in the dry summer months when the demand averages 0.4 mgd with a maximum day flow of 0.5 mgd. The storage tank at the WRRF is used to meet the diurnal recycled water demands, and reclaimed water is pumped with five pumps (2-40 hp and 3-125 hp) to various end users. The recycled water pump station was constructed with space for two additional 120 hp distribution pumps. The City is currently pursuing grant funding to conduct a Recycled Water Facilities Planning Study to determine the feasibility of delivering recycled water to new potential users, including evaluation of WRRF Project Existing Facility Page 3-19 regulatory compliance strategies, identification of customers, quantification and timing of demands, and evaluation of the infrastructure and costs needed to convey water from the WRRF to the end users, including pumping facilities, pipelines, and storage. As described in later sections, the TSO deadline is a major schedule driver for the WRRF upgrade. As a result, the recommendations for the WRRF upgrade presented in this report are based on the assumption that discharge to San Luis Obispo Creek will continue such that the project can proceed on schedule; however, the recommendations for treatment upgrades should be reevaluated following the conclusion of the Recycled Water Facilities Planning Study. 3.1.11. Plant Water A listing of the existing plant water (3W) facilities is provided in Table 3-9. There is one tank (4,000 gal) and pumps (2-300 gpm per pump). The 3W wet well is located downstream of chlorine contact basins 1 and 2 and upstream of sodium bisulfite addition. Disinfected and dechlorinated effluent overflows into a wet well which is pumped into a pressurized 3W distribution tank. The pumping frequency is governed by water level sensors in the pressurized 3W well. Treated effluent not used for plant use is conveyed from the wet well to the outfall via a 36-inch effluent pipeline. Table 3-9. Existing Plant Water (3W) Facilities at the WRRF Equipment Description Units Value Comment 3W Pumps Two vertical turbine pumps gpm 300 per pump 3W Tank One hydropneumatic tank gal 4,000 3.1.12. Dissolved Air Flotation Thickener A summary of the existing solids thickening facilities is provided in Table 3-10. The DAFT thickens primary and waste activated sludge as well as primary and secondary scum prior to anaerobic digestion. The biofilter solids and scum pass through a snail removal classifier prior to being combined with primary sludge and WAS. A picture of the existing DAFT facilities is presented in Figure 3-18. WRRF Project Existing Facility Page 3-20 Table 3-10. Existing Thickening Facilities at the WRRF Equipment Description Units Value Comment Vortex Grit Chamber One vortex type centrifugal solids classifier For snail removal in biofilter solids Raw Sludge Grinders Two motorized grinders gpm 800 per grinder Dissolved Air Flotation Tank One round tank inside solids handling building ft ft 35 diameter 11 SWD Pressurization Pumps Two pumps gpm 450 per pump Air Dissolution Tanks Two tanks psig Air : Solids Mass Ratio 40-60 0.015-0.025 Following snail removal, all the streams combine and enter the DAFT facility. The DAFT unit has a diameter of 35 feet and side water depth of 11 feet. The DAFT facility has air dissolution tanks that release pressurized air to create micron-sized bubbles to float solids. Following air dissolution, the solids are settled/floated in the DAFT and separated. The thickened solids are conveyed to anaerobic digestion and the DAFT return stream (subnatant) is conveyed to the aeration basin feed. Figure 3-18. Picture of the Existing DAFT Facilities The DAFT is covered and an activated carbon canister is used for odor control. WRRF Project Existing Facility Page 3-21 3.1.13. Anaerobic Digesters A summary of the existing digestion facilities is provided in Table 3-11. The anaerobic digesters destroy volatile solids to meet Class B biosolids. Table 3-11. Existing Digestion Facilities at the WRRF Equipment Description Units Value Comment Digesters Three round, fixed-cover digesters MG MG MG 0.53 0.30 0.23 Tanks are in series Digesters are listed in order from Digester 1 to Digester 3 Digester Mixing (Digester #1) Two gas sparge lines with one gas mixer/compressor Digester Mixing (Digester #1) One gas sparge line with one gas mixer/compressor Digester Heating Two submerged, serpentine hot water heat exchangers MMBTU/hr 0.72 0.36 Digester 1 heating capacity Digester 2 heating capacity Ferrous Chloride Tanks Two chemical feed storage tanks gal 3,600 Ferrous Chloride Feed Pumps Two chemical feed disk diaphragm pumps gph 12.3 per pump Approximately 20-24 gallons of ferrous chloride are fed to the digesters each day The WRRF has three digesters in series, where the first two digesters are used as primary digestion and the third digester is used for storage. A picture of Digesters 1 and 2 is shown in Figure 3-19. The volume of the first two digesters is a combined 0.83 MG, whereas the third digester volume is 0.23 MG. The third digester is the oldest and not mixed or heated because it is used as a holding tank. Digesters 1 and 2 have a gas mixing system. Ferrous chloride solution (2-3,600 gal per tank) is used to reduce odors in the digesters and hydrogen sulfide in the digester gas. The ferrous chloride solution is fed by two disk diaphragm pumps (12.3 gph per pump). Figure 3-19. Picture of Existing Digesters 1 and 2 WRRF Project Existing Facility Page 3-22 3.1.14. Dewatering and Storage A summary of the existing dewatering facilities is provided in Table 3-12. The dewatering facility produces a cake for hauling biosolids off-site. Table 3-12. Existing Dewatering Facilities at the WRRF Equipment Description Units Value Comment Screw Press One mechanical dewatering screw press gpm dry lb/hr 65 at 2% solids 500 (min) Installed as part of the WRRF Energy Efficiency Project Dewatered solids are typically transported with a loader to the most northern portion of the WRRF site so that Engel & Gray trucks can easily access the dewatered solids Belt Filter Press Redundancy for the screw press meter 1 wide Liquid polymer added to digested solids prior to dewatering Solids Storage Redundancy for mechanical dewatering Dewatered Solids Pump One positive displacement pump Sludge Drying Bed Plan to abandon in the near future 1,000 sf 37.5 The WRRF replaced the belt filter press with a screw press as part of the WRRF Energy Efficiency Project. A graphic rendering of a dewatering screw press is presented in Figure 3-20. The screw press selection was based on energy efficiency, the ability to operate with little or no operator attention, and cake production performance. The screw press will have a peak hydraulic loading rate of approximately 65 gpm (500 lb/hr) and staff intends to operate the screw press approximately 14 to 16 hours per day. For periods when the screw is off-line, Digester 3 has sufficient capacity to store digested solids. Figure 3-20. Rendering of a Dewatering Screw Press The belt filter press (shown in Figure 3-21) and the solids storage bed will serve as redundant units. The City intends to abandon the sludge drying beds in the near future now that the screw press is operational. The belt filter press is at or near the end of its useful life. WRRF Project Existing Facility Page 3-23 Figure 3-21. Picture of the Existing Belt Filter Press 3.1.15. Supernatant Lagoon A summary of the existing supernatant lagoon facilities is provided in Table 3-13. The supernatant lagoon is used to hold dewatering filtrate and drying bed supernatant, which is then pumped back to downstream of the headworks. Table 3-13. Existing Supernatant Lagoon Facilities at the WRRF Equipment Description Units Value Comment Dewatering Supernatant Lagoon Aerated equalization lagoon with impervious clay and Hypalon liner acre 0.33 Allows continuous feed of ammonia-rich liquid return stream from sludge drying beds Supernatant Pumps Two pumps Lagoon Aerator Surface mixer hp 5 The lagoon is roughly one-third of an acre and it provides about one to two weeks of storage depending on water depth. To minimize odors, the lagoon is aerated with a 5-hp surface aerator. The supernatant lagoon provides operational flexibility because it allows the high-strength filtrate to be slowly returned to the front of the plant during low flow and load periods. WRRF Project Existing Facility Page 3-24 Figure 3-22. Picture of the Supernatant Lagoon 3.2. Existing Plant Operation This section describes the current operational strategy for the WRRF, including blending, operations staffing, maintenance frequency, laboratory responsibility, and other existing operational issues. 3.2.1. Wet Weather Operation The secondary treatment system is not sized to handle peak wet weather flows. The following describes the flow diversions that occur during peak flow events, which is referred to herein as blending: Peak wet weather flows greater than 22 mgd typically are routed from the aerated grit effluent box to the PEDB. From the PEDB, flow can be routed to several locations: i) biofilter #3 (via recirculation pumps), ii) peak shave to the flow equalization pond, or iii) if the two way valve is open at the secondary effluent diversion box (SEDB) (connecting the two boxes together), it will flow to SEDB, where the blend flow weir gate is dropped, allowing excess flow to be diverted to the nitrified effluent junction box (NEJB). The recirculation pump chamber pumps primary effluent and secondary effluent (recycle flow) to Biofilter 3. When flows exceed approximately 15 mgd, primary and secondary effluent is routed from the recirculation pump chamber to the SEDB; from there, the flow is routed to the NEJB and ultimately to the chlorine contact basins. The aeration basins are bypassed when secondary effluent flows exceed approximately 8 to 9 mgd. The bypass occurs at the SEDB, where flows can be diverted to the NEJB and from there to the chlorine contact basins. WRRF Project Existing Facility Page 3-25 During times of blending (when influent flows exceed 8 to 9 mgd), the filters and cooling towers are shut down and bypassed. Blended flows enter the NEDB and are routed directly to disinfection. 3.2.2. Discharge Permit Compliance The WRRF has consistently met the effluent discharge and receiving stream requirements of its previous permit (Table 3-14). Historical final effluent quality of select constituents is provided in Table 3-15. Table 3-14. Summary of Previous Discharge Limits for Selected Pollutants (R3-2002-0043) Parameter Unit Average Annual Average Monthly Average Weekly Maximum Daily Instantaneous Maximum Biological Oxygen Demand, 5-day (BOD) mg/L -- 10 30 50 -- Total Suspended Solids (TSS ) mg/L -- 10 30 75 -- Un-ionized Ammonia (as N) mg N/L 0.025 (Annual Running Mean)(a) -- -- -- -- Coliform(b) MPN/100 mL -- 23 2.2 240 (a) In-stream criteria (i.e., non-discharge limit). (b) The median number of fecal coliforms shall not exceed 2.2 MPN/100 mL or the median number of total coliforms shall not exceed 23 MPN/100 mL. Coliform numbers shall be determined for the last 7-days samples were taken. The maximum number of total coliforms in any sample shall not exceed 240 MPN/100 mL. Table 3-15. Historical Plant Performance Data WRRF Sampling Identification WRRF Sampling Location Average BOD mg/L Average TSS mg/L Average Ammonia mg N/L Fecal Coliforms MPN/100 mL INF Raw Influent 381 340 42 -- PEFF Primary Clarifier Effluent 140 59 36 -- SEFF Secondary Clarifier Effluent 72 38 25 -- NEFF Final Clarifier Effluent -- <10 0.42 -- FEFF Filter Effluent <10 <10 0.26 2.7 X 104 Effluent 001 Discharge <10 <10 0.26 <2.2 A plot of the historical final effluent (post disinfection) TSS and BOD is shown in Figure 3-23. There is a limited dataset on BOD (13 samples) but they are all less than 10 mg/L. The TSS in the final effluent has historically met the average and maximum day limits. Figure 3-24 provides a plot of final effluent total ammonia concentration (ionized and unionized fractions). The final effluent total ammonia value is on average 0.26 mg N/L. There are occasions where the final effluent total ammonia concentration exceeds 1 mg N/L; these typically occur in wet weather months but there have been instances in recent years where concentrations increase in the fall and spring. The previous permit limitation is an annual running mean un-ionized ammonia limit of 0.025 mg N/L; at a pH of 7.1, this equates to a total ammonia concentration of approximately 2.6 mg-N/L. The annual running mean of historic data has consistently been below this limitation. WRRF Project Existing Facility Page 3-26 Figure 3-23. Historical Effluent TSS and BOD Concentrations Figure 3-24. Historic Effluent Total Ammonia Concentrations 0 10 20 30 40 50 60 70 80 90 Jan-11Jul-11Jan-12Jul-12Jan-13Jul-13Jan-14Jul-14 mg / L EFF, TSS EFF, BOD 30 per. Mov. Avg. (EFF, TSS) 0 2 4 6 8 10 12 14 16 18 20 Jan-11Jul-11Jan-12Jul-12Jan-13Jul-13Jan-14Jul-14 mg N / L EFF, Total Ammonia Average Weekly TSS and BOD Limits Average Monthly TSS and BOD Limits Maximum Day BOD Limits Maximum Day TSS Limits Average Historical Effluent Total Ammonia = 0.26 mg N/L Annual Running Mean Limit as Effluent Total Ammonia at pH = 7.1 WRRF Project Existing Facility Page 3-27 3.2.3. Operations The WRRF is staffed seven-days per week from 7:00 am to 5:30 pm. A breakdown of daily staffing at the WRRF is presented in Table 3-16. The number of operators on site ranges from three on the weekends (two with the normal shift and one with the later shift) to six on Wednesdays (four with the normal shift, one as the rover shift, and one with the later shift). In addition to the operations staff, the WRRF has full-time laboratory and maintenance staff. The laboratory staff is on-site 7 days per week with a minimum of 2 staff on-site on any given day. The laboratory staff is on-site from 6 am to 430 pm. Table 3-16. WRRF Operations Staffing Day of the Week Number of Operators on Duty Shift Times Monday, Tuesday, Thursday, Friday 4 7:00 am to 5:30 pm Wednesday 7 7:00 am to 5:30 pm Saturday and Sunday 3 7:00 am to 5:30 pm The additional staffing on Wednesday is intended for meetings, trainings, and to do maintenance and repairs on equipment, such as annual maintenance on pumps, blowers, tank emptying and cleaning, etc. Typically, maintenance activities that require tanks or units to be taken out of service are performed during dry weather periods so that a unit can be offline for an extended duration. Based on discussions with staff, the primary clarifiers, grit bays, and others are inspected annually, with one unit being taken out of service at a time during low flow periods. The anaerobic digesters are cleaned every 5 to 7 years during low flow periods (one unit taken out of service at a time). The DAFT facilities are cleaned twice per year. Other maintenance activities that typically are performed during low flow periods due to inadequate equipment redundancy include the recirculation pumps and the aeration basins. 3.2.4. Water Quality Laboratory The laboratory has predefined sampling locations for routine sampling. A listing of the various sampling locations at the WRRF is provided in Table 3-17. Table 3-17. Sampling Locations at the WRRF WRRF Sampling Identification WRRF Sampling Location Sampler Type BSC Barscreen – Immediately upstream of the bar screen Time-Paced Composite Sampler INF Raw Influent – Immediately upstream of the Parshall flumes Flow-Paced Composite Sampler PEFF Primary Clarifier Effluent Time-Paced Composite Sampler SEFF Secondary Clarifier Effluent Time-Paced Composite Sampler AERF Aeration Bays Feed Time-Paced Composite Sampler NEFF Final Clarifier Effluent Time-Paced Composite Sampler FEFF Final Effluent - after the chlorine contact tanks Flow-Paced Composite Sampler Effluent 001 Discharge - going into the creek Grab Sample The water quality laboratory analyzes a portion of its collected samples and ships the remaining samples to an outside laboratory. A listing of which samples are analyzed by the water quality laboratory and outside laboratories is shown in Table 3-18. WRRF Project Existing Facility Page 3-28 Table 3-18. Analytical Sampling Distribution by the WRRF and Outside Laboratories Parameter WRRF Laboratory Outside Laboratory Alkalinity X Ammonia X Bioassay, Acute Bioassay X Biochemical Oxygen Demand (BOD) X California Toxics Rule (CTR) Priority Pollutants Suite X Chemical Oxygen Demand (COD) X Color X Conductivity X Dissolved Organic Carbon X Fecal Coliform X Flows X Hardness X Metals (Suite of Compounds under the Basin Plan) X Nitrosodimethylamine (NDMA) X Organics (Suite of Compounds under the Basin Plan) X pH X Soluble BOD X Soluble COD X Temperature X Total Kjeldahl Nitrogen (TKN) X Total Coliform X Total Organic Carbon X Trihalomethanes (THMs) X TSS X Turbidity X 3.2.5. Operational Issues The WRRF consistently meets effluent discharge and receiving stream requirements; however improvements can be made in the plant that will reduce maintenance time, increase process flexibility, and improve process control. A summary of operational and maintenance issues for the existing plant are listed below. Additional equipment preferences and operations and maintenance issues are also described in Section 3.3 Condition Assessment of Existing Treatment Plant. FLOW EQUALIZATION POND The existing equalization pond is used during dry weather conditions for diurnal equalization and/or for emergency conditions. The pond is typically not used for wet weather equalization; during peak wet weather events, blending is practiced as described in Section 3.2.1. The existing basin (Table 3-3) is asphalt lined; however, it does not have baffles to partition storage or spray down equipment to facilitate cleaning. The lack of spray down equipment results in solids accumulation within the pond, which results in odor issues. Additionally, any solids removed from the basin are dried on the northern perimeter of the basins which also contributes to odor issues. WRRF Project Existing Facility Page 3-29 The return pump at the pond is operated on a manually set timer. To optimize the availability of the storage volume, the pump could be automated to operate on level control and/or flow paced to influent flow. INFLUENT FLOW METERS The two Parshall flumes have a rated capacity of 15.9 mgd/each (Appendix I, TM No. 9.1 – Influent and Effluent Flow Monitoring), and are located immediately downstream of the aerated grit chambers. The flumes are not able to measure peak flows to the plant and air binding is also suspected. The known issues with the Parshall flumes include: Poor inlet conditions lead to inaccurate flow measurements. Surcharging of the flumes due to downstream hydraulic constraints does not allow the plant to measure flows greater than 22 mgd (both flumes in service), thus peak flows greater than 22 mgd are not recorded. Data is translated to a circle chart which requires manual chart interpretations and estimations of peak hour flows that can introduce inaccuracies and errors. Accurate influent flow measurement is important for plant operation, permit compliance and effective automated control strategies (e.g., flow pacing). FILTER COMPLEX The new mono-media and underdrains replaced under the WRRF Energy Efficiency Project have resulted in WRRF staff needing to manually backwash each filter cell. Refinement of the control strategies is recommended to provide staff with the ability to automate backwashes. DIGESTERS There is a lack of redundancy with the anaerobic digesters, particularly when Digester 1 is taken out of service for cleaning. Because the digesters are two different sizes, Digester 1 can only be taken out of service during low flow periods (summer months when Cal Poly is out of session). If Digester 1 needs to be taken out of service for extended durations, there would be capacity constraints with only Digester 2 online. STRUVITE Struvite issues became problematic two years ago in the digesters and related piping. Struvite crystals [magnesium ammonium phosphate (MAP)] are formed by chemical precipitation somewhere in the biosolids handling process. The limiting element in MAP formation is typically magnesium. About the same time struvite became an issue, the WRRF replaced caustic soda with magnesium hydroxide, Mg(OH)2 for alkalinity addition in the aeration basins. The WRRF struggled to maintain pH and alkalinity with caustic soda so the decision was made to use magnesium hydroxide instead. The switch to magnesium hydroxide has addressed the pH and alkalinity stability in the liquid stream, but it has most likely resulted in struvite formation in the digesters. Staff have indicated that they plan to conduct studies to look at alternatives to Mg(OH)2 as a means to control and minimize struvite formation in the digesters and downstream equipment. 3.3. Condition Assessment of Existing Treatment Plant Two site walks were conducted in September and October 2014 to visually assess the condition of the existing equipment and facilities at the WRRF. The first visit (September 30 through October 1, 2014) was performed to visually inspect and assess the condition of electrical equipment at the WRRF Project Existing Facility Page 3-30 WRRF. The second site visit was conducted on October 16 and 17, 2014 and was performed to assess the condition of mechanical equipment at the WRRF. During both site visits, interviews with O&M staff were performed to identify routine maintenance items and general equipment condition, and visual inspections of equipment were performed. The results of the mechanical equipment condition assessment are detailed in Appendix E, TM No. 5 – Asset Planning and Rehabilitation. The results of the electrical equipment condition assessment are provided in Section 10 and Appendix M, TM No. 10.2 – Electrical and I&C. Recommendations for mechanical equipment are summarized in Table 3-19. Equipment that was identified to be replaced as part of the WRRF Project include: Primary sludge and scum pumps Aeration butterfly valves and actuators Filter valve actuators Unit 4 Tank Drain Sump Pump Sodium hypochlorite and sodium bisulfite chemical feed piping 3W pumps Digester gas mixing system Table 3-19. Summary of Condition Assessment Recommendations by Process Area Process Area Recommendation Equalization Pond • Replacement not needed at this time. • Provision for a redundant or shelf spare pump. • Provide control upgrades/automation for return pumps. Headworks(a) • The influent wet well has limited access. It has not had a condition assessment since 1993. • 2, Vertical Turbine pumps in good condition and replacement is not recommended at this time. • 2, Horizontal, centrifugal pumps. Staff preference for vertical, centrifugal pumps. Aerated Grit (b) • Grit pumps in good condition. Confirm pumps are compatible with new grit washing system. If pumps can meet pressure and flow requirements of new system – replacement is not recommended at this time. • Replace grit piping with glass lined pipe and with long radius elbows to minimize clogging/pressure loss. • Install new submersible pump seal pumps with rail system. Primary Clarifiers • Replace primary sludge pumps. • Replace primary scum pumps. • Condition of mechanisms unknown. Inspection during next scheduled maintenance is recommended. • Provide shelf spare motor for mechanism. Biofilter 3(c) • Biofilter 3 will be decommissioned as part of the upgrades and was not inspected. Secondary Clarifier 3 • Secondary Clarifier 3 will be decommissioned as part of the upgrades. Paint on portions of the mechanism is starting to fail. The mechanism should be re-conditioned in failing areas to keep it in service until the upgrades are operational. • Air binding issues with the scum pump should be addressed to keep the pump operational until the upgrades are complete. • Sludge pump is in good condition and replacement is not recommended at this time. WRRF Project Existing Facility Page 3-31 Process Area Recommendation Aeration Basins(d) • Diffusers are in good condition –replacement is not recommended at this time. • Replace butterfly valves for air distribution. • Actuators for butterfly valves should be replaced unless replacement is performed during new blower installation. Final Clarifiers 4 and 5 • Mechanisms are in good condition – replacement is not necessary. RAS/WAS Pumps • RAS and WAS pumps are in good condition - replacement is not recommended at this time. Ferrous Chloride Metering Pumps • Pumps appear to be in good condition – replacement is not recommended at this time. Magnesium Hydroxide Metering Pumps • Pumps appear to be in good condition – replacement is not recommended at this time. Filtration System • Replacement and/or expansion of filter influent pump station is needed to accommodate higher filtration rates in the future. • Filter media and underdrain system replaced in 2014 and was not evaluated. • Replacement of filter valve actuators is recommended. • Additional evaluation of backwash pumps is needed to determine if they are adequate with the new media. If capacity is inadequate, pumps should be replaced. The pumps are in good condition and do not need to be replaced if the capacity is sufficient. • Waste backwash water pumps are in good condition – replacement is not necessary at this time. • Backwash air blowers are in good condition. The size/capacity of the blowers should be further evaluated with the new media. Unit 4 Tank Drain Sump • One of two submersible pumps is having noise issues. The noise issue should be further investigated and replaced if the pump is failing. • The second submersible pump is in good condition and replacement is not necessary. Cooling Towers • Cooling tower effluent pumps are in good condition – replacement is not recommended at this time. • Cooling tower media was replaced in 2014 and therefore replacement is not recommended at this time. Disinfection Chemical Storage • The upgrades will convert disinfection to UV; sodium bisulfite and aqueous ammonia will no longer be needed onsite. Smaller quantities of sodium hypochlorite will still be retained onsite for use with the recycled water system. • Sodium hypochlorite and sodium bisulfite pumps appear to be in good condition and replacement is not recommended at this time. • Chemical feed piping is not in good condition and should be replaced for continued use through the upgrades. 3W System • One 3W pump is leaking and requires repairs. • Replacement to the 3W pumps should be considered as part of the upgrades. Recycled Water System • The recycled water pumps appear to be in good condition and replacement is not recommended at this time. DAFT • Replacement of the grinder for influent flows to the DAFT is not recommended at this time. • The DAFT pumps are in good condition and replacement is not recommended at this time. The upgrades should consider replacement of the DAFT with a new, energy efficient thickening system. A redundant unit should be provided. • The thickened sludge pumps are in good condition and replacement is not recommended at this time. Anaerobic Digesters • The digester gas mixing system should be replaced with a new pump or draft tube mixing system. • The boiler is in good condition and replacement is not recommended at this time. • The hot water pumps are in good condition and replacement is not recommended at this time WRRF Project Existing Facility Page 3-32 Process Area Recommendation • Condition of heat exchangers is unknown at this time – it is recommended that during next planned maintenance, the heat exchangers condition be assessed. Solids Dewatering • The BFP, polymer system, feed pump and conveyor are in good condition and replacement is not recommended at this time because the BFP will be used as a redundant unit after completion of the Energy Efficiency Project. Supernatant Lagoon • Surface Aerator in good condition. • Return pump replacement not recommended at this time. (a) Screens, screening washer compactor, and screenings conveyor to be replaced as part of Energy Efficiency Project. Therefore, existing screens and screenings equipment were not evaluated. (b) Grit washing and compaction equipment has been replaced under the Energy Efficiency Project, and therefore was not evaluated. (c) Biofilters 1 and 2 have been decommissioned. (d) Aeration blowers were not included in list because two new blowers are being installed by the City in 2015. 3.4. Existing Site and Surroundings Figure 3-25 provides an aerial image of the WRRF and neighboring properties. The plant is bordered by Highway 101 to the west, San Luis Obispo Creek and the Bob Jones Trail to the east, and Prado Road to the north. The City uses the land directly west of the WRRF filtration facility for a Transit Bus Yard. The property to the west of the aeration basins is used by the City as a materials storage yard. On the north side of Biofilter 3, is the Prado Day Center and Gun Range. The WRRF property continues south and west of the main plant site. Appendix C, TM No. 3 – Site Planning, includes an aerial image of this parcel of land. The parcel of land is bordered to the west by Highway 101, to the east by San Luis Obispo Creek and residences, and to the south by undeveloped property. The WRRF is located to the north of this property. The Bob Jones Trail runs through the middle of the property. This area of the WRRF formerly contained an effluent storage pond, chlorine contact basin and disinfection/operations building. The treatment facilities on this parcel of land are no longer used for treatment and have been decommissioned, but not demolished. A site planning study was performed to identify land within the WRRF fence line that is available for use as part of the upgrade, as well as land outside of the WRRF fence line that could be available for the upgrades. Figure 3-26 identifies that the Prado Day Center Lot and Gun Range could be available for use by the WRRF, as well as the materials storage yard. Additional areas within the WRRF fence line that are available for use are also identified in Figure 3-26. There are plans to construct an overpass that connects Highway 101 with Prado Road. The overpass will be located northeast of the plant site and will result in the plant access road being relocated to the east of its current location. 3.5. Existing Traffic and Access around Site and Site Security Figure 3-26 identifies vehicle access to the WRRF from Prado Road. There are two main access roads from Prado Road that provide entry to the plant. The main access road is located to the north of Biofilter 3 and is the primary egress and ingress to the plant. The second access point is an access road on the northeast side of the equalization pond. From these two access roads, plant vehicles, delivery trucks and employee vehicles are able to enter the plant and access all areas of the plant. The WRRF is surrounded by a chain link fence. WRRF Project Existing Facility Page 3-33 3.6. Existing Site Topography The existing site is primarily paved with landscaped areas located throughout the plant. There is a gradual elevation change along the site. The northeast end of the plant is at a finished grade elevation of approximately 130 feet and the southern end of the plant is at a finished grade elevation of approximately 122 feet. There is approximately a 2-foot finished grade elevation change between the final clarifiers and the tertiary treatment and disinfection facilities. Refer to Figure 3-27. Based on recent HEC-RAS modeling efforts prepared by the Wallace Group (Wallace Group, August 2014), the WRRF is within the 100-year flood zone. The 100-year flood elevation changes across the site. At the north end of the plant, the 100-year flood elevation is approximately at elevation 137.25 feet and at the southern end of the plant (south of the chlorine contact basins) the 100-year flood elevation is approximately 126.0 feet. Remainder of page intentionally blank. WRRF Project Existing Facility Page 3-34 Page intentionally blank. ^_ So u t h W R R F S i t e SL O T r a n s i t B u s Y a r d Ma t e r i a l s S t o r a g e A r e a Ci t y C o r p o r a t i o n Y a r d Pr a d o D a y C e n t e r & G u n R a n g e JB Dewar, Inc. Wa t e r R e s o u r c e R e c o v e r y F a c i l i t y So u r c e : E s r i , i - c u b e d , U S D A , U S G S , A E X , G e o E y e , G e t m a p p ing, Aerogrid, IGN, IGP, and the GIS User Community, Copyright:© 2012 Esri, DeLorme, NA V T E Q , T o m T o m Ci t y o f S a n L u i s O b i s p o W a t e r R e s o u r c e R e c o v e r y F a c i l ity FIGURE 3-26 ± 0 5 0 0 1 , 0 0 0 25 0 Fe e t 1 i n c h = 3 3 3 . 3 f e e t US-101 S Prado Rd S Higuera St WR R F P r o j e c t Ex i s t i n g F a c i l i t y Pa g e 3 - 3 6 Pa g e i n t e n t i o n a l l y l e f t b l a n k . WR R F P r o j e c t Ex i s t i n g F a c i l i t y Pa g e 3 - 3 7 Fi g u r e 3 - 2 6 . S i t e A v a i l a b i l i t y WR R F P r o j e c t Ex i s t i n g F a c i l i t y Pa g e 3 - 3 8 Pa g e i n t e n t i o n a l l y l e f t b l a n k . WR R F P r o j e c t Ex i s t i n g F a c i l i t y Pa g e 3 - 4 0 Pa g e i n t e n t i o n a l l y l e f t b l a n k . 4. Regulatory Compliance Page 4-1 4. Regulatory Compliance This section summarizes the discharge limitations in the City’s renewed NPDES permit as well as the conditions in the new Time Schedule Order (TSO). In addition, this section presents a summary of potential future regulatory changes that were considered when developing recommendations for the WRRF upgrades. Additional information is provided in Appendix G, TM No. 8 – Regulatory Compliance. 4.1. Renewed Permit Conditions The WRRF’s NPDES discharge permit (Order R3-2014-0033; Permit Number CA0049224) was renewed in September 2014. This permit, effective on December 1, 2014, supersedes the previous NPDES discharge permit (Order R3-2002-0043; Permit Number CA0049224). A copy of the permit is included with Appendix G, TM No. 8 – Regulatory Compliance. The WRRF is currently rated for 5.1 million gallons per day (mgd) for average dry weather flow (ADWF) conditions and currently treats an average of approximately 3.1 mgd under ADWF conditions. After being treated, the water is either discharged to San Luis Obispo Creek or recycled. The NPDES permit identifies several beneficial uses for flow discharged to San Luis Obispo Creek: municipal and domestic (MUN); agricultural supply (AGR); ground water recharge (GWR); water contact recreation (REC1); non-contact water recreation (REC2); wildlife habitat (WILD); cold fresh water habitat (COLD); warm fresh water habitat (WARM); migration of aquatic organisms (MIGR); fish spawning, reproduction, and/or early development (SPWN); freshwater replenishment (FRESH); commercial and sport fishing (COMM). In order to satisfy the listed beneficial uses, the WRRF must maintain a minimum 1.6 mgd flow discharged to San Luis Obispo Creek. The new permit conditions are summarized in Table 4-1. Key permit conditions that may impact the recommended upgrades include more stringent discharge limits for nitrogen species, disinfection byproducts, nitrosamines, and dissolved oxygen. In addition to the renewed permit, a TSO (R3- 2014-0036) was also issued that prescribes interim effluent limitations for THMs and nitrates with final limitations going into effect on November 30, 2019 (refer to Appendix G, TM No. 8 – Regulatory Compliance). These are also described below. 4.1.1. Nutrients The nutrient limits included in the renewed permit are limited to nitrogen species, specifically un- ionized ammonia and nitrate. The ammonia limit has not changed since the previous permit. The permit requirements that have changed regarding ammonia are the sampling frequency and the averaging period. The renewed permit requires a weekly grab sample and compliance for a maximum day limit (as opposed to previous annual running mean). The un-ionized ammonia concentration is then calculated based on pH and temperature of the effluent at the time of sample collection. The limitation states that the effluent must not cause the un-ionized ammonia concentration in the San Luis Obispo Creek to exceed 0.025 mg-N/L. The WRRF upgrades will need to address ammonia compliance. WR R F P r o j e c t Re g u l a t o r y C o m p l i a n c e Pa g e 4 - 2 Ta b l e 4 - 1 . R e n e w e d N P D E S D i s c h a r g e L i m i t s f o r S e l e c te d P o l l u t a n t s ( R 3 - 2 0 1 4 - 0 0 4 3 ) Pa r a m e t e r U n i t Av e r a g e D r y We a t h e r F l o w Av e r a g e An n u a l Av e r a g e Mo n t h l y Av e r a g e We e k l y Ma x i m u m Da i l y Instantaneous Minimum Instantaneous Maximum Ma x i m u m E f f l u e n t D i s c h a r g e F l o w m g d 5 . 1 - - - - - - - - - - - - Bi o l o g i c a l O x y g e n D e m a n d , 5 - d a y (B O D ) mg / L - - - - 1 0 3 0 5 0 - - - - lb / d - - - - 4 2 5 1 , 2 7 5 2 , 1 2 5 - - - - To t a l S u s p e n d e d S o l i d s ( T S S ) m g / L - - - - 1 0 3 0 7 5 - - -- lb / d - - - - 4 2 5 1 , 2 7 5 3 , 1 9 0 - - - - Un - i o n i z e d A m m o n i a ( a s N ) m g N / L - - - - - - - - 0 . 0 2 5 (a ) - - - - In t e r i m N i t r a t e a s ( N ) (b ) m g N / L - - - - 4 2 . 6 - - - - - - - - Ni t r a t e ( a s N ) m g N / L - - - - 1 0 - - - - - - - - Co l i f o r m (c ) M P N / 1 0 0 m L - - - - 2 3 2 . 2 - - - - 2 4 0 Di s s o l v e d O x y g e n m g / L - - - - - - - - - - 4 . 0 - - pH s . u . - - - - - - - - - - 6 . 5 8 . 3 In t e r i m C h l o r o d i b r o m o m e t h a n e (b ) g / L - - - - - - - - - - - - 4 2 In t e r i m D i c h l o r o b r o m o m e t h a n e (b ) g / L - - - - - - - - - - - - 3 6 Fi n a l C h l o r o d i b r o m o m e t h a n e (d ) g / L - - - - 0 . 4 0 - - 1 . 0 - - - - Fi n a l D i c h l o r o b r o m o m e t h a n e (d ) g / L - - - - 0 . 5 6 - - 1 . 0 - - - - N- N i t r o s o d i m e t h y l a m i n e ( N D M A ) g / L - - - - 0 . 0 0 0 6 9 - - 0 . 0 0 1 4 - - - - (a ) I n - s t r e a m c r i t e r i a ( i . e . , n o n - d i s c h a r g e l i m i t ) . (b ) I n t e r i m l i m i t s l i s t e d i n r e n e w e d T S O R 3 - 2 0 1 4 - 0 0 36 v a l i d t h r o u g h N o v e m b e r 3 0 , 2 0 1 9 . (c ) T h e m e d i a n n u m b e r o f f e c a l c o l i f o r m s s h a l l n o t ex c e e d 2 . 2 M P N / 1 0 0 m L f o r t h e l a s t 7 - d a y s s a m p l e s w er e t a k e n . N o m o r e t h a n o n e s a m p l e s h a l l e x c e e d 2 3 MP N / 1 0 0 m L t o t a l c o l i f o r m i n a n y 3 0 - d a y p e r i o d . T h e m a x i m u m n u m b e r o f t o t a l c o l i f o r m s i n a n y s a m p l e s h al l n o t e x c e e d 2 4 0 M P N / 1 0 0 m L . (d ) F i n a l l i m i t s c o m p l i a n c e b y N o v e m b e r 3 0 , 2 0 1 9 . WRRF Project Regulatory Compliance Page 4-3 The nitrate limit, at 10 mg-N/L for average monthly conditions, is new. Similar to ammonia, the sampling requirements include a grab sample taken once per week. Upgrades are needed to achieve nitrate removal. The TSO requires compliance with the new nitrate limit by November 30, 2019. 4.1.2. Disinfection Byproducts Interim discharge limitations were established for the WRRF in TSO R3-2010-0013 for the disinfection byproducts (DBPs) chlorodibromomethane (CDBM) and dichlorobromomethane (DCBM). The interim discharge limits are valid until March 31, 2015, after which the discharge limits were prescribed to be consistent with the TSO. Since the City is still undertaking the necessary steps to comply with the permit limits, the earlier TSO was renewed and the interim effluent limitations were extended to be valid until November 30, 2019. Disinfection upgrades are required to meet the prescribed limits. 4.1.3. Nitrosamines Similar to DBPs, the inclusion of a limit for N-nitrosodimethylamine (NDMA), at 0.00069 µg/L for maximum month effluent limits and 0.0014 µg/L for maximum daily effluent limits, has implications for the selection of a disinfection technology. It is also noted that the prescribed limits are several magnitudes below the detection limit of 50 to 25,000 µg/L associated with EPA Method 625. 4.1.4. Dissolved Oxygen The renewed permit includes both a discharge limit, at 4.0 mg/L instantaneous minimum, and a year round receiving water limit for dissolved oxygen (DO). The previous permit did not have an instantaneous minimum discharge limit and the year round receiving water limit is more stringent than the previous permit. 4.1.5. Temperature The renewed permit has a temperature impact on the receiving water body limit. Effluent discharged shall not cause the receiving water temperature to increase more than 5 °F above receiving water temperature. The previous permit had a similar requirement. 4.2. Future Limits Although it is difficult to predict the future, it is necessary to consider future limits such that the proposed upgrades can accommodate changes in the future. The following subsections describe the key parameters that could impact upgrade recommendations, including water conservation, water recycling, contaminants of emerging concern, phosphorus, averaging periods, and air emissions. 4.2.1. Role of Water Conservation The City has successfully implemented water conservation measures within its service area and as a result has observed increases in influent ammonia concentrations (Figure 4-1). The most recent increases in concentrations may also be attributed to drought conditions which result in additional water conservation as well as reduced groundwater infiltration into the collection system. WRRF Project Regulatory Compliance Page 4-4 Figure 4-1. Historical Raw Influent Ammonia Concentrations While the increase in water conservation is beneficial from a water supply standpoint, there is an unintended consequence at the WRRF. The rated capacity at the WRRF is based on flow, not loads. By having concentrations increase over time, the load associated with the rated capacity increases over time. The implications are that unit processes might not have as much rated flow capacity and the amount of consumables per unit flow increases directly with water conservation. For example, the amount of energy demand, chemical demand, and unit biosolids production per unit flow increases with water conservation. 4.2.2. Role of Recycled Water The City plans to increase the volume of recycled water used in the future. A plot of recycled water usage over the last few years is provided in Figure 4-2. The average annual demand is about 0.15 mgd. There is a seasonal trend where demand increases in the dry season. During the peak dry season (July and August), the demand increases to a range of 0.3 to 0.5 mgd. An increase in the use of recycled water will result in a reduction of the constituent loads discharged to the creek. However, the increased use will not provide a reprieve for discharge limits based on concentration. 0 10 20 30 40 50 60 70 80 90 100 Jan-11Jul-11Jan-12Jul-12Jan-13Jul-13Jan-14 Am m o n i a C o c n e n t r a t i o n , m g N / L WRRF Project Regulatory Compliance Page 4-5 Figure 4-2. Historical Recycled Water Volume 4.2.3. Nutrients The key nutrients of interest for regulatory purposes are typically nitrogen and phosphorus. While there is a nitrogen limit in the renewed permit, it is possible that the limit could become more restrictive in the future. In addition, it is possible that a phosphorus limit could be added in the future. Thus, the recommended upgrades for the WRRF should be implemented with the ability to accommodate future upgrades, as needed, for additional nutrient removal. 4.2.4. Contaminants of Emerging Concern Contaminants or compounds from pharmaceuticals and/or personal care products are being discovered in watersheds at very low concentrations (e.g., ppb or ppt). Some of these contaminants have been determined to be endocrine disrupters (Kolpin et al, 2002). The contaminants mimic estrogen and, therefore, may disrupt the endocrine (hormone) system of both animals and humans. These contaminants are known in the water industry as contaminants of emerging concern (CEC). It is well documented that as treatment plants improve treatment performance, specifically those that transition from secondary treatment to nitrogen removal by increasing the solids residence time (SRT), the ability to remove overall CECs also increases. This increase in removal is highly dependent on the CEC constituent of interest. The longer SRT for ammonia removal translates to an increased surface area on mixed liquor for sorption, elevated biomass concentration, and the enzymes that carry out nitrification (Horz et al., 2004). The enzyme responsible for the oxidation of ammonia to nitrite, ammonia monooxygenase, is commonly referred to as ‘promiscuous’ because it has the ability to assist in the biodegradation of a wide-range of compounds such as CECs (Vader et al., 2000). 0 100,000 200,000 300,000 400,000 500,000 600,000 Jan-11Jul-11Jan-12Jul-12Jan-13Jul-13Jan-14 Re c y c l e d W a t e r , g a l WRRF Project Regulatory Compliance Page 4-6 There is uncertainty on which CECs will be regulated in the future (if any). However, the existing unit processes at the WRRF provide a level of treatment for removing CECs that would match other publicly owned treatment works (POTWs) (except those with membrane removal processes). 4.2.5. Human Health Criteria The USEPA is recommending a modification on human health criteria. The proposed criteria result in modifications to the assumptions used to calculate the criteria (e.g., changes in body weight, fish consumption amount and frequency, water consumption, etc.). The implications of such modifications are more stringent limits. Refer to Appendix G, TM No. 8 – Regulatory Compliance for additional information. Whether the SWRCB decides to take action to update the statewide criteria (e.g., California Toxins Rule) to reflect the updated criteria is unclear. Thus, it is important that the proposed WRRF upgrades consider such modifications to the rule-making. 4.2.6. Disinfection Indicators The USEPA is in the process of developing Ambient W ater Quality Criteria to protect human health based on virus quantitation. The USEPA has outlined a schedule for developing virus criteria and indicated that this will be done in the next one to two years. Details are not yet available regarding the virus indicator and numeric limits for wastewater dischargers. It is likely that bacteriophage will be adopted as the viral indicator. Regardless of which virus indicator type is selected by the USEPA, it is anticipated that the WRRF will be able to meet the updated USEPA limits. The previous and renewed permits both have Fecal and Total Coliform limits that are considerably more stringent than limits seen nationally. In addition, as described later in this plan, the recommended disinfection technology is ultraviolet (UV) disinfection, which will be designed to meet unrestricted Title 22 requirements. 4.2.7. Biosolids Currently the WRRF is producing Class B biosolids that are hauled offsite to a privately owned composting facility and/or landfill. The growing public concern associated with Class B biosolids, increasingly stringent future regulations with land application and/or alternative daily cover (ADC) at landfills, as well as the high costs associated with biosolids hauling could potentially lead the City to move towards Class A production in the future. 4.2.8. Air Emissions The implementation of more stringent nutrient limits has the potential to result in adverse environmental impacts, such as an increase in energy demand, greenhouse gas (GHG) production, land requirements and residuals disposal. For example, the adverse environmental impact on GHG emissions for variable nutrient discharge limits is presented in Figure 4-3. As shown, the energy demand increases with each treatment level and it is the dominant parameter for GHG emissions. WRRF Project Regulatory Compliance Page 4-7 Figure 4-3. GHG Emissions Distribution per Treatment Level for a 10 mgd Nominal Plant (Falk et al., 2013) Remainder of page intentionally blank. -2,000 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 CO 2 eq u i v a l e n t t o n n e s / y r N2OEmissions (w/Data Range as Bars) Biosolids Hauling and CH4 Emissions DeepWell Injection Aeration ChemicalsPumping/ Mixing Miscellaneous Cogeneration WRRF Project Regulatory Compliance Page 4-8 Page intentionally blank. 5. Flow and Loading Projections Page 5-1 5. Flow and Load Projections This section presents an overview of the existing flow and load conditions at the WRRF as well as projected flows and loads through 2035 General Plan buildout. Flow definitions and additional information is included in Appendix A, TM No.1 - Wastewater Characterization. 5.1. Existing Conditions Based on an analysis of historical flow and loading data for the five-year period between January 2009 and January 2014, the existing flow and loads for the WRRF were calculated as well as peaking factors. 5.1.1. Existing Flow and Loads The ADWF is the average daily flow during the dry season with insignificant influence of rainfall or rainfall induced infiltration over the calendar year. ADWF is considered the normal wastewater flow generated from all water users in the service area, including residential, commercial, and industrial dischargers. An analysis of historical flows indicated that typically the lowest influent flows to the WRRF occur in July, August, and September. The existing ADWF is approximately 3.1 mgd, which is based upon historical influent flows for the months of July, August, and September from 2009 through 2013. This flow does not include contributions from Cal Poly, which are currently estimated to be 0.35 mgd. Thus, the historical ADWF with Cal Poly contributions (ADWFCP) is 3.5 mgd. The ADWF TSS and ammonia loads to the WRRF (with Cal Poly contributions) are approximately 10,400 lbs/day and 1,300 lbs/day, respectively. Influent BOD and Total Kjeldahl Nitrogen (TKN) are not routinely monitored at the WRRF. 5.1.2. Peaking Factors Peaking factors were determined from the historical data and are used to project future flows and loads. As noted in the 2011 WRRF Master Plan, the peaking factors are assumed to remain the same for future conditions, and do not account for changes in flow and load patterns due to water conservation efforts. This approach is recommended at this time because design criteria will be driven by TSS and BOD loads. While influent flows may potentially decrease with future water conservation, that conservation will not result in a reduction in loads. Due to the uncertainty with how much flow reduction could occur in the future, use of historical flow and load peaking factors is recommended for projections. Flow peaking factors are calculated by dividing the historical averaging period flow of interest by the historical average annual (AA) flows as follows: ADWFCP Peaking Factor = Historical ADWFCP ÷ Historical AA Table 5-1 provides historical flow and corresponding calculated peaking factors. For additional information, refer to Appendix A. WRRF Facility Flow and Load Projections Page 5-2 Table 5-1. Peaking Factors for Historical Flows Averaging Period Historical Flow (mgd) Peaking Factor with respect to AA Average Dry Weather Flow with Cal Poly (ADWFCP) 3.5 0.9 Average Annual Flow (AA) 3.9 1.0 Maximum Month Flow (MM) 5.4 1.4 Maximum Week Flow (MW) 7.4 1.9 Maximum Day Flow (MD) 11.1 2.9 Peak Hour Flow (PH)(a) 32.0 8.2 (a) Staff have indicated that peak hour flows exceed the capacity of the flow meter. The value included in the table corresponds to the capacity of preliminary treatment. The peaking factors for loads are calculated using the same methodology described above. Table 5-2 presents peaking factors for TSS and ammonia, respectively. Table 5-2. Peaking Factors for Historical TSS and Ammonia Loads Averaging Period Historical TSS Load (lb/d) TSS Peaking Factor with respect to AA Historical Ammonia Load (as N) (lb N/d) Ammonia Peaking Factor with respect to AA ADWFCP Load 10,400 1.0 1,300 1.0 AA Load 10,900 1.0 1,370 1.0 MM Load 15,500 1.4 1,900 1.4 MW Load 20,900 1.9 2,200 1.6 MD Load 28,400 2.6 2,700 2.0 Since BOD and TKN are not monitored daily at the plant, the peaking factors for these compounds are assumed to be the same as that for TSS and ammonia, respectively. 5.2. Projections The following subsections present two methods for projecting future flows as well as the recommended flow and loading projections. 5.2.1. Population Projection Using data from the City’s General Plan - Chapter 8 Water and Wastewater (2010), historical wastewater generation rates were developed based on population and annual ADWF rates (July through September). From 2004 through 2011, the wastewater generation rates ranged from 80 to 100 gallons per capita per day (gpcd), which is within the typical range of wastewater generation rates for residential communities in the United States (WEF MOP 8). Most recently in 2012 and 2013, a lower generation rate of about 60 gpcd was observed. Drought conditions in addition to water conservation measures implemented within the City may be the cause of the observed decline in the wastewater generation rate. For planning purposes, a per capita wastewater generation rate of 92.5 gpcd for ADWF conditions was used, which is consistent with what the City has used in past studies and evaluations (refer to Appendix A for additional information). The buildout population within the service area is projected to be 53,700 (City of San Luis Obispo, 2013). This population projection is in-line with the 2035 Land Use and Circulation Element (LUCE) adopted in 2014. Based on this information, the projected ADWF at buildout is 4.9 WRRF Facility Flow and Load Projections Page 5-3 mgd. The projected contribution from Cal Poly is estimated to be 0.47 mgd. Thus, the ADWFCP is projected to be 5.4 mgd. It is recommended that the City update the wastewater generation rate and the associated ADWF projections as additional data become available, particularly if lower generation rates become the norm. 5.2.2. Land Use/Development Projection In addition to the population based projection, future land use and development within the wastewater service area was also used to project the future ADWF. Under this approach, the ADWF projection was based on wastewater generation rates for various land use categories (e.g., single family dwelling, retail, motel/hotel, etc) being applied to projected development within the wastewater service area. The details of this approach are provided in the Wastewater Collection System Infrastructure Renewal Strategy (WSC, June 2014). Using this approach, the ADWFCP projection is 5.4 mgd. 5.2.3. Flow Projections Based on the projections described above, the projected ADWFCP is 5.4 mgd. As noted earlier, if additional data demonstrate a lower per capita wastewater generation rate than the value used, the City may want to update the ADWFCP projection. Based on an ADWFCP of 5.4 mgd, Table 5-3 presents the projected flows for AA, MM, MW, MD, and PH. Table 5-3. Projected Flows and Loads of Selected Constituents Averaging Period Peaking Factor Flow (mgd) Average Dry Weather w/ Cal Poly 0.9 5.4 Average Annual 1.0 6.1 Maximum Month 1.4 8.4 Maximum Week 1.9 11.4 Maximum Day 2.9 17.3 Peak Hour(a) -- 33.5 (a) Peak hour flow is based on the results of collection system monitoring (V&A 2012) and modeling. Refer to Appendix J, TM No.9.2 - Influent Hydrograph Simulation for the WRRF for additional information. The projected peak hour flow represents the maximum sustained hour flow that can be conveyed to the WRRF during a 10-year, 24-hour storm event. The WRRF facilities will be designed to convey or store this peak hour flow to avoid overflows at the plant and within the collection system. The projected peak hour flow of 33.5 mgd was developed using flow metering and collection system modeling performed by V&A in 2010 and 2011 (V&A, 2012) as well as additional modeling as described in Appendix J, TM No. 9.2 – Influent Hydrograph Simulation for the WRRF. It should be noted that the City has undergone collection system repairs for inflow and infiltration (I/I) reduction and intends to continue with collection system repairs in the future. The majority of past repairs were performed prior to the V&A Study and therefore the results from the study were considered to accurately reflect current conditions and were used to conservatively project peak hour flows. It is recommended that the City continue with additional flow metering and collection system modeling to monitor peak hour flows into the WRRF and to confirm if additional I/I reduction has been achieved. If the additional efforts demonstrate that peak hour flows into the plant will be lower than the projected 33.5 mgd, the design criteria should be modified. WRRF Facility Flow and Load Projections Page 5-4 5.2.4. Load Projections Projected TSS and ammonia loads were calculated based on the historical per capita unit loading and peaking factors presented in the previous subsections. The results are presented in Table 5-4. Projected BOD and TKN loads were calculated based on TSS and ammonia projected loads. Ratios of BOD to TSS and ammonia to TKN were selected from the literature and all available data. BOD to TSS ratios of 0.81 and 1.09 for historical and projected loadings, respectively, were used in the 2011 Master Plan flows and loads analysis. The BOD to TSS ratio for 2009 through 2013 was estimated on average at 0.85. The projected BOD loadings presented herein are calculated for both the lowest and highest 2011 Master Plan estimated BOD to TSS ratios (as shown in Table 5-4). This approach presents the potential range of BOD loads for design of the facility upgrades. TKN loads were determined in a similar manner as BOD, except only one value of the ammonia to TKN ratio was selected (0.66). The ammonia to TKN ratio is based on values in Metcalf and Eddy (2013) as well as professional experience. Resulting TKN projected loads are also shown in Table 5-4. 5.2.5. Summary of Flow and Load Projections A summary of the projected flows and loads are presented in Table 5-4. These values are based on an analysis of historical WRRF data for the five year period from January 2009 through January 2013. Table 5-4. Summary of Projected Buildout Flows and Loads Parameter Units ADWF AA MM MW MD PH Flow mgd 5.4 6.1 8.4 11.4 17.3 33.5 TSS lb/d 12,300 12,900 18,300 24,700 33,400 - BOD (low)(a) lb/d 9,900 10,400 14,800 20,000 27,100 - BOD (high)(b) lb/d 13,400 14,100 19,900 26,900 36,400 - Ammonia (as N) lb N/d 1,500 1,600 2,200 2,600 3,200 - TKN (as N) lb N/d 2,300 2,400 3,300 3,800 4,800 - TSS mg/L 272 253 261 260 231 - BOD (low)(a) mg/L 221 205 211 210 187 - BOD (high)(b) mg/L 297 276 284 283 252 - Ammonia (as N) mg N/L 34 32 31 27 22 - TKN (as N) mg N/L 51 47 47 40 33 - (a) BOD:TSS ratio assumed at 0.81. (b) BOD:TSS ratio assumed at 1.09. (c) Peak hour flow is based on the results of collection system monitoring (V&A 2012) and the Wastewater Collection System Infrastructure Renewal Strategy (WSC, 2014). As previously described, there is some uncertainty associated with the projections, due to changes in water conservation, metering, and lack of sampling data. Thus, it is recommended that as additional information is made available, the projections be revisited and updated as appropriate. 6. Capacity Assessment Page 6-1 6. Capacity Assessment This section provides a summary of the capacity assessment that was performed on existing treatment facilities at the WRRF. The purpose of the capacity evaluation was to rate the capacity of existing facilities so that improvements, expansions and upgrades at the WRRF can be identified to meet NPDES permit limitations, and to accommodate build-out flows and loads as well as recycled water demands. As part of the capacity assessment, flow equalization for diurnal and wet weather flows was reviewed to minimize the sizing (e.g., capacity constraints) of downstream treatment facilities. The flow equalization analysis was used to set the peak hour flow requirements. Appendix H, TM No. 9 – Capacity Considerations, presents the detailed evaluation that was performed (note that additional refinement of capacity requirements was conducted, which is not reflected in Appendix H). 6.1. Flow Equalization The WRRF currently has a 4 MG flow equalization pond located on the northeastern portion of the site. The pond is typically used for diurnal equalization to provide constant organic loading to the secondary system during dry weather conditions. During wet weather events, peak flows bypass secondary treatment and are blended with nitrified effluent prior to disinfection and discharged to San Luis Obispo Creek. Because blending is currently used at the WRRF, flow equalization of peak wet weather flows is not typically employed. During storm events, staff tries to keep the pond empty in case an emergency diversion to the pond is needed. Based on the discharge limitations in the WRRF’s renewed permit, blending will no longer be employed (see Section 7.1.2) during wet weather events in order to remain in compliance with the discharge limitations. For this reason, flow equalization was reviewed at the WRRF for peak wet weather events. Diurnal equalization is expected to be discontinued as a routine practice; therefore it is not considered for plant expansion. However, the existing secondary clarifier will be decommissioned and could be repurposed for diurnal equalization in the future if circumstances change. For the wet weather equalization analysis, it is assumed that flows at the PEDB are diverted to equalization. Diversion of influent flows upstream of primary clarification would be performed under emergency conditions. The flow equalization analysis was used to set the peak hour flow requirements for wet weather flow conditions. 6.1.1. Diurnal Equalization Although it is not included in the planned facility improvements, diurnal equalization was originally considered (using the existing secondary clarifier) and later eliminated. Thus, it is reviewed here to determine whether to simply decommission the existing secondary clarifier in-place or to demolish it. The evaluation of diurnal equalization was based on primary effluent being diverted to equalization under normal operating conditions. Diurnal equalization was reviewed using influent hydrographs from April 2014. April was selected because it is typically a dry month and the ADWF includes contributions from Cal Poly (ADWFCP). The hydrographs for existing conditions were reviewed, and WRRF Facility Capacity Assessment Page 6-2 the flows were increased to reflect future design (buildout) conditions. Figure 6-1 provides the ADWFCP hydrograph that was used to determine diurnal equalization needs. Figure 6-1. Hydrographs for Diurnal Flow Equalization Analysis (April 7, 2014 – ADWFCP contribution) Influent flows greater than the average daily flow would be diverted to equalization; when influent flows are less than the average daily flow, flows would be routed from equalization to the aeration basins. Based on the buildout hydrograph in Figure 6-1, the required volume for diurnal flow equalization was estimated to be 0.9 MG. The existing secondary clarifier has a volume of approximately 0.9 MG. As described in Section 7, the secondary clarifier will not be required after the upgrades because the biofilter will be decommissioned. Thus, the secondary clarifier could be repurposed for diurnal equalization if desired. As a result, it is recommended that the secondary clarifier tank be decommissioned in-place for potential improvements in the future should diurnal equalization be desirable. The secondary clarifier is located adjacent to the aeration basin and hydraulically upstream of secondary treatment. 6.1.2. PWWF Equalization During wet weather events, primary effluent and/or screened and degritted influent would be diverted to equalization. Diversion of influent flows upstream of screening and grit removal would only be performed under emergency conditions. The hydraulic grade line downstream of the primaries is also limiting, requiring a diversion upstream in order to completely fill and maximize the use of the existing equalization pond. 0.0 2.0 4.0 6.0 8.0 10.0 12.0 0:006:0012:0018:000:00 Fl o w ( m g d ) Time 'April 7, 2014'Buildout Condition ADWFCP at buildout = 5.4 mgd ADWFCP (existing) = 3.5 mgd WRRF Facility Capacity Assessment Page 6-3 Peak wet weather influent hydrographs of two historic rain events were evaluated (January 1-3, 2011 and March 19-20, 2011) to determine equalization needs under existing conditions. For future conditions, the City’s collection system hydraulic model was used to develop influent hydrographs that include I/I in addition to future baseline flows. Model hydrographs, shown in Figure 6-2, were developed for the design storm event, which has been defined as the 10-year, 24-hour storm. Additional information regarding the development of the hydrograph is included in Appendix J, TM No. 9.2 – Influent Hydrograph Simulation for the WRRF. Figure 6-2. Influent Hydrograph for 10-Year, 24-Hour Design Storm at Buildout (2035) The capacity of flow equalization is dependent on influent flows as well as downstream treatment capacity. Under existing conditions, the aeration basins and final clarifiers limit secondary treatment capacity to influent flows as low as 5.1 mgd (typically 8 to 9 mgd). Based on the current capacity of the aeration basins and final clarifiers and no changes in the upstream collection system, the volume needed for flow equalization under the design storm condition would be approximately 13.5 MG. At 13.5 MG, the required equalization volume is approximately 3.5 times greater than the current equalization capacity and would be difficult to site at the WRRF. Therefore, it is necessary to expand the capacity of the secondary and downstream treatment processes to accommodate higher flows and loads. The existing 4 MG pond requires improvements to raise the perimeter berm to protect it from inundation during a 100 yr flood event (refer to Section 10). This improvement will also allow for up to 5.4 MG of equalization storage during PWWF events. With this additional volume, the secondary treatment system (aeration basins, final clarifiers, RAS/WAS pumping) would need to be sized to accommodate peak hour flows up to 16 mgd (refer to Figure 6-3). Appendix I, TM No. 9.1 – Influent and Effluent Flow Monitoring provides the details of the flow balance that was performed to determine the capacity requirements and select a preferred flow equalization facility. 0 5 10 15 20 25 30 35 40 020406080100120 Fl o w ( M G D ) Time (hours) WRRF Facility Capacity Assessment Page 6-4 Figure 6-3. Equalized Influent Flow using the Expanded 5.4 MG Flow Equalization Pond in a 10-year 24-hr Storm Figure 6-4 provides an approximate layout and dimensions for the improvements to the existing flow equalization pond. The values shown are anticipated to provide adequate flood protection during a 100 yr flood event and provide up to 5.4 MG of internal storage. Remainder of page intentionally blank. 16.00 mgd 0.00 mgd 5.00 mgd 10.00 mgd 15.00 mgd 20.00 mgd 25.00 mgd 30.00 mgd 35.00 mgd 40.00 mgd 0 hr24 hr48 hr72 hr96 hr120 hr144 hr168 hr192 hr216 hr240 hr Influent Hydrograph (No EQ)Max 1.5 Day (5.4 MG) WRRF Facility Capacity Assessment Page 6-5 Figure 6-4. Layout of improved Wet-Weather Equalization Pond The capacity requirements for the downstream tertiary treatment facilities (filtration, cooling and disinfection), will be based on a 16 mgd peak flow. Nitrified effluent could be equalized in the existing 1 MG filter feed equalization basins (located adjacent to the chlorine contact basins) as added capacity in the event that the filters require backwashing during a peak wet-weather event. 6.2. Approach A steady state mass balance was developed for the W RRF and used to evaluate the process loading and performance. The calibrated model was then used to rate the capacity of each major unit process. The calculated capacity was compared against buildout conditions as a means to identify the limiting unit processes. The model accounts for the facilities that are being completed as part of the WRRF Energy Efficiency Project. The diurnal and wet weather flow equalization analysis from Section 6.1 was used in the analysis. For this analysis, both the firm and total capacity is presented for major unit processes. The updated individual treatment unit process capacities are based on criteria from a combination of prior reports prepared for the WRRF and professional opinion. A listing of the liquid and solids stream criteria are provided in Table 6-1 and Table 6-2, respectively. WRRF Facility Capacity Assessment Page 6-6 Table 6-1. Existing Liquid Stream Treatment Unit Capacity Criteria Unit Process Units Capacity Criteria Averaging Period Source Pumping Stations mgd Firm pumping capacity or ability to bypass/divert PH Engineer’s Recommendation Screens mgd Firm treatment capacity or ability to bypass/divert PH Engineer’s Recommendation Grit Removal min 3 PH Water Environment Federation Manual of Practice 8 Primary Clarifiers – Detention Time hr 2.0 AA Engineer’s Recommendation Primary Clarifiers – Surface Overflow Rate gpd/sf 1,250 MM Engineer’s Recommendation Primary Clarifiers – Peak Surface Overflow Rate gpd/sf 2,500 PH Engineer’s Recommendation Biofilter Trickling Filters lb/1,000 cf/d 150 MM Water Environment Federation Manual of Practice 8 Aeration Basins – MLSS mg/L 3,500 MM Engineer’s Recommendation Aeration Basins – Oxygen Uptake Rate (OUR) mg/L/hr 70 MM Engineer’s Recommendation Secondary/Final Clarifiers gpd/sf 1,200 MD Engineer’s Recommendation Secondary/Final Clarifiers lb/d/sf 30 MM Engineer’s Recommendation RAS % 100 MM Engineer’s Recommendation Filtration – Average Loading Rate gpm/sf 5 AA For periods of water reclamation; 1 unit out of service Filtration – Peak Loading Rate gpm/sf 8 PH For wet weather events; 1 unit out of service Chlorination – Detention Time (non-recycled water periods) min 20 PH Engineer’s Recommendation Table 6-2. Existing Solids Stream Treatment Unit Capacity Criteria Unit Process Units Capacity Criteria Averaging Period Source Dissolved Air Flotation Thickener gpd/sf 2,950 MM WEF MOP 8 Dissolved Air Flotation Thickener lb/d/sf 48 MM WEF MOP 8 Anaerobic Digester days 15 MM USEPA 503 Regulations for Class B Biosolids Screw Press hr/week 168 MM WRRF Specifications Screw Press gpm 66 MM WRRF Specifications Screw Press lb/hr 500 MM WRRF Specifications For processes governed by average annual (AA), maximum month (MM), maximum week (MW), or maximum day (MD) averaging periods, the calculated capacity values are translated to ADWFCP values. For example, the aeration system is governed by MD, so the MD flow is translated to ADWFCP using flow peaking factors. For those governed hydraulically by peak flows [i.e., peak hour (PH)], such rated capacity values are listed as peak flow capacity. For example, pump station WRRF Facility Capacity Assessment Page 6-7 capacity is listed as the peak pumping capacity. The flow peaking factors used in the capacity assessment were presented in Table 5-1. 6.3. Liquid Unit Processes A summary of the future plant capacity for the liquid stream is illustrated in Figure 6-5. The desired capacity is at or greater than 5.4 mgd ADWFCP for projected flows and loads, as well as the ability to hydraulically convey up to 33.5 mgd PH flows through the plant. As shown in Figure 6-5, the liquid stream has several unit processes with capacities below the desired treatment capacities, including the following: Influent pumping station Screens Primary clarifiers Aeration basins Final clarifiers RAS pumping Filtration pumping station Filtration Cooling towers and cooling tower pumping The influent pumping station and screens capacities are slightly below buildout peak flows. The smaller influent pumps will be replaced in the next two years; slightly larger pumps should be considered at the time of replacement to provide the plant with adequate capacity in the future. Two new mechanical bar screens were installed as part of the WRRF Energy Efficiency Project and a bypass line (with a manual screen) can be used under emergency conditions. The hydraulic profile in Section 8 reviewed projected peak hour conditions and it was determined that improvements/ modifications to the headworks in addition to those being implemented as part of the WRRF Energy Efficiency Project were not needed. The capacity of the primary clarifiers is slightly under the design ADWFCP condition, when a unit is taken out of service for inspection and maintenance. Rather than constructing a third primary clarifier, the secondary system can be designed to accommodate additional loading during these planned maintenance activities and therefore an additional primary clarifier is not needed. As shown in Figure 6-5, the RAS pumps have adequate capacity to meet design ADWFCP conditions. However, the configuration of the RAS pumps requires additional pumps to be added with new final clarifiers. Therefore, as further described in Section 7, four additional RAS pumps will be added (two per clarifier). As described in Section 7, the existing aeration basins, filter feed pumping station, filter complex, cooling system, and disinfection facilities will be expanded, modified, or replaced as part of the WRRF Project. WR R F F a c i l i t y Ca p a c i t y A s s e s s m e n t Pa g e 6 - 8 Fi g u r e 6 - 5 . L i q u i d S t r e a m P l a n t C a p a c i t y p e r U n i t P ro c e s s RRF Facility Capacity Assessment Page 6-9 6.4. Solid Unit Processes The capacities of the solids treatment facilities (Figure 6-6.) are dependent on the WRRF redundancy requirements. Figure 6-6. Solids Stream Plant Capacity per Unit Process The DAFT and anaerobic digesters have firm capacities below the desired 5.4 mgd ADWFCP, which can be attributed to a lack of redundancy. However, the total capacity is at or exceeds 5.4 mgd ADWFCP for both processes. The new screw press has a capacity of 5.4 mgd ADWFCP and can meet buildout flows and loads. While the existing belt filter press could provide redundancy to the new screw press, the belt filter press is at near the end of useful life, thus, it is recommended that the belt filter press be replaced with a second screw press for redundancy. This also offers the advantages of common equipment performance for both operations and maintenance. 6.5. Capacity Assessment Recommendations This plant-wide treatment capacity analysis for the WRRF considered flow equalization and recycled water production, as well as on-going equipment replacement and upgrades under the WRRF Energy Efficiency Project. As previously described, flow equalization was reviewed for peak wet weather events. Based on the model hydrograph, equalization of peak wet weather flows (greater than 16 mgd) can be achieved by expanding the equalization basin to 5.4 MG. Thus, the secondary treatment system, tertiary filtration, cooling and disinfection can be sized to treat PH flows up to 16 mgd. 0 2.4 5.4 8.0 6.6 5.4 0 1 2 3 4 5 6 7 8 9 DAFTAnaerobic DigestersNew Screw Press Ra t e d C a p a c i t y p e r U n i t P r o c e s s ( m g d ) Firm Capacity Total Capacity Required ADWFCP WRRF Facility Capacity Assessment Page 6-10 Table 6-3 provides a summary of the findings from the capacity analysis and recommended WRRF plant expansion/upgrades. The rated capacity values are based on the criteria presented in Table 6-1 and Table 6-2. Table 6-3. Summary of Capital Needs Item Existing Rated Capacity (Firm/Total) Recommendations Liquid Unit Processes Influent pumping station 32.0 mgd / 54.0 mgd as Peak Flow • Confirm if existing pumps can meet 33.5 mgd. • Replace pumps in future, if they do not satisfy the 33.5 mgd firm pumping capacity. Screens 16.0 mgd / 32.0 mgd as Peak Flow • Two screens operational during wet weather flows. Aerated Grit 29.3 mgd / 58.6 mgd at Peak Flow • No improvements/expansions necessary Influent Flow Meters 22 (total) mgd as Peak Flow • Replace/modify flow meters to accurately record/measure peak flows. Biofilter Pumping Station 8.6 mgd / 17.2 mgd as Peak Flow • No improvements/expansions necessary. This will be decommissioned as part of the WRRF upgrades. Biofilter & Secondary Clarifier 6.7 (total) mgd as ADWFCP • No improvements necessary – biofilter will be demolished and secondary clarifier will be decommissioned. Aeration Basins 5.1 (total) mgd as ADWFCP • Expansion of aeration basins/blowers (PH equal to 16 mgd) is necessary to accommodate buildout flows and loads and to eliminate wet weather blending. Final Clarifiers 5.0 (total) mgd as ADWFCP • Expansion of final clarifiers (PH equal to 16 mgd) is necessary to accommodate buildout flows and loads. Filter Pumping Station 5.2 mgd / 7.8 mgd as Peak Flow • Expansion of filter pump station to accommodate a PH flow of 16 mgd is necessary. Filtration – Recycled Water Production (Dry Season) 5.0 mgd as ADWFCP • ADWFCP capacity is based on maximizing recycled water production. Filtration – Peak Flows during Wet Season 8.3 mgd / 11.1 mgd as Peak Flow • Expansion of filters to accommodate a PH flow of 16 mgd is necessary to meet permit limits. Disinfection (Chlorination/Dechlorination) 13.9 (total) mgd as Peak Flow • Chlorine contact basins to be decommissioned and replaced with new disinfection system. Effluent Cooling Insufficient data to provide a value • Recommended facilities based on WRRF empirical data Solids Unit Processes Thickening (DAFT) 0 mgd / 8.0 mgd as ADWFCP • Redundant thickener recommended. Anaerobic Digesters 2.4 mgd / 6.6 mgd as ADWFCP • Redundant digester recommended to provide adequate HRT when a unit is out of service. Dewatering 5.4 mgd / 5.4 mgd as ADWFCP • Replace the belt filter press with a second screw press for redundancy. Refer to Sections 7 and 8 for additional information related to the facility upgrades and hydraulic profile, respectively. 7. Treatment Plant Upgrades Page 7-1 7. Treatment Plant Upgrades The following subsections describe the recommended treatment upgrades for the WRRF, including flow equalization, headworks, primary clarifiers and sludge pumping, secondary treatment, tertiary filtration, cooling, disinfection, solids thickening, anaerobic digestion, biosolids dewatering, and sidestream treatment. In addition to these subsections, for additional information and background, refer to Appendix D, TM No. 4 - Disinfection Study; Appendix E, TM No. 5 – Asset Planning and Rehabilitation; Appendix G, TM No. 8 – Regulatory Compliance; Appendix H, TM No. 9 – Capacity Assessment; and Appendix O, TM No. 12 – Process Alternatives Analysis. A site plan of the recommended upgrades is provided in Section 12. 7.1. Flow Equalization Currently the WRRF has the ability to equalize primary influent and effluent in the equalization pond, which has a volume of approximately 4 MG. Under emergency conditions, raw influent and/or primary influent can also be diverted to this pond. As described in Section 3, the pond is primarily used for diurnal equalization of primary effluent. Additionally, there are two equalization tanks, referred to as the filter feed equalization basins that can store nitrified effluent (see the site plan in Section 12). 7.1.1. Diurnal Equalization Although diurnal flow equalization is currently the standard practice, it is not anticipated for the upgraded WRRF. Currently, the biofilter 3 recirculation pumping station is the hydraulic bottleneck for diurnal flows. Decommissioning this pumping station will resolve this issue and avoid the need for diurnal equalization. If desired in the future, the existing secondary clarifier could be repurposed. Rather than demolishing this clarifier, it should be decommissioned in place for future use. 7.1.2. Wet Weather Equalization Peak wet weather flows will be equalized to minimize the sizing of downstream facilities since blending will no longer be employed at the plant (refer to Section 3 for a discussion of existing blending practices). As described in Section 6, influent flows greater than 16 mgd will be diverted to the equalization pond for storage until influent flows subside. In order to prevent inundation during the 100-yr storm event, the existing pond will be reconstructed with a perimeter berm that will prevent inflow during flooding. This additional elevation has the added benefit of increasing the available storage volume in the pond from 4.0 MG to approximately 5.4 MG. The top of the soil berms will be asphalt lined to enable operator and vehicle access around each sub-basin. Staff has indicated a desire to line the basin floors and walls to further facilitate maintenance and cleaning; the existing pond floor and walls are asphalt lined. Because the ponds will be infrequently used (limited to flows >16 mgd), compartmentalizing the ponds was not included. For the purposes of this Facility Plan, it was assumed that the floor and walls of the sub-basins will be concrete lined, which results in a more conservative cost assumption. WRRF Facility Treatment Plant Upgrades Page 7-2 The equalization pond return pump station will be re-configured as part of the upgrades to increase the maximum operating water surface elevation, provide a redundant pump, additional automation (e.g., level control), and to provide adequate return pumping capacity. Water cannons will also be installed to facilitate washdown of the pond after use. 7.1.3. Filter Feed Equalization Currently there are two filter feed equalization basins that provide a total storage capacity of 1 MG. Nitrified effluent is routed to these basins and then pumped to the filter feed channel. Currently, during wet weather events (influent flows greater than approximately 8 to 9 mgd), the filters and cooling towers are bypassed, however after the upgrades are complete, all flows will be filtered prior to disinfection. Nitrified effluent could be equalized in the existing 1 MG filter feed equalization basins as added capacity in the event that the filters require backwashing during a peak wet-weather event. Expansion of this facility is not likely to provide much additional benefit because the pump out period from the influent wet-weather EQ pond occurs over such a long period of time (approximately three days). 7.2. Headworks The headworks facility was found to be in good condition and no equipment was identified as needing replacement (refer to Section 3). A significant portion of equipment at the headworks is being replaced as part of the Energy Efficiency Project, including the screens, screenings pumps and conveyors, screenings washer compactors, and grit washing and dewatering equipment. Additionally, staff has indicated that within the next few years, they plan to replace the 5 mgd, horizontal centrifugal pumps at the influent pump station. Based on the condition of the existing equipment and the conclusions of the capacity study, improvements to the screens, influent pumps and grit washing equipment are not required as part of the upgrades. Staff has indicated a desire to upgrade grit removal at the plant to a more energy efficient technology, such as vortex grit removal. Despite the energy intensive nature of aerated grit, the facility is fully functional, performs sufficiently well, and the grit washing and dewatering equipment were recently upgraded under the WRRF Energy Efficiency Project. As a result, replacing the aerated grit was not considered a high priority for the expansion project and not considered further. 7.3. Primary Clarifiers and Sludge Pumping The primary clarifiers at the WRRF will be maintained for future operations. The primary clarifiers are taken out of service for inspection on an annual basis. Based on discussions with staff, the primary clarifier mechanisms need to be replaced. The mechanisms are over 50 years old and the last inspection within the past five-years showed wear on the metal structures. Thus, replacement of the mechanisms is recommended. During site visits and discussions with staff it was determined that the existing sludge pumps do not have adequate suction lift capacity to pull sludge from the lower blanket. The pumps are also reaching the end of their useful life and replacement is recommended. In addition, staff conveyed concerns regarding differential settlement in PC2; surveying should be performed to confirm tank settlement and a structural assessment should be conducted to confirm settlement as well as the concrete condition. For the purposes of the Facilities Plan, allowances have been included for rehabilitation of the top two to three feet of the primary clarifiers, and for replacement of the weirs. WRRF Facility Treatment Plant Upgrades Page 7-3 Currently, thickening in the primary clarifiers is not performed and a thin, primary sludge (less than 0.5 percent solids) is pumped to the solids handling facility. It is assumed in the future that this operation would continue such that a self-priming, centrifugal pump could be used. The WRRF upgrades include provisions for a new primary sludge pump pit and two, new centrifugal pumps (one duty, one standby). The existing primary scum piston pumps have reached the end of their useful life and replacement is recommended. Therefore the upgrades include provisions for the installation of two new primary scum pumps, at the new primary sludge pump pit. 7.4. Secondary Treatment A systematic step-wise approach, as shown in Figure 7-1, was taken to develop a recommended strategy for secondary treatment to meet the new permit limits described in Section 4. The evaluation included three workshops in which technologies were first screened (12 technologies in total), then preferred alternatives evaluated (four technologies in total), and, finally, a technology was recommended for the WRRF Upgrade. Figure 7-1. Secondary Treatment Technology Screening and Evaluation Approach The following subsections summarize the results from each step in the screening and evaluation process. For additional information, refer to Appendix O, TM No. 12 – Process Alternatives Analysis. 7.4.1. Secondary Treatment Alternatives Table 7-1 presents the twelve technologies that were considered. These technologies were screened using economic and non-economic criteria (refer to criteria below) to reduce the number of technologies for further evaluation. Table 7-1. List of Alternative Technologies for Screening Technology Number Technology 1 Modified Ludzack-Ettinger (MLE) (Conventional with and without contact stabilization) 2 VertiCel® (Oxidation Ditch) 3 High Rate A/B Process 4 Integrated Fixed-Film Activated Sludge (IFAS) 5 BioMag® 6 Nereda® Granular Sludge Develop Prospective Technologies List Technologies Screening Alternative Development and Evaluation Facility Needs Economic Analysis Non-Economic Analysis Recommended Alternative WRRF Facility Treatment Plant Upgrades Page 7-4 Technology Number Technology 7 Biobrimstone® 8 Denitrification Filters 9 Wetlands 10 Membrane Bioreactor (MBR) 11 MBR Parallel Treatment with Bioaugmentation 12 Mainstream Anaerobic Treatment For the purposes of the screening analysis, technologies were compared to the Modified Ludzack- Ettinger (MLE) technology, which was originally recommended in the City’s 2011 WRRF Master Plan. MLE represents one of many activated sludge-based nitrogen removal configurations. Others include, but are not limited to: Endogenous denitrification Simultaneous nitrification/denitrification Return activated sludge re-aeration 4-stage Bardenpho Step feed with anoxic/oxic zones Rather than include the various configurations in the screening, the configurations were lumped under MLE. Further analysis during the design phase is appropriate to confirm the most efficient configuration. Other design features to consider include baffling, how to waste WAS, flow pacing of RAS, and others. The following criteria were used to screen the technologies: Ability to Meet Permit Limits Technology Status Good Neighbor (odor) Minimize Chemicals (safety and TDS concerns) Ability to Meet Lower Limits Compatibility with Biosolids Treatment Facilitate Flow Equalization Ease of Operation Relative Capital Cost Relative O&M Cost GHG Emissions Ease of Implementation WRRF Facility Treatment Plant Upgrades Page 7-5 For each criterion, the twelve technologies were considered relative to the baseline alternative, MLE. The top four technologies were then carried forward for further evaluation, including: High Rate A/B Process Conventional nitrification/denitrification using the MLE process Conventional nitrification/denitrification using the VertiCel® technology BioMag® Additional details of the twelve technologies considered, the screening criteria and screening analysis are provided in Appendix O, TM No. 12 – Process Alternatives Analysis. 7.4.2. Recommended Secondary Treatment Technology Based on a detailed evaluation of the four alternatives listed in the prior subsection, MLE was carried forward as the recommended alternative. However, the facilities recommended in this Facilities Plan have the flexibility to be converted to a High Rate A/B process if future analyses indicate it is preferred over the MLE process. Refer to Subsection 7.4.3 below for additional discussion related to the High Rate A/B process. The facility needs for the recommended alternative, MLE, are based on an attenuated peak flow of 16 mgd that will feed the activated sludge facility. As described in Section 4, the key discharge requirements that impact the secondary treatment under the adopted NPDES permit are as follows: Un-ionized Ammonia – maximum day limit of 0.25 mg N/L un-ionized in the receiving water body (San Luis Obispo Creek). Nitrate – average monthly limit of 10 mg N/L The un-ionized ammonia limit is based on the levels in San Luis Obispo Creek. Given that the WRRF discharge makes up nearly all the flow during certain periods of the year, the evaluation was based on the WRRF discharging water at an un-ionized ammonia level of 0.25 mg N/L. The un- ionized ammonia discharge levels are dependent on water temperature and pH. Given the variability in possible effluent levels, a conservative maximum day limit of 2.5 mg N/L as total ammonia was assumed. A dynamic BioWin® model using default wastewater characterization values was constructed for the recommended MLE alternative. A model itinerary was developed that considered maximum monthly and maximum day conditions seen at the WRRF during buildout flows and loads. The itinerary included the attenuated daily peak flow (16 mgd), as well as the diurnal variation during this maximum day event. A screen capture of the BioWin® model with (top) and without (bottom) sidestream treatment is presented in Figure 7-2. Further information regarding sidestream treatment recommendations is presented in Section 7.11. BioWin® simulations were performed with and without sidestream treatment to evaluate the ability to reliably meet the nitrate limits. The key benefit of sidestream treatment at the WRRF is carbon management for meeting the nitrate limits, energy efficiency, and chemical efficiency. WRRF Facility Treatment Plant Upgrades Page 7-6 Figure 7-2. BioWin® Screen Capture for the Recommended Secondary Treatment Alternative, MLE, with (Top) and without (Bottom) Sidestream Treatment The BioWin® output plots for ammonia and nitrate with and without sidestream treatment are presented in Figure 7-3 and Figure 7-4, respectively. The ammonia results represent the final clarifier total ammonia effluent for an itinerary that includes maximum month and maximum day averaging periods. As shown, the final clarifier modeling results reliably meet the total ammonia objective, 2.5 mg N/L, with and without sidestream treatment. Similar to ammonia, the nitrate results represent the final clarifier nitrate effluent for an itinerary that includes maximum month and maximum day averaging periods. With sidestream treatment present, (refer to Figure 7-3), the final clarifier effluent reliably meets the average monthly nitrate limit, 10 mg N/L. In contrast, the WRRF would struggle to reliably meet the nitrate limit without sidestream treatment present, as shown in Figure 7-4. The BioWin® model relied on a limited primary effluent dataset for determining the BioWin® activated sludge feed. According to the limited dataset, the WRRF is short on carbon without sidestream treatment and would thus require an external carbon source to reliably meet the average monthly 10 mg N/L limit. It is recommended that the WRRF WRRF Facility Treatment Plant Upgrades Page 7-7 continue sampling primary effluent to define whether an external carbon source is required to reliably meet the 10 mg N/L limit. Figure 7-3. BioWin® Final Clarifier Ammonia and Nitrate Effluent Levels for Maximum Month and Maximum Day Scenarios (includes Sidestream Treatment) Figure 7-4. BioWin® Final Clarifier Ammonia and Nitrate Effluent Levels for Maximum Month and Maximum Day Scenarios (excludes Sidestream Treatment) 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 Sep-24Sep-25Sep-26Sep-27Sep-28Sep-29Sep-30Oct-01 mg / L SE Ammonia N SE Nitrate N 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 Sep-24Sep-25Sep-26Sep-27Sep-28Sep-29Sep-30Oct-01 mg / L SE Ammonia N SE Nitrate N WRRF Facility Treatment Plant Upgrades Page 7-8 If the WRRF decides to not implement sidestream treatment, an external carbon source might be required to reliably meet the average monthly nitrate limit. The selection of an external carbon source is governed by a combination of cost, safety, dose control, and denitrification process type. A pure chemical is recommended for the WRRF because they are the most proven and reliable. Unfortunately, the most common chemical form, methanol, poses a safety risk due to its flammability. Despite the safety issues associated with methanol, it is a proven and reliable commodity on the scale required by the City. A picture of a methanol chemical feed facility from Scotts Valley, CA is shown in Figure 7-5. Figure 7-5. Methanol Chemical Feed Facility at the Scotts Valley, CA Water Reclamation Facility In addition to methanol, there are other external carbon source options available for use in wastewater treatment applications, including (Gu et al. 2010): Pure chemicals (e.g., methanol, ethanol, acetate, sugar, and butanol) Commercially available (e.g., Unicarb, Micro C™, etc) Raw industrial/agricultural byproducts (e.g., crude glycerin, corn syrup, brewery waste, etc.) Sludge fermentation products Electron donors (e.g., hydrogen gas, methane, etc.) Additional analysis should be conducted to select a preferred external carbon source if it is determined to be necessary. WRRF Facility Treatment Plant Upgrades Page 7-9 The recommended MLE will require 1.3 MG of additional activated sludge volume. The recommended configuration provides three new aeration basins with continued use of the existing aeration basins (total of five basins). Each basin will have a volume comparable to the existing two basins (about 0.43 MG each). Two additional final clarifiers are also necessary, assuming the same footprint as the existing clarifiers (80’ diameter). It is possible that one larger diameter clarifier (115 foot diameter) could be used instead of two smaller clarifiers (80 foot diameter) to reduce capital costs. Two additional final clarifiers are indluded to simplify flow splitting, better control sludge age if wasting occurs in the finals, and because it is easier to schedule maintenance. To maintain a similar RAS pumping configuration, two RAS pumps for each additional final clarifier will be installed. While the existing WAS pumps have adequate capacity, improvements are needed to provide wasting from the new aeration basins. Additionally, staff has indicated that while they have the ability to waste from the common RAS header, the configuration does not work well. Therefore, although it has not been included in the recommendations, it may be appropriate to add new WAS pumps for each additional final clarifier to provide the ability to waste from the common RAS header and to waste from the aeration basin mixed liquor channel. An added recommended feature is inclusion of a classifying selector in the WAS wasting design. The benefit of a classifying selector is the ability to handle foaming/filaments if they become a future issue. 7.4.3. High Rate A/B For the purposes of this Facilities Plan, MLE is the recommended secondary treatment process. It can be carried through design and construction with the flexibility to convert to High Rate A/B at a later time. Alternatively, if new information is available sooner, the conversion could happen during the predesign or design phase. The key steps in testing the viability of converting the MLE to High Rate A/B technology is as follows: 1. Test the potential viability of the High Rate A/B technology with a bench-top test. Testing occurred in May 2015 with a plan that compares existing primaries against the A-Stage. The results from this step should serve as the initial decision point on whether to consider the technology any further. 2. If the results from Step 1 are favorable, the City should consider piloting High Rate A/B. A pilot will provide the WRRF staff with an opportunity to familiarize themselves with the technology, determine whether the technology can reliably meet the renewed NPDES permit, and confirm whether the benefits of High Rate A/B outweigh those of the MLE technology. 3. If the results from Step 1 are favorable, the MLE site plan should be developed to provide the flexibility to modify the existing primaries to operate as an A-stage (or construct a separate A- stage basin) and reduce the footprint of the MLE (i.e., B-stage). 4. If the pilot testing results in Step 2 are favorable, the WRRF should consider visiting a full-scale High Rate A/B facility. At this time, there are about 12 installations in Europe. The technology has gained considerable interest in the U.S., but there are currently no full scale installations. Both Hampton Roads Sanitation District and DC Water are considering full-scale High Rate A/B technology. WRRF Facility Treatment Plant Upgrades Page 7-10 5. If the pilot testing results from Step 2 suggest the WRRF can reliably meet the renewed NPDES Permit with the High Rate A/B technology, the MLE design should be modified for the High Rate A/B technology. These steps should serve as the roadmap in determining whether the High Rate A/B process is appropriate for implementation at the WRRF. 7.5. Tertiary Filtration As described in Section 4, the WRRF’s new NPDES permit (Order R3-2014-0033) was renewed in September 2014. To meet the permit limits, the WRRF will no longer be able to bypass peak flows around the advanced treatment system during wet weather events. Therefore, the advanced treatment facilities will need to be expanded to treat the peak flows. Three alternatives were evaluated for the expansion of the tertiary filtration facility, including mono- media filters, disk filters, and compressible media filters, as described further in the following subsections. 7.5.1. Filtration Alternatives The plant currently uses granular media filtration (GMF) for tertiary treatment. There are currently four mono-media (sand) filters of 240 sf surface area each (960 sf total) capable of treating up to 8.3 mgd at a filter loading rate of 8.0 gpm/sf with one unit out of service. Expansion of the existing granular media filter facility was determined to be the most straightforward option for treating peak flows. In addition, disk filters and compressible media filters (CMF) were also considered as alternative treatment technologies. If the WRRF is considering disk or CMF filters, site visits and pilot testing is recommended to ensure either technology can treat peak flows. A detailed evaluation of the three filter technologies is provided in Appendix P, TM No. 13 – Filter Technology Evaluation, and the major findings are summarized below. ALTERNATIVE 1: EXPANSION OF GRANULAR MEDIA FILTRATION GMF technology is a proven technology that reliably treats wet weather flows. The GMF process works by introducing influent at the top of the filter and allowing it to flow downward through the granular filtration media. The GMF is an in-depth filter that traps successively smaller solids particles as it moves through the media. GMF is backwashed with an air scour every few days to remove solids buildup in the filters. This alternative would include an expansion of the existing filter technology at the plant by adding two additional GMF filter cells with the same filtration surface area per cell as existing filters (240 sf per cell). The expected footprint of the expansion would likely be about 50 percent in size to the existing facility. The filter feed flow equalization basins could be used for filter backwash storage during a peak wet-weather event. The GMF loading rate would be 8 gpm/sf under peak wet weather conditions with one unit out of service. During dry weather conditions with four cells online, the loading rate would be well under 5 gpm/sf. WRRF Facility Treatment Plant Upgrades Page 7-11 ALTERNATIVE 2: DISK FILTERS Disk filters are an established technology that use a cloth piling, a metal mesh, or a plastic mesh to remove particles as water passes through the separation medium. Regardless of medium type, the solids removal mechanism for all disk filter technologies relies on surface filtration. Several different disk configurations exist and vary by manufacturer. In some configurations, the disk is submerged in the influent stream and influent passes from the outside, depositing solids on the surface, and through the media where effluent is collected. In other configurations, influent enters the center of the filter and moves from the inside to the outside effluent tank. Backwash requirements are similar for both configurations during which only a few disks are taken offline at a time but the rest of the unit remains online. In general, the backwashing requirements are lower for disk filters than GMF and CMF. The media and disk configuration will determine overall disk media performance. For example, during storm events, the outside-in flow path of a cloth pile media disk filter allows for handling of a much higher solids spike than the inside-out flow path of the polyester media. Cloth media is available in two nominal pore sizes (5- and 10-micron), whereas metal mesh media is nominally 10- micron but can reject a higher proportion of smaller particles. The disk filter option would include two or more disk filters of either woven cloth piling, polyester, or woven steel mesh media with a filter design loading rate of 6 gpm/sf (up to 16 gpm/sf for steel mesh media). The filters would be installed in steel tanks (although concrete tanks are an option) with an overall footprint smaller than the GMF option. ALTERNATIVE 3: COMPRESSIBLE MEDIA FILTERS The CMF technology has been around for several decades but there are very few tertiary treatment installations in California. CMF uses a synthetic compressible media (1.25 inch polyphenylene sulphide fuzzy balls) installed in a compact, modular cell. CMFs can use either a downflow or upflow configuration; in either configuration, influent flows though the media as opposed to around the media. Compression of the media creates a porosity gradient in the filter that allows stratification and removal of particles of varying size as solids move through the filter. The CMF is capable of very high rate filtration (up to 40 gpm/sf approved for Title 22 recycled water flows) but there is only one Title 22 approved manufacturer of the equipment. A CMF alternative would include a four cell filter arrangement with an overall filter loading rate of up to 40 gpm/sf. The filters would be arranged as adjacent 7 feet by 7 feet cells and have the smallest overall footprint of the filter technologies discussed. 7.5.2. Evaluation of Filtration Alternatives The major advantages and disadvantages of the technology are described below. A more detailed evaluation of the alternatives is provided in Appendix P, TM No. 13 – Filter Technology Evaluation. ALTERNATIVE 1: EXPANSION OF GRANULAR MEDIA FILTRATION The major advantages of GMF technology are that it is a proven technology and the least complex option for expansion. The plant was designed to accommodate future filter expansion and ample space is available for additional cells adjacent (northeast) to the existing filters. Operators are familiar with this technology and expansion will minimize changes in operational procedures. Additionally, the GMF is Title 22 compliant and the filtration technology lends itself to phosphorus WRRF Facility Treatment Plant Upgrades Page 7-12 removal (if required in the future). The deep media bed translates to the highest quality filtered water of the technologies considered. The major disadvantages of GMF technology are the high capital cost, relatively large footprint, and higher headloss and energy requirements when compared to disk and CMF technologies. ALTERNATIVE 2: DISK FILTER The major advantages of using disk filters are lower capital cost than GMF, smaller footprint than GMF, and lower backwash percentage of feed flow compared to GMF. The major disadvantages of the disk filters are the propensity for pre-treatment chemicals, their operational complexity, and lack of filter depth to remove finer particles. As evidenced during the site visit to the City of Santa Cruz, CA, the operators need to constantly feed pre-treatment chemicals in order to reliably operate. Since the Santa Cruz, CA site visit, an evaluation of disk filter installations in CA found wide ranging pre-treatment requirements. There are over 30 installations of the Aqua- Aerobic and Kruger technologies in CA. A portion of facilities that we spoke with operated the technology as advertised (6 gpm/sf), whereas others require large doses of pre-treatment chemicals and frequent backwashing. For example, the Eastern Municipal San Jacinto Plant in Hemet, CA uses the Aqua-Aerobics AquaDisk filter technology and they are limited to a filter loading rate of 2.2 gpm/sf. The additional operator complexity refers to operators having to maintain two different filtration systems at the plant (including the existing conventional mono-media sand filters) during wet weather conditions. A lack of filter depth results in smaller particles passing through the media compared to GMF units unless pretreatment (e.g., coagulation and flocculation) is provided upstream. Disk filters also have marginal capacity to reliably remove phosphorus (after chemical addition) because particle sizes tend to be smaller and chemicals have a propensity to “blind” the filters. ALTERNATIVE 3: COMPRESSED MEDIA FILTERS The major advantages of the CMFs are the smallest relative footprint and lowest capital cost (67 percent of GMF). The major disadvantage is that there are very few installations and a proven record of reliability has not yet been established in California. Similar to the disk filters, an evaluation of CMF installations throughout CA was carried out as presented in Table 7-2. In general, the installations all seemed satisfied with the performance. In all cases, pre-treatment chemicals were used but at wide ranging doses. The operator at Soledad reported that key to a CMF technology is the pre-treatment reaction tank residence time (30 mins residence time). The CMF will also add operational complexity, as the operation of two different filtration systems, including the existing mono-media sand filters, would need to be synchronized at the plant. In addition, only one CMF manufacturer has achieved Title 22 compliance and would therefore require sole-source procurement of the technology. Piloting of the CMF is necessary to determine treatability and performance during wet weather events. Results of pilot testing would verify whether additional infrastructure would be necessary (i.e. pretreatment flocculation basins) to meet stringent disinfection and permit requirements. WR R F F a c i l i t y Tr e a t m e n t P l a n t U p g r a d e s Pa g e 7 - 1 3 Ta b l e 7 - 2 . C o m p r e s s i b l e M e d i a F i l t e r I n s t a l l a t i o n s in C A Lo c a t i o n De s i g n Fl o w , m g d Pr e - T r e a t m e n t Ch e m i c a l T y p e Pr e - T r e a t m e n t Ch e m i c a l D o s e Pr e - T r e a t m e n t Re a c t i o n T a n k s Di s i n f e c t i o n Co m m e n t Yo u n t v i l l e Sa n i t a r y D i s t r i c t 0. 4 P o l y A l u m 1 2 g p d Y e s S o d i u m H y p o c h l o r i t e Ma l a g a 0 . 4 5 P o l y A l u m u n k n o w n N o U V • Di d n o t u s e t h e p r i o r y e a r a n d l i m i t e d be f o r e t h a t • Pr e t t y e a s y t o m a i n t a i n a n d f u n c t i o n a l Ca n a d a W o o d s , Ca r m e l 0. 1 5 u n k n o w n u n k n o w n u n k n o w n • Cu r r e n t l y n o t u s e d o r u n d e r u t i l i z e d . • Sa t i s f i e d w i t h p a s t p e r f o r m a n c e • Su s c e p t i b l e t o f a i l u r e a n d p r o b a b l y n o t su s t a i n a b l e f o r t h e n e x t 2 0 y e a r s . So l e d a d 5 . 5 P o l y A l u m < 0 . 5 p p m Ye s ; 3 0 m i n s w i t h cu r r e n t f l o w s UV • Sa t i s f i e d • De s i g n e d f o r 3 0 g p m / s f • Th e k e y t o s u c c e s s f u l o p e r a t i o n i s t h e 3 0 mi n u t e s r e a c t i o n t i m e i n t h e p r e - tr e a t m e n t r e a c t i o n t a n k . Li n d a 1 2 . 7 u n k n o w n u n k n o w n u n k n o w n • Pr e t t y s t r a i g h t - f o r w a r d Gr a t o n 0 . 5 Pr o p r i e t a r y Po l y m e r a n d Su r f a c t a n t 1 m L / h r Y e s , S A F P a s t e u r i z a t i o n • Fi l t e r s p e r f o r m i n g f a i r l y w e l l b u t p o s s i b l y un d e r s i z e d • Pr o b l e m s w i t h c o m p u t e r i n t e r f a c i n g . • On c e p e r w e e k c l e a n i n g r e q u i r e d . WRRF Facility Treatment Plant Upgrades Page 7-14 7.5.3. Recommendation The expansion of GMF, with two additional filter cells, is the recommended process moving forward into predesign, and the basis of the opinion of probable costs. Only the GMF technology is capable of in-depth filtration and providing a reliable filter effluent quality for wet weather flows without requiring pilot testing before plant predesign. The plant was designed to accommodate expansion of the GMFs; therefore it will be the least difficult option to both construct and operate. It is assumed that the existing backwash and air scour facilities will be used with the expanded filters. New filter feed pumps would be required to increase the capacity to match the filters. If the WRRF decides to implement disk or CMF technologies, site visits and pilot testing are recommended to better understand operational issues and performance, determine pretreatment requirements, and update life-cycle costs based on this information. 7.6. Cooling The existing plant configuration has three cooling towers located upstream of the filtration complex. All three cooling towers are routinely used for current flows. Additional cooling facilities are required in order to meet the renewed NPDES permit temperature requirements. The analysis presented in the following subsections considered four different cooling technologies for increasing the WRRF’s cooling capacity. Historical cooling tower data (January 2010 to present) was analyzed to confirm that additional cooling capacity is required for buildout flows and loads. A plot of the number of cooling towers on- line over time is provided in Figure 7-6. The use of all three cooling towers has typically occurred in the fall/shoulder months when wet weather events can occur. In more recent years (2013 and 2014) three cooling towers were operated for extended durations in summer and fall months, and almost 50 percent of the year. This additional use in recent years is attributed to concerns over reliably meeting the NPDES permit temperature limits. Figure 7-7 presents the temperature values over time for several locations, including San Luis Obispo Creek upstream of the WRRF, the WRRF discharge, and creek temperature increase associated with the WRRF discharge. The data suggests that the WRRF occasionally exceeds the temperature delta limit, five DegF, as evidenced by four violations over the last three years. These violations have all occurred with two or three cooling towers on-line. Additionally, cooling towers are limited in the approach temperature delta of about 5 DegF. The approach temperature represents the maximum difference between the effluent temperature and the ambient wet bulb temperature. In order to reliably meet the projected future flows and loads, additional cooling capacity is recommended. Simply adding additional cooling towers will not facilitate reliably meeting the temperature requirements due to the occasional approach temperature threshold. As a result, a new cooling technology or a combination of cooling towers used along with a new cooling technology is necessary to meet the temperature requirements. WRRF Facility Treatment Plant Upgrades Page 7-15 Figure 7-6. Number of Cooling Towers On-Line over Time Figure 7-7. Temperature over Time 0 1 2 3 Jan-10Jul-10Feb-11Aug-11Mar-12Sep-12Apr-13Nov-13May-14Dec-14 Nu m b e r o f C o o l i n g T o w e r s O n - L i n e 0 5 10 15 20 25 Jul-12Oct-12Jan-13May-13Aug-13Nov-13Mar-14Jun-14Sep-14Dec-14 Te m p e r a t u r e ( F ) Upstream Creek Temp WRRF Discharge Temp Temp Increase in Creek Renewed NPDES Permit Limit for Temperature Increase in Creek WRRF Facility Treatment Plant Upgrades Page 7-16 7.6.1. Cooling Alternatives Four cooling technologies were considered, including a) addition of new cooling towers, b) chillers using a heat exchanger (e.g., plate and frame), c) ground heat source pumping (GHSP), and d) spray pond cooling system. The following subsection presents the evaluation of these alternatives. 7.6.2. Evaluation of Cooling Alternatives A cooling technology comparison matrix is provided in Table 7-3. The comparison considers both economic and non-economic criteria. The existing cooling towers in their current location are a viable method for cooling as long as they are well-maintained. However, keeping the cooling towers at their current location in the process scheme has significant drawbacks, as biofouling on the media will continue to be problematic and it is not feasible in the long-term to use chlorine at the filter feed due to the THM limits. Moving the cooling towers downstream of disinfection has an inherent risk in meeting the NDPES permit in the event there is any bacteria regrowth in the cooling tower. The attraction in moving cooling downstream of disinfection is that only discharge water would be cooled (i.e., no recycled water) and the propensity for biofouling on cooling tower media would be reduced. However, the WRRF could violate its coliform limits. Of the three other technologies considered, the only potentially viable option is the chiller cooling system. The ground source heat pump requires four to five acres, the drilling of upwards of 1,000 wells at 400 feet deep, and it is equipment intensive. The spray ponds are likely unable to reliably meet the renewed NPDES permit requirements, and may negatively affect the existing wetland. The chiller cooling system would provide the best temperature control to meet the effluent temperature requirements. However, this alternative is expensive, estimated at approximately three times the capital cost of cooling towers. Furthermore, the annual operating cost for a chiller is about five times more costly than cooling towers. This additional energy demand might be problematic for maintaining the lower tier PG&E energy rates at the WRRF. Remainder of page intentionally blank. WR R F F a c i l i t y Tr e a t m e n t P l a n t U p g r a d e s Pa g e 7 - 1 7 Ta b l e 7 - 3 . C o o l i n g T e c h n o l o g i e s C o m p a r i s o n M a t r i x Lo c a t i o n Co o l i n g T o w e r Up s t r e a m o f F i l t e r s (s t a t u s q u o ) Co o l i n g T o w e r Do w n s t r e a m o f Fi l t e r s Co o l i n g T o w e r Do w n s t r e a m o f Di s i n f e c t i o n GS H P S p r a y P o n d s C h i l l e r Ab i l i t y t o m e e t r e n e w e d N P D E S pe r m i t d i s i n f e c t i o n l i m i t s Ye s M a y b e N o Y e s P r o b a b l y N o t Y e s Co o l s r e c y c l e d w a t e r Y e s Y e s N o N o Y e s N o Ca p i t a l C o s t Lo w ($ 0 . 1 5 - 0 . 3 0 / g p d ) Lo w ($ 0 . 1 5 - 0 . 3 0 / g p d ) Lo w ($ 0 . 1 5 - 0 . 3 0 / g p d ) Hi g h L o w (a ) High ($0.50-0.65/gpd) Op e r a t i o n s C o s t M e d i u m M e d i u m M e d i u m L o w L o w H i g h Fo o t p r i n t S m a l l S m a l l S m a l l Me d i u m (4 t o 5 o f a c r e s ) Hu g e (1 0 ’ s t o 1 0 0 ’ s o f ac r e s ) Large Ab i l i t y t o c a p t u r e b i o f o u l i n g ma t e r i a l d o w n s t r e a m Ye s N o N o - - Y e s - - Pr o p e n s i t y f o r b i o f o u l i n g H i g h M e d i u m L o w - - U n k n o w n Medium Vi s u a l B l i g h t a n d N o i s e H i g h M e d i u m L o w - - H i g h H i g h Co n s t r u c t i o n S e q u e n c i n g N o t a n i s s u e N o t a n i s s u e N ot a n i s s u e E a s y E a s y E a s y (a ) D o e s n o t i n c l u d e c o n s i d e r a t i o n f o r t h e p r o c u r e m en t o f a d d i t i o n a l l a n d i f n e e d e d , w h i c h c o u l d b e s i gn i f i c a n t . WRRF Facility Treatment Plant Upgrades Page 7-18 7.6.3. Recommendation Additional cooling capacity is required in the near-term to meet the temperature limits, especially during the shoulder months. The use of cooling towers may not guarantee the lower effluent temperatures will always be reached, whereas chiller systems can be sized to meet the low effluent temperature requirements. Cooling towers in combination with a chiller system will allow the cooling towers to provide most of the cooling at a lower energy cost and the chiller system to provide additional cooling to meet regulatory requirements under worst-case scenario conditions. Additionally, the chiller will only cool water that is discharged to San Luis Obispo Creek. The recommended combined system is presented in Figure 7-8. The combined system includes adding a fourth and fifth cooling tower at the existing cooling towers, upstream of disinfection, coupled with a heat exchanger/chiller system to treat disinfected water that will be discharged to the San Luis Obispo Creek. The heat exchanger/chiller system includes a chiller with a water circuit recirculating water between the chiller and a sixth cooling tower and a refrigerant circuit between the chiller and a heat exchanger immersed in Plant effluent. Plant effluent will gravity flow through the heat exchanger and will be cooled by exchanging heat with the refrigerant. The sixth cooling tower will be collocated with and dedicated to the chiller operation. As it is on a separate loop, isolated from Plant effluent, there will be more flexibility to chemically condition the condenser water to inhibit fouling of the media. 7.7. Disinfection The renewed NPDES permit includes more stringent effluent limitations of disinfection byproducts (DBPs) and coliform limits. The disinfection facilities at the WRRF will need to be designed for compliance with these regulatory requirements by the mandatory compliance date defined in the draft Time Schedule Order No. R3-2014-0036. Additionally, because recycled water is produced at the WRRF, the disinfection facilities will need to meet Title 22 requirements for unrestricted reuse. 7.7.1. Technology Evaluation An evaluation of disinfection technologies was performed as part of the Facilities Plan to evaluate technologies that are suitable for use at the WRRF. A two-step approach was taken: Step 1 – Preliminary evaluation which includes a screening review of the disinfection alternatives. This preliminary evaluation is used to establish which alternative(s) is the most viable disinfection process and should be retained for further evaluation, and which alternative(s) should be eliminated from consideration beyond the preliminary evaluation. Step 2 – Evaluation of the most viable disinfection alternative(s) which includes technology comparison, facility description, capital cost estimate and life cycle cost analysis. Appendix D, TM No. 4 – Disinfection Study, provides the detailed analysis performed for this Facilities Plan. Table 7-4 provides a summary of the technologies that were reviewed and screened and the conclusions of the screening. WRRF Facility Treatment Plant Upgrades Page 7-19 Figure 7-8. Recommended Cooling Configuration for the (A) Cooling Towers and (B) Heat Exchanger/Chillers WRRF Facility Treatment Plant Upgrades Page 7-20 Table 7-4. Disinfection Technology Screening Results Technology Conclusion Chlorination/ Dechlorination • Existing WRRF data indicates that the existing chlorine disinfection system will not comply with the new THM limitations. The stringent regulatory limitation on THMs effectively eliminates the existing chlorination practice as a viable disinfection process. Chloramination • Full scale practice of chloramination is difficult and O&M intensive to reduce the chance of free chlorine formation (results in THM formation) and/or the presence of free ammonia (results in potential ammonia permit violations). NDMA has been demonstrated to be a byproduct of chloramination. The stringent regulatory limitation on both THMs and NDMA effectively eliminates chloramination as a viable disinfection process for the WRRF. Chlorine Dioxide • Site specific pilot testing at the WRRF showed that chlorine dioxide cannot reliably achieve fecal coliform of 2.2 cfu/100mL and THMs were generated in concentrations higher than anticipated discharge limits. For these reasons, chlorine dioxide disinfection is not considered to be a viable option for disinfection at the WRRF. Ozone • Ozonation as a final disinfection step without subsequent biofiltration has been shown to increase NDMA concentration in drinking water treatment (Asami et al., 2009) and has varied impacts on effluent quality such as reducing estrogenic activity while increasing toxicity and retarding growth in some test organisms (Stalter et al. 2010). Because the new NPDES permit includes an NDMA limit, ozone is not viable as a final disinfectant at the WRRF. Pasteurization • Pasteurization is an emerging technology in wastewater disinfection and installations are limited to small scale plants (less than 0.5 mgd capacity). To implement pasteurization, a post pasteurization cooling facility is likely required, in addition to or in lieu of the existing cooling towers, to ensure regulatory compliance of the discharge temperature requirements. The regulatory limitation on discharge temperature and the fact that there are no operating pasteurization installations at the scale of the WRRF eliminates pasteurization as a viable disinfection process for the WRRF. Peracetic Acid • Onsite testing demonstrated that low residual Peracetic Acid (PAA) and fecal coliform compliance cannot be achieved at the same time using PAA as a disinfectant for the WRRF final effluent. In addition, PAA will not meet the potential regulatory requirements for viruses. These issues eliminate disinfection with PAA as a viable disinfection process for WRRF. UV • Disinfection study results (May 2014) have shown that UV is effective in disinfecting WRRF tertiary effluent to meet the regulatory requirements. UV is a viable option at the WRRF. 7.7.2. UV Disinfection Recommendations UV disinfection is the recommended alternative for final effluent disinfection at the WRRF. With UV as the main process technology for final effluent disinfection, sodium hypochlorite will not be eliminated entirely from the plant. Water recycling regulations require the plant effluent for reuse to have chlorine residual. Sodium hypochlorite will also be used in several areas for house keeping purposes, such as periodic filter maintenance cleaning and potential future sludge bulking control, etc. The overall volume of chlorine required will be significantly less with the addition of UV disinfection. An evaluation of UV lamp type, reactor configuration, and UV lamp orientation was performed. The following is recommended at the WRRF based on the evaluation: Low pressure high output (LPHO) lamps Open channel configuration Horizontal, vertical or diagonal/inclined lamp orientations WRRF Facility Treatment Plant Upgrades Page 7-21 Additionally, the following constraints were identified for application at the WRRF: UV system suppliers shall have UV system(s) validated in the US, with an applicable dose- based sizing algorithm. The UV system validation shall be via USEPA UV Design Guidance Manual (UVDGM), International UV Association (IUVA) low-dose protocols, and National Water Research Institute (NWRI) Ultraviolet Disinfection Guidelines for Drinking Water and Water Reuse (2012) to allow direct comparisons of UV disinfection systems The system has been approved or is in the process of getting approval for California Title 22 non-restricted reuse application The system shall be compatible with the water quality expected in the tertiary filter effluent and the expected flow operating ranges The system shall be commercially available and in practice in North America Suppliers shall have past history of systems sized similarly to the WRRF capacity levels. The system shall operate under gravity flow conditions with low-head configuration System footprint, inclusive of the approach and exit channels, UV modules and power/control centers, shall be capable of fitting within the practical constraints of the proposed WRRF site Preliminary performance criteria (Table 7-5) were established for the LPHO UV disinfection system and system quotations from three disinfection suppliers (Ozonia, Trojan, and WEDECO), were obtained. Table 7-5. UV Disinfection Performance Criteria Parameter Criteria Comments Peak Flow (mgd) 16 Maximum filter influent pumping rate Disinfection Influent TSS (mg/L) 10 Maximum based on discharge requirement Disinfection Influent BOD (mg/L) 10 Maximum based on discharge requirement Fecal coliform (cfu/100mL) 2.2 Average weekly not to exceed 7-day median Total coliform (MPN/100mL) 23 Average weekly not to exceed in any 30-day period Total coliform (MPN/100mL) 240 Not to exceed any time Disinfection Influent Temperature 40°F / 75°F Minimum/maximum UV Dose (mJ/cm2) 100 Minimum at peak flow and the end of lamp life MS2 bacteriophage bioassay based UVT % 55 Minimum at 254 nm End of Lamp Life Factor (EOLL) 0.5 Technology dependent, maximum at 0.9 Sleeve Fouling Factor (FF) 0.8 Technology dependent, maximum at 0.9 The required hydraulic capacity of 16 mgd for the UV disinfection system was determined using the potential future filter capacity and the equalized peak hourly flow rate. The UV system is sized to provide disinfection for maximum flow of 16 mgd without any redundancies. This UV system provides disinfection up to 12 mgd for unrestricted recycling with a redundant UV bank in each channel as required by Title 22 reuse standards. WRRF Facility Treatment Plant Upgrades Page 7-22 Construction cost estimates and life cycle cost estimates were developed based on information provided by each manufacturer. The following conclusions are made based on the evaluation: UV technology is proprietary and the UV equipment or systems vary among suppliers in terms of lamp technology, ballast location, reactor configuration and control strategy, etc. Footprint requirements, a key element of siting, range from approximately 3,000 square feet to 3,500 square feet for the WRRF UV disinfection system. The vertical UV disinfection system (Ozonia Aquaray 3X) has a smaller footprint than the horizontal (Trojan UV3000Plus) and the diagonal (Wedeco Duron) systems. The annual power cost, which is the major O&M cost associated with the UV system, is approximately $100,000 to $150,000. Given the above conclusions, an open channel UV disinfection system with LPHO lamps is the recommended disinfection technology. Further selection and optimization of the technology can be performed during preliminary design. A competitive pre-selection process may be warranted, using an “evaluated bid” approach. In this approach, the system with the best value based on an acceptable combination of life-cycle costs and non-economic factors would be selected, and the UV disinfection facility would be designed around the equipment of the selected vendor 7.8. Solids Thickening The WRRF currently uses one DAFT for co-thickening of primary, secondary (biofilter sludge), and waste activated sludges. The DAFT is covered and odor control is provided. Currently, there is a single DAFT tank, with duty and standby recirculation and thickened sludge pumps. The condition of the DAFT equipment was identified to be good and not in need of replacement at this time. The capacity assessment identified a need for a redundant thickening system to provide flexibility for staff to perform maintenance and provide operational flexibility. Additionally, staff have indicated that they would prefer a less energy intensive system with less mechanical equipment for ease of operation and maintenance. 7.8.1. Technology Evaluation It is recommended that the WRRF consider conversion of the DAFT to an alternative technology that uses less energy, provides similar or better performance, and has lower O&M requirements. It is assumed that co-thickening of primary and waste activated sludge will continue. The thickener return piping would be maintained where liquids are returned to the aeration basins. There is little or no benefit in modifying the liquid return stream piping. Alternative thickening technologies suitable for co-thickening include: Gravity belt thickeners, Rotary drum thickeners, and Centrifuges. A brief overview of each technology is provided below followed by a summary of advantages and disadvantages of each technology (Table 7-6). WRRF Facility Treatment Plant Upgrades Page 7-23 ALTERNATIVE 1. GRAVITY BELT THICKENERS A gravity belt thickener (GBT) consists of a porous belt that acts as a filter, allowing water to drain through the belt while solids are captured on the belt (Figure 7-9). Polymer is mixed with the sludge prior to entering the GBT to increase the solids capture. GBTs are typically not enclosed, which makes the system more susceptible to odors and splashing. The operation is fairly wet which also can increase corrosion if installed indoors. Typically, GBTs require more operator attention and fine tuning than other technologies. The belt is susceptible to clogging, also called blinding, from fine sands, polymer overdose, and/or scum/oil and grease. Belt cleaning with a solvent can reduce the clogging frequency. There are several moving parts and more bearings to replace with the GBT, which increase maintenance costs. Maintenance of the GBT primarily consists of belt and bearing replacement. The frequency of belt replacement varies but the average life is 2,000 to 4,000 duty hours (or 83 to 166 days). As shown in Figure 7-9, the GBTs can be installed with an enclosure over the belt to reduce odors and splashing of solids. The enclosure over the GBTs can increase operations and maintenance activities because access to the belt and bearings is hindered which increases the difficulty of replacing these parts. Routine washdown of the interior side of the enclosure may also be necessary to provide staff with a clean area for visual inspection of the GBT. Figure 7-9. Gravity Belt Thickener Photograph (Courtesy of Ashbrook) ALTERNATIVE 2. ROTARY DRUM THICKENERS A rotary drum thickener (RDT), or rotary screen thickener, consists of a rotary drum and a drive. A cylindrical screen inside of the rotary drum captures solids as it rotates, allowing water to pass through the screen. A rotary screw thickener operates using the same principle as an RDT but uses an auger located inside the screen to convey the solids from the feed end of the drum to the outlet. For the purpose of this evaluation, the rotary screw thickener was included under the RDT category. Similar to other thickening processes, polymer addition is necessary to achieve the desired solids capture rate and thickened sludge product. Flocculation is also a necessary requirement upstream of the drum. Figure 7-10 provides a schematic and photograph of a RDT. The RDT is contained which minimizes odors and splashing. As with the GBT, high scum content in the feed sludge can impact performance and high grease levels can blind the drum screen. (No Enclosure) (With Enclosure) WRRF Facility Treatment Plant Upgrades Page 7-24 Figure 7-10. RDT Rendering and Schematic (Courtesy of FKC) ALTERNATIVE 3. CENTRIFUGE Centrifuges are a proven technology for thickening WAS and have also been used in co-thickening applications. A centrifuge operates by allowing sludge to enter a stationary tube where it is fed into a rotating bowl. Figure 7-11 provides a photograph of a thickening centrifuge. The bowl rotates at speeds up to 3,400 revolutions per minute creating centrifugal forces that push solids to the outer wall of the bowl. A conveyor rotates in the opposite direction of the rotor collecting the solids and discharging them to a chute at the end of the bowl. The liquid separated from the solids is called centrate. During the process of separation, the centrate is conveyed to the other end of the equipment from the solids. Centrifuges typically have small footprints but require relatively large amounts of energy to create the centrifugal forces. These high speeds also cause the equipment to wear more quickly than other, slower rotating thickening equipment. However, centrifuges are utilized for thickening because they have the potential to produce a more concentrated sludge than other technologies. Additionally, centrifuges typically require a low dose of polymer and in some cases no polymer to achieve the required percent solids. Figure 7-11. Centrifuge Photograph (Courtesy of Centrisys) WRRF Facility Treatment Plant Upgrades Page 7-25 TECHNOLOGY EVALUATION Table 7-6 provides an overview of the advantages and disadvantages of each technology. With any of the noted technologies, a blend tank to mix primary and waste activated sludge upstream of the thickener is recommended because it would provide the ability to feed consistent quality sludge to the thickener allowing performance and polymer dosage to be optimized. Table 7-6. Evaluation of Sludge Thickening Technologies Alternative Advantages Disadvantages Alternative 1 Gravity Belt Thickener • Low energy demand • Comparable polymer usage to RDT • Similar solids recovery rate and washwater requirements to RDT • Operational history with co-thickening in a DAFT • Open unit subject to splashing compared with centrifuge or RDT • Indoor installation is preferable to provide odor control • Larger footprint than centrifuge or RDT • More moving parts and maintenance requirements compared to RDT • Belt can blind with high grease loads from primary scum/sludge Alternative 2 Rotary Drum Thickener • Low energy demand • Enclosed system which facilitates odor control • Smaller footprint than gravity belt thickener • Comparable polymer usage to GBT • Similar solids recovery rate and washwater requirements to GBT • Operational history with co-thickening • Drum screens can blind with primary scum Alternative 3 Centrifuges • Small footprint • Enclosed system that facilitates odor control • Lower polymer consumption than GBT or RDT • Comparable washwater use to GBT and RDT • Operational history with co-thickening • High energy demand • High speed operation increases wear and tear and increases equipment maintenance • Potential for lower solids capture rate • More complex operation that requires fine tuning Based on this preliminary evaluation, rotary drum thickening is recommended for application at the WRRF because it is energy efficient, has lower O&M requirements, and the thickening unit is enclosed to facilitate odor control at the plant. Due to the low speed that the rotary drum thickener operates at, routine maintenance typically consists of drive chain replacement every seven years and trunnion or bearing replacement every three to five years. The RDT can also be operated unattended more easily to provide the ability to feed the anaerobic digesters over a 24 hour period, which optimizes digester performance. 7.8.2. Solids Thickening Recommendations The RDTs would be sized to handle peak flows and solids loads during future conditions. For planning purposes, it was assumed that two thickeners would be installed (one duty, one standby) each with a capacity of 400 to 500 gpm; the thickeners would operate over a 24-hour period. During peak loading events that are unusual or infrequent, it is assumed that two units could be operated, if needed. WRRF Facility Treatment Plant Upgrades Page 7-26 As noted above, a blend tank is recommended upstream of the rotary drum thickeners. The DAFT tank could be repurposed as a blend tank and pump mixing would be used to keep the sludge mixed and to feed the rotary drum thickeners. The DAFT could also be repurposed as a fats, oils, and grease (FOG) receiving facility. Repurposing the DAFTs as a blend tank is recommended for the plant upgrades because it is an affordable use of this tank with minor modifications. If the City decides to move forward with FOG this might be a good use of this tankage. Before that decision is made, it makes sense to use this tankage to blend thickener feeds. The rotary drum thickeners would be located adjacent to the DAFT tank, on an elevated platform. A canopy over the thickeners would be provided. Because the DAFT equipment was found to be in good condition and because the WRRF has operated with a single DAFT tank for years, conversion to a new thickening technology could be phased or implemented at a later time, if necessary. 7.9. Anaerobic Digesters The WRRF has three digesters in series, whereby the first two digesters are used as primary digestion and the third digester is used for storage. The volume of the first two digesters is a combined 0.83 MG, whereas the third digester volume is 0.23 MG. The third digester is the oldest and is not mixed or heated. Digesters 1 and 2 have a gas mixing system. The mixing system for Digester 1 needs replacement. Digesters 1 and 2 have adequate volume with both units in service to meet the build out flows and loads. However, there is a lack of redundancy if the larger Digester 1 is taken offline for cleaning and maintenance – Digester 2 could be overloaded and not meet Class B biosolids standards. It is recommended that Digester 2 be replaced with a new digester of equal capacity to Digester 1. This strategy will offer much needed redundancy for buildout flows and loads. The third anaerobic digester (0.23 MG) is used as storage prior to dewatering. As a result, the digester does not have a “rated process capacity” in the traditional sense because it is not used for treatment. Rather, it is used to provide flexibility in dewatering frequency. Once Digester 2 is replaced with a unit of equal or greater capacity as Digester 1, Digester 3 will not be required for storage as Digesters 1 and 2 will have adequate capacity to feed dewatering. It is recommended that the old Digester 2 be repurposed for sidestream treatment, as further described later in this Section. It is recommended that Digester 3 be decommissioned once Digester 2 is replaced with a unit of equal or greater capacity as Digester 1. 7.10. Biosolids Dewatering As part of the WRRF Energy Efficiency Project, one screw press was recently installed. Prior to that, The WRRF relied on a single belt filter press and sludge drying beds for solids dewatering. The existing belt filter press will serve as a redundant unit to the new screw press until a redundant screw is installed. The screw press has a peak hydraulic loading rate of approximately 65 gpm (500 lb/hr). This corresponds to an ADWFCP capacity of 5.4 mgd. The belt filter press has adequate capacity to serve as a redundant unit; however, it is at or near the end of its useful life. Thus, it is recommended that the belt filter press be replaced with a second, redundant screw press to provide common equipment for ease of operations and maintenance and to avoid a failure of the belt filter press. WRRF Facility Treatment Plant Upgrades Page 7-27 7.11. Sidestream Treatment / Return Stream Management The sidestream refers to the in-plant return sidestreams. The return sidestreams at the WRRF include the following: Filter backwash Thickening return sidestream Digester return sidestream Lagoon supernatant (fed with dewatering return sidestream) Sludge drying bed return Plant drain The return sidestreams from digestion and lagoon supernatant are of particular interest since they represent a source of high nitrogen loads. These sidestreams represent about 20 percent of the total nitrogen load discharged from a WRRF (Fu and Siegrist, 2004). Furthermore, the sidestream is a low flow (typically a few percent of raw influent) and highly concentrated with nutrients (>500 mg N/L), which is ideal for cost effective and compact nitrogen removal. The overall benefits of removing ammonia and/or total nitrogen in the sidestream are as follows: Warm water and concentrated nutrients (favorable kinetics; small footprint) Low flows (ability to equalize) More cost-effective as $/lb nutrient removed than liquid stream treatment Ability to implement more efficient nitrogen removal pathways (e.g., Deammonification) Easier to phase construction than liquid stream treatment Removal of existing supernatant lagoon The sidestream process can remain operational to provide additional reliability and reduce the overall nutrient removal cost if more stringent nitrogen limits are required in the future. Given the benefits of sidestream treatment, a sidestream treatment evaluation was performed, as described in the subsections below. 7.11.1. Sidestream Treatment / Return Stream Management Comparison Four technologies and/or operating strategies were evaluated for the WRRF: Manage the existing supernatant lagoon Established sidestream treatment technology: Nitrifying Sequencing Batch Reactor (NSBR) Emerging sidestream treatment technology: Deammonification Technology (e.g., DEMON®) Embryonic sidestream treatment technology: Zeolite/Anammox The following subsections provide background on each technology. ALTERNATIVE 1. MANAGE THE EXISTING SUPERNATANT LAGOON FACILITIES The supernatant lagoons are used to store dewatering return sidestreams prior to returning to preliminary treatment. The WRRF has the ability to manage the time of day when the supernatant WRRF Facility Treatment Plant Upgrades Page 7-28 lagoon is returned to preliminary treatment. One strategy to reduce overall effluent nitrogen concentrations is to match the supernatant lagoon pumping periods with the periods of lowest raw influent nitrogen concentrations. The advantage in this operational strategy is to avoid construction of new facilities and more evenly distribute nitrogen loads in the liquid stream. The disadvantages are the lagoon space requirements, odors, and visual blight associated with the lagoon as it is located along the Bob Jones Bike Trail. ALTERNATIVE 2. NITRIFYING SEQUENCING BATCH REACTOR The nitrifying sequencing batch reactor (NSBR) is an established technology that has been in use for decades since the first installations in the 1960s. It was not until the 1980s that NSBRs became widely accepted and implemented. The NSBR configuration has been the most commonly utilized reactor configuration for sidestream treatment. The NSBR is a fill and draw activated sludge system for wastewater treatment. In this system, wastewater is added to a single “batch” reactor, treated to remove pollutants, and then discharged. Aeration and clarification can all be achieved using a single batch reactor. There are five operational steps in a SBR: fill, react, settle, decant, and idle. Figure 7-12 displays the sequence of operational steps for a NBSR. Figure 7-12. Nitrifying Sequencing Batch Reactor Operational Steps Rather than denitrifying in the NSBR sidestream reactor, the nitrate produced in the sidestream process can be recycled to plant headworks to combat odors. Nitrate is preferentially reduced over sulfate and thus prevents formation of hydrogen sulfide (Zhang, et al., 2008). The reduced nitrate FILL BOD5 CO2 + Biomass REACT NH4+-N NO3-N Anoxic (if necessary) NO3--N N2+CO2 SETTLE Biomass separation DRAW Effluent discharge IDLE Waste sludge Influent Air Air WRRF Facility Treatment Plant Upgrades Page 7-29 also produces oxygen which can oxidize odorous sulfides to sulfate. Any nitrate that bleeds through the headworks should be removed in the downstream primary clarifier using influent BOD as the carbon source. However, heavily loading the primaries with nitrate can result in flotation of solids in the primaries, known as “primary popping”. A list of the advantages and disadvantages for implementing the NSBR technology at the WRRF is provided in Table 7-7. Most of the advantages relate to the simple reactor configuration. It is not necessary to pilot the NSBR for sidestream applications given that the NSBR is a well-understood, established technology. NSBR performance can be modeled and accurately predicted with present- day mechanistic activated sludge simulation models, such as BioWin®. Table 7-7. Nitrifying Sequencing Batch Reactor Technology Advantages and Disadvantages Advantages • Established technology • Single reactor vessel with common wall construction • Operational flexibility and control • Modest footprint • Potential capital savings by incorporation of separation/other equipment within common basin • Reduce final effluent ammonia discharge concentration about 20 percent Disadvantages • Similar energy requirements to liquid stream ammonia removal • Alkalinity addition required (if full ammonia removal desired) • Oxygen transfer limitations result in large reactor volume • Heavy reliance on automated systems to control process • Potential to wash out non-settled biomass during decant phase • Possible poor settling due to low heterotrophic population • Potential flotation of solids in primary from biological denitrification ALTERNATIVE 3. DEAMMONIFICATION TECHNOLOGY Deammonification is an emerging technology that relies on a shortcut in the nitrogen metabolism pathway for efficient ammonia removal. It is carried out in two steps by two distinct groups of autotrophic organisms. In the first step, half of the ammonia is oxidized to nitrite (known as nitritation) by ammonia oxidizing organisms (AOOs) and in the second step the residual ammonia and nitrite are anaerobically converted to nitrogen gas by anaerobic ammonia oxidizing (anammox) bacteria. Step 1: (oxidize half the ammonia load to nitrite): +1.5 →++2 (1) Step 2: (convert ammonia and nitrite to nitrogen gas): +→()+2 (2) The sidestream alkalinity demand is roughly one-half the NSBR technology because only half the ammonia load is oxidized to nitrite during the first step. Additionally, the anammox second step relies on inorganic carbon for nitrogen removal. Using inorganic carbon over BOD should save the WRRF from adding an external carbon source in the liquid stream (if necessary). WRRF Facility Treatment Plant Upgrades Page 7-30 Deammonification has emerged as a cost effective, efficient, and reliable option to treat high strength ammonia wastewater treatment streams, in particular to treat in-plant return sidestreams from dewatering of anaerobic digested sludge. The technology has been applied to more than 100 full scale facilities worldwide. These installations operate well and require a modest level of operator attention. There are two full-scale deammonification plants in operation in the US; both at Hampton Roads Sanitation District. However, there are dozens in the design phase. The process can either be attached or suspended growth with single stage, dual stage, or a batch process. For each configuration, there are several vendors. A list of the advantages and disadvantages for implementing a deammonification technology at the WRRF is provided in Table 7-8. The key advantages are the reduced energy and chemical demands, the potential to avoid an external carbon source in the liquid stream, and a smaller footprint than NSBR. The primary disadvantages are a pilot is recommended, it suffers from long process start-ups, and it has more complex controls than the NSBR. Table 7-8. Deammonification Technology Advantages and Disadvantages Advantages • Smallest footprint compared to other biological processes evaluated • Only 50% of the ammonia load needs to be oxidized to nitrite • 60% energy reduction compared to full nitrification (due to reduced oxygen demand) • No carbon is required for anammox nitrogen removal • The alkalinity demand for nitrogen removal is reduced by about 45% • Relatively low sludge production • Remove total inorganic nitrogen (about 85%); about 15% of the ammonia is converted to nitrate • Reduce final effluent ammonia discharge concentration about 20 percent Disadvantages • Few US installations (several facilities in design and construction phase); over 100 global installations • New technology for operators • Susceptible to process upsets with long start-ups • Technology sensitivity to variable feed composition • Many process configurations are proprietary technologies. ALTERNATIVE 4. ZEOLITE/ANAMMOX TECHNOLOGY Zeolite/Anammox is an embryonic technology that was developed in Northern California in the mid- 2000’s. It is a hybrid technology that leverages the benefits of zeolite and anammox bacteria. Zeolite is a microporous, aluminosilicate mineral that has a high cation exchange capacity (CExC). A picture of zeolite mineral is provided in Figure 7-13. This high CExC has a high affinity for ammonium adsorption which is immobilized on the surface. The benefit of immobilizing ammonium is that the nutrient is removed from solution and concentrated on the surface of the zeolite, very attractive to bacterial biofilms. WRRF Facility Treatment Plant Upgrades Page 7-31 Figure 7-13. Zeolite Media on Left and Zeolite/Anammox Pilot Plant on Right The use of zeolite for ammonium removal from wastewater has been in practice for decades. Truckee Meadows Water Reclamation Facility (TMWRF) used zeolite to remove ammonium following secondary treatment for approximately 30 years. TMWRF had reliable performance with ammonium levels leaving the zeolite technology at less than 1 mg N/L. Despite reliable ammonium removal, zeolite media had to be regenerated (i.e., ammonium removed) once all the zeolite ion exchange sites were saturated. Regeneration was performed using high strength brine, with sodium replacing the ammonium ions. Due to concerns over high TDS from the brine, TMWRF replaced the zeolite technology with nitrification/denitrification in the early 2000's. Rather than relying on harsh chemicals (e.g., brine) to regenerate the zeolite, zeolite/anammox relies on anammox bacteria to regenerate the zeolite surface by removing the sorbed ammonia. By using continuous biological regeneration the Zeolite/Anammox technology avoids the disadvantages of earlier zeolite-based ammonium removal systems. The technology relies on zeolite serving as medium to adsorb ammonium and promote biofilm growth. A biofilm rich with anammox and AOOs coat the zeolite, and as the zeolite adsorbs ammonium the biofilm continuously regenerates the zeolite by converting the adsorbed ammonium to nitrogen gas. A picture of a zeolite/anammox pilot at Union Sanitary District is provided in Figure 7-14. There are currently no full-scale zeolite/anammox installations but there are several on-going or completed pilots: Union Sanitary District, Central Contra Costa Sanitary District, San Francisco Public Utilities Commission, Oro Loma Sanitary District, and others. A list of the advantages and disadvantages for implementing the zeolite/anammox technology at the WRRF is provided in Table 7-9. The key advantages are the reduced energy and chemical demands, the potential to not add an external carbon source in the liquid stream (similar to deammonification technologies), and low maintenance. The primary disadvantages are a pilot is recommended, it is an embryonic technology with no full-scale installations, odor concerns, and it has a relatively large footprint (>1 acre) compared to the other alternatives. WRRF Facility Treatment Plant Upgrades Page 7-32 Figure 7-14. Zeolite/Anammox Pilot Beds at Union Sanitary District in 2012. Table 7-9. Zeolite/Anammox Technology Advantages and Disadvantages Advantages • Ability to remove ammonium and total nitrogen in a single process • Low energy demand • No supplemental alkalinity required as it relies adsorption and Anammox removal processes • No supplemental carbon required as it relies on Anammox removal processes • Uses a proven technology to remove ammonium, zeolite • Low biosolids production • Relatively low cost • Simple reactors (ponds, raised berms, etc.) • Minimal maintenance (self-regulating process) Disadvantages • Embryonic technology not yet demonstrated at full-scale • Uses an emerging biological process, Anammox bacteria to remove total nitrogen • Odor concerns • New technology for operators • Relatively large footprint compared to the other alternatives WRRF Facility Treatment Plant Upgrades Page 7-33 7.11.2. Recommended Sidestream Treatment Technology The benefits of sidestream treatment make it an attractive option for the WRRF. Replacing the supernatant lagoons will reduce odors and remove the visual blight along the Bob Jones Bike Trail. Among the sidestream treatment options evaluated, a deammonification technology is recommended. The deammonification technology was selected over NSBR technologies due to the carbon management benefit in the liquid stream. A deammonification technology was selected over zeolite/anammox due to the embryonic technology status and relatively large footprint of the latter. Deammonification facility needs are provided in Table 7-10. The required tank volume at build-out flows and loads is comparable to Digester 2. Thus, if Digester 2 is replaced with a larger digester (as described later in this Section), it could be used to equalize the deammonification technology feed flow. Also, if Digester 3 is decommissioned, this area could be used to house the deammonification technology. Table 7-10. Sidestream Treatment Deammonification Facility Needs Criteria Unit Current Build-Out Projected Comment Feed Loading Flow mgd 0.06 0.09 BOD lb/d 130 190 TSS lb/d 630 940 NH4-N lb N/d 660 990 Sidestream Feed / Effluent Flow Equalization Volume Total MG 0.03 0.03 Assumes 0.25-day HRT equalization for both feed/effluent Feed Pumping Capacity mgd 0.09 0.09 Ability to bypass flows Number of Pumps No 2 2 1 Duty; 1 Standby Capacity Each mgd 0.09 0.09 1 Duty; 1 Standby TDH ft 35 35 Deammonification Reactor Temperature °C 24 24 Based on minimum values SRT day 1-3 1-3 Conservative value for the Ammonia Oxidizing Organisms (AOOs) Number of Tanks No 1 1 Reactor Total Volume MG 0.21 0.32 Decant rate MG/Cycle 0.015 0.023 Oxygen Demand lb/hr 70 110 OUR mg/L/hr 30 30 Blower required scfm 700 1,010 Firm capacity Blower Power hp 40 60 WRRF Facility Treatment Plant Upgrades Page 7-34 7.12. Odor Control The City has identified odor control as a high priority at the plant due to its proximity to public facilities (e.g., Bob Jones Trail), and the City’s commitment to being a good neighbor. Currently, the majority of odors at the WRRF are located at the supernatant lagoon and the equalization pond. The elimination of the diurnal equalization practice will reduce odors at the equalization pond and the supernatant lagoon will be decommissioned and removed. There are opportunities to phase odor control improvements at the WRRF. A phased approach would allow the City to confirm the performance of odor control measures taken prior to proceeding with other odor control projects. As a first step, it is recommended that odor control be provided for the solids dewatering building and collection bin, sidestream equalization and treatment, solids thickening, and the headworks. Table 7-11 provides a summary of the ventilation air flow estimates and assumptions. Table 7-11. Summary of Odor Control Assumptions Area Air Flow Estimate Odor Control System Location Headworks: Headspace from pump station, screens, grit removal, and collection bins. 4,500 scfm Soil Bed Biofilter Southwest of equalization pond Solids Thickening RDTs and headspace for DAFT tank 1,000 scfm Activated Carbon Canister Adjacent to DAFT Solids Dewatering Ventilate building, collection bin, and screw thickeners 8,500 scfm Soil Bed Biofilter Southwest of equalization pond (common with headworks) Sidestream Equalization and Treatment: Ventilate headspace from Digester 2 and new EQ Tank (at Digester 3) 2,000 scfm Soil Bed Biofilter Southwest of equalization pond (common with headworks) A soil bed biofilter was assumed for all areas with the exception of the solids thickening area. The soil bed biofilter was selected because it is a low maintenance system that is easy to operate and effective in controlling odors. Also, the biofilter requires the largest footprint and represents a conservative odor control system from a space planning standpoint. Currently, the solids thickening area has a small carbon canister that treats foul air from the DAFT. It was assumed that the carbon canister unit would be replaced with a similar type of system for the solids thickening area only. Following the upgrade, it is recommended that the City conduct an Odor Control Master Plan to identify locations that generate odors. Once identified, additional odor control projects can be prioritized. The Odor Control Master plan should specifically consider the odors produced in the activated sludge anoxic zones and the primary clarifiers. It should be noted that odor control was not included for the equalization pond. Currently the equalization pond is a source of odors at the plant because the pond is used daily and staff are not able to drain the pond completely. This leads to long-term, unaerated, storage of primary effluent which results in odors. The future plant operation will not rely on use of the equalization pond on a daily basis; the intent is for the pond to only be used during significant wet weather events. Additionally, the equalization pond will be concrete lined and outfitted with water cannons to assist with wash down to help minimize odors. WRRF Facility Treatment Plant Upgrades Page 7-35 7.13. Summary of Recommended Treatment Upgrades The previous subsections describe upgrades for the liquid and solids processes at the WRRF. Figure 7-15 provides a process flow diagram of the WRRF after the proposed upgrades. The opinion of probable construction cost for the recommended upgrades is included in Section 13 and a site plan is included in Section 12. The following recommended upgrades are required to meet discharge permit requirements by November 30, 2019: New PE pipeline and PEDB retrofits (as described in Section 8). Aeration Basins, including three new basins, new blowers and blower building, diffusers, mixed liquor pumps and mixers, and chemical feed. Final clarifiers, including two new clarifiers, a feed flow-split structure, and new RAS and WAS pumps. Two new filter feed pumps. Tertiary filtration, including two new monomedia filters, new backwash pumps and air scour blowers. Cooling towers, includes two new cooling towers with pumps following filtration, and a chiller system following disinfection to trim temperature. The chiller system includes a heat exchanger, chiller, and a new cooling tower. UV Disinfection. The design criteria for these upgrades are summarized in Table 7-12. In addition to the upgrades required to meet the new permit requirements, the following upgrades are recommended to address capacity, redundancy, condition, O&M, energy efficiency and odor concerns: Primary clarifiers rehabilitation, new mechanisms and weirs, new sludge and scum pumps, new primary sludge pump pit. Equalization pond, including lining of the existing pond and addition of water cannons for cleaning. Solids treatment includes new thickening and conversion of the DAFT to a blend tank, a new screw press, and a new anaerobic digester. Sidestream treatment includes one new tank to replace Digester 3 and conversion of Digester 2 to an aerated tank, blowers and a diffused air system. Odor control for the headworks, solids thickening, solids dewatering, and sidestream treatment. The design criteria for these upgrades are presented in Table 7-13. WRRF Facility Treatment Plant Upgrades Page 7-36 Page intentionally blank. WR R F F a c i l i t y Tr e a t m e n t P l a n t U p g r a d e s Pa g e 7 - 3 8 Pa g e i n t e n t i o n a l l y b l a n k . WRRF Facility Treatment Plant Upgrades Page 7-39 Table 7-12. Design Criteria for Upgrades Required for Permit Compliance Process Area Design Criteria / Data Aeration Basins Total No. of Basins Total Volume of Basins Side Water Depth Sludge Age (aerobic) Anoxic Volume Aerobic Volume Internal ML Recycle Rate MLSS at Maximum Month Condition 5 (2 – existing, 3-new) (2.2 MG) (0.86 MG – existing, 1.29 MG – new) 15 ft 6.5 days 0.65 MG 1.5 MG 300% of influent flow 3,500 mg/L Aeration Blowers No. Motor Size Air Flow at Maximum Day Conditions 5 (2-existing, 3-new) 150 hp (2-existing) 250 hp (3-new) 13,500 scfm Methanol Addition(a) No. of Storage Tanks Tank Volume per Tank Estimated Dose at Maximum Month Chemical Metering Pump Type No. of Pumps 2 2,000 gallons, each 12 mg/L peristaltic 1 duty, 1 standby Final Clarifiers No. Diameter Side Water Depth Surface Overflow Rate at Maximum Month Solids Loading Rate at Maximum Month 4 (2- existing, 2-new) 80 ft 15.5 ft (existing) 18-ft (new) 460 gpd/ft2 23 lbs/day/ft2 RAS Pumps Total No. of Pumps Type Capacity Motor 8 pumps (4-existing, 4-new) Non-clog vertical turbine 2.5 mgd/each 10 hp, Variable Frequency Drive WAS Pumps Total No. Type Capacity Motor 2 (1 duty, 1 standby) Non-clog centrifugal pumps 100 gpm/each 5 hp/each, Variable Frequency Drive Filter Feed Pump Station Total No. of Pumps Pump Type Capacity per Pump Motor 5 Vertical Turbine 4.0 mgd/each 50 HP, Variable Frequency Drive WRRF Facility Treatment Plant Upgrades Page 7-40 Process Area Design Criteria / Data Tertiary Filtration Total No. of Cells Area per Cell Media Type Effective Size Media Depth Filter Loading Rate at ADWFCP Filter Loading Rate at PH Backwash Water Volume 6 (2 new, 4 existing) 240 sf Mono-Media Silica Sand 1/8 in 6 ft 2.3 gpm/sf 8.0 gpm/sf with one unit out of service 28,800 gallon per backwash Evaporative Cooling Towers Total No. of Towers Fan Size Tower Recirculation Pumps No. of Pumps Pump Type Motor Chiller and Heat Exchanger No. Chiller Size per Chiller No. Heat Exchangers No. Towers Tower Fan Size Chiller Recirculation Pumps No. of Pumps Pump Type Motor Condenser Recirculation Pumps No. of Pumps Pump Type Motor Cooling Tower Feed Pumps No. of Pumps Motor Size 5 (3-existing, 2-new) 40 HP, each 5 Horizontal, end-suction centrifugal 15 hp, constant speed 3 220 tons 3 1 90 HP 1 Horizontal, end-suction centrifugal 25 hp, constant speed 1 Horizontal, end-suction centrifugal 55 hp, constant speed 5 15 HP, constant speed UV Disinfection System Type Reactor Configuration Number of Channels Banks per Channel Lamps per Bank UV Dose UV Transmittance End of Lamp Life Factor Sleeve Fouling Factor Low Pressure, High Output Open Channel 2 5-7 (specific to manufacturer) 70 -105 (specific to manufacturer) 100 mJ/cm2 55 percent 0.5 0.8 (a) Methanol facility needs require additional data analysis. The BioWin® model with sidestream treatment using a deammonification technology suggests methanol is not required. However, if sidestream treatment using a deammonification technology is not included then the BioWin® model suggests that an external carbon source is required. The analysis is currently based on limited data that will be augmented with on-going sampling. Furthermore, other carbon sources should be considered if carbon augmentation is required (e.g., other pure chemicals, commercially available chemicals, industrial/agricultural byproducts, etc.) WRRF Facility Treatment Plant Upgrades Page 7-41 Table 7-13. Design Criteria for Additional Upgrades Process Area Design Criteria / Data Primary Sludge Pumps No. Pump Type Capacity Motor 2 Recessed Impeller, Centrifugal Pumps 150 gpm/each 7.5 hp/each (Constant Speed) Primary Scum Pumps No. Pump Type Capacity Motor 2 Positive Displacement Pump 125 gpm/each 7.5 hp/each (Constant Speed) Wet Weather Flow Equalization No. of Basins Total Volume Bottom Lining Material 1(equalization pond) 5.4 MG Concrete Solids Thickening Type No. of Units Capacity per Unit RDT 2 (1 duty, 1 standby) 500 gpm/each Thickened Sludge Pumps No. Type Capacity Motor 2 Progressive Cavity 50 gpm/each 7.5 hp/each Anaerobic Digesters Mixing System Total No. Total Volume For Digester 1 2 (1 existing, 1 new) 1.06 MG (0.53 MG existing; 0.53 MG new) Sidestream Treatment Feed Pump (filtrate to SST EQ) No. Capacity Motor Equalization Tank Volume Feed Pump (from EQ to Reactor) No. Capacity Motor SST Reactor Volume No. of Blowers Blower Motor Size 2 (1 duty/1 standby) 100 gpm 5 HP, constant speed 0.23 MG 2 (1 duty, 1 standby) 100 gpm 5 HP 0.32 MG 2 (1 duty, 1 standby) 60 hp/each WRRF Facility Treatment Plant Upgrades Page 7-42 Process Area Design Criteria / Data Odor Control Headworks, SST and Dewatering Area Air Flow Rate Odor Control Media Solids Thickening Air Flow Rate Odor Control Media 15,000 scfm Biofilter 1,000 scfm Activated Carbon 8. Hydraulics Page 8-1 8. Hydraulics This section presents the existing hydraulic profile for the WRRF as well as the hydraulic profile for the proposed upgrades. 8.1. Existing Hydraulic Profile Currently peak hour flows to the WRRF are unknown due to flow metering issues. The peak hour flows are estimated to equal to the capacity of the existing headworks (about 25 mgd). During wet weather events, flows greater than 22 mgd can be routed to the PEDB at the aerated grit effluent diversion box. Influent flows greater than 16 mgd bypass the trickling filters, and flows greater than 5.1 mgd bypass the aeration basins. The bypass flows are routed to the nitrified effluent distribution box and from there are conveyed to the chlorine contact basins for disinfection and dechlorination prior to discharge to the Creek. When secondary treatment is bypassed, staff shuts down the filters and cooling towers because the system can not handle the higher solids loads. 8.2. Proposed Hydraulic Profile The projected peak hour influent flow to the WRRF is 33.5 mgd and the average annual flow is projected to be 6.1 mgd. A hydraulic profile for these two conditions was developed for the WRRF upgrades. After the upgrades are complete, all influent flows will receive secondary treatment, filtration, cooling (as needed) and UV disinfection prior to being discharged. 8.2.1. Wet Weather Equalization Hydraulics The equalization pond will be improved to store up to 5.4 MG. The new operating levels for the pond will be EL 123.3 (empty, varies) to EL 132.3 (full). This additional volume will equalize flows to secondary treatment during the design storm event down to a peak of 16 mgd. Primary effluent will be diverted and flow by gravity to equalization for flows exceeding 16 mgd. The primary clarifiers have a capacity of 22 mgd. Plant influent flows greater than 22 mgd will be routed to the equalization pond from upstream of the headworks flumes. Additionally, the primary effluent diversion point operates at a HGL of about EL 129.0. Therefore, to use the storage available in the pond above that elevation, the headworks diversion point (EL 134.0) will have to be used. This will be necessary during very large storm events such as the 10-yr 24-hr design storm. The schematic below (Figure 8-1) provides an illustration of peak hour flows that will be routed to each area of the plant. Figure 8-2 provides the proposed hydraulic profile for future average annual and peak hour conditions. WRRF Facility Hydraulics Page 8-2 Based on the plant hydraulics the following modifications are recommended to convey the peak hour flows noted in Figure 8-1 through each process area: Increase the size of the primary influent pipeline (currently 24-inch to 27-inch pipeline) to a 30-inch pipeline. Modify the PEDB to provide flexibility and flow control to divert wet weather flows to the equalization pond. Modify the recirculation pump station such that primary effluent can be routed through the structure to go to the equalization pond or to the aeration basins. Replace existing 30-inch primary effluent pipeline (portion of the pipe is 27") from the PEDB to recirculation pump station. Replace existing 30-inch primary effluent bypass pipeline with a 42-inch pipeline (pipeline conveys flow from the recirculation pump station to the secondary effluent diversion box). Increase the capacity of the filter feed pump station to 16 mgd. Replace the existing 24-inch nitrified effluent pipeline, from the filter feed equalization basin to the filter influent channel, with a 30-inch pipeline. Install a new pump station to feed filtered effluent to the cooling towers. The existing cooling tower effluent pumps will remain in place to provide the ability to operate multiple pass cooling. Install a new 36-inch pipeline from UV disinfection to the 3W pumping station. Treated effluent (after disinfection) will continue to pass through the existing 3W pump station; effluent not used for plant demands will flow by gravity through the heat exchanger to the Creek or be diverted for recycled water use. Figure 8-1. Proposed Peak Hour Flow Schematic Influent PH = 33.5 mgd Headworks Aeration Basins Filters Cooling UV PCs FCs Tertiary + Cooling + Disinfection PH = 16 mgd PCs PH = 22 mgd Secondary Treatment PH = 16 mgd Peak Cooling Flows > 16 mgd Flows > 22 mgd Flows > 16 mgd Wet Weather EQ Pond Filter Feed EQ Basin WR R F F a c i l i t y Hy d r a u l i c s Pa g e 8 - 4 Pa g e i n t e n t i o n a l l y b l a n k . 9. Operational and Control Strategies Page 9-1 9. Operational and Control Strategies This section describes the preliminary operational and control strategies for the WRRF following implementation of the upgrades described in Section 7. The following section highlights the operational strategies for process areas that will have control modifications as part of this project. 9.1. Operational Strategy Section 7 provides a process flow diagram of the WRRF after the proposed upgrades. Dry weather and wet weather operations are described in the following sections. 9.1.1. Dry Weather Operation As shown in the process flow diagram, raw influent wastewater will be screened, fed to the influent pumping station, and pumped to aerated grit removal. Influent flow measuring mag meters will be placed on the discharges of each plant influent pump (four in total). The aerated grit facility has the ability to operate with only one of the two units for day to day operations. Both units would be in service during the wet weather season. After grit removal, the flow is split between Parshall flumes, which will be no longer used for flow measurements. The biosolids return sidestream and the filter backwash are introduced on the backend of the Parshall flumes prior to being fed into dedicated primary clarifiers. Primary effluent will be routed from the PEDB to the aeration basins. Primary effluent will be combined with RAS in the aeration basin influent channel as currently designed and operated with an equal split using influent weir gates. Mixed liquor (RAS + PE) will enter two anoxic zones followed by a minimum of two aeration zones. The anoxic zones will have submersible mixers to keep solids in suspension. The aerated zones will be supplied with fine bubble diffusers for aeration and mixing. The air headers to each aeration zone will have actuated butterfly valves that will be automated and controlled through the blower master control panel. DO probes will be provided in each aerated zone. Additionally, ammonia probes will be provided in each aerated zone for a minimum of one per treatment train. A mixed liquor return pump will be installed at the end of the last aerated zone and return nitrified mixed liquor to the anoxic zone entrance (immediately downstream of the RAS and PE entrance). Mixed liquor will then be routed to the online final clarifiers. The final clarifiers are fed in a flocculating center well with inboard launders. The RAS pumps were replaced as part of the WRRF Energy Efficiency Project with variable frequency drives pumps. The RAS pumps are flow-paced using mag meters that measure RAS discharge flows. The WAS will be wasted from either the mixed liquor channel as currently done at the WRRF or from the RAS lines. Regardless of wasting location, the WAS flow will be fixed. A fixed WAS flow is appropriate for facilities with flow-paced RAS. The final clarification effluent will be conveyed to the filter feed flow equalization basins. From there flow will be pumped to the online filters. Additional pumps will be added to provide firm capacity for 16 mgd. The cooling towers will be reconfigured to pump filtered effluent to the inlet of the cooling towers. A bypass line will be provided so that flows not discharged to the Creek can bypass cooling. WRRF Facility Operational and Control Strategies Page 9-2 The cooled effluent will be conveyed to the new UV disinfection facilities and either discharged or sent to recycled water storage. After the WRRF upgrades, primary sludge, WAS, and scum will continue to be co-thickened prior to digestion. A new mechanical thickening system, rotary drum thickener (RDT), is recommended. The primary sludge, WAS and scum will be blended in a tank upstream of the RDT. The DAFT will be repurposed as a blend tank upstream of the RDT. Thickened sludge will be pumped to the anaerobic digesters (one existing and one new with the same or greater capacity). The biogas produced will be treated and used with the cogen facility. The two digesters would operate in parallel and digested solids would be pumped to the new screw press dewatering system. The screw presses are expected to operate approximately 14 to 16 hours per day. Pressate from the screw presses will be routed to a new equalization basin that uses former Digester 3. From the equalization basin, the pressate will be pumped to former Digester 2, which will be repurposed as a deammonification reactor for sidestream treatment. Section 7 provides details on the operation of a deammonification reactor. The goal of the reactor will be to reduce ammonia concentrations and loads in the plant return streams. The supernatant from the deammonification reactor can then be returned to the front of the plant without impact to the secondary treatment system. 9.1.2. Wet Weather Operation After the WRRF upgrades, the wet weather operation at the WRRF will be similar to the dry weather operation. The primary difference in the operation is that peak wet weather flows will be equalized and all wet weather will receive full secondary and tertiary treatment. The following describes the differences between wet weather and dry weather operation: Due to hydraulic constraints, the primary clarifiers will have capacity to treat flows up to 22 mgd. Flows greater than 22 mgd will be diverted to the equalization pond, upstream of the primary clarifiers. Primary effluent flows greater than 16 mgd will be diverted at the PEDB to the equalization pond (downstream of primary clarification). Wet weather flows stored in the equalization pond will be pumped and returned to the activated sludge system. Nitrified effluent will be equalized in the existing 1 MG filter feed equalization basins during filter backwash cycles. The activated sludge facility will be designed with the ability to operate in contact stabilization mode. The goal of contact stabilization mode is to reduce solids loading on the final clarifiers during peak wet weather events. Contact stabilization mode will involve routing primary effluent to the aerated zones of the basins and diverting RAS to the anoxic zones of the basins. Internal mixed liquor return will not operate while in contact stabilization mode. 9.2. Preliminary Control Strategy 9.2.1. Wet Weather Flow Equalization Currently, wet weather flows are not regularly diverted to equalization, and instead are disinfected and discharged to the Creek. After the WRRF upgrades, wet weather flows will receive full secondary, tertiary and disinfection treatment. Peak flows greater than 16 mgd will be passively WRRF Facility Operational and Control Strategies Page 9-3 diverted to the equalization pond at the PEDB. As described in Section 7, it is assumed that the PEDB will be retrofitted to allow passive diversion (e.g., adjustable weir gate) to the pond. The equalization pond is currently manually controlled. As part of the upgrades, automation for the equalization pond return pumping will be provided. VFD controlled pumps will be installed to operate on level control in the pond. A level indicator will also be provided to allow staff to monitor the pond level remotely. A meter will be installed to monitor the return flow rate. Additionally, if desired, the return pump speed could be programmed to automatically start at an influent flow setpoint when the pond level is at a given setpoint. 9.2.2. Influent Flow Measurement New magnetic flow meters will be installed on the discharges of each influent pump. A total influent flow will be calculated in the PLC using the total of the combined readings from the 4 new meters. 9.2.3. Diurnal Flow Equalization Diurnal flow equalization is not included in the recommended facilities. Although the existing secondary clarifier will be decommissioned, it could modified and used for diurnal storage in the future if equalization is desired. 9.2.4. Grit Removal The existing aerated grit facility as described in Section 3 has the ability to manually bring online a second tank and/or take a tank out of service. Automation of the grit system is not anticipated or necessary. The second tank would be brought online, manually, when influent flows reach a predetermined flow setpoint. 9.2.5. Aeration Basins/Secondary Treatment Wet weather flows will receive secondary treatment. Similar to the existing operational strategy, primary effluent will be combined with return activated sludge (RAS) in the aeration basin influent channel. The primary effluent and RAS will enter the anoxic zones of each basin followed by the aerated zones. A mixed liquor return pump, in each basin will pump mixed liquor to the anoxic zone to achieve denitrification. The mixed liquor return pump will be flow paced to the influent flow meters. RAS, WAS and AB influent, and ML flow monitoring will be provided. Each train will be provided with DO, ammonia, nitrate and pH probes, at a minimum. The ammonia probes will provide real-time monitoring of ammonia concentrations and in the future could be tied to the blower control strategy, if desired. The nitrate probes also provide real-time measurement of nitrate and will assist operations with monitoring/adjusting the mixed liquor return pump rate as well as monitoring and adjusting the carbon (methanol) addition (if needed). The pH probes can be used to automate alkalinity addition. DO meters will be provided in each aeration zone of each train and will be used with the blower control strategy. The new and existing aeration blowers will be installed in a lead-lag configuration and will be connected to a common header that is routed to the aeration basins. The on-line blowers will be automatically controlled to maintain setpoint DO levels in the aerated zones of each train. A slow acting DO control loop will be used to modulate the air control valves. As an energy saving measure, the control system will monitor the position of each zone control valve to be sure that at least one valve is open to a preset most open valve position. If the most open valve position falls below the preset position, indicating too high of a header pressure, the blower speed will be reduced in small steps until the most open valve is at the preset position. If the most open valve is above the WRRF Facility Operational and Control Strategies Page 9-4 preset position, indicating too little header pressure, the blower speed will be increased until the most open valve is at the preset position. If the online blower reaches 100 percent speed for a preset time a second blower will be started. If the blower reaches a preset minimum speed for a preset time a blower will be taken offline. There will be a preset minimum speed at which a single on-line blower can operate and a minimum position for the air control valves in order to provide adequate mixing. The aeration basins will be provided with the ability to operate in contact stabilization mode during wet weather events. Contact stabilization mode results in lower solids loading rates to the final clarifiers and minimizes the potential for solids to be lost over the clarifier weirs. Operation in contact stabilization mode is illustrated in Figure 9-1 (normal operation mode is illustrated in Figure 9-2 for comparison). RAS is routed to the front of the basins, and primary effluent is routed to the back of the basins. This mode of operation will be provided to give operations flexibility during wet weather events. Switching into contact stabilization mode during wet weather events will be an operational decision based on influent flows, forecasted storms and durations, and sludge settleability. The flow trigger to switch to contact stabilization mode is a design feature that will be resolved by the selected designer. Figure 9-1. Contact Stabilization Mode Figure 9-2. Normal Operational Mode INF Pri Clar ANX Final Clar IMLR RAS AER Contact Stabilization Bypassfor Wet Weather Events INF Pri Clar ANX Final Clar IMLR RAS AER WRRF Facility Operational and Control Strategies Page 9-5 9.2.6. Final Clarification ML from the aeration basins is split to each of the final clarifiers using cutthroat flumes. Underflow from each final clarifier will be pumped with two RAS pumps. The RAS pumps on the existing final clarifiers were replaced with variable frequency drives pumps as part of the WRRF Energy Efficiency Project. These RAS pumps are flow-paced using mag meters that measure RAS discharge flows. This control strategy will be used for the new final clarifiers. Two new RAS pumps will be installed with each new final clarifier. WAS pumping will be configured to allow wasting from the ML channel of the aeration basins or from the RAS common header. WAS pumps will be sized to enable continuous wasting (24 hours per day, seven days per week).The WAS pumps will be operated to meet an operator flow setpoint. A set WAS flow is appropriate for facilities with flow-paced RAS. The WAS wasting configuration is a design feature; a classifying selector is recommended as it provides the ability to control foaming/filaments if this becomes a future issue. 9.2.7. Effluent Cooling The effluent cooling process will consist of a combination of evaporative cooling with a refrigerant cooling reserve that will be used during peak heat load events. The evaporative cooling system will consist of augmenting the existing 3 cooling towers with an additional 2 cooling towers. The evaporative system will continue to cool the filter effluent upstream of the disinfection facility as there is a potential for bacterial re-growth in the cooling tower media. The refrigerant based cooling system will be located downstream of disinfection as it is a closed conduit that doesn’t increase re- growth potential. In this location, it will only cool the portion of the flow that will be discharged to the Creek. It will normally be called to start when all the available cooling towers are already operating. Currently the cooling towers are operated manually and influent and effluent temperatures are manually recorded. Temperature monitoring (influent and effluent) and level control for the cooling towers will be provided with operator setpoints that can be modified. This will provide staff with the data to improve and optimize cooling tower operation as well as comply with permit limitations. Filtered effluent will be pumped with new pumps to the cooling towers and cooling tower recirculation pumps will be provided to allow multiple pass cooling. The cooling towers can be bypassed if cooling is not needed based on Creek temperatures or if all of the flow is for recycled water production. Cooling tower feed pumps will be progressively called to start by a local PLC as cooling demands increase. Operators may preselect which of the cooling towers are available to operate. Once all of the available cooling towers are in operation, further increases in heat load or falling creek temperatures will result in a call to start the refrigerant cooling system (chiller). A temperature sensor upstream of the chillers will allow the PLC to shut the chiller system down again once the cooling towers are again able to provide adequate 9.2.8. UV Disinfection The UV disinfection channels will be designed to operate at a constant water surface elevation. Each channel will have multiple UV banks that will be brought on and offline based on flows and UVT. The UV system is controlled by the UV system local control panel which includes a microprocessor- based controller that provides monitoring and control of all UV functions. The UV system local panel will have a data link to the plant SCADA system so the UV operation can be monitored and setpoints changed on the plant SCADA. The intensity of the UV is controlled by the local control panel and generally is based on plant flow and UV transmittance monitors within the UV system. The UV WRRF Facility Operational and Control Strategies Page 9-6 system operation is typically flow-paced by turning off/on banks of UV lamps or stepping down power input (down to 50% typically) in response to flow rate changes. The UV local control panel will include a graphic operator interface panel for local monitoring and control of the UV. The UV system will be on standby power from the proposed standby generator at switchboard R. 9.2.9. Solids Thickening The DAFT will be upgraded to a low energy technology such as a RDT. The DAFT tank will be used as a blend tank upstream of the thickeners to receive primary sludge, WAS and scum. Pump mixing will be used to keep solids from settling out of the tank and to feed the RDTs. Thickened sludge will be pumped to the anaerobic digesters using progressive cavity pumps. The RDTs can run continuously (24 hours per day, seven days per week). A level sensor in the blend tank will allow staff to monitor the RDT operation remotely, and increase or reduce feed pump speeds as needed. 9.2.10. Anaerobic Digestion The upgrades include construction of a new digester to replace Digester 2. The new digester will be the same volume as Digester 1. The digesters will be operated as a parallel process as this provides improved volatile solids destruction over digesters in series. Both digesters would be used for typical operation. Digesters would be taken off-line for maintenance. Operating in parallel simplifies the ability to take digesters off-line for maintenance. Feed piping to the digesters will allow both digesters to be fed on a timer based cycle. Automation will be added to improve digester operation and controls. The automation to be provided includes monitoring and controls for digester temperature, gas pressure, carbon dioxide, gas production and boiler operation. When sidestream treatment is constructed, the WRRF will no longer have a solids dewatering feed tank. There will be adequate capacity in the new Digester to hold solids and feed them to dewatering. Additionally, dewatering is planned to occur over a 14 to 16 hour day (7 days per week), which will modify/reduce the volume needs for the dewatering feed tank. 9.2.11. Sidestream Treatment Sidestream treatment of pressate from the dewatering screw presses was identified as an upgrade that would replace the existing supernatant lagoon. Conversion of Digester 2 into as equalization tank to feed the sidestream treatment reactor and replacing Digester 3 with a sidestream treatment reactor is described in detail in Section 7. Digester 2 would be used for flow equalization. Level monitoring would be provided in this tank. The flow would be routed to Digester 2, which would serve as the treatment reactor. Aeration blowers would be required and would operate with the deammonification technology specific controls associated with the particular technology. Monitoring of pH and ammonia would also be used to assist operations with having real time data on the performance of the reactors (ammonia probe). A flow meter on the discharge line and the feed line would be provided. 10. Additional Upgrades Page 10-1 10. Additional Upgrades This section presents recommended upgrades at the WRRF in addition to those upgrades for the treatment process. Specifically, this section presents upgrades for the electrical system, SCADA and I&C, onsite stormwater management, and flood management. 10.1. Electrical System Upgrades An evaluation of the condition of the electrical and instrumentation and controls (I&C) was performed to assess the condition and capacity of the electrical and I&C facilities and identify improvements needed at the WRRF. Appendix M, TM No. 10.2 – Infrastructure Planning, Electrical and I&C, contains the detailed analysis that was performed as well as the conclusions and recommendations. 10.1.1. Existing Facilities The WRRF is served by two PG&E 480 volt, 3 phase, 4 wire electrical services. The main service (Plant Service 1) is rated for 3,000 amperes (amp) and is located in the plant electrical building. This service consists of a 3,000 amp Main Switchgear (MSG) which includes PG&E metering, main 3,000 amp breaker, feeder breaker for the 150 KW digester gas cogeneration unit and feeder breakers for each major plant load center including MCC A1, A2, B1, B2, J1, J2, F1, F2 and H. A natural gas/propane standby generator rated 560 KW (700 KVA) is available to provide standby power to motor control centers (MCC) A1, A2, B1, B2, J1E, J2E and H and panelboards F and G through individual automatic transfer switches (ATS). This generator can only serve a portion of the plant load during power outages and the ATSs can be used to shed plant load to match the generator capacity. The City is presently purchasing electricity service at the main plant from PG&E on a primary rate schedule and owns the service transformer. The other plant service (Plant Service 2) is rated for 1,200 amps, consists of a service switchboard with PG&E meter, future standby generator breaker and feeders for MCC-R (including pumps WRP 101 and 201), pumps WRP 301, 501, 701, two spare 400 ampere feeders and a Square D Accusine active harmonic control unit for control of harmonics for the pump variable frequency drives (VFD’s). This service presently serves the recycled water pumps at the WRRF. This service, the VFD’s and MCC-R are located in an electrical building in the Recycled Water Area, located in the southwestern area of the site. Figure 10-1 provides the location of the existing MCCs and plant service. Currently all load centers are radially fed with single feeders from the main switchboard, MSG. This system has been trouble free over the years it has been in use. WRRF Facility Additional Upgrades Page 10-3 10.1.2. Electrical Loads The existing loads on the various plant load centers are shown in Table 10-1. Both the total connected load (all plant load) and the demand load (maximum load that can occur concurrently) are shown. The loads include the plant improvements underway including installation of two high-speed turbo blowers, 150 KW cogeneration unit and abandonment of the Turblex and two Lamson blowers. There is capacity available for future plant electrical loads and most load centers are only nominally loaded as shown in Table 10-1. Table 10-1. Existing Electrical Loads PANEL PANEL FEEDER CAPACITY EXISTING LOAD, KVA Amperes KVA Connected Demand MCC-A1 400 266 265 230 MCC-C 150 100 20 15 MCC-A2 400 266 187 150 MCC-B1 300 199 42 22 MCC-B2 300 199 55 30 MCC-J1 800 532 600 408 Admin Bldg. 175 116 166 128 MCC-J1E 150 100 79 44 MCC-J2 800 532 477 259 MCC-J2E 50 33 65 34 MCC-F1 1200 798 332 238 MCC-G1 600 399 85 47 MCC-F2 1200 798 274 199 MCC-G2 600 399 63 13 MCC-H 400 266 81 54 SWBD-MSG 3000 2494 2791 1871 SWBD-R 1200 798 487 352 MCC-R 400 266 122 102 (a) MCC – Motor control center (b) SWBD – Switchboard Based on the facility improvements described in Section 7, future electrical loads were developed. The ability of the plant to serve the expected loads for the WRRF expansion is shown in Table 10-2 in a format similar to Table 10-1. The expected loads were estimated to include expansion of the aeration basins and blowers, tertiary filters, cooling towers and conversion to ultraviolet (UV) disinfection. The projected future demand load of 3285 KVA for SWBD – MSG is greater than its capacity of 2494 KVA, but with a conservative diversity factor of 70 percent applied to this total plant demand load the actual demand is 2300 KVA, well within the switchboard capacity. The diversity factor considers that not all motors and loads are operating at full motor horsepower or at rated load and that not all loads will be operating exactly concurrently. A factor of 70 percent is considered to be conservative for this facility. The plant electrical system has the ability to serve these expected plant load increases with some reserve for additional future load except for the standby generation system. WRRF Facility Additional Upgrades Page 10-4 Table 10-2 Projected Electrical Loads PANEL PANEL FEEDER CAPACITY FUTURE LOAD, KVA Amperes KVA Connected Demand MCC-A1 400 266 405 370 MCC-C 150 100 20 15 MCC-A2 400 266 217 170 MCC-B1 300 199 162 142 MCC-B2 300 199 55 30 MCC-J1 800 532 818 520 Admin Bldg. 300 199 166 128 MCC-J1E 150 100 79 44 MCC-J2 800 532 608 390 MCC-J2E 50 33 65 34 MCC-F1 1200 798 754 649 MCC-G1 175 116 76 36 MCC-F2 1200 798 710 635 MCC-G2 175 116 28 8 MCC-H 400 266 81 54 SWBD-MSG TOTAL 3000 2494 4244 3285 Overall Diversity Factor (70%) for SWBD-MSG SWBD-MSG Total Diversified Load 2300 SWBD-R 1200 798 1032 882 MCC-R 400 266 112 102 10.1.3. Major Electrical Equipment Condition Assessment Major plant electrical equipment was visually inspected to determine the current condition in order to determine suitability for continued service. A summary of the major electrical equipment condition is shown in Table 10-3. The following general observations relate to the equipment condition. Table 10-3. Summary of Electrical Equipment Condition Assessment Equipment Condition Short Circuit Bracing, Amperes Suitable For Continued Service SWBD-MSG Good 75,000 Yes MCC-A1 Very Good 42,000 Yes MCC-A2 Very Good 42,000 Yes MCC-B1 Very Good 42,000 Yes MCC-B2 Very Good 42,000 Yes MCC-J1 Very Good 42,000 Yes MCC-J2 Very Good 42,000 Yes MCCJ1E Very Good 42,000 Yes MCC-J2E Very Good 65,000 Yes MCC-F1 Very Good 65,000 Yes MCC-F2 Very Good 42,000 Yes WRRF Facility Additional Upgrades Page 10-5 Equipment Condition Short Circuit Bracing, Amperes Suitable For Continued Service MCC-G1 Very Good 42,000 Yes MCC-G2 Very Good 42,000 Yes MCC-H Very Good 65,000 Yes MCC-C Fair Unknown Yes (1) MCC-D Abandoned Standby Generator Good - Yes (2) SWBD EG Good 50,000 Yes SWBD-R Very Good Unknown Yes MCC-R Very Good Unknown Yes ATS’s (9) Very Good Matches respective MCC Yes (a) Under present use. Replace if load is to be added. (b) Undersized for current plant needs, see improvement schedule. The following conclusions were made from the condition assessment: 1. Minor electrical equipment including lighting and power panelboards, dry type transformers, stand alone VFD’s, ATS’s and similar equipment are in good condition and are serviceable for continued use. 2. Both main electrical service switchboards are in serviceable condition. Some of the paint on switchboard MSG in the electrical building is faded due to sun exposure at some time (it is now inside a building), but this does not impact its serviceability. 3. All of the MCC’s except MCC-C are Westinghouse Model 2100 which are no longer manufactured, but spare parts are available. These MCC’s are all in excellent condition, are located inside buildings and are suitable for continued service. The existing MCC’s will probably be serviceable for another 15 years. However, it will probably become desirable to replace them to take advantage of newer MCC features such as arc-flash reduction and “smart” MCC features before they become unserviceable. 4. MCC-C is a very old Autocon unit located in a NEMA 3R outdoor enclosure. This MCC is in fair condition and would not be suitable for service as a major MCC under future conditions. It currently serves only three pumps which in the future will be critical during wet weather events. If additional loads need to be added to MCC-C in the future or if the MCC needs to be moved, MCC-C should be upgraded otherwise it can continue to service the existing load. 5. There are nine ATS’s which transfer plant load to the standby generator during a power failure. These transfer switches are located in the various electrical buildings and are in excellent condition. See the discussion related to standby generation for additional comments. 6. The existing standby generator is a Caterpillar 560 KW propane gas driven unit and is located in the electrical building. It is also capable of operation on natural gas. This unit is only used as a standby generator and is not used for peak shaving as it has no capability for synchronizing onto a hot bus and is not PG&E approved for parallel operation with the PG&E system. The generator is in excellent condition and has about 400 operating hours but is much too small to serve even existing loads. There are feeders from the standby generator switchboard, SWBD EG, to each of the seven standby generator powered MCC’s (MCC A1, A2, B1, B2, J1E, J2E and H) and to WRRF Facility Additional Upgrades Page 10-6 Panelboards LP-F and LP-F1 (Electrical building and Telemetry Shop) and LP-G (solids thickening). Switchboard EG is located in the electrical building and is in serviceable condition. 7. The short circuit (fault interrupting) rating of each major equipment is shown in Table 3. All of the major electrical equipment is adequately rated for the maximum fault current except for MCC-C. This is not a critical MCC and the feeder breaker for MCC-C in MCC-A2 can interrupt and clear any potential fault in MCC-C. All of the ATS’s are rated for fault currents in excess of the highest possible fault current. 8. Confirmation that the various adjustable trip plant circuit breakers are properly coordinated so the breaker closest to a fault will trip first is necessary. It is recommended that a coordination study be undertaken as part of the WRRF upgrades to determine correct circuit breaker settings. The breakers should be adjusted to these recommended settings. 9. Current practice and code requirements require arc flash labelling for essentially all electrical equipment for new installations. Generic arc flash labels such as Brady Catalog #101518 should be installed on existing plant electrical equipment. An arc flash study should be conducted on the plant electrical equipment as part of the WRRF upgrades and more detailed arc flash labels installed which show the level of protective clothing required at each electrical panel. 10.1.4. Electrical System Recommendations The proposed upgraded single line diagrams for plant and reclamation electrical systems are shown in Figure 10-2 and Figure 10-3. The following plant electrical system improvements are recommended. 1. The plant standby generation system is undersized for the existing plant and is much too small for the planned plant improvements. The standby generator is rated 560 KW (700 KVA) and is too small even when the plant is operating under dry weather conditions. The present system of multiple ATS’s is complicated and does not allow operation of secondary biological treatment or filtration during power outages. The existing ATS’s can not remain in service for load shedding purposes as they and the associated feeders are too small. It is recommended that a standby generator sized adequately for the plant load with a single 3000 amp ATS be installed at the electrical building. This will allow full plant operation during power outages. This system can also be designed to allow the use of the cogeneration system during power outages if the cogenerator is isolated from PG&E by the ATS. This standby generator should be sized for 2000 KW (2500 KVA) so the full plant demand can be served, should be installed outdoors with a weather protection enclosure and integral base fuel tank. We recommend the installation of a diesel powered generator as it will be much smaller and less expensive compared to a gas powered generator. The existing generator building can be used for other purposes. 2. Serve the UV electrical load from SWBD-R and install a standby generator and ATS at SWBD-R as there is no existing standby generator at this location. This generator should be sized for the full capacity of SWBD-R, 1000 KW. The existing standby generator is too small to be moved to serve SWBD-R and it would not be cost effective to move it because of the high cost of moving. 3. The WRRF upgrades should include requirements for a short circuit/coordination/arc flash study, arc flash labeling of all existing and new electrical panels and adjustment of all protective device settings. The contract should include testing of all existing protective devices for proper operation. WRRF Facility Additional Upgrades Page 10-7 4. All electrical panels should be labelled with the location of the primary disconnect for each panel. 5. The existing radial feed system has been trouble free over the years. If a radial feeder is lost it is possible to bring in a portable generator to serve that load center until the feeder can be repaired or replaced. The dual feeder system may provide some measure of increased continuity of service of reliability, but at greatly increased cost and complication. Implementation of the dual feeder system would require additional underground duct banks and an expanded switchboard MSG for the added feeders. Based on past plant experience, the cost to convert to a dual feeder system is not justified based on a very slight increase in continuity of service and reliability. 6. A loop system for the 12kV service can be considered in the future if additional 480 volt load centers are needed. 7. It is recommended that power monitors be added to the major load centers such as switchboards and MCC’s for purposes of power and energy management. This can be done as part of the next plant upgrade or when major equipment is replaced. Power monitors have a wide range of capability and are relatively inexpensive to install. They can be tied into existing PLC’s using a data link in order to take advantage of their range of capabilities. 8. All of the MCC’s except MCC-C are Westinghouse Series 2100, are in excellent condition and are suitable for continued service. Existing Autocon MCC-C should be replaced if it is moved or if any additional load is to be added as it is very old and is not of modern construction. While the Westinghouse Series 2100 MCC’s would probably provide satisfactory service for another 15 or 20 years newer MCC’s have advanced features that will probably dictate replacement before the end of their actual service life. These new features include “smart” construction which allows complete monitoring of the MCC drives over a single digital data link which can be connected directly into the PLC network just like the other PLC’s. There are also other advanced features such as IR monitoring and certain arc flash protection features. It is recommended that the existing MCC’s be retired and replaced over a period of time in conjunction with other projects or if major new load is to be added to a MCC. This replacement could commence with the next major plant upgrade project. Replacement of MCC’s while keeping the plant in service is tricky and must be carefully planned. The dual MCC arrangement at most of the locations at the City plant will facilitate this replacement because many critical loads are split between the dual MCC’s at each location. 9. Any major future expansion of the plant electrical load will likely require a new higher capacity electrical service. The existing electrical service is adequate for the planned plant upgrade. Any future service expansion will probably require the installation of additional 480 volt load centers and expansion of the 12 kV primary system. WRRF Facility Additional Upgrades Page 10-10 10.2. Instrumentation and Control Upgrades 10.2.1. Existing SCADA and PLC System The current plant SCADA System consists of seven older Bristol-Babcock (Emerson) 3330 DPC’s and two newer Bristol-Babcock “Control Wave” DPC’s configured in hot standby. These DPC’s are currently hard wired on one new central SCADA Dell computer based work station, which is operating on Intellution iFIX64 SCADA software, through a data concentrator. There is also a larger wall mounted monitor. This work station is located in the Operations Building. This is the only iFIX64 SCADA work station in the plant. The old iFIX32 based work station is still in place in the Operations Building because it contains Data View software to be able to communicate with the older Bristol- Babcock 3330 DPC’s. The iFIX32 work station will be abandoned when it is no longer needed for the Bristol-Babcock 3330 DPC’s. The iFIX64 contains alarm autodialer software which will dial the designated operator’s cell phones with a text message of the alarm condition. This alarm software will also dial the designated standby operator when the plant is unattended from seven o’clock pm to six o’clock am and leave an alarm message. 10.2.2. Existing SCADA Equipment There are a number of SCADA/PLC upgrades being undertaken through the WRRF Energy Efficiency Project. These improvements will be completed by the end of 2015 and include the following: Installation of fiber optic backbone communication throughout the plant. This work is currently underway by Electrocraft Contractors. Replacement of the seven Bristol-Babcock 3330 DPC’s with Allen Bradley ControlLogix PLC’s. The new PLC’s will be installed by TESCO in the existing DPC cabinets for ease of wiring the inputs and outputs (I/O) since the wires already exist in the cabinets. These PLC’s will be connected to the new fiber optic Ethernet data link to SCADA. The two newer Bristol-Babcock “Control Wave” hot standby DPC’s will remain in place at this time as they are compatible with iFIX64 and contain sufficient I/O’s. The existing SCADA data concentrator will be removed when the new PLC’s are in place. There are no planned changes in PLC I/O points or control functions under this current project. The City’s control integrator, South Coast Systems, will continue to configure the iFIX64 system for the new PLC hardware. For the purposes of this Facility Plan, it is assumed that existing facilities include upgrades made under the Energy Efficiency Project: 1. Seven Allen Bradley ControlLogix PLC based RTU’s in the plant at the following locations. These are presently Bristol Babcock (Emerson) 3330 DPC’s, but are in the process of being replaced with Allen Bradley ControlLogix PLC’s installed into the existing cabinets. (a) Main Electrical Building. (b) Filter Tower 1. (c) Filter Tower 2. (d) MCC-B. (e) MCC-G. WRRF Facility Additional Upgrades Page 10-11 (f) MCC-J. (g) MCC-R. 2. Two newer Bristol-Babcock “Control Wave” hot standby DPC’s in the plant at the following locations: (a) MCC-A Building, DPC-A. (b) MCC-J Building, DPC-B. 3. Fiber optic plant Ethernet network installed throughout the plant. 4. iFIX64 SCADA software based operator work station on Dell desktop computer with flat screen monitor, located in Operations Building. 5. Wall mounted 32 inch flat screen monitor located adjacent to work station in Operations Building. 6. iFIX32 SCADA software based operator work station on Dell desktop computer with monitor located in Operations Building. This workstation is used only to access data from the older Bristol- Babcock 3330 DPC’s and will be abandoned when all of those DPC’s are replaced with Allen Bradley ControlLogix PLC’s under the current SST Program. 7. Data concentrator which is used to access data from the older Bristol-Babcock 3330 DPC’s and will be abandoned when those older DPC’s are all replaced. 10.3. WRRF Controls The plant control is mostly manual with very little automation. Automation, among other benefits, aids in rapid response to emergency situations and provides remote monitoring and control capabilities. After discussions with plant staff the following plant functions should be monitored and automated as follows: 1. The equalization pond control is manual. Operators currently use the pond to shave off diurnal and emergency peaks and would like a more automated system to return these stored flows back to the plant at a controlled flow rate during low flow periods using VFD controlled pumping, meter the flow and monitor the pond level; in other words automate the return from the pond in order to minimize the impact on the plant. It is recommended that the control of the return flow be automated. 2. Provide additional monitoring and automation of the aeration system which is a well proven technology and would fit in well with the new blowers. This automation would include added monitoring, flow meters and control of air blowers and valves. These monitoring features can result in a reduced energy and chemical demand. This could include: (a) Air valve monitoring and control (b) Blower control (c) pH, temperature and ammonia monitoring (d) RAS, WAS, AB influent and ML flow monitoring 3. Cooling tower and chiller control and monitoring to include control level in towers, monitor influent and effluent water temperature, program the pump operation according to cooling tower level and be able to change set points. WRRF Facility Additional Upgrades Page 10-12 4. Provide better digester performance by automatically controlling digester temperature and monitoring digester temperature, pressure, carbon dioxide, flows, gas production, boiler operation and mixing. 5. Increase use of surveillance cameras (at least 17 locations have been identified). 6. Install motor actuators for a number of large gate valves that are difficult to operate or are not accessible. 7. Expand SCADA system to be able to monitor and control various pumps and drives throughout the plant including monitoring run times. 8. Monitor power and energy usage of plant. 9. Add flow meters throughout the plant including the potable water used for the recycled water system. 10. Monitor additional levels including chemical tanks, plant drains, supernatant lagoon and influent wet well. 11. Monitor and control plant access at entrance gate and back gate (Gate D). 12. Provide chlorine residual information and tie into the chlorine dosing system for automatic control. This will focus on chlorine addition for recycled water prior to distribution. 13. Expand the alarms brought into SCADA and be able to change alarm set points at SCADA. 14. Be able to historically trend the data brought into SCADA from the various equipment and processes in the plant. In general the plant control should be set up in the following manner: 1. Highest level control; automatic from the PLC. In this automatic control mode the process component under control will automatically be maintained within a preset setpoint or control band which will be maintained by the PLC. Operators may set the control parameters within which the control will operate. These parameters, setpoints and tuning constants can be set by the operator from SCADA or from a local operator interface where available. 2. Manual control from SCADA or operator interface where the operator can manually start and stop drives, manually set analog variables and otherwise assume control. 3. Manual local control from hard switches locally at the drive and/or at motor control centers. This mode is the lowest level control and can be used for testing, maintenance, adjustment or emergency control. 4. All drives will be set up so the drive can be stopped locally in an emergency and can be locked out in the off position at the local disconnect or at the motor control center depending on the arrangement of the drive. 10.4. SCADA System Improvements The following presents recommended improvements to the SCADA system as part of the WRRF upgrades: 1. New major equipment containing PLC’s should be specified with Allen Bradley PLC’s where possible and be set up for connection into the existing PLC Ethernet network so the equipment WRRF Facility Additional Upgrades Page 10-13 PLC can be accessed directly from SCADA. Most manufacturers can accommodate this arrangement and can provide Allen Bradley PLC’s for compatibility with the plant PLC’s and with the plant SCADA. 2. Implement separate SCADA and PLC fiber optic Ethernet networks. See the typical SCADA block diagram in Figure 10-4. 3. Extend SCADA network from Operations Building to all locations where work stations, printers and plant HMI’s are desired. 4. Extend PLC network from operations building to all PLC locations including manufacturer’s equipment that contains a PLC such as, MCC’s, filters, UV and dewatering. 5. Provide local HMI’s for all PLC based process control panels including filters, UV, and dewatering for local process control and monitoring. 6. Provide a plant HMI or work station at all locations where access to plant SCADA data is needed or convenient such as operations building, administration building and filtration. 7. The PLC network should terminate at the historian work station so all PLC data is processed and controlled by the historian and the other plant work stations and HMI’s will receive PLC data through the historian. 10.5. Stormwater Management This Subsection provides a stormwater management plan for the WRRF for consideration during the planning of future treatment upgrades. The recommendations presented in this subsection represent the results of an analysis that included the following elements: Performing a hydrologic analysis for the project area considering future upgrades by evaluating drainage area, imperviousness, soils conditions, precipitation and land use conditions to develop stormwater runoff volumes and maximum outfall peak discharges. Developing LID recommendations and stormwater retention facilities that will improve stormwater quality and flood protection throughout the WRRF. Performing a hydraulic analysis for the project area to determine finish floor elevations for proposed structures and other critical infrastructure to remain above the inundation by riverine flooding for a 100-year flood event. Evaluating flood management alternatives and developing recommendations for improvements to address inundation by riverine flooding for a 100-year flood event. The details of this analysis are presented in Appendix L, TM No.10.1 – Infrastructure Planning, Stormwater. Stormwater management recommendations for each of the eight (8) delineated watersheds covering the WRRF are provided. Recommendations include minor upgrades, such as reconfiguring existing vegetated areas to include LID features, to major upgrades, such as incorporating LID/stormwater collection features as part of newly constructed buildings and treatment facilities. The stormwater management recommendations provided do not protect the WRRF when the San Luis Obispo Creek overtops its banks and flows into the facility. Additional flood protection measures must WRRF Facility Additional Upgrades Page 10-14 be considered to reduce/remove the risk of San Luis Obispo Creek overtopping its banks; recommended upgrades are provided to protect against flood flows. 10.5.1. Existing Conditions The WRRF’s developed area is approximately 30 acres in size and is primarily paved with small vegetated/dirt swales distributed throughout. Additional acreage to the southwest of the developed area is vegetated open space and wetlands. Stormwater runoff is collected at different locations throughout the facility and transported via concrete swales, vegetated ditches, and culverts to three existing outfalls to the San Luis Obispo Creek as well as overland release to open areas southwest of the WRRF. Outfalls A and B flow to the Creek through piped storm drain systems which are controlled by manual release gates. Outfall C flows through a recently constructed vegetated bioswale and only flows out to the creek through an overflow basin inlet during large storm events. The WRRF maintains its own Industrial Storm Water Pollution Prevention Plan (SWPPP) satisfying requirements of the local Central Coast Regional Water Quality Control Board (CCRWQCB). The City’s Bus Barn facility is adjacent to the WRRF and collects contained runoff from the bermed bus parking area and drains through an in-ground oil/sediment separator before flowing into a shared storm drain with WRRF stormwater runoff collected and released through Outfall B. 10.5.2. Site Drainage Recommendations Figure 10-5 illustrates the proposed site drainage for the eight watershed areas on the WRRF site. Hydrologic stormwater runoff volumes and associated depths of LID facilities were developed for each watershed area, as shown in Table 10-4. Refer to Appendix L, TM No. 10.1 – Infrastructure Planning, Stormwater, for specific recommendations for each watershed and additional information related to the analysis. Table 10-4. LID Storage Volumes Watershed ID Contributing Drainage Area requiring LID Upgrades (ac) Required LID Storage Volume(a) (ac-ft) Maximum Water Depth of LID Basin(b) (ft) Maximum Water Depth of LID Basin including Freeboard(c) (ft) A 3.2 1.1 -- -- B 2.6 0.9 2.8 3.8 C 2.3 0.8 2.7 3.7 D 2.8 1.0 1.9 2.9 E 2.2 0.8 2.5 3.5 F 2.5 0.9 2.8 3.8 G 2.2 0.8 1.9 2.9 H 4.5 1.5 1.5 2.5 -- Not applicable for Watershed A is it does not currently need LID or stormwater collection improvements since utilizing the open area southwest of the WRRF (a) Based on a 10-year, 24-hour storm event. (b) The percolation rate of the soil has not been taken into consideration when computing the maximum water depth. Once percolation rates are known, depths can be reduced accordingly. Maximum depths are provided for planning purposes only. (c) Assumes 1.0 foot of freeboard. WR R F F a c i l i t y Ad d i t i o n a l U p g r a d e s Pa g e 1 0 - 1 6 Pa g e i n t e n t i o n a l l y b l a n k . ! ! ! ! SanLuisObispo Creek Filter FeedEqualizationBasin AerationBasins EqualizationBasin Laboratory, Operations, & Welcome Center EQ Pond Garden/PublicGreen Space SludgeDrying Beds Headworks PC 1 PC 2FC 1FC 2 Entrance FC 4 FC 5Filters FutureUpgrades Garden/PublicGreen Space Interpretive Center ProposedOutfall D ExistingOutfall C ExistingOutfall A ExistingOutfall B £¤101 D A F H G B C E F: \ P r o j e c t s \ 0 2 8 _ 2 2 6 6 6 4 _ C i t y _ o f _ S L O _ W R R F _ U p g r a d e s \ m a p _ d o c s \ m x d \ P r o p o s e d _ W R R F _ S i t e D r a i n a g e . m x d _ 5 / 1 2 / 2 0 1 5 _ e m e s b a h - 010020030050Feet Main MapExtent 0 50 10025Meters HDR | 2015 City of San Luis Obispo City of San Luis ObispoWater ReclamationRecovery Facility !Outfall LocationCulvert ConnectionEmergency Overflow Path Data Source: HDR, ESRIMap information was compiled from the bestavailable sources. No warranty is made for itsaccuracy or completeness.Projection is California State Plane Zone 5. Figure 10-5Proposed WRRFSite Drainage A Pr a d o R d Watershed BoundaryImpervious AreaPervious AreaIsolated Pervious AreaSelf Contained Area WR R F F a c i l i t y Ad d i t i o n a l U p g r a d e s Pa g e 1 0 - 1 8 Pa g e i n t e n t i o n a l l y b l a n k . WRRF Facility Additional Upgrades Page 10-19 10.5.3. Recommended Flood Protection Improvements As described in Appendix L, TM No. 10.1 – Infrastructure Planning, Stormwater, several flood protection concepts were considered to reduce or eliminate the risk of flooding at the WRRF during a 100 year storm event. Many of the measures would involve major offsite improvements which represent major investments with long planning and design schedules. While these projects could provide benefit if implemented in the future, it was determined that the least costly and most readily implementable project, with the least impact on neighboring properties would be an on-site improvement option in which existing facilities would be upgraded and new facilities designed to avoid inundation. An initial review of the WRRF facilities was conducted to determine the magnitude of the on-site improvements that would be required to prevent inundation. Table 10-5 provides a summary of the WRRF facilities that were determined to be potentially vulnerable, based on their Top-of-Wall (TOW) or Finish Floor elevation (FFEL) being within 0.5 foot of the projected flood elevation. It is recommended that improvements be designed to provide a minimum of two feet freeboard. Table 10-5. Recommended Flood Control Improvements Facility Name Facility Plan Proposed Status TOW / FFEL 100 YR WSEL Above/ (Below) Proposed Improvement Wet Weather EQ Pond Upgrade / Rehab 131.7 ft 132.3 ft (0.6)ft Regrade berm around pond before planned relining project EQ Pond Control Structure Upgrade / Rehab 131.7 ft 133.1 ft (1.4)ft Concrete wall to connect to berm MCC-C (EQ Pond) Maintain 131.7 ft 133.1 ft (1.4)ft 3 ft Perimeter wall, steps, conduit seal, sump pump Bar Screens Upgrade / Rehab 130.5 ft 131.3 ft (0.8)ft Raise Steel Curb by 18IN. Replaces lower section of handrail Influent Pumping Maintain 130.5 ft 131.3 ft (0.8)ft Raise Concrete Curb MCC-A Building (Headworks) Maintain 130.0 ft 130.9 ft (0.9)ft 2 ft Perimeter wall, steps, conduit seal, sump pump Primary Clarifiers Maintain 130.7 ft 131.3 ft (0.5)ft Raise Concrete Curb Primary Effluent Diversion Box Maintain 130.5 ft 131.3 ft (0.8)ft Raise Concrete Curb Aeration Basins (existing) Maintain 130.0 ft 131.3 ft (1.3)ft Raise Concrete Curb Spiral Energy Dissipator Maintain 126.3 ft 126.8 ft (0.5)ft Raise Concrete Curb Cooling Towers Expand 125.5 ft 126.8 ft (1.2)ft Flood Wall/Footing & Stair (2) (a) WSEL – Water Surface Elevation Direct access to individual facilities may be difficult during the peak of the flooding event. Site improvements designed to ensure physical access such as elevated roadways, also create barriers to the flow and could affect upstream flood elevations. Instead, it is recommended that the facilities be designed to maintain necessary operational control through automation and the SCADA system. WRRF Facility Additional Upgrades Page 10-20 10.5.4. Other Stormwater Management Considerations Additional considerations were identified during the stormwater management planning process. These considerations are summarized briefly below. Additional information is included in Appendix L, TM No. 10.1 – Infrastructure Planning, Stormwater. Protect Outfall during High Creek Flows.. The outfalls should be protected by flap gates preventing Creek water from backing into the bioswale basins. If the interior drainage system cannot drain to the creek, flooding within the WRRF may occur. Existing drainage outfall elevations should be compared against San Luis Obispo Creek water surface elevation profiles to determine if outfalls are set at the proper elevation to allow for maximum discharge during large creek flood events. This analysis should also be conducted to properly set new drainage outfalls elevations as well. Identify Existing Underground Utilities. It is important to identify where underground existing utilities are to design LID facilities properly. Designers will need to ensure that bioswales are draining properly and not draining out through pipeline gravel conduits. Collect Soils Percolation Rate Data. Percolation testing of existing soil at proposed LID improvements locations is required to compute accurate infiltration rates for design. Protect Site during Construction. Construction BMPs are critical to protect bioretention swales from sediment buildup and to allow plants to establish. Increased Operations and Maintenance. O&M services will increase to maintain the constructed LID facilities. At a minimum, annual removal of collected sediment and debris is necessary. Collected sediment can reduce the infiltration rate of infiltration/bioswales. Long–term maintenance will require full replacement of materials after an unknown number of years. Irrigation Required During Plant Establishment. Irrigation will be required to establish plants for one to two years. In addition to the considerations above, it is further recommended that the City take the following next steps to provide flood protection at the WRRF: 1. Verify the HEC-RAS model has been reviewed, approved, and accepted by the City’s hydraulic engineer. It is currently assumed that this model satisfies FEMA’s technical review standards. 2. Pursue a Conditional Letter of Map Revision (CLOMR) and/or Letter of Map Revision (LOMR) for large changes to FEMA’s Flood Insurance Rate Map. 3. Construct all new infrastructure with adequate freeboard above the 100-year water surface elevation to prevent inundation. 10.6. Renewable Energy As previously described, the WRRF receives electricity from PG&E as well as natural gas from Southern California Gas Company. As part of the WRRF Energy Efficiency Project, the City recently installed a new cogeneration system. The 150 kW cogeneration system is an internal combustion engine that will produce electricity from digester gas. The waste heat will then be used to heat the digesters. The improvements proposed in this Facilities Plan will increase the plant’s electrical usage by 30 percent, to approximately 2,600 kWh per MG treated. Considering an average annual flow of 6.1 mgd, WRRF Facility Additional Upgrades Page 10-21 this results in an average annual energy usage of 5,800 MWh per year. With rising electricity costs and increasing electrical usage, additional renewable energy generation opportunities were considered. Three renewable energy generation opportunities were evaluated, including solar photovoltaic (PV), wind power, and micro-hydropower. Appendix F, TM No. 6 – Renewable Energy, contains the detailed analysis that was performed as well as the recommendations. Based on the results of the renewable energy assessment, solar PV projects are economically viable. Due to declining solar PV costs and increasing PG&E rates, solar PV is expected to remain economical in the future, but the life cycle cost estimates should be revisited at the time of construction to verify project economics. As shown on the site plan presented in Section 12, solar PV could be implemented on the following facilities: Water Resource Center (new structure) Carport over Guest Parking (new structure) Carport over Employee Parking (new structure) Maintenance Shop (new structure) Blower Building (new structure) Dewatering Building (existing structure) Learning Center (existing structure) Plant Electrical Building (existing structure) Recycled Water Clearwell (existing structure) Wind power and micro-hydro are less favorable than solar PV and do not appear to provide meaningful energy generation potential to offset WRRF electricity costs. WRRF Facility Additional Upgrades Page 10-22 Page intentionally blank. 11. Building Programming Page 11-1 11. Building Programming The WRRF Project presents an opportunity to reinforce and support the collaborative culture of the facility staff, and create an asset for the community. The Water Resource Center and Learning Center will support the collaborative culture of the staff and engage and educate the community on the water cycle, including wastewater treatment. A series of stakeholder interviews and a community workshop were held to communicate the scope and goals of the WRRF Project and better understand the concerns and preferences of interested parties and the ratepayers. Through these outreach activities, community members have expressed their support for a learning center and/or elements at the WRRF. Some members of the community expressed that the learning center be integrated with and accessible from the Bob Jones bike trail. Refer to Appendix U, Community Workshop Summary, for additional information related to the concerns and preferences of project stakeholders. Interviews were also conducted with City staff, including: Operators, Water Quality Laboratory Technicians, Maintenance Technicians, the WWRF Supervisor, the Chief Plant Operator, the Lead Maintenance Technician, the Deputy Director - Wastewater, and the Utilities Department Director. The purpose of the interviews was to review the existing and future operational and programmatic needs of the staff. The interviews allowed the WRRF staff to develop the desired components for the water quality laboratory, operations center, maintenance shop, management offices, support spaces, and the learning center. The City is also considering co-locating facilities for the collection system and distribution system staff at the new WRRF maintenance facility; however, the scope of the collection system and distribution system facilities has not been included in the Facilities Plan. The City is exploring these options and opportunities in parallel with the WRRF Project and plans to conduct a separate needs assessment and programming with collection system and distribution system staff that could be incorporated with the program for the WRRF Program. Based on the results of the needs assessment for the WRRF Project, the WRRF Project will include two new buildings and retrofits to the existing administration building to transform it into a learning center. A summary of the building programming needs is provided in Table 11-1 and further information for each building component is provided in Appendix T, Building Program. The existing major buildings at the WRRF consist of the operations building, administration building (water quality laboratory and management offices), mechanical shop, welding shop, and switchgear building. The Water Resource Center will house the management, operations, and water quality laboratory staff, as well as a welcome lobby for visitors. The Learning Center will include interactive visitor spaces, a teaching lab, and other public amenities. The new maintenance shop will include new work spaces for maintenance staff as well as a machine shop and welding shop. WRRF Facility Building Programming Page 11-2 The proposed locations of the Water Resource Center and the Maintenance Shop are illustrated on Figure 12-2 in the following Section. A rendering of the Water Resource Center is presented in Figure 11-1 and a site plan of the Water Resource Center is included Figure 11-2. Table 11-1. Summary of Building Programming Needs Building Building Component Total Size (sq. ft.) Water Resource Center Management Offices 1,555 Water Quality Lab 2,390 Operations Center 837 Support Spaces (Conference rooms, locker rooms, restrooms, etc.) 7,382 Subtotal Water Resource Center 12,164 Maintenance Shop Office and workstations 486 Maintenance Shop 5,508 Subtotal Mechanical Shop 5,994 Total New Buildings 18,158 Learning Center (Retrofitted Administration Building) 3,140 Pa g e 1 1 - 3 Figure 11-1. Rendering of Water Resource Center WR R F F a c i l i t y Bu i l d i n g P r o g r a m m i n g Pa g e 1 1 - 4 Pa g e i n t e n t i o n a l l y b l a n k . WR R F F a c i l i t y Bu i l d i n g P r o g r a m m i n g Pa g e 1 1 - 5 Figure 11-2. Water Resource Center Site Plan WR R F F a c i l i t y Bu i l d i n g P r o g r a m m i n g Pa g e 1 1 - 6 Pa g e i n t e n t i o n a l l y b l a n k . 12. Site Planning Page 12-1 12. Site Planning This section presents the proposed site plan for the WRRF upgrades, including landscaping concepts and public amenities, and identifies existing facilities that will be demolished as well as site access and security at the plant. 12.1. Facilities to be Demolished Figure 12-1 presents the existing structures and facilities that will be demolished under the WRRF upgrades. For facilities that have been decommissioned, such as Biofilter 1 and 2, demolition can occur at any time. Other facilities, such as Biofilter 3, need to remain operational until new facilities are constructed. As shown on Figure 12-1, the decommissioned chlorine contact tank and associated facilities at the south end of the plant will also be demolished. Section 13 addresses construction sequencing to address this issue. 12.2. Locations for New Treatment Facilities As described in Section 3.4, a site planning study was performed to identify land within and adjacent to the WRRF that could be utilized for the upgrades. As was described in Section 3.4, the Prado Day Center Lot and Gun Range as well as the materials storage yard are available for use. In addition, there are plans to construct an overpass of Highway 101 at Prado Road. The overpass will be located northwest of the plant site and will result in the plant access road being relocated to the east of its current location. These opportunities and constraints were considered in the development of the site plan. For additional information, refer to Appendix C, TM No. 3 – Site Planning. Figure 12-2 presents the proposed site plan for the WRRF upgrades. Siting of the process units was developed to minimize relocation of existing pipelines and utilities and to locate processes in close proximity to upstream and downstream processes, where feasible. As shown the Water Resource Center, which will house the operations staff and laboratory facilities, is located at the plant entrance where the Prado Day Center is currently located. The research area, maintenance building, and future BMX bike park (public amenities) were sited after treatment structures were sited, and with input from the City and WRRF staff. As the City moves forward with design of the upgrades, consideration should be given to reserve land within the plant site for future upgrades that may be needed to address future regulations. Figure 12-3 illustrates a preliminary plan for landscaping at the WRRF, including new vegetation and wetlands along the Prado Road frontage, and vegetation throughout the perimeter of the plant. Figure 12-4 provides additional information related to the public amenities, including the learning center area, the wetland demonstration gardens, and the staff and public patio spaces. Figure 12-4 also identifies a potential route for typical public tours of the WRRF with specific stopping points near the equalization pond, headworks, the abandoned secondary clarifier, aeration basins, final clarifiers, filtration and cooling, and disinfection. WRRF Facility Site Planning Page 12-2 12.3. Access and Security The following subsections describe concepts for perimeter access, vehicle access, intrusion detection, building access, interior sensitive areas, remote buildings, and security system integration. 12.3.1. Perimeter Access The WRRF currently has a chain-link fence surrounding the plant and the fencing should be maintained. Because areas and access to the plant will be modified, the chain link fence will need to be extended and modified in select locations. Figure 12-2 provides the updated site plan and includes the perimeter fencing that is recommended. In areas that have high visibility with the public, a more decorative fence such as one made by the Omega Corporation may be desired. This Omega style of fence is manufactured with a climb and cut resistant fabric to provide adequate security, while providing a non-institutional look. For areas that do not have high visibility to the public, an eight-foot chain-link fence with a 12-inch high, vertically- mounted, barbed-wire top rigger is recommended. The condition of the existing chain link fence along the entire perimeter of the WRRF is unknown. For the purposes of this facility plan, it is assumed that new fencing is needed along the northern WRRF border. At this location, Omega style fence was assumed. Along the remaining plant perimeter, it is assumed that the existing chain link fence is in fair condition and replacement at select locations (approximately 25 percent) was needed. 12.3.2. Vehicle Access Currently visitors, employees, and delivery trucks enter the plant from one of two roads. The first access road is on the west side of the Prado Day Center; the second access road is to the west of the existing equalization pond. In the future, a single access road will be provided from Prado Road, as shown in Figure 12-2. The access road will be located to the west of the equalization pond. For security, it is recommended that all vehicle access portals into the WRRF be equipped with motorized gates. Employee vehicles will be able to enter the WRRF using ingress and egress stanchions equipped with proximity card readers, intercom and video camera. The card reader should be a HID Max Prox or equivalent and provide a read range of approximately 30 inches. This allows the vehicles of different heights to utilize a single reader. WRRF visitor traffic that requires vehicle entry into the plant (e.g., chemical delivery trucks, etc.) would enter the WRRF after checking in with administrative staff. Vehicle gates during business hours would be monitored to control visitor and delivery traffic in and out of the facility. Assigned personnel would verify all non-employee business with administrative staff prior to admittance, issue visitor ID passes, control gate operations and monitor facility security systems. Visitors to the WRRF that do not require vehicle access inside the plant would be directed to the visitor parking area by signage. To minimize visitor traffic inside the plant, the visitor parking area should be located outside the plant perimeter fence, near the operations building (refer to Figures 12-2 and 12-3). Visitors would check in with administrative staff prior to admittance, and then would be issued a visitor ID pass. WR R F F a c i l i t y Si t e P l a n n i n g Pa g e 1 2 - 4 Pa g e i n t e n t i o n a l l y b l a n k . WR R F F a c i l i t y Si t e P l a n n i n g Pa g e 1 2 - 6 Pa g e i n t e n t i o n a l l y b l a n k . CITY OF SAN LUIS OBISPO | WATER RESOURCE RECOVERY FACILITY SITE PLAN JUNE 5, 2015 0’80’160’240’40’320’ FLOOD PROTECTION BERM AND NEW EQ POND LINER EQ POND EQ RETURN FLOW PUMP STATION WATER RESOURCE CENTER WITH SOLAR PANELS STAFF ENTRY GATE FUTURE BMX BIKE PARK RESERVE FOR FUTURE UPGRADES/CAL POLY RESEARCH CENTER POSSIBLE FUTURE RV WASTE RECEIVING FACILITY NEW CITY CORP YARD ENTRANCE SOLAR PANELS OVER PARKING PLANT ENTRY GATE ABANDONED CLARIFIER (FUTURE DIURNAL FLOW EQ BASIN IF NEEDED) NEW MAINTENANCE SHOP WITH SOLAR PANELS AERATION BLOWER BUILDING WITH SOLAR PANELS AERATION BASIN EFFLUENT FLOW SPLIT STRUCTURE FINAL CLARIFIER 4 AERATION BASINS 1&2 AERATION BASIN 3 AERATION BASIN 4 AERATION BASIN 5 RELOCATED MCC’S MgOH2STORAGE METHANOL STORAGE SLUDGE DRYING BEDS FILTERS 5 & 6 FILTERS 1,2,3 & 4 LEARNING CENTER WITH SOLAR PANELS ELECTRICAL BUILDING WITH SOLAR PANELS COOLING TOWERS FLOW EQUALIZATION BASINS EFFLUENT CHILLER PLANT THICKENING 1,000 KW STANDBY GENERATOR 2,000 KW STANDBY GENERATOR SOLIDS BLEND TANK PRIMARY SLUDGE PUMP STATION NEW DIGESTER 2 COGENERATION SIDESTREAM TREATMENT FUTURE FOG RECEIVING STATION SIDESTREAM TREATMENT EQUALIZATION EXISTING BIOSWALE FERROUS CHLORIDE STORAGE SOLAR PANELS ON DEWATERING BUILDING INFLUENT PUMP STATION, SCREENING, AND NEW FLOW METERING RECYCLED WATER TANK WITH SOLAR PANELS NEW GRAVEL ACCESS ROAD AND GATE BIKE STORAGE VACUUM TRUCK CLEANOUT FACILITY FACILITY VEHICLE PARKING STAFF PATIO CONFERENCE ROOM PATIO STAFF PARKING WITH SOLAR PANELS CAMPUS ENTRY DIRECTIONAL SIGNAGE WETLAND WETLAND & BOARDWALK/ EDUCATIONAL DEMONSTRATION GARDEN BOB JONES TRAIL PR A D O R O A D VISITOR PARKING HWY 101 CITY TRANSIT FACILITY ODOR CONTROL BIOFILTER FINAL CLARIFIER 5 FINAL CLARIFIER 6 FINAL CLARIFIER 7 RAS PUMPING PRIMARY CLARIFIER 2 PRIMARY CLARIFIER 1 UV DISINFECTION WR R F F a c i l i t y Si t e P l a n n i n g Pa g e 1 2 - 8 Pa g e i n t e n t i o n a l l y b l a n k . CITY OF SAN LUIS OBISPO | WATER RESOURCE RECOVERY FACILITY SITE PLAN JUNE 5, 2015 0’80’160’240’40’320’ FLOOD PROTECTION BERM AND NEW EQ POND LINER EQ POND EQ RETURN FLOW PUMP STATION WATER RESOURCE CENTER WITH SOLAR PANELS STAFF ENTRY GATE FUTURE BMX BIKE PARK RESERVE FOR FUTURE UPGRADES/CAL POLY RESEARCH CENTER POSSIBLE FUTURE RV WASTE RECEIVING FACILITY NEW CITY CORP YARD ENTRANCE SOLAR PANELS OVER PARKING PLANT ENTRY GATE ABANDONED CLARIFIER (FUTURE DIURNAL FLOW EQ BASIN IF NEEDED) NEW MAINTENANCE SHOP WITH SOLAR PANELS AERATION BLOWER BUILDING WITH SOLAR PANELS AERATION BASIN EFFLUENT FLOW SPLIT STRUCTURE FINAL CLARIFIER 4 AERATION BASINS 1&2 AERATION BASIN 3 AERATION BASIN 4 AERATION BASIN 5 RELOCATED MCC’S MgOH2STORAGE METHANOL STORAGE SLUDGE DRYING BEDS FILTERS 5 & 6 FILTERS 1,2,3 & 4 LEARNING CENTER WITH SOLAR PANELS ELECTRICAL BUILDING WITH SOLAR PANELS COOLING TOWERS FLOW EQUALIZATION BASINS EFFLUENT CHILLER PLANT THICKENING 1,000 KW STANDBY GENERATOR 2,000 KW STANDBY GENERATOR SOLIDS BLEND TANK PRIMARY SLUDGE PUMP STATION NEW DIGESTER 2 COGENERATION SIDESTREAM TREATMENT FUTURE FOG RECEIVING STATION SIDESTREAM TREATMENT EQUALIZATION EXISTING BIOSWALE FERROUS CHLORIDE STORAGE SOLAR PANELS ON DEWATERING BUILDING INFLUENT PUMP STATION, SCREENING, AND NEW FLOW METERING RECYCLED WATER TANK WITH SOLAR PANELS NEW GRAVEL ACCESS ROAD AND GATE BIKE STORAGE VACUUM TRUCK CLEANOUT FACILITY FACILITY VEHICLE PARKING STAFF PATIO CONFERENCE ROOM PATIO STAFF PARKING WITH SOLAR PANELS CAMPUS ENTRY DIRECTIONAL SIGNAGE WETLAND WETLAND & BOARDWALK/ EDUCATIONAL DEMONSTRATION GARDEN BOB JONES TRAIL PR A D O R O A D VISITOR PARKING HWY 101 CITY TRANSIT FACILITY ODOR CONTROL BIOFILTER FINAL CLARIFIER 5 FINAL CLARIFIER 6 FINAL CLARIFIER 7 RAS PUMPING PRIMARY CLARIFIER 2 PRIMARY CLARIFIER 1 UV DISINFECTION PUBLIC TOUR ROUTE/STOPS1 1 2 3 4 5 6 7 POTENTIAL BIKE TOUR TO OUTFALL 7-POINT WALKING TOUR LEARNING CENTER AREA The outdoor space connected to the Interpretive Center will provide a group picnic area and intimate amphitheater amongst the trees. This space will allow for community groups of all sorts to gather, learn and lunch in association with a WRRF tour, as well as a great space to congregate on select Open House education days, during which the public can access the Interpretive Center via the Bob Jones Trail. 1 2 2 3 WETLAND DEMONSTRATION GARDENS As part of the public space surrounding the Operations Building/Welcome Center, a wetland demonstration garden with a circulating boardwalk and educational signage will provide opportunities for the public to learn about the WRRF systems and it’s relationship to the natural surrounding habitat. These gardens will also be the public face of the WRRF, being clearly visible from Prado Road. STAFF & PUBLIC PATIO SPACES The main conference room inside the Operations building will open up directly onto an outdoor patio, providing a flexible gathering space for talks and events, immediately adjacent to the boardwalk and wetland. The WRRF staff will also have a dedicated private patio space, sectioned off from the public patio by a divider that can be open in the event the WRRF staff should want to expand the space for a larger gathering. 3 2 1 WR R F F a c i l i t y Si t e P l a n n i n g Pa g e 1 2 - 1 0 Pa g e i n t e n t i o n a l l y b l a n k . WRRF Facility Site Planning Page 12-11 12.3.3. Intrusion Detection Immediately contiguous to the inside of the fence line, the City should consider designating an area free of obstructions called a clear zone. This clear zone provides an area of surveillance of the entire WRRF perimeter. It is further recommended that the City consider pole or parapet mounted pan, tilt, and zoom (PTZ) equipped color video cameras to automatically assess any intrusions of the clear zone. Lighting for the cameras could be incorporated on the mounting brackets so that they pan and tilt with the cameras. This ensures that the required lighting level would be maintained no matter where the camera is directed. Infrared and/or motion sensing lighting should be considered to reduce light pollution. The interior roads and building walls would be lit for security and video surveillance. Landscaping planted around the buildings should be the low-lying type to prevent hiding areas. Trees around the facility perimeter should be limbed up 10 feet from the ground to facilitate surveillance and located away from fence lines and building walls to prevent the trees from becoming an aid to climbing and/or an obstruction to video surveillance fields of view. 12.3.4. Building Access Door position switches are recommended to monitor all entrances to the various buildings. Proximity card readers should be provided on specific doors based on the door’s function and frequency of use. All offices and interior spaces that are designed with windows should be equipped with glass break detection. The intrusion detection and access control alarms should be pushed out to cell, radio or other selected communication devices determined during the design phase. Depending on the system selected, the system may have visual/audio capabilities. Visitor access to the new operations offices should be restricted to the main lobby by physical barriers (e.g., doors or gates secured with key card access). The lobby should also be equipped with video surveillance. Doors leading to private space should be controlled by card readers and existing key locks should be replaced with key card access or similar. The intent would be to preclude visitor access to the employee circulation of the facility. 12.3.5. Interior Sensitive Areas Designated areas within the facility, such as server room, SCADA, the chemical storage areas and staff workstations should be compartmentalized to add an extra level of security to limit access to these security sensitive locations. Access control for these sensitive areas should, if feasible be controlled by technology utilizing proximity cards. The chemical delivery sites as well as the digester handling areas should also be provided with a closed circuit video camera triggered by a motion detector to monitor and record the activity in this area. A duress alarm could be provided for employee safety. 12.3.6. Remote Buildings Currently, there are no planned remote buildings at the WRRF. Should remote facilities become necessary in the future, the remote buildings could be provided with access control readers and an intrusion detection system. The intrusion detection system would include door position switches as well as dual technology (passive infrared/microwave) motion detectors. A limited number of video cameras would be added to these sites in strategic locations for video surveillance to assess any intrusion. Lighting to support the cameras for nighttime operations must also be provided. WRRF Facility Site Planning Page 12-12 12.3.7. Security System Integration All security related systems for the WRRF should be integrated into a security monitoring system. Video surveillance, building perimeter and microwave intrusion sensors, an intercom substation at the employee entrance and access control systems should interface with the current system to provide seamless monitoring and operation of all devices. The cameras that monitor critical assets/areas should be displayed for real time monitoring. The video surveillance system will be interfaced with the card access control/intrusion detection system for automatic camera "call up" at the security monitoring station during an event. All surveillance cameras should be recorded and available for forensic review including video clips "tagged" with an associated event. Access control workstations would be provided at the new operations building to monitor the security systems locally. 13. Project Implementation Page 13-1 13. Project Implementation This section describes permitting and construction sequencing considerations for the WRRF Project, presents a preliminary implementation schedule, and presents the opinion of probable cost for the WRRF Project and associated O&M costs, as well as recommended next steps. 13.1. Permitting Considerations The following subsection provides an overview of the permitting strategy for CEQA specific to the WRRF project. The CEQA strategy considers the additional requirements needed to be eligible for State Revolving Fund (SRF) loans. A list of other permits and approvals necessary for the upgrades is also provided in this section. 13.1.1. Environmental Permit Strategy As described in the City’s Program Environmental Impact Report (EIR) for the City’s Land Use and Circulation Elements Update (LUCE), an upgrade of the WRRF is planned in response to stricter discharge limits required by the CCRWQCB, to increase capacity to serve the City’s population at General Plan buildout, and to replace existing aged facilities at the end of their service life. The proposed improvements and upgrades at the WRRF will require compliance with the California Environmental Quality Act (CEQA). The City plans to utilize the Clean Water State Revolving Fund (CWSRF) Program to finance the proposed improvements and upgrades to the WRRF. The CWSRF Program is partially funded by the USEPA, and as such, is subject to federal environmental regulations as well as additional “CEQA-Plus” environmental documentation and review. All applicants seeking CWSRF financing must comply with both CEQA and federal cross-cutting regulations, including the Clean Air Act (CAA), Endangered Species Act (ESA), and the National Historic Preservation Act (NHPA). Based on the current understanding of the project and the project area, review of the City’s LUCE EIR and the proposed site plan, and the potential presence of sensitive receptors, biological resources, and cultural resources, the proposed improvements may result in potential temporary (construction) and/or permanent (operational) impacts that could require the preparation of an EIR. In order to initiate the CEQA compliance process, an Initial Study (IS) Checklist should be prepared for the WRRF improvements project, per the “CEQA-Plus” guidelines. The IS Checklist will assist the City in determining if the proposed project may have a significant impact on the environment and to what extent. If no significant impacts are identified, then the IS will support the preparation and adoption of a Mitigated Negative Declaration (MND). If potentially significant impacts are identified in the IS, then an EIR will need to be prepared; however, the IS Checklist will help to focus the analysis to be provided in the EIR. WRRF Facility Project Implementation Page 13-2 13.1.2. Project Permits In addition to CEQA, the project may have to comply with other Federal, State, and Local regulations and ordinances. The regulations and ordinances listed below represent a preliminary assessment of permitting requirements, which should be refined following finalization of project design and preparation of a detailed project description. Clean Water Act (CWA), Section 404. Permit from the U.S. Army Corps of Engineers for discharges of dredged or fill material into waters of the United States, including wetlands. California ESA. Consultation with the California Department of Fish and Wildlife, and take authorization as applicable. California Native American Heritage Commission (NAHC). Consultation and coordination with the NAHC. CWA, Section 401. Water Quality Certification from CCRWQCB. CWA, Section 402. NPDES General Permit from the CCRWQCB for general construction activities and General Permit for Discharges with Low Threat to Water Quality. FEMA CLOMR/LOMR for flood control improvements. Caltrans Encroachment Permit. San Luis Obispo County Air Pollution Control District. Authority to Construct and Permit to Operate. City and County. Building, grading, and encroachment permits, as appropriate. PG&E. Approval for new power infrastructure to the site. 13.2. Construction Sequencing Considerations A conceptual level construction sequencing plan was developed for the improvements described in Sections 7, 10 and 11. The sequencing plan addresses priorities with respect to meeting the schedule requirements in the TSO and to address facilities that need to be brought online prior to demolition of other facilities. Four construction stages are anticipated, as presented in Table 13-1. Figure 13-1 further illustrates the facilities included in each stage. One consideration in the sequencing plan relates to UV disinfection, which needs to be operational by November 30, 2019 per the TSO (TSO R3-2014-0036). Currently, there are no UVT data during blending events and the filters are not operated during blending due to the high solids load. Therefore, it is difficult to determine the feasibility of operating UV disinfection with unfiltered, blended water. As a result, construction of both UV disinfection and filtration is included in Stage 1 with the assumption that at least two chlorine contact basins will remain in service until Stage 2 (secondary treatment upgrades) is complete and operational. This would provide the City with the ability to rely on chlorine disinfection during blending events, until the secondary treatment upgrades are completed. Relying on chlorine disinfection during blending events would facilitate compliance with the coliform limitations, but could present challenges with meeting the DBP and/or NDMA limitations. WR R F F a c i l i t y Pr o j e c t I m p l e m e n t a t i o n Pa g e 1 3 - 4 Pa g e i n t e n t i o n a l l y b l a n k . WRRF Facility Project Implementation Page 13-5 Table 13-1. Construction Sequencing Stages Stage Demolition Construction Stage 1 • Partial demolition of 1 Chlorine Contact Basin • Biofilter 1 and 2 • Cal Poly Research Area • Filter Expansion (including filter feed pumps) • Cooling Towers • Effluent Chiller • UV Disinfection • Standby Generator for Reuse area of plant Stage 2 • Biofilter 3 • Chlorine Contact Basins 2 through 4 • Primary Effluent Diversion Box Retrofits • Aeration Basins • Aeration Blower Building and Blowers • New Final Clarifiers • Chemical Feed • Standby Generator for Main Plant and MCC Relocation • Paving of Internal Plant Roads Stage 3 • Primary Sludge Pump Station • Control Building (former) • Prado Day Center • Digester 3 • Sludge Drying Beds • Odor Control • Primary Weir and Sludge/Scum Pump Replacement • Anaerobic Digester • Solids Thickening • Paving / New Entry to Plant • Vacuum Truck Cleanout Facility • Water Resource Center • Maintenance Facility Stage 4 • Supernatant Lagoon • Decommissioned Chlorine Contact Basins South of WRRF • Equalization Pond • Equalization Pond Return Pumping Improvements • Solids Dewatering • Sidestream Treatment • Learning Center • Gardens / Public Center As the City continues to move forward with design procurement, it is recommended that discussions with the CCRWQCB continue, to determine if the final THM permit limitations can be extended. The construction sequencing plan should also be refined to determine if there is flexibility to move the secondary treatment upgrades into Stage 1 followed by filtration and UV disinfection in Stage 2. This would avoid staff having to operate two different disinfection systems, as well as potential issues with permit compliance. 13.3. Implementation Schedule A preliminary implementation schedule is provided in Figure 13-2. The schedule assumes that the construction contract is awarded in October 2017. The construction duration is estimated to be just over three years and assumes that equipment is not pre-purchased by the City. As the City proceeds with the SRF loan application and design procurement, and selects project delivery options, the implementation schedule should be revisited and refined accordingly. Particularly if the City chooses to preselect and/or pre-purchase any equipment, the construction schedule may be updated to reflect modifications to the schedule. Also, WRRF Facility Project Implementation Page 13-6 detailed construction sequencing will be needed as the project moves forward to address seasonal outages of processes. Figure 13-2. Implementation Schedule 13.4. Opinion of Probable Cost Table 13-2 presents a summary of the opinion of probable costs for the WRRF upgrades. Appendix V – Cost Estimates, provides the detailed construction cost estimates that were developed, by process area as well as a summary of key assumptions that were made for cost estimating purposes. The construction costs are presented in 2014 dollars and were then escalated to the midpoint of construction (2019) using a three percent escalation rate. Major assumptions associated with the development of the opinion of probable project costs include: A 30 percent construction contingency was applied on Divisions 2 through 16. Division 1 costs were applied at 15 percent of Divisions 2 through 16. Specialty foundations (e.g., pile foundations) are not included in the estimate. Seismic and structural upgrades of existing structures have not been included. Tertiary filtration costs assume GMF and use of the existing backwash facilities with the new filters. Costs do not include relocation of the Cal Poly Research Area or the Prado Day Center. Demolition of these facilities is included. WRRF Facility Project Implementation Page 13-7 Table 13-2. Opinion of Probable Construction Costs Process Area Opinion of Probable Costs Flow Equalization $1,501,000 Headworks Odor Control $788,000 Primary Clarifiers $2,879,000 Aeration Basins $14,121,000 Final Clarifiers $4,272,000 Tertiary Filtration and Cooling $6,163,000 UV Disinfection $7,485,000 Renewable Energy Generation $1,066,000 Solids (Digestion, Thickening, Dewatering) $6,759,000 Sidestream Treatment $3,642,000 Flood Protection $1,500,000 General Site $11,090,000 Water Resource Center $4,800,000 Learning Center and Public Amenities $1,505,000 Maintenance Building $1,953,000 Total Construction Costs in 2014 Dollars(a) $69,524,000 Allowance for Design, Environmental, Permitting, and Construction Management(b) $20,857,000 Total Project Cost in 2014 Dollars $90,381,000 Total Project Cost in 2019 Dollars(c) $104,777,000 (a) Total construction costs include 30 percent construction contingency. (b) Estimated at 30 percent of construction. (c) Escalated using three percent per year. 13.5. O&M Costs Some aspects of the WRRF operations & maintenance (O&M) can be expected to increase with increasing loading on the facility in the future. O&M costs can be attributed to some basic categories including, power, chemical, equipment consumables, disposal fees and operator labor. Table 13-3 provides a summary of estimated chemical, power, and consumables expenses by major process area, based on the buildout operating condition of 5.4 mgd ADWF. As summarized in Table 13-3, the estimated annual O&M cost, at buildout flows, is estimated to be approximately $1.6 million, of which approximately 65 percent is attributed to power. WRRF Facility Project Implementation Page 13-8 Table 13-3. Estimated O&M Costs for Buildout Operating Condition Process Annual Energy Annual Chemical Annual Consum- ables Annual Total ($/yr) Usage (MWh/yr) Cost ($/yr)(a) Usage (/yr) Cost ($/yr) Flow Equalization (Wet Weather) 3 $1,000 14,000 gal $51,000(b) - $52,000 Headworks & Influent Pumping 644 $104,000 - - - $104,000 Primary Clarifiers and Sludge Pumping 41 $7,000 - - - $7,000 Secondary Treatment 2,500 $400,000 91,000 gal $250,000(c) - $650,000 Tertiary Filtration & Influent Pumping 360 $58,000 - - - $58,000 Cooling 1,800 $288,000 10,000 gal $48,000(d) - $336,000 Disinfection 970 $156,000 - - $190,000(e) $346,000 Solids Thickening 125 $20,000 47,960 lbs $39,000(f) - $59,000 Anaerobic Digesters 2 $1,000 - - $2,000 $3,000 Biosolids Dewatering 50 $8,000 25,300 lbs $21,000(f) - $29,000 Sidestream Treatment 401 $65,000 - - - $65,000 Odor Control 657 $106,000 - - - $106,000 Building Energy and Miscellaneous Loads 345(g) $55,000 - - - $55,000 Cogeneration (1,100) ($176,000) - - - ($176,000) Photovoltaic (416) ($67,000) - - - ($67,000) Total(h) 6,382 $1,026,000 - $409,000 $192,000 $1,627,000 (a) Power costs are estimated at $0.16/kWh to represent an annual average, including those months when higher tier rates are triggered. (b) Based on ferric chloride at $3.60/gal. (c) Based on magnesium hydroxide at $2.75/gal. (d) Assumes that Peracetic Acid is used for fouling, at $4.80/gal. (e) Includes replacement of lamps, ballasts, sleeves, wipers, and sensors. (f) Based on polymer at $0.80/lb. (g) Estimated at 5 percent of plant load. (h) Does not include pumping for recycled water, disposal costs, or labor. WRRF Facility Project Implementation Page 13-9 13.6. Next Steps The next steps in the implementation of the WRRF upgrade include the following: Continue additional sampling to determine raw influent flows and loads, as well as information required to design the nutrient removal technologies: MLE or High Rate A/B and sidestream treatment. A summary is provided in Table 13-4. This list is intended to verify the raw influent flows and loads, confirm the primary clarifier performance, and assist with carbon management decision making at the WRRF. Once the designer is selected, the additional sampling request can be augmented to provide any necessary supplemental information for designing the facilities. Conduct UVT testing to support development of design criteria for the UV disinfection system. The WRRF has collected UVT data from mid January to mid May 2015. Additional UVT monitoring is recommended to cover the entire wet weather season, typically from October to April, in accordance with the industry accepted National Water Research Institute (NWRI) UV guidelines. Evaluate alternative disinfectants to sodium hypochlorite (e.g., peracetic acid, etc.) for maintaining unit processes throughout the plant, such as the filter towers, nitrified effluent box, and cooling towers. Complete the bench testing evaluation for the High Rate A/B process for secondary treatment as an alternative to MLE. If the outcome is positive, conduct additional research (e.g., visit a full scale plant, conduct pilot testing, etc.) and consider adjusting recommended facilities to include in predesign and design. Conduct structural analysis of concrete tanks constructed before 1985, including the existing primaries. Conduct study to re-rate the existing filters and confirm recommended filtration technology for expansion, if an alternate media is desired. Continue flow monitoring analysis to support hydrograph simulation and refinement of flow projections. Conduct sidestream treatment evaluation to select preferred deammonification technology. Conduct temperature monitoring to support development of design criteria for the cooling towers and chiller. Conduct site visits of operational facilities and talk with staff to assist with technology and equipment selection. Procure an environmental consultant and initiate environmental review. Procure a design consultant and initiate predesign. Complete the Recycled Water Facilities Planning Study and update recommendations if appropriate. WRRF Facility Project Implementation Page 13-10 Table 13-4. Continued Sampling Locations, Analyses and Basis for the Sampling Sample Location Analyses Basis/Reason Raw Influent (at influent composite sampler or upstream of barscreens) Ammonia, Alkalinity, BOD, Soluble BOD, COD, Soluble COD, TSS, and TKN • To verify TSS/BOD, TSS/COD and Ammonia/TKN ratios for current and projected loads • To better understand seasonal variation Primary Effluent Ammonia, BOD, Soluble BOD, COD, Soluble COD, TSS, and TKN • To confirm primary clarifier performance • Required for nutrient removal design • To better understand seasonal variation Lagoon Supernatant Ammonia, Nitrate, and Alkalinity • Required for nutrient removal design 14. References Page 14-1 14. References Asami, M.; Oya, M.; Kosaka, K. (2009) A nationwide survey of NDMA in raw and drinking water in Japan. Science of The Total Environment, 407(11):3540-3545. Brown and Caldwell (2011) Water Reclamation Facility Plan. Prepared for the City of San Luis Obispo Water Resource Recovery Facility, San Luis Obispo, CA. City of San Luis Obispo (2013) Water and Wastewater Impact Development Impact Fees. City of San Luis Obispo. San Luis Obispo, CA Falk, M.W., Reardon, D.J., Neethling, J.B., Clark, D.L., Pramanik, A. (2013) Striking the Balance between Nutrient Removal, Greenhouse Gas Emissions, Receiving Water Quality, and Costs. Wat. Environ. Res., 85(12):2307-2316. Fux, C and Siegrist, H. (2004) Nitrogen removal from sludge digester liquids by nitrification/denitrification or partial nitritation/anammox: environmental and economical considerations. Water Sci. Technology. 50(10):19-26. Gu, A.Z., et al. (2010) Protocol to evaluate alternative external carbon sources for denitrification at full-scale wastewater treatment plants, WERF research project NUTR1R06b. Horz, H.-P., Barbrook, A., Field, C.B., Bohannan, B.J.M. (2004) Ammonia-oxidizing bacteria respond to multifactorial global change. Proceedings of the Nat. Acad. Sci., 101(42):15136-15141. Kolpin, D.W., Furlong, E.T., Meyer, M.T., Thurman, E.M.; Zaugg, S.D.; Barber, L.B.; Buxton, H.T.(2002) Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S.streams, 1999-2000: a national reconnaissance. Environ. Sci. Technol., 36(6):1202- 1211. Metcalf and Eddy, Inc.; Tchobanoglous, G.; Burton, F.L.; Stensel, H.D.; (2013) Wastewater Engineering: Treatment and Resource Recovery. Published by McGraw-Hill Education – Europe and United States. Stalter, D.; Magdeburg, A.; Oehlmann, J. (2010) Comparative toxicity assessment of ozone and activated carbon treated sewage effluents using an in vivo test battery. Water Research, 44(8):2610-2620. V&A (2012) Sanitary Sewer Flow Monitoring and Inflow/Infiltration Study. Vader, J.S., van Ginkel, C.G., Sperling, F., de Jong, J., de Boer, W., de Graaf, J. S., van der Most, M., Stokman, P.G.W. (2000) Degradation of ethinyl estradiol by nitrifying activated sludge. Chemosphere 41(8): 1239-1243. WSC (2014) Site Planning Technical Memorandum (2014 Facility Plan). City of San Luis Obispo Water Resource Recovery Facility, San Luis Obispo, CA. WRRF Facility References Page 14-2 Zhang, L., De Schryver, P., De Gusseme, B., De Muynck, W., Boon, N., & Verstraete, W. (2008). Chemical and biological technologies for hydrogen sulfide emission control in sewer systems: a review. Water research, 42(1), 1-12. Water Resource Recovery Facility Facilities Plan City of San Luis Obispo San Luis Obispo, CA APPENDICES June2015 Appendices A. TM No.1 – Wastewater Characterization B. TM No.2 – System-Wide Conceptual Alternatives C. TM No.3 – Site Planning D. TM No.4 – Disinfection Study E. TM No.5 – Asset Planning and Rehabilitation F. TM No.6 – Renewable Energy Generation Study G. TM No.8 – Regulatory Compliance H. TM No.9 – Capacity Consideration I. TM No.9.1 – Influent and Effluent Flow Monitoring J. TM No.9.2 – Influent Hydrograph Simulation for the WRRF K. TM No. 9.3 – Wet Weather Flow Equalization L. TM No.10.1 – Infrastructure Planning, Stormwater M. TM No.10.2 – Infrastructure Planning, Electrical and I&C N. TM No 10.3 – Infrastructure Planning, Site Access and Security O. TM No 12 – Process Alternatives Analysis P. TM No. 13 – Filter Technology Evaluation Q. TM No. 14 – Cooling Technology Evaluation R. TM No. 15 – Additional Sampling S. TM No. 16 – High Rate A/B Bench Testing Protocol T. Building Program U. Community Workshop Summary V. Cost Estimates W. Value Engineering Comments and Responses Note: Some information presented in the technical memoranda included in the appendix may have been updated during the finalization of the Facilities Plan. Where there are discrepancies, the reader should rely on the information presented in the Final Facilities Plan. WRRF Project Appendices Page intentionally blank. Appendix A TM No. 1 - Wastewater Characterization Date: 5/14/2015 Prepared by: Mike Falk, PhD, PE; Irina Lukicheva, PhD Reviewed by: Holly Kennedy PE; Mallika Ramanathan, PE; Jeff Szytel, PE Project: WRRF Project SUBJECT: TM NO. 1 – WASTEWATER CHARACTERIZATION The purpose of this technical memorandum (TM) is to present the analysis of historical flows and loads and projected flows and loads for the City of San Luis Obispo (City) Water Resource Recovery Facility (WRRF). The results of this analysis, in conjunction with the new NPDES permit limits, will provide the basis for the process selection and design criteria for the WRRF Facilities Plan. Contents Introduction .............................................................................................................................. 3 Background .............................................................................................................................. 3 Averaging Periods .................................................................................................................................... 3 Previous Work .......................................................................................................................................... 5 Data Analysis ........................................................................................................................... 7 Historical Flows ......................................................................................................................................... 7 Historical Loads ........................................................................................................................................ 9 Approach ................................................................................................................................................ 13 Analysis Results .....................................................................................................................15 Historical Average Dry Weather Flow (ADWF) and Loads ..................................................................... 15 Peaking Factors ...................................................................................................................................... 16 Flow Peaking Factors ......................................................................................................................... 16 Loads Peaking Factors ....................................................................................................................... 17 Projected Flows ...................................................................................................................................... 18 Population projection .......................................................................................................................... 18 Land Use/Development Projection ..................................................................................................... 19 Recommend Flow Projections ............................................................................................................ 19 Projected Peak Flow........................................................................................................................... 19 Projected Loads ...................................................................................................................................... 19 Projected Flows and Loads .................................................................................................................... 20 Conclusions ............................................................................................................................21 References ..............................................................................................................................22 Appendix A. Annual Peaking Factors, Flows and Loads ...................................................... 1 Appendix B. Lognormal Distribution and Curve Fit of 5-year Data ...................................... 3 Appendix C. Historic Wastewater Generation Rates ............................................................. 7 WRRF Project TM No. 1 – Wastewater Characterization Page 2 of 30 List of Tables Table 1. Summary of Existing NPDES Discharge Limits for Selected Pollutants (R3-2002-0043) .............. 4 Table 2. Historic and Projected Influent Flows and Loads from 2011 Master Plan Update ......................... 6 Table 3. Flow and Population Projections for 2030 ...................................................................................... 7 Table 4. BOD and TKN Average Values and their Relationship to Other Parameters, 2009-2013 ........... 13 Table 5. Peaking Factors for Historical Flows ............................................................................................. 17 Table 6. Peaking factors for Historical TSS Loads ..................................................................................... 17 Table 7. Peaking Factors for Historical Ammonia Loads ............................................................................ 17 Table 8. Peaking factors for Historical BOD Loads .................................................................................... 18 Table 9. Peaking Factors for Historical TKN Loads .................................................................................... 18 Table 10. Historical TSS Unit Loading Rates.............................................................................................. 20 Table 11. Historical Ammonia Unit Loading Rates ..................................................................................... 20 Table 12. Projected Buildout Flows and Loads of Selected Constituents .................................................. 20 Table 13. Summary of Projected Buildout Flows and Loads ...................................................................... 21 List of Figures Figure 1. Daily Influent Flow, Effluent Flow (Includes Recycled Water Flows) and Precipitation for January 2009 - January 2014 ............................................................................................................... 8 Figure 2. Daily Influent Peak Flow for January 2009 - January 2014 ........................................................... 8 Figure 3. Daily Influent TSS Concentration for January 2009 - December 2013 ......................................... 9 Figure 4. Daily Influent TSS Load and Measured Rainfall .......................................................................... 10 Figure 5. Daily Influent Ammonia Concentrations for January 2009-December 2013 ............................... 11 Figure 6. Daily Influent Ammonia Load and Measured Rainfall for January 2009-December 2013 .......... 11 Figure 7. Influent BOD Loads and Measured Rainfall ................................................................................ 12 Figure 8. Statistical Plot of Daily Concentrations of Hypothetical Compound (Used only for Statistical Probability Approach Demonstration Purposes) ................................................................ 14 WRRF Project TM No. 1 – Wastewater Characterization Page 3 of 30 Introduction The City of San Luis Obispo (City) Water Resource Recovery Facility (WRRF) was recently issued a tentative National Pollutant Discharge Elimination System (NPDES) discharge permit (Order R3- 2013-0033; Permit Number CA0049224) in December 2013. This permit will supersede the previous NPDES discharge permit (Order R3-2002-0043; Permit Number CA0049224). The key changes in the new tentative NPDES discharge permit are more stringent discharge limits for nitrogen ion species and trihalomethanes (THMs). The draft tentative NPDES permit is scheduled to be adopted in fall 2014 and be in effect through 2019. The existing NPDES permit discharge (Order R3-2002- 0043; Permit Number CA0049224) requirements for selected parameters are summarized in Table 1. The WRRF currently treats an average of approximately 4.0 million gallons per day (mgd) and has a rated capacity of 5.1 mgd average dry weather flow (ADWF). The WRRF treats municipal wastewater flow from the City, California Polytechnic State University (Cal Poly), and the San Luis Obispo County Airport. The treated water is either discharged to the San Luis Obispo Creek or recycled to various users. Currently effluent wastewater values reliably meet or exceed discharge permit limits. The purpose of this technical memorandum (TM) is to present the analysis of historical flows and loads and projected flows and loads for the WRRF. The results of this analysis, in conjunction with the new NPDES permit limits, will provide the basis for the process selection and design criteria for the WRRF Facilities Plan, designed to meet new effluent discharge limitations. Background The flows and loads analyzed in this TM are based on raw influent wastewater data. Influent raw wastewater flow is measured by a flume located at the headworks located between the aerated grit tanks and primary clarifiers. Flow measured at this flume also receives supernatant from the lagoons that store dewatered filtrate. Therefore, the raw influent is manually calculated by taking the difference between the influent wastewater and the lagoon supernatant. The raw influent wastewater constituents are collected daily as composite samples at the headworks and analyzed for total suspended solids (TSS), ammonia, alkalinity and pH. The composite sampling location does not include the lagoon supernatant. The WRRF does not currently analyze raw influent wastewater for biochemical oxygen demand (BOD), total Kjeldahl nitrogen (TKN), or any phosphorus species. Averaging Periods The existing and tentative NPDES permit has limits based on various averaging periods as shown in Table 1 (e.g., average monthly). The baseline flows and loads to meet the discharge permit are based on meeting the averaging periods identified within the permit, as well as defining other key loading conditions important in unit process sizing. WRRF Project TM No. 1 – Wastewater Characterization Page 4 of 30 Table 1. Summary of Existing NPDES Discharge Limits for Selected Pollutants (R3-2002-0043) Parameter Unit Average Dry Weather Flow Average Annual Average Monthly Average Weekly Maximum Daily Instantaneous Minimum Instantaneous Maximum Rated Capacity mgd 5.2 -- -- -- -- -- -- Biological Oxygen Demand, 5-day (BOD) mg/L -- -- 10 30 50 -- -- Total Suspended Solids (TSS ) mg/L -- -- 10 30 75 -- -- Un-ionized Ammonia (as N) mg N/L -- 0.025 (Annual Running Mean) -- -- -- -- -- Fecal Coliform MPN/100 mL -- -- -- 2.2 (7 day median) -- -- -- Total Coliform MPN/100 mL -- -- -- -- 23 (more than once in any 30 day period) -- 240 pH s.u. -- -- -- -- -- 6.5 8.3 Selenium g/L -- -- 4.1 -- 8.2 -- -- Bromoform g/L -- -- 4.3 -- 8.6 -- -- Cyanide g/L -- -- 4.3 -- 8.6 -- -- Interim Chlorodibromomethane(a) g/L -- -- -- -- -- -- 42 Interim Dichlorobromomethane(a) g/L -- -- -- -- -- -- 27 Final Chlorodibromomethane(b) g/L -- -- 0.40 -- 0.8 -- -- Final Dichlorobromomethane(b) g/L -- -- 0.60 -- 1.1 -- -- Note: Based on NPDES Permit No. CA0049224 issued in May 2002 (Modified in 2005) (a) Interim limits used through February 28, 2010. (b) Final limits compliance by March 1, 2010. WRRF Project TM No. 1 – Wastewater Characterization Page 5 of 30 Descriptions of the averaging periods that either must be met for compliance with the existing or tentative NPDES permit or are useful in design are as follows (note that the tentative NPDES permit does not contain these definitions): Average Dry Weather Flow (ADWF): ADWF is defined as the average monthly flow over the three driest consecutive months of the year. Historically, the driest months typically occur July through September, where the groundwater table is at or near normal and runoff is not occurring. As a result, the amount of inflow and infiltration (I&I) from the groundwater is low, and the flows are principally from residential and commercial areas. Average Annual (AA): AA establishes the average flow and load that is used to assess annual operational costs. It is calculated as the total volume in million gallons (MG) entering the WRRF over the year divided by 365 days. Maximum Month (MM): MM is defined as the month at which maximum flows and loads occur over the course of a year. Historically, this occurs in January, February or March. This condition establishes the critical performance loading to the biological processes. For example, the aeration system must meet this loading condition at all times in order to ensure proper biological growth while simultaneously meeting discharge limits. Anaerobic digesters are another example of a process where the maximum month loading determines the process requirements. Compliance with the permit limits apply to MM conditions since this is typically the most stressed condition for the WRRF. Maximum Week (MW): MW is defined as the week during which maximum flows and loads occur over the course of a year. Historically, this occurs during the winter months. Maximum Day (MD): MD is defined as the maximum daily flow and load throughout the year. MD is expected to occur during the winter months, typically, during the maximum month of flows. Peak Hour (PH): The PH flow is a function of precipitation, I/I into the sewer system, and the hydraulics of the sewer system. PH flows represent the sustained one hour maximum wet weather flow and are less critical to biological processes. The hydraulic capacity of the WRRF will need to accommodate the PH flow. Minimum Flow: Minimum flow is considered the lowest diurnal flow which typically occurs during the early morning hours. Minimum flow is necessary for designing turn down capacity of influent pumps, and hydraulics of influent sewers. In addition, the City’s population is influenced by whether Cal Poly is in session. This period is referred to herein as the “non-student period”. This influence is particularly apparent during summer months, the period which overlaps with ADWF conditions. During this time, flows and loads are at the minimum. Previous Work In 2011, the City updated the wastewater treatment master plan (2011 Master Plan), which had previously been prepared in 2000. The update included an updated analysis of flows and loads. The WRRF Project TM No. 1 – Wastewater Characterization Page 6 of 30 report was based on analyzing historical plant data from January 1, 1997 to December 31, 2007. The methodology used to calculate the peaking factors is described in the 2011 Master Plan. Plant data was used for flows, TSS and ammonia from the above mentioned period to calculate historical TSS and ammonia load peaking factors based on the particular calendar day when the peaks occurred. Table 2 summarizes historical and projected flows and loads from the 2011 Master Plan. Projected flows and loads peaking factors were assumed to be the same as for historical data. This strategy does not account for any changes in concentrations per capita in time, such as water conservation that might take place in the future. Table 2. Historic and Projected Influent Flows and Loads from 2011 Master Plan Update Parameter(a) Flow/Load Peak 30d Load Peak 14d Load Peak 7d Load Peak Day Load Historical ADWF 3.96 mgd - - - - Suspended Solids (TSS ) 11,250 lb/d 16,600 lb/d 18,600 lb/d 19,400 lb/d 25,800 lb/d Biological Oxygen Demand, 5-day (BOD) 9,112 lb/d 13,400 lb/d 15,100 lb/d 15,700 lb/d 20,900 lb/d Ammonia 1,197 lb-N/d 1,660 lb-N/d 1,780 lb-N/d 1,870 lb-N/d 2,970 lb-N/d Projected (rounded up to nearest 100 lb/d for TSS; 10 lb/d for Ammonia) ADWF 5.55 mgd - - - - Preliminary Treatment Capacity 32.0 mgd - - - - Primary Treatment Capacity 32.0 mgd - - - - Secondary Treatment Capacity 20.0 mgd - - - - Suspended Solids (TSS ) 15,800 lb/d 23,300 lb/d 26,100 lb/d 27,200 lb/d 36,200 lb/d Biological Oxygen Demand, 5-day (BOD) 17,300 lb/d 25,500 lb/d 28,600 lb/d 29,800 lb/d 39,700 lb/d Ammonia 1,680 lb-N/d 2,320 lb-N/d 2,490 lb-N/d 2,630 lb-N/d 4,170 lb-N/d (a) Source: Brown and Caldwell 2011 Wastewater Master Plan Update. The BOD load from historical data (Table 2) was calculated based on the monthly composite sample average BOD:TSS ratio of 0.81. This value is based on the previous BOD:TSS analyses conducted at the plant. In case of future projections, the engineer’s best judgment of wastewater BOD:TSS ratio of 1.09 was used, instead of 0.81. The decision to use 1.09 was based on more typical BOD:TSS ratios encountered at other wastewater treatment plants. The Projected ADWF flow of 5.55 mgd in Table 2 was calculated based on historical per capita flow multiplied by projected population in 2030. The 2030 plant flow projections in the 2011 Master Plan were based on two population growth scenarios, which were both different from the previous 2000 Master Plan Projections. Table 3 compares flow and population projections for annual population growth of 0.49% and 1.0%. The 2000 Master Plan used projections based on 0.49% population growth and based on a higher assumption of flow per capita (102 vs. 97 gpcd). Despite the updated population projections and per capita flow in 2011 Master Plan, the previously projected 5.55 mgd was used for the projected flows and loads in the 2011 Master Plan. WRRF Project TM No. 1 – Wastewater Characterization Page 7 of 30 Table 3. Flow and Population Projections for 2030 Year Population by 2030 ADWF (mgd)(a) Normalized Flow (gpcd) Master Plan (2000) Projections Assuming 0.49 % Annual Population Growth 49,772 5.55 102 Master Plan Update (2011) Projections Assuming 0.49 % Annual Population Growth 49,675 5.29 97 Master Plan Update (2011) Projections Assuming 1.0 % Annual Population Growth 55,247 5.83 97 (a) Includes Cal Poly flow of 0.47 mgd. Data Analysis This section presents the historical data for flows, and concentrations and loads for key wastewater parameters. Historical Flows The daily average influent and effluent flows are plotted on the primary vertical axis (left-hand axis) in Figure 1. Effluent flow data in Figure 1 is a sum of effluent flow meter readings and recycled water flow meter readings. The daily measured rainfall is provided on the secondary vertical axis (right- hand axis)1. The key observations of the historical flow data are: The dry season typically occurs from July through September. The wet season typically occurs from October through May. Peak day flow typically could occur anytime during the wet season. A peak day flow of 14.3 mgd occurred on March 20, 2011 (based on effluent flow) Prior to 2012, effluent flow data was consistently lower than influent flow data. After 2012, the trend reversed. For this reason, staff has raised concerns regarding the accuracy of the influent and/or effluent flow measurement. The instantaneous peak flow data is provided in Figure 2. The historical instantaneous peak is about 20.5 mgd with a frequency of six times over five years (2009 to 2013 period). 1 Rain gage data measured at San Luis Obispo Station # 52 (CIMIS) WRRF Project TM No. 1 – Wastewater Characterization Page 8 of 30 Figure 1. Daily Influent Flow, Effluent Flow (Includes Recycled Water Flows) and Precipitation for January 2009 - January 2014 Figure 2. Daily Influent Peak Flow for January 2009 - January 2014 0.0 0.5 1.0 1.5 2.0 2.5 3.0 0 2 4 6 8 10 12 14 16 Ja n - 0 9 Ma r - 0 9 Ma y - 0 9 Ju l - 0 9 Se p - 0 9 No v - 0 9 Ja n - 1 0 Ma r - 1 0 Ma y - 1 0 Ju l - 1 0 Se p - 1 0 No v - 1 0 Ja n - 1 1 Ma r - 1 1 Ma y - 1 1 Ju l - 1 1 Se p - 1 1 No v - 1 1 Ja n - 1 2 Ma r - 1 2 Ma y - 1 2 Ju l - 1 2 Se p - 1 2 No v - 1 2 Ja n - 1 3 Ma r - 1 3 Ma y - 1 3 Ju l - 1 3 Se p - 1 3 No v - 1 3 Ja n - 1 4 Pr e c i p i t a t i o n ( i n ) Fl o w ( m g d ) INF, Flow adjusted (exl sump returns)EFF Calculated, Flow (inludes recycled water)SLO, Precipitation 0 5 10 15 20 25 Ja n - 0 9 Ma r - 0 9 Ma y - 0 9 Ju l - 0 9 Se p - 0 9 No v - 0 9 Ja n - 1 0 Ma r - 1 0 Ma y - 1 0 Ju l - 1 0 Se p - 1 0 No v - 1 0 Ja n - 1 1 Ma r - 1 1 Ma y - 1 1 Ju l - 1 1 Se p - 1 1 No v - 1 1 Ja n - 1 2 Ma r - 1 2 Ma y - 1 2 Ju l - 1 2 Se p - 1 2 No v - 1 2 Ja n - 1 3 Ma r - 1 3 Ma y - 1 3 Ju l - 1 3 Se p - 1 3 No v - 1 3 Ja n - 1 4 Fl o w ( m g d ) WRRF Project TM No. 1 – Wastewater Characterization Page 9 of 30 Historical Loads Daily influent TSS concentration and load data are presented in Figure 3 and Figure 4, respectively. Data points with TSS concentrations above 1,200 mg/L were considered erroneous and excluded from the analysis. Key observations from the historical TSS data are as follows: The TSS concentration profile does not have a distinctive yearly pattern. There is a slight increase in the average daily concentrations in 2011-2013 compared to previous years. Otherwise, the values typically lie between 300 to 350 mg/L. The influent TSS loads fluctuate within the range of 6,000 to 16,000 lb/day (average load is 10,600 lb/d TSS). Higher TSS loads appear to coincide with wet weather. It is speculated that during wet weather events, a considerable amount of grit and solids that have settled out in the collection system are conveyed to the WRRF. The lowest TSS loads coincide with dry weather and period of low student population during summer time. Figure 3. Daily Influent TSS Concentration for January 2009 - December 2013 0 200 400 600 800 1,000 1,200 1,400 1,600 Ja n - 0 9 Ma r - 0 9 Ma y - 0 9 Ju l - 0 9 Se p - 0 9 No v - 0 9 Ja n - 1 0 Ma r - 1 0 Ma y - 1 0 Ju l - 1 0 Se p - 1 0 No v - 1 0 Ja n - 1 1 Ma r - 1 1 Ma y - 1 1 Ju l - 1 1 Se p - 1 1 No v - 1 1 Ja n - 1 2 Ma r - 1 2 Ma y - 1 2 Ju l - 1 2 Se p - 1 2 No v - 1 2 Ja n - 1 3 Ma r - 1 3 Ma y - 1 3 Ju l - 1 3 Se p - 1 3 No v - 1 3 TS S C o n c e n t r a t i o n ( m g / L ) INF, TSS Removed data points WRRF Project TM No. 1 – Wastewater Characterization Page 10 of 30 Figure 4. Daily Influent TSS Load and Measured Rainfall Daily influent ammonia concentration and load data are presented in Figure 5 and Figure 6, respectively. Key observations from the historical ammonia data are as follows: Ammonia concentrations are lowest during winter months, which are attributed to a wet weather dilution effect. Compared to TSS concentrations, the increase in average daily concentrations for years 2011-2013 is more profound for ammonia. The influent ammonia loads fluctuate within the range of 600 to 2,000 lb N/day (average load is 1,300 lb N/d). Similar to TSS, the lowest ammonia loads coincide with dry weather and non-student period during summer time. 0.0 1.0 2.0 3.0 4.0 5.0 6.0 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 Ja n - 0 9 Ma r - 0 9 Ma y - 0 9 Ju l - 0 9 Se p - 0 9 No v - 0 9 Ja n - 1 0 Ma r - 1 0 Ma y - 1 0 Ju l - 1 0 Se p - 1 0 No v - 1 0 Ja n - 1 1 Ma r - 1 1 Ma y - 1 1 Ju l - 1 1 Se p - 1 1 No v - 1 1 Ja n - 1 2 Ma r - 1 2 Ma y - 1 2 Ju l - 1 2 Se p - 1 2 No v - 1 2 Ja n - 1 3 Ma r - 1 3 Ma y - 1 3 Ju l - 1 3 Se p - 1 3 No v - 1 3 Pr e c i p i t a t i o n ( i n ) TS S L o a d i n g ( l b / d a y ) INF Calculated, TSS load SLO, Precipitation 30 per. Mov. Avg. (INF Calculated, TSS load) WRRF Project TM No. 1 – Wastewater Characterization Page 11 of 30 Figure 5. Daily Influent Ammonia Concentrations for January 2009-December 2013 Figure 6. Daily Influent Ammonia Load and Measured Rainfall for January 2009-December 2013 0 10 20 30 40 50 60 70 80 90 100 Ja n - 0 9 Ma r - 0 9 Ma y - 0 9 Ju l - 0 9 Se p - 0 9 No v - 0 9 Ja n - 1 0 Ma r - 1 0 Ma y - 1 0 Ju l - 1 0 Se p - 1 0 No v - 1 0 Ja n - 1 1 Ma r - 1 1 Ma y - 1 1 Ju l - 1 1 Se p - 1 1 No v - 1 1 Ja n - 1 2 Ma r - 1 2 Ma y - 1 2 Ju l - 1 2 Se p - 1 2 No v - 1 2 Ja n - 1 3 Ma r - 1 3 Ma y - 1 3 Ju l - 1 3 Se p - 1 3 No v - 1 3 Am m o n i a C o n c e n t r a t i o n ( m g / L ) INF, NH4 0.0 1.0 2.0 3.0 4.0 5.0 6.0 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 Ja n - 0 9 Ma r - 0 9 Ma y - 0 9 Ju l - 0 9 Se p - 0 9 No v - 0 9 Ja n - 1 0 Ma r - 1 0 Ma y - 1 0 Ju l - 1 0 Se p - 1 0 No v - 1 0 Ja n - 1 1 Ma r - 1 1 Ma y - 1 1 Ju l - 1 1 Se p - 1 1 No v - 1 1 Ja n - 1 2 Ma r - 1 2 Ma y - 1 2 Ju l - 1 2 Se p - 1 2 No v - 1 2 Ja n - 1 3 Ma r - 1 3 Ma y - 1 3 Ju l - 1 3 Se p - 1 3 No v - 1 3 Pr e c i p i t a t i o n ( i n ) Am m o n i a L o a d i n g ( l b / d a y ) INF Calculated, Ammonia load SLO, Precipitation 30 per. Mov. Avg. (INF Calculated, Ammonia load) WRRF Project TM No. 1 – Wastewater Characterization Page 12 of 30 BOD loading data for 2009-2013 was limited. Figure 7 presents the available BOD data during that period. A limited number of sample points (44 samples, Table 4) limited the ability to confidently quantify the average BOD loading or specific ratio of BOD to TSS. Due to the same limited number of samples, the 2011 Master Plan had assumed a ratio of BOD to TSS and applied that for all averaging periods. The ratio of 0.81 BOD to TSS was used in historic data analysis and 1.09 BOD to TSS in the projected values. For a typical municipal raw wastewater, BOD loadings are either equal to or higher than TSS loadings, unless there is an influence of an industrial discharger. TSS and BOD concentrations for municipal wastewater are typically in the range of 120 mg/L to 400 mg/L and 110 mg/L to 350 mg/L, respectfully (Metcalf and Eddy, 2003). Historical TSS concentration for the WRRF averages approximately 365 mg/L, making it a high-strength municipal wastewater. The City is currently performing additional influent sampling and analyses for BOD and TSS to confirm the estimated ratios. Figure 7. Influent BOD Loads and Measured Rainfall TKN loading data was also limited for 2009 through 2013. 20 data points had TKN concentration measurements. The average TKN values and the relationship with ammonia are summarized in Table 4. From these values it is apparent that TKN concentrations are below ammonia concentrations, which contradicts the definition of TKN as a sum of ammonia nitrogen and organic nitrogen. A default ammonia to TKN ratio of 0.66 was used in the 2011 Master Plan. This value is consistent with the typical composition of domestic wastewater with various strengths (Metcalf and 0.0 1.0 2.0 3.0 4.0 5.0 6.0 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 Ja n - 0 9 Ma r - 0 9 Ma y - 0 9 Ju l - 0 9 Se p - 0 9 No v - 0 9 Ja n - 1 0 Ma r - 1 0 Ma y - 1 0 Ju l - 1 0 Se p - 1 0 No v - 1 0 Ja n - 1 1 Ma r - 1 1 Ma y - 1 1 Ju l - 1 1 Se p - 1 1 No v - 1 1 Ja n - 1 2 Ma r - 1 2 Ma y - 1 2 Ju l - 1 2 Se p - 1 2 No v - 1 2 Ja n - 1 3 Ma r - 1 3 Ma y - 1 3 Ju l - 1 3 Se p - 1 3 No v - 1 3 Pr e c i p i t a t i o n ( i n ) BO D L o a d i n g ( l b / d a y ) INF Calculated, BOD load SLO, Precipitation WRRF Project TM No. 1 – Wastewater Characterization Page 13 of 30 Eddy, 2003). The City is also undergoing additional sampling to confirm the ratio and confirm influent loads. Table 4. BOD and TKN Average Values and their Relationship to Other Parameters, 2009-2013 Parameter BOD Concentration (mg/L) BOD:TSS TKN Concentration (mg/L) Ammonia:TKN Number of samples 44 44 20 20 Average 280 0.85 27 1.35 Max - 1.36 - 1.93 Min - 0.49 - 0.98 Standard Deviation - 0.20 - 0.27 Approach There are several approaches for calculating flows and loads based on historical data, including: Calendar method, where the parameters are analyzed per each calendar year of available data. Statistical probability method, where each calendar year daily data is fit to normal and lognormal distribution to determine the best fit. The benefit of using the statistical probability analysis is that it gives the insight into potential outliers in the data and can also be used to extrapolate the data set beyond the current basis. As an example, Figure 8 shows the log-normal plot of the hypothetical data. This plot shows that the data follows a log normal distribution quite well, but some outliers are seen above the 95th percentile. Using the statistical plot, it is possible to select the maximum month (11/12th percentile) and maximum day (364/365th percentile) values. The statistical approach to design prevents oversizing and ensures efficient operation while meeting critical process conditions. The last type of analysis is the same as the one described previously, but instead of using each calendar year data set separately, all the data is combined into one set for analysis. The analysis presented herein is based the statistical probability approach where the data was analyzed by calendar year and combined. Initially, historical flows and loads patterns, as presented in the previous section and shown in Figure 1 through Figure 4 were examined to determine the most suitable data range for the analysis. 2012 and 2013 flows and loads data was notably different from the previous years, which is most likely due to drought conditions. This dramatic difference required the flows and loads analysis to be performed with a more extended period of at least last five years on a year to year and combined basis. First, the statistical probability approach data analysis was performed per each calendar year. The statistical analysis confirmed the differences between 2012 and 2013 data compared to previous years (annual loads and peaking factors are included in Appendix A). WRRF Project TM No. 1 – Wastewater Characterization Page 14 of 30 Second, the statistical probability approach data analysis was performed for the combined 5-year data set. This analysis is considered to be more statistically robust since it prevents underestimation of the peaking factors due to abnormally low peaking factors and flows and loads taking place during drought years. Figure 8. Statistical Plot of Daily Concentrations of Hypothetical Compound (Used only for Statistical Probability Approach Demonstration Purposes) An overview of the steps associated with calculating flows and loads using the statistical probability approach described above are as follows: 1. Select the months representing ADWF in each year data set. 2. Calculate the ADWF, AA, MM, MW, and MD flow and load for combined data set (2009 – 2013 data). A lognormal distribution demonstrated a better fit for the WRRF data. AA, MM, MW, and MD occur at 50th percentile, 91.7 percentile (11 months/12 months), 98.1 percentile (51 weeks/52 weeks), and 99.7 percentile (364 days/365 days), respectively. ADWF and load occur at the 50th percentile of the ADWF month data subset. a. The probability method allows ADWF, AA, MM, MW, and MD flow and loads to be determined independently of each other. For example, the MM flow and load might occur during different months of the calendar year. This offers a more conservative approach. Log-Normal Probability Distribution 1 10 100 1000 -4-3-2-101234 Percent of values less than or equal to the indicated value Log-Normal Values Raw Data Values Max Month = 158 mg/L Max Day = 290 mg/L Outliers WRRF Project TM No. 1 – Wastewater Characterization Page 15 of 30 b. Analysis of each year data was performed in order to compare the peaking factors calculated from the combined data set to each individual year and make sure that there were no abnormally high peaking factors for any of the years. The data tables with peaking factors for each calendar year are included in Appendix A. 3. Calculate the peaking factors for combined data (ADWF:AA, MM:AA, MW:AA, MD:AA) using the values determined in Step 1. 4. Use the peaking factors and projected ADWF flow to calculate the AA, MM, MW and MD flows. After that, calculate historic AA concentration (i.e., 50th percentile of AA data for years 2009-2013) by back calculating (e.g., AA TSS load divided by the AA flow). 5. Calculate the historical AA unit loading as lb/d/capita for each calendar year by dividing the AA loads from each calendar year by the corresponding population. 6. Calculate the buildout AA loads by multiplying the projected population by the historical average unit loading per capita determined in Step #5. 7. Determine the projected flows and loads for ADWF, MM, MW, and MD averaging periods. To calculate, apply the peaking factors determined in Steps #3 to projected AA flow (Step #4) and AA loads determined in Step #5. 8. Determine projected BOD and TKN loads by applying assumed multiplier to TSS and ammonia loads respectively. For the purposes of this analysis, both low and high BOD to TSS ratios from the 2011 Master Plan were used to estimate the possible range of projected BOD loadings. In addition, The 2011 Master Plan vale of 0.66 for the ammonia to TKN ratio was used in this analysis. 9. Calculate the projected concentrations for each averaging period by back calculating (e.g., MM TSS load divided by the MM flow). Analysis Results The following subsections present the results of the flows and loads analysis based on the approach outlined above. Historical Average Dry Weather Flow (ADWF) and Loads As previously described, the ADWF is the average daily flow during the dry season with insignificant influence of rainfall or rainfall induced infiltration over the calendar year. ADWF is considered the normal wastewater flow generated from all water users in the service area, including residential, commercial and industrial dischargers. An analysis of historic flows indicated that typically the lowest influent flows to the WRRF occur in July, August and September. The ADWF to the WRRF was determined to be 3.1 mgd, which is based upon historic influent flows for the months of July, August and September from 2009 through 2013. WRRF Project TM No. 1 – Wastewater Characterization Page 16 of 30 This flow does not include contributions from Cal Poly. The university is considering year round classes. In order to account for this potential flow and load, the historical Cal Poly wastewater generation rates during the month of October were added to the historical ADWF flow. The historical Cal Poly wastewater generation rates from 2005 to 2013 have averaged 0.35 mgd. . The historic ADWF with Cal Poly contributions (ADWFCP) is 3.5 mgd. The Cal Poly wastewater generation rates for October (0.35 mgd) were verified by quantifying the additional raw influent flow at the WRRF for October compared against the corresponding ADWF flows (July through September). The WRRF sees on average increase in flow of about 0.49 mgd for the month of October compared against the corresponding ADWF flows (July through September). This 0.49 mgd value excludes the year of 2009 where there were several wet weather events in October. An average value of 0.49 mgd is marginally larger than the Cal Poly generation rates. This would be expected given the additional flows that students contribute as they leave campus limits throughout the day. As a result, the 0.35 mgd contribution from Cal Poly seems reasonable and used for this effort. ADWF loads were calculated using the influent flow multiplied by the measured historical ADWF constituent concentration. Appendix A includes historic constituent concentrations that were used for load calculations. The same statistical approach for flows was used with the TSS and ammonia loads to determine the ADWF, AA, MM, MW and MD TSS and ammonia loading to the WRRF. The historic ADWF TSS and ammonia loads (with Cal Poly contributions) to the WRRF were estimated to be 10,400 lb/day and 1,300 lb/day, respectively. Because influent BOD and TKN are not routinely monitored at the WRRF, it was not possible to perform a statistical analysis on loading into the plant for these constituents. The approach to projecting BOD and TKN loads into the plant is provided in subsequent sections. Peaking Factors Peaking factors were determined from the historical data and are used to project future flows and loads. As in 2011 Master Plan, the peaking factors are assumed to remain the same for future conditions, and do not account for changes in flow and load patterns due to water conservation efforts. This approach is recommended at this time because Facilities Plan design criteria will be dictated by TSS and BOD loads. While influent flows may potentially decrease with future water conservation, the loads will remain constant. Due to uncertainty with how much flow reduction could occur in the future, use of historic flow and load peaking factors is recommended for projections. Flow Peaking Factors Flow peaking factors are calculated by dividing the historical averaging period flow of interest by the historical AA flows as follows: ADWFCP Peaking Factor = ADWFCP ÷ Historical AA Table 5 provides historical flow and corresponding calculated peaking factors. Annual flow peaking factors are included in Appendix A. WRRF Project TM No. 1 – Wastewater Characterization Page 17 of 30 Table 5. Peaking Factors for Historical Flows Averaging Period Historical Flow (mgd) Peaking Factor with respect to AA Average Dry Weather Flow with Cal Poly 3.5 0.9 Average Annual Flow 3.9 1.0 Maximum Month Flow 5.4 1.4 Maximum Week Flow 7.4 1.9 Maximum Day Flow 11.1 2.9 Peak Hour Flow (a) 32.0 8.2 (a) Staff have indicated that peak hour flows exceed the capacity of the flow meter. The value included in the table corresponds to the capacity of preliminary treatment Loads Peaking Factors The peaking factors for loads are calculated using the same methodologies as flows. As with the flows, Table 6 and Table 7 present peaking factors for TSS and ammonia, respectively. Annual peaking factors and concentrations are provided in Appendix A. Table 6. Peaking factors for Historical TSS Loads Averaging Period Historical TSS Load (lb/d) Peaking Factor with respect to AA Average Dry Weather Load with Cal Poly 10,400 1.0 Average Annual Load 10,900 1.0 Maximum Month Load 15,500 1.4 Maximum Week Load 20,900 1.9 Maximum Day Load 28,400 2.6 Table 7. Peaking Factors for Historical Ammonia Loads Averaging Period Historical Ammonia Load (as N) (lb N/d) Peaking Factor with respect to AA Average Dry Weather Load with Cal Poly 1,300 1.0 Average Annual Load 1,370 1.0 Maximum Month Load 1,900 1.4 Maximum Week Load 2,200 1.6 Maximum Day Load 2,700 2.0 Since BOD and TKN are not monitored daily at the plant, it was not possible to establish the peaking factors for these compounds based on the historic data. Thus, the same peaking factors were applied to BOD loads for different flow scenarios as to TSS loads and to TKN as to ammonia (Table 8 and Table 9). WRRF Project TM No. 1 – Wastewater Characterization Page 18 of 30 Table 8. Peaking factors for Historical BOD Loads Averaging Period Historical BOD Load (lb/d) Peaking Factor with respect to AA Average Dry Weather Load with Cal Poly - 1.0 Average Annual Load - 1.0 Maximum Month Load - 1.4 Maximum Week Load - 1.9 Maximum Day Load - 2.6 Table 9. Peaking Factors for Historical TKN Loads Averaging Period Historical TKN Load (as N) (lb N/d) Peaking Factor with respect to AA Average Dry Weather Load with Cal Poly - 1.0 Average Annual Load - 1.0 Maximum Month Load - 1.4 Maximum Week Load - 1.6 Maximum Day Load - 2.0 Projected Flows Future flow and load projections were developed to serve as the design condition for the WRRF Facilities Plan. Two methods were used to project the ADWFCP and are described in more detail below: Population Projection, and Land Use/Development Projection. Population projection Using data from the City’s Unified General Plan - Chapter 8 Water and Wastewater (2010), historic wastewater generation rates were developed based on population and annual ADWF rates (July through September). From 2004 through 2011, the wastewater generation rates ranged from 80 to 100 gallons per capita per day (gpcd), which is within the typical range of wastewater generation rates for residential communities in the United States (WEF MOP 8). Most recently in 2012 and 2013, a lower generation rate of about 60 gpcd was observed. Appendix C provides the historic population, flows, and the calculated per capita generation rates. Drought conditions in addition to water conservation measures implemented within the City may be the cause of the observed decline in the wastewater generation rate. For planning purposes, a per capita wastewater generation rate of 92.5 gpcd for ADWF conditions was used, which is consistent with what the City has used in past studies and evaluations (City of San Luis Obispo, March 2009 document, provided in Appendix C). The buildout population within the service area is projected to be 53,700 (City of San Luis Obispo, 2013). Based on this information, the projected ADWF at buildout is 4.9 mgd. If the projected contributions from Cal Poly (0.47 mgd) are included, the ADWFCP is 5.4 mgd. It is recommended that the City update the wastewater WRRF Project TM No. 1 – Wastewater Characterization Page 19 of 30 generation rate and the associated ADWF projection as additional data become available, if it confirms the lower generation rate. Land Use/Development Projection A second approach, which looks at future land use and development within the wastewater service area through build out conditions, was taken to project the future ADWF. Under this approach, the ADWF projection was based on wastewater generation rates for various land use categories (e.g., single family dwelling, retail, motel/hotel, etc) being applied to projected development within the wastewater service area. The details of this approach are provided in the Wastewater Collection System Infrastructure Renewal Strategy (WSC, June 2014). Using this approach, the ADWFCP projection is 5.4 mgd. Recommend Flow Projections The projected ADWFCP using both methodologies resulted in similar values of 5.4 mgd, which provides confidence in the projection. It is recommended that a projected ADWFCP of 5.4 mgd be used at this time for the Facilities Plan. As noted earlier, if additional data demonstrate a lower per capita wastewater generation rate than the value used, the City may want to update the ADWFCP projection. Flow projections were developed for the AA, MM, MW, and MD conditions using the historic peaking factors in Table 5. Projected Peak Flow The projected peak hour flow represents the maximum sustained hour flow that can be conveyed to the WRRF during a 10-year, 24-hour storm event. The WRRF facilities will be designed to convey this peak hour flow through the plant to avoid overflows at the plant and within the collection system. The projected peak hour flow of 33.5 mgd was developed by using flow metering and collection system modeling performed by V&A in 2010 and 2011 (V&A, 2012) as well as additional modeling efforts performed for the Wastewater Collection System Infrastructure Renewal Strategy (WSC, June 2014). It should be noted that the City has undergone collection system repairs for inflow and infiltration (I/I) reduction and intends to continue with collection system repairs in the future. The majority of past repairs were performed prior to the V&A Study and therefore the results from the study were considered to accurately reflect current conditions and were used to conservatively project peak hour flows. It is recommended that the City continue with additional flow metering and collection system modeling to monitor peak hour flows into the WRRF and to confirm if additional I/I reduction has been achieved. If the additional efforts demonstrate that peak hour flows into the plant will be lower than the projected 33.5 mgd, the design criteria should be modified. Projected Loads Projecting loads forward is based on loads associated with population and/or land use projections. In the case of SLO, both the population and land use projections produced comparable results as presented in the previous section, which simplifies load projections. The historical per capita unit loads were calculated and projected forward based on projected growth. WRRF Project TM No. 1 – Wastewater Characterization Page 20 of 30 The historic average annual per capita unit loads for TSS and ammonia are shown in Table 10 and Table 11, respectively. The average per capita unit loads over five years were calculated for each constituent and applied for the projected loads. Similar to the peaking factors, the projected BOD and TKN loads are based on the TSS:BOD and Ammonia:TKN relationships. Table 10. Historical TSS Unit Loading Rates Year Population Average Annual TSS Load (lb/d) Average Annual TSS Unit Loading Rate (lb/d/capita) 2009 44,829 11,647 0.26 2010 45,418 11,169 0.25 2011 45,768 12,581 0.27 2012 45,878 10,001 0.22 2013 46,107 9,199 0.20 Average 0.24 Table 11. Historical Ammonia Unit Loading Rates Year Population Average Annual Ammonia Load (as N) (lb N/d) Average Annual Ammonia Unit Loading Rate (lb/d/capita) 2009 44,829 1,514 0.034 2010 45,418 1,395 0.031 2011 45,768 1,331 0.029 2012 45,878 1,274 0.028 2013 46,107 1,334 0.029 Average 0.030 Projected Flows and Loads The projected flows and loads for each averaging period is provided in Table 12. Table 12. Projected Buildout Flows and Loads of Selected Constituents Averaging Period Flow (mgd) TSS Load (lb/d) BOD Load (lb/d), BOD/TSS= 0.81 BOD Load (lb/d), BOD/TSS= 1.09 Ammonia Load (as N) (lb N/d) TKN Load (as N) (lb N/d) Average Dry Weather w/ Cal Poly 5.4 12,300 9,900 13,400 1,500 2,300 Average Annual 6.1 12,900 10,400 14,100 1,600 2,400 Maximum Month 8.4 18,300 14,800 19,900 2,200 3,300 Maximum Week 11.4 24,700 20,000 26,900 2,600 3,800 Maximum Day 17.3 33,400 27,100 36,400 3,200 4,800 Peak Hour (a) 33.5 (a) Peak hour flow is based on the results of collection system monitoring (V&A 2012) and the Wastewater Collection System Infrastructure Renewal Strategy (WSC, 2014). WRRF Project TM No. 1 – Wastewater Characterization Page 21 of 30 The projected TSS and ammonia loads were calculated based on the historical per capita unit loading rates for AA, followed by peaking factors for the other averaging periods as presented in the previous subsections. The projected BOD and TKN loads were calculated based on TSS and ammonia projected loads. Ratios of BOD to TSS and ammonia to TKN were selected from the literature and all available data. As noted previously, BOD to TSS ratios of 0.81 and 1.09 for historic and projected loadings, respectively, were used in the 2011 Master Plan flows and loads analysis. The BOD to TSS ratio for 2009 through 2013 was estimated on average at 0.85. The projected BOD loadings presented herein are calculated for both the lowest and highest 2011 Master Plan estimated BOD to TSS ratios (as shown in Table 12). This approach presents the potential range of BOD loads for design of the facility upgrades. TKN loads were determined in a similar manner as BOD, except only one value of the ammonia to TKN ratio was selected (0.66). The ammonia:TKN ratio is based on values in Metcalf and Eddy (2013) as well as HDR’s professional experience. Resulting TKN projected loads are also shown in Table 12. Conclusions A summary of the projected flows and loads are presented in Table 13. These values are based on an analysis of historical WRRF data from 2009 through 2013. Table 13. Summary of Projected Buildout Flows and Loads Parameter Units ADWF AA MM MW MD PH Flow mgd 5.4 6.1 8.4 11.4 17.3 33.5 TSS lb/d 12,300 12,900 18,300 24,700 33,400 - BOD (low)(a) lb/d 9,900 10,400 14,800 20,000 27,100 - BOD (high)(b) lb/d 13,400 14,100 19,900 26,900 36,400 - Ammonia (as N) lb N/d 1,500 1,600 2,200 2,600 3,200 - TKN (as N) lb N/d 2,300 2,400 3,300 3,800 4,800 - TSS mg/L 272 253 261 260 231 - BOD (low)(a) mg/L 221 205 211 210 187 - BOD (high)(b) mg/L 297 276 284 283 252 - Ammonia (as N) mg N/L 34 32 31 27 22 - TKN (as N) mg N/L 51 47 47 40 33 - (a) BOD:TSS ratio assumed at 0.81 (b) BOD:TSS ratio assumed at 1.09 (c) Peak hour flow is based on the results of collection system monitoring (V&A 2012) and the Wastewater Collection System Infrastructure Renewal Strategy (WSC, 2014). It is recommended that the City performs additional monitoring as follows to confirm flow projections as well as assumed constituent ratios: Wastewater Generation Rates: Continue to monitor generation rates to determine if a lower per capita generation rate should be used to project the ADWFCP. The City should consider modifying the projected flow, if warranted. WRRF Project TM No. 1 – Wastewater Characterization Page 22 of 30 Peak Hour Influent Flows: Perform additional flow monitoring (collection system and at the plant) during the wet weather season to obtain more accurate peak hour flow measurements. Additional collection system modeling can be performed to confirm if the flow monitoring conclusively demonstrates I/I reduction. The projected peak hour flows should be modified accordingly. Influent Wastewater Characterization Sampling: Continue to monitor influent BOD, TSS, TKN and ammonia to confirm the ratios that were assumed. Flow Measurement: Perform additional investigation to confirm the accuracy of influent and effluent flow meters and make necessary upgrades and/or improvements to provide accurate measurement under low and peak flow conditions. Modify Design Criteria: As the City continues to collect additional characterization and flow monitoring data, it is recommended that the design criteria for the WRRF be modified, as necessary. References Brown and Caldwell (2011) Water Reclamation Facility Master Plan. City of San Luis Obispo; San Luis Obispo, CA. City of San Luis Obispo (2013) Water and Wastewater Impact Development Impact Fees. City of San Luis Obispo. San Luis Obispo, CA V&A (2012) Sanitary Sewer Flow Monitoring and Inflow/Infiltration Study. City of San Luis Obispo, San Luis Obispo, CA. Water Environment Federation in collaboration with American Society of Civil Engineers (1998) WEF Manual of Practic 8 Design of Municipal Wastewater Treatment Plants. Fourth Addition. Water Systems Consulting, Inc. (2014) Wastewater Collection System Infrastructure Renewal Strategy. City of San Luis Obispo, San Luis Obispo, CA. WRRF Project TM No. 1 – Wastewater Characterization Appendix A. Annual Peaking Factors, Flows and Loads Table A-1. ADWF Peaking Factors, Flows and Loads for Each Year Analyzed 2009 2010 2011 2012 2013 5-year data Flow Flow (mgd) 3.67 3.41 3.21 2.57 2.74 2.57 PF (to AA) 0.84 0.79 0.77 0.76 0.87 0.76 TSS Load (lb/d) 10,059 10,042 9,930 7,806 8,435 Concentration (mg/L) 329 353 371 363 369 PF (to AA) 0.86 0.90 0.79 0.78 0.92 NH4 Load (lb/d) 1,250 1,203 1,257 1,026 1,107 Concentration (mg/L) 49 49 50 59 58 PF (to AA) 0.83 0.86 0.94 0.81 0.83 Table A-2. Average Annual Peaking Factors, Flows and Loads for Each Year Analyzed 2009 2010 2011 2012 2013 5-year data Flow Flow (mgd) 4.39 4.32 4.15 3.39 3.15 3.89 PF (to AA) 1.00 1.00 1.00 1.00 1.00 1.00 TSS Load (lb/d) 11,647 11,169 12,581 10,001 9,199 10,951 Concentration (mg/L) 318 310 363 354 350 337 PF (to AA) 1.00 1.00 1.00 1.00 1.00 1.00 NH4 Load (lb/d) 1,514 1,395 1,331 1,274 1,334 1,374 Concentration (mg/L) 41 39 38 45 51 42 PF (to AA) 1.00 1.00 1.00 1.00 1.00 1.00 Table A-3. Maximum Month Peaking Factors, Flows and Loads for Each Year Analyzed 2009 2010 2011 2012 2013 5-year data Flow Flow (mgd) 5.34 6.61 5.81 4.49 4.16 5.39 PF (to AA) 1.22 1.53 1.40 1.33 1.32 1.38 TSS Load (lb/d) 14948 14005 20555 15205 12889 15525 Concentration (mg/L) 335 254 424 406 371 346 PF (to AA) 1.28 1.25 1.63 1.52 1.40 1.42 NH4 Load (lb/d) 2,011 1,838 1,912 1,813 1,782 1,865 Concentration (mg/L) 45 33 39 48 51 42 PF (to AA) 1.33 1.32 1.44 1.42 1.34 1.36 WRRF Project TM No. 1 – Wastewater Characterization Table A-4. Maximum Week Peaking Factors, Flows and Loads for Each Year Analyzed 2009 2010 2011 2012 2013 5-year data Flow Flow (mgd) 6.53 9.69 8.47 5.33 4.54 7.35 PF (to AA) 1.49 2.25 2.04 1.57 1.44 1.89 TSS Load (lb/d) 18,262 17,449 28,176 18,325 16,882 20,962 Concentration (mg/L) 335 216 399 412 446 342 PF (to AA) 1.57 1.56 2.24 1.83 1.84 1.91 NH4 Load (lb/d) 2,406 2,073 2,360 2,020 1,970 2,183 Concentration (mg/L) 44 26 33 45 52 36 PF (to AA) 1.59 1.49 1.77 1.59 1.48 1.59 Table A-5. Maximum Day Peaking Factors, Flows and Loads for Each Year Analyzed 2009 2010 2011 2012 2013 5-year data Flow Flow (mgd) 7.90 11.57 13.21 6.30 4.95 11.12 PF (to AA) 1.80 2.68 3.18 1.86 1.57 2.86 TSS Load (lb/d) 30774 23965 47852 21480 20979 28356 Concentration (mg/L) 467 248 434 409 508 306 PF (to AA) 2.64 2.15 3.80 2.15 2.28 2.59 NH4 Load (lb/d) 2,705 2,537 2,588 2,963 2,239 2,706 Concentration (mg/L) 41 26 23 56 54 29 PF (to AA) 1.79 1.82 1.94 2.33 1.68 1.97 WRRF Project TM No. 1 – Wastewater Characterization Appendix B. Lognormal Distribution and Curve Fit of 5-year Data Figure B-1. Lognormal Distribution of Daily Average Flow Data from 2009 to 2013 Figure B-2. Lognormal Distribution of Dry Weather Daily Flow from 2009 to 2013 WRRF Project TM No. 1 – Wastewater Characterization Figure B-3. Lognormal Distribution of Average Daily TSS Loadings from 2009 to 2013 Figure B-4. Lognormal Distribution of Average Daily Ammonia Loadings from 2009 to 2013 WRRF Project TM No. 1 – Wastewater Characterization Figure B-5. Lognormal Distribution of Dry Weather Daily Average TSS Loadings from 2009 to 2013 Figure B-6. Lognormal Distribution of Dry Weather Daily Average Ammonia Loadings from 2009 to 2013 WRRF Project TM No. 1 – Wastewater Characterization Page intentionally blank. WRRF Project TM No. 1 – Wastewater Characterization Appendix C. Historic Wastewater Generation Rates Historic Wastewater Generation Rates Year Population1 ADWF2 (mgd) Wastewater Generation Rate (gpcd) 2004 44,298 3.5 80 2005 44,687 4.0 90 2006 44,559 4.5 100 2007 44,433 4.1 92 2008 44,579 4.2 94 2009 44,829 3.7 80 2010 45,179 3.8 80 2011 45,528 3.4 80 2012 45,878 2.9 60 2013 46,107 2.7 59 1 – Population is from the City’s Unified General Plan – Chapter 8 Water and Wastewater (2010). 2 – ADWF from 2004 through 2006 is from the 2011 Master Plan, and does not include Cal Poly flows. NA – Data Not Available WRRF Project TM No. 1 – Wastewater Characterization Page intentionally blank. Appendix B TM No. 2 - System-Wide Conceptual Alternatives Date: 7/2/2014 To: Carrie Mattingly Phone: (805) 781‐7205 Utilities Director 879 Morro St. San Luis Obispo, CA 93401 CC: Dave Hix; Howard Brewen Prepared by: Jeroen Olthof, P.E.; Matthew Rodrigues, E.I.T. Reviewed by: Lianne Williams, P.E.; Jeff Szytel, P.E.; Holly Kennedy, P.E. Project: WRRF Project SUBJECT: TECHNICAL MEMORANDUM #2 – CONCEPTUAL ALTERNATIVES (FINAL) The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road. These upgrades represent a significant investment and will help the City implement its long‐term strategy for wastewater management. The Program Management (PM) Team has already begun analyzing historical flows to the WRRF in order to estimate the future flows and loads to the plant. However, the future flows and loads to the WRRF could be significantly affected by strategy decisions made by the City in relation to its wastewater collection system, its production of recycled water, and its management of biosolids. In each of these areas there are alternative strategies that, if selected by the City for implementation, would affect future flows and loads to the WRRF. The City is currently completing three related planning projects: a Recycled Water Master Plan (RWMP), a Water Master Plan (WMP) and a Wastewater Collection System Infrastructure Renewal Strategy (WCSIRS). The RWMP will characterize the current and potential future demand for recycled water, and it will include an analysis of future recycled water alternatives. The WMP will identify capital improvements for the water distribution system, and describe the City’s water supply portfolio. The WCSIRS will define a recommended set of collection system upgrades based on the current condition of the system and a capacity evaluation using a newly developed hydraulic model. This conceptual alternatives evaluation is not intended to replace the more detailed analysis in the RWMP and the WCSIRS. 2 This memorandum describes the evaluation of conceptual alternatives performed by the PM Team and key City management and staff, and provides recommendations for continued development of the WRRF Project. The memorandum is organized as follows: Contents Executive Summary ....................................................................................................................................... 2 Conceptual Alternatives ................................................................................................................................ 3 Evaluation Process ...................................................................................................................................... 10 Evaluation Criteria ................................................................................................................................... 10 Weighting of Criteria ............................................................................................................................... 11 Assignment of Scores .............................................................................................................................. 11 Evaluation of Alternatives ........................................................................................................................... 12 Recommendations ...................................................................................................................................... 13 Executive Summary The PM Team and key City management and staff (Project Team) conducted an evaluation of several conceptual alternatives for wastewater management within the City, with the goals of establishing an appropriate context and identifying prudent strategies for moving forward with the WRRF Project. The conceptual alternatives were intended to be broad representations of distinct management strategies, and included: (1) Future Base Case; (2) Minimize Peak Flow to the WRRF; (3) Maximize Energy Production; and (4) Maximize Recycled Water Production. The alternatives were evaluated and scored using a “triple bottom line” approach, considering economic, social and environmental factors. The highest‐scoring alternative was the Future Base Case, which validates the City’s current direction in wastewater management. Minimizing peak flow to the WRRF, maximizing recycled water production, and maximizing energy production, were ranked second, third and fourth, respectively. Based on the discussion during the evaluation workshop, and subsequent discussion among the Project Team, the following recommendations are proposed: 1. Maximize recycled water production at the WRRF. The Project Team recommends that the WRRF Project incorporate processes and/or facilities to allow operational flexibility and maximize recycled water production as additional demands are identified. 2. Anticipate reductions to future I/I in the collection system. The Project Team recommends that the WRRF Project be designed to adapt to future reductions in peak flows, as well as the potential for higher constituent concentrations associated with reduced dilution from infiltration and inflow (I/I). 3 3. Provide flexibility to accommodate the future addition of a FOG receiving station and co‐ digestion at the WRRF. Although the City does not want to include a FOG receiving station with the WRRF Project at this time, the Project Team recommends that the WRRF Project be designed considering the possibility of adding FOG receiving and co‐digestion at some point in the future, as conditions and/or City priorities change. 4. Provide flexibility at the WRRF to accommodate the future construction of a satellite reuse facility within the City’s collection system. The Project Team recommends that the WRRF Project be designed considering the potential for a satellite treatment plant to be constructed in the future, including consideration for the associated impacts to flow and constituent concentrations at the WRRF. Conceptual Alternatives The Project Team held a workshop to brainstorm conceptual alternatives for long‐term management of the City’s wastewater resources. During the workshop, the team defined four conceptual alternatives to use as a basis for comparison. Each conceptual alternative includes WRRF upgrades to address the new discharge limitations for disinfection by‐products and nutrients, and to accommodate buildout flows. The conceptual alternatives were considered to be mutually exclusive, recognizing that the recommended project would likely include some combination of features from each of these conceptual alternatives to achieve an optimized outcome. The conceptual alternatives discussed during the workshop are as follows: Future Base Case. This conceptual alternative extends the City’s currently documented collection system management, recycled water production, and biosolids handling strategies into the future. Minimize Peak Flow to the WRRF. This conceptual alternative would have a goal of minimizing the peak wastewater flow to the WRRF. Maximize Energy Production. This conceptual alternative would have a goal of generating as much energy as possible from biogas production and cogeneration. Maximize Recycled Water Production. This conceptual alternative would have a goal of maximizing the production of recycled water from the City’s wastewater stream. The Project Team identified elements of each conceptual alternative that would set it apart from the other alternatives. In identifying specific elements of each alternative, the Project Team recognized that elements can be characterized by what component of the system they impact. Five system components were identified: the collection system; the WRRF; San Luis Obispo Creek; recycled water; and biosolids. These system components are illustrated in Figure 1. For each of these five components, the Project Team identified elements that could be a part of each conceptual alternative to set it apart from the other alternatives. A list of these elements is shown in Table 1. 4 Figure 1. System Components Table 1. Potential Elements to Implement each Conceptual Alternative Conceptual Alternative System Component Element Future Base Case Collection System Collection system upgrades. Construct improvements to address capacity and condition related deficiencies in the collection system. WRRF Upgrades for new limits and future flows. Upgrade treatment processes to meet new discharge limits, and handle projected future flow (updated estimates of the future flow are currently being prepared). San Luis Obispo Creek Discharge effluent not used as recycled water. Under current conditions, the WRRF treats approximately 4 million gallons per day (mgd), of which approximately 300,000 gallons per day (gpd) is used as recycled water. The remainder is discharged to San Luis Obispo Creek. The plant’s discharge permit requires a minimum daily discharge of approximately 1.6 mgd to maintain fish habitat. Recycled Water Continue serving existing customers and implement RWMP improvements. The RWMP may identify new customers and recommend infrastructure improvements to facilitate distribution of recycled water. For the Future Base Case, it was assumed that the system would continue to meet current demands, and that the City would implement the recycled water system improvements identified in the RWMP. Collection System WRRF San Luis Obispo Creek Recycled Water Biosolids 5 Conceptual Alternative System Component Element Biosolids Truck to Santa Maria. Biosolids from the WRRF are currently trucked to a compost facility in Santa Maria. For this element the City would continue to send digested and dewatered biosolids to Santa Maria. Minimize Peak Flow to WRRF Collection System Aggressive I/I reduction. The City could pursue an aggressive program of I/I reduction, including additional smoke and dye testing; rehabilitation of mains, manholes, and laterals; and potential requirements for private owners to inspect and repair service laterals. I/I reduction would not be expected to reduce the solids or nutrient loading to the WRRF. Collection System Remote wet weather storage. The City could construct a storage facility in the collection system to store excess flows during wet weather events and reduce the peak flow that enters the WRRF. This facility could be a buried structure located at a strategic point in the collection system. After the storm event, the stored wastewater would be released back into the collection system for treatment at the WRRF. This facility would not be used for equalization of the diurnal variation of dry weather flows. WRRF Upgrades for new limits and reduced peak flows. Upgrade treatment processes to meet new discharge limits. This element would differ from the Future Base Case in that it would be expected that future peak flows would be reduced. Maximize Energy Production Collection System Collection system upgrades. Construct improvements to address capacity and condition related deficiencies in the collection system. WRRF FOG receiving station at WRRF. Under this element the City would construct a facility at the WRRF to collect FOG from dischargers. The waste would be co‐digested with solids from the current treatment process to maximize biogas production. Maximize Recycled Water Production Collection System Restrict water softeners. One of the potential obstacles in marketing more recycled water is the level of Total Dissolved Solids (TDS). Some cities have restricted or banned the use of in‐home water softeners, which discharge brine to the collection system. WRRF Maximize tertiary treatment capacity. This element would include tertiary capacity to maximize recycled water production at the WRRF. 6 Conceptual Alternative System Component Element San Luis Obispo Creek Meet only minimum discharge. Under this element the City would seek to discharge only the required minimum flow to San Luis Obispo Creek (approximately 1.6 mgd). All available wastewater in excess of this amount would be targeted for use as recycled water. Recycled Water Satellite reuse. The City is currently evaluating the feasibility of a satellite water reuse facility. Such a facility could be located along a major trunk line in the collection system. It would treat wastewater to produce recycled water, allowing the use of recycled water in areas not served by the current distribution system. Recycled Water Expanded recycled water distribution system. Under this element the City would plan to continue producing recycled water at the WRRF, but would expand the distribution system to allow recycled water to be delivered to more customers. Recycled Water Recycled water storage. Both on a diurnal and a seasonal basis, the demand for recycled water varies over time differently than the supply of wastewater effluent. The City could identify locations or facilities that could be used for the storage of recycled water. Storage would help match the supply of recycled water to the demand. The elements can also be organized by system component, as shown in Table 2. Table 2. Elements by Conceptual Alternative and System Component Potential Elements for each System Component Conceptual Alternative Collection System WRRF San Luis Obispo Creek Recycled Water Biosolids Future Base Case Capacity and condition related upgrades Upgrades for new limits and future flows Discharge effluent not used as recycled water Continue serving existing customers and implement RWMP improvements Truck to Santa Maria 7 Potential Elements for each System Component Conceptual Alternative Collection System WRRF San Luis Obispo Creek Recycled Water Biosolids Minimize Peak Flow to WRRF Capacity and condition related upgrades Aggressive I/I reduction Remote wet weather storage Upgrades for new limits and existing flows Discharge effluent not used as recycled water Continue serving existing customers and implement RWMP improvements Truck to Santa Maria Maximize Energy Production Capacity and condition related upgrades Upgrades for new limits and existing flows FOG receiving station at WRRF Discharge effluent not used as recycled water Continue serving existing customers and implement RWMP improvements Truck to Santa Maria Maximize Recycled Water Production Capacity and condition related upgrades Restrict water softeners Maximize tertiary treatment capacity at the WRRF Upgrades for new limits and existing flows Meet only minimum discharge Satellite reuse Expanded recycled water distribution system Recycled water storage Truck to Santa Maria Schematic diagrams were developed for each alternative and are shown in the figures below. 8 Figure 2. Schematic of Conceptual Alternative: Future Base Case Figure 3. Schematic of Conceptual Alternative: Minimize Peak Flow to the WRRF 9 Figure 4. Schematic of Conceptual Alternative: Maximize Energy Production Figure 5. Schematic of Conceptual Alternative: Maximize Recycled Water Production 10 Evaluation Process The Project Team developed an evaluation process to identify criteria for success and assign scores to each alternative strategy based on how well it met the City’s criteria. The Project Team first defined a set of criteria that match the City’s key goals and objectives. Weighting factors were then assigned to each criterion to reflect the relative importance of the different criteria. The Project Team then assigned scores for each alternative based on how well it met the criteria. Scores and weights were combined to yield an aggregate score for each alternative. Evaluation Criteria The Project Team identified a number of criteria that could be used to measure how well a conceptual alternative meets the City’s objectives. These criteria were developed in part from the Program Charter. They are divided into three categories, reflecting the three contributors to a Triple Bottom Line: economic, social, and environmental. The criteria are listed in Table 3. Table 3. Evaluation Criteria Category Criterion Description Economic Value for ratepayers' investment This criterion is based on how the value received by the City relates to the required investment. Flexibility Short term flexibility is the ability to adapt to changes in regulations or unexpected conditions. Long‐term flexibility is the ability to adapt to long‐term changes such as demographic changes or changes in water use patterns. Robustness The reliability of the equipment or processes that will be needed to implement a strategy, and how well the equipment and processes can be expected to stand the test of time, including reliable compliance. Simplicity A higher degree of simplicity indicates less potential for process failure or operator error due to the complexity of an element or strategy. Scalability This criterion represents the degree to which a strategy that works well on a limited or trial basis can be scaled up to address City‐wide issues and accommodate future growth. Social Creates and sustains partnerships The alternative is conducive to fostering partnerships with other project stakeholders. Positive community engagement This criterion gauges how an alternative will affect the City’s ability to engage community members and build broad‐ based community support for the WRRF and its mission. Good neighbor The alternative allows the City and the WRRF to build goodwill with citizens and businesses near the WRRF. 11 Category Criterion Description Environmental Maximize sustainable resource recovery The alternative helps the City meet its goal of recovering available resources from wastewater. Manage salts and pollutants in the basin The management of salts and nutrients is an increasingly important issue for wastewater dischargers and recycled water producers; this criterion gauges how an alternative affects the City’s ability to effectively manage these constituents. Construction impacts to the community The short‐term impacts related to construction of improvements (e.g., noise, dust, vibration). Operations impacts to the community The long‐term impacts related to new operations (e.g., increased truck traffic for hauling organic waste). Reliable compliance The alternative’s impact on the City’s ability to consistently meet environmental regulations. Weighting of Criteria A total of 13 criteria were identified in the three categories (economic, social, and environmental). The Project Team felt that the 13 criteria were not equally important in assessing an alternative’s performance in meeting the City’s objectives. Therefore, the Project Team assigned a weight of 1, 2, or 3 to each criterion (with 3 being the highest‐scoring or most important) to reflect their relative importance. The weights assigned to each criterion are shown in Table 4. Table 4. Criteria Weights Category Criterion Weight Economic Value for ratepayers' investment 3 Flexibility 2 Simplicity 3 Scalability 1 Robustness 2 Social Creates and sustains partnerships 2 Positive community engagement 2 Good neighbor 3 Environmental Maximize sustainable resource recovery 2 Manage salts and pollutants in the basin 2 Construction impacts to the community 1 Operations impacts to the community 2 Reliable compliance 3 Assignment of Scores The Project Team developed a scoring guide to facilitate the assignment of scores for each alternative. For each criterion, an alternative was given a score of 1, 3, or 5. These scores were assigned in a 12 workshop setting and entered in a spreadsheet for calculation of an aggregate score. The guidelines that were developed to help the scoring assignment process are shown in Table 5. Table 5. Guidelines for Assignment of Scores Category Criterion Score 1 3 5 Economic Value for ratepayers' investment Low relative value for overall investment Moderate value for overall investment High value for overall investment Flexibility Less flexible Typical More flexible Robustness Less robust; higher risk Typical More robust; less uncertainty Simplicity More complex Typical Less complex Scalability Not scalable Neutral Scalable Social Creates and sustains partnerships Impedes partnerships Allows partnerships Fosters partnerships Positive community engagement Discourages positive community engagement Permits positive community engagement Encourages positive community engagement Good neighbor Expected to harm relations Neutral Expected to improve relations Environmental Maximize sustainable resource recovery Reduces recovery of resources Neutral Maximizes resource recovery Manage salts and pollutants in the basin Reduces ability to manage Neutral Enhances ability to manage Construction impacts to the community Significant negative impacts Typical Minimal impacts or positive enhancements Operations impacts to the community Significant negative impacts Typical Minimal impacts or positive enhancements Reliable compliance Uncertainty in compliance Typical Increased confidence in compliance Evaluation of Alternatives In the workshop, the Project Team evaluated the conceptual alternatives, and through consensus, scored each criterion and conceptual alternative. The results of the scoring process are summarized in Table 6. 13 Table 6. Weighted Scores for Each Conceptual Alternative Evaluation Criteria Total Va l u e fo r ra t e p a y e r s ' in v e s t m e n t Fl e x i b i l i t y Si m p l i c i t y Sc a l a b i l i t y Ro b u s t n e s s Cr e a t e s an d su s t a i n s pa r t n e r s h i p s Po s i t i v e co m m u n i t y en g a g e m e n t Go o d ne i g h b o r Ma x i m i z e su s t a i n a b l e re s o u r c e re c o v e r y Ma n a g e sa l t s an d po l l u t a n t s in th e ba s i n Co n s t r u c t i o n im p a c t s to th e co m m u n i t y Op e r a t i o n s im p a c t s to th e co m m u n i t y Re l i a b l e co m p l i a n c e Weight 3 2 3 1 2 2 2 3 2 2 1 2 3 Future Base Case 3 5 3 3 5 5 5 5 5 3 3 3 5 116 Minimize Peak Flow to WRRF 3 5 5 5 5 5 1 3 3 3 1 1 5 100 Maximize Energy Production 5 1 1 3 3 5 3 3 5 1 1 1 3 78 Maximize RW Production 5 3 1 5 3 5 5 3 5 1 1 1 5 94 Recommendations The highest‐scoring alternative was the Future Base Case, which validates the City’s current direction in wastewater management. Minimizing peak flow to the WRRF, maximizing recycled water production, and maximizing energy production, were ranked second, third and fourth, respectively. Based on the discussion during the evaluation workshop, and subsequent discussion among the Project Team, the following recommendations are proposed: 1. Maximize recycled water production at the WRRF. The maximize recycled water production alternative received low scores relative to the other alternatives for simplicity as well as construction and operations impacts to the community, primarily related to implementation of a satellite reuse facility. However, that conceptual alternative scored highly relative to the other alternatives for value for the ratepayers’ investment, scalability, and maximizing sustainable resource recovery, and is consistent with the City’s long‐term strategy to further develop its recycled water resource. Therefore, the Project Team recommends that the WRRF Project 14 incorporate processes and/or facilities to allow operational flexibility and maximize recycled water production as additional demands are identified. 2. Anticipate reductions to future I/I in the collection system. The alternative to minimize peak flow to the WRRF received low scores relative to the other alternatives for positive community engagement as well as construction and operation impacts to the community, primarily related to implementation of flow equalization within the collection system. However, it scored highly relative to the other alternatives for simplicity, scalability and robustness. The WWCIRS is envisioned to identify strategic improvements to the collection system that will not only address capacity and condition related deficiencies, but will also reduce I/I. Therefore, the Project Team recommends that the WRRF Project be designed to adapt to future reductions in peak flows, as well as the potential for higher constituent concentrations associated with reduced dilution from I/I. 3. Provide flexibility to accommodate the future addition of a FOG receiving station and co‐ digestion at the WRRF. The alternative to maximize energy production at the WRRF received low scores relative to the other alternatives for flexibility and simplicity, as well as construction and operations impacts to the community. However, it scored highly relative to the other alternatives for value for the ratepayers’ investment and maximizing sustainable resource recovery. Although the City does not want to include a FOG receiving station with the WRRF Project at this time, the Project Team recommends that the design consider the possibility of adding FOG receiving and co‐digestion at some point in the future, as conditions and/or City priorities change. 4. Provide flexibility at the WRRF to accommodate the future construction of a satellite reuse facility within the City’s collection system. Although the City is not proceeding with a satellite reuse facility at this time, they continue to investigate technologies and partnerships that could support the development of a satellite reuse facility in the future. To‐date, the City’s discussions have centered on considering a satellite reuse facility to serve Cal Poly. Therefore, the Project Team recommends that the WRRF Project be designed considering the potential for a satellite treatment plant to be constructed in the future, including consideration for the associated impacts to flow and constituent concentrations at the WRRF. Appendix C TM No. 3 - Site Planning Date: 12/15/2014 To: Carrie Mattingly Phone: (805) 781‐7205 Utilities Director 879 Morro St. San Luis Obispo, CA 93401 CC: Dave Hix; Howard Brewen; Pam Ouellette Prepared by: Jasmine Diaz, E.I.T., Matt Rodrigues, E.I.T. Reviewed by: Jeffrey Szytel, P.E., Holly Kennedy, P.E., Lianne Williams, P.E. Project: WRRF Project SUBJECT: TECHNICAL MEMORANDUM #3 – SITE PLANNING STUDY (FINAL) The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long‐term strategy for resource management. The Program Management Team (PM Team) is in the early phases of developing planning criteria, project context, and high level goals and objectives for the WRRF Project leading up to the development of a Facilities Plan. The purpose of this memorandum is to document the availability, opportunities, constraints, considerations and preferences for utilizing the various areas throughout the site for current and/or future planned improvements. On June 10, 2014, the PM Team and key City management and staff (Project Team) conducted a workshop and site walk at the WRRF to develop the vision and preferences for development of the WRRF site, as well as document WRRF site constraints, considerations and opportunities. This technical memorandum describes the results of that workshop and the associated site planning study performed by the PM Team. The memorandum is organized as follows: WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 2 of 47 Contents WRRF Area Designations ............................................................................................................................... 2 Project Background ....................................................................................................................................... 4 WRRF Energy Efficiency Project ................................................................................................................ 4 Site Context ............................................................................................................................................... 6 Stakeholder Interviews and Community Outreach .................................................................................. 8 Site Planning Study ....................................................................................................................................... 8 Workshop .................................................................................................................................................. 8 Site Evaluation .......................................................................................................................................... 8 Site Opportunities and Constraints ......................................................................................................... 14 Adjacent Areas ........................................................................................................................................ 20 Appendix A – Site Walk Worksheets ........................................................................................................... 21 Appendix B – WRRF Energy Efficiency Project Design Drawings ................................................................ 26 Appendix C – GIS Underground Utilities ..................................................................................................... 35 Appendix D – Community Workshop Issue Identification Results ............................................................. 42 WRRF Area Designations The WRRF site is divided into multiple process areas, or “Units,” to differentiate operational responsibilities by process and spatial location. The PM Team utilized these designations for the site planning study. In addition, the PM Team defined the “Adjacent Areas” and “Open Space Area”. The Unit and Area boundaries are shown in Figure 1, and defined below. WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 3 of 47 Figure 1 Aerial view of SLO WRRF indicating boundaries of each Unit and area Units and Areas Unit II, Solids. Consists of all solids handling processes including the operations building, headworks infrastructure, the DAFT, anaerobic digesters, ferrous chloride chemical station, cogeneration equipment, sludge dewatering units, motor control center (MCC) A, MCC G, the supernatant lagoon and the sludge drying beds. The southern boundary of Unit II is the Bob Jones Bike Trail. Unit III, Aerobic. Consists of all clarifiers, biofilter #1 (decommissioned), biofilter #2 (decommissioned), biofilter #3 (on‐line), aeration basins, caustic soda and magnesium hydroxide chemical station, existing Cal Poly Algae Field Station, MCC B, equalization basin and the switchgear electrical building. Unit IV, Disinfection. Encompasses all tertiary treatment facilities at the southwest end of the site. Infrastructure within the bounds of Unit IV includes the filter towers, administrative building, WRRF water chemistry laboratory, secondary effluent equalization tanks, cooling towers, sodium bisulfite and sodium hypochlorite chemical station, anhydrous ammonia chemical station (decommissioned), disinfection channels, recycled water pump station, MCC R, MCC J (includes MCC M & MCC N) and recycled water underground storage tank. Area A, Adjacent Areas. The adjacent areas are defined as the surrounding properties which have the potential for relocation. Potential for relocation of the existing facilities within this WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 4 of 47 area will be determined through negotiations between City staff, WRRF staff and the affected project stakeholders, including the Prado Day Center and SLO Transit. Area OS, Open Space Area. The southwest end of the WRRF property is bounded by the 101 freeway to the northwest, abandoned disinfection infrastructure to the south and the Bob Jones Bike Trail to the southeast. The Open Space Area, totaling roughly 22.8 acres, contains a constructed wetland, decommissioned disinfection facilities, diversion ponds and the access road to the outfall at San Luis Obispo Creek. Project Background The following sections provide background and context that help to frame the site planning study. WRRF Energy Efficiency Project The City is currently implementing energy related upgrades to the WRRF through the WRRF Energy Efficiency Project. The WRRF Energy Efficiency Project is being implemented as a public/private partnership through PG&E’s Sustainable Solutions Turnkey (SST) program. Construction for the WRRF Energy Efficiency Project is expected to conclude in late 2015. Improvements being implemented as part of the WRRF Energy Efficiency Project are summarized in Table 1 and shown in Figure 2. Energy Efficiency improvement “Identifiers” in Table 1 correspond to the annotations in Figure 2. For a detailed description of the measures, refer to the Investment Grade Analysis Report prepared by PG&E and AECOM. Appendix B contains a subset of the design plans for each improvement. Table 1 WRRF Energy Efficiency Project infrastructure upgrades and process improvements ENERGY EFFICIENCY IMPROVEMENTS Identifier Improvement Location Process Existing Infrastructure Affected WRRF 1 Install cogeneration system that generates electricity and heat onsite from digester gas Unit II: Solids Digestion Existing micro‐turbine system will be removed; New digester heating system interconnection will be installed WRRF 2 Upgrade headworks, including headworks equipment replacement, grit screening and washing system, and seasonal shut down of one grit chamber Unit II: Solids Primary Treatment Removal and replacement of bar screens, and screenings washing and dewatering equipment; New grit screening and washing equipment and check valves downstream of grit pumps; Existing grit pumps will remain WRRF 3* Add timers to primary sludge pump station to satisfy desired sludge depth in primary clarifiers Unit III: Aerobic Primary Treatment and Solids Thickening Primary sludge pumps will run on timers WRRF 4 Install screw press to achieve higher solids concentration Unit II: Solids Solids Dewatering Existing belt press will remain operable WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 5 of 47 WRRF 5 Install RAS pump VFDs to allow speed of RAS pumps to vary with influent flow to WRRF Unit III: Aerobic Secondary Treatment Replacement of existing RAS pump motors; Installation of VFDs and corresponding instrumentation and controls; Installation of magnetic flow meter on pump discharge line from Final Clarifier #5 WRRF 6 Upgrade filter towers, including replacement of control system, filter media and underdrain Unit IV: Disinfection Tertiary Treatment Filter control system will be removed and replaced; Filter media will be replaced with monomedia increasing filter capacity; Underdrain will be replaced with S‐ type underdrain; VFDs will be added to backwash pumps WRRF 7 Modify aeration tank air pressure controls to adjust discharge header pressure set‐ point based on real‐ time valve position Unit III: Aerobic Secondary Treatment Existing valve controllers and/or PLC interface will be modified to integrate to blower master control panel PLC; Programming will be modified to enable the most open valve and pressure reset sequence WRRF 8 Install LED outdoor lighting Site‐wide Electrical Exterior light fixtures throughout plant will be upgraded to LED lights WRRF 9 Upgrade SCADA systems, including replacement of existing RTUs with Allen‐ Bradley PLCs Site‐wide O&M Allen‐Bradley PLCs will be installed throughout plant; Some DPCs will be consolidated; PLCs will interface with SCADA via new fiber optic network (separate project); Existing Data Concentrator will be dismantled (no longer be required) *Project WRRF 3 is currently under review and may not be implemented. WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 6 of 47 Figure 2 Site locations of WRRF Energy Efficiency Project improvements Site Context Due to the geographic location of the WRRF, proximity of several future developments, bike crossing extensions, and road improvements, the City anticipates increasing and sustained high levels of traffic surrounding the WRRF, including pedestrians, cyclists and motor vehicles. The west side of the plant is bounded by the 101 Freeway, the north end of the site is bounded by what will become a major cross‐ town thoroughfare (Prado Road), and the eastern and southern portions of the property are bounded by the Bob Jones bike trail and San Luis Obispo Creek. These proposed improvements to off‐site areas are illustrated in Figure 3. There are many proposed improvements in the area surrounding the WRRF that present an opportunity to incorporate impactful interpretive elements, appealing landscape and welcoming access points at the boundary of the WRRF. The site perimeter must provide a balance of access and security while promoting integration of the WRRF and the surrounding public elements. During site planning, the Project Team will consider potential impacts to neighboring residences and businesses, including odor, noise and construction disturbance. WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 7 of 47 Fi g u r e 3 Ae r i a l co n t e x t ma p of pr o j e c t si t e , pl a n n e d in f r a s t r u c t u r e im p r o v e m e n t s an d pu b l i c access connections WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 8 of 47 Stakeholder Interviews and Community Outreach The PM Team conducted a series of stakeholder interviews and held a community workshop to communicate the scope and goals of the WRRF Project and better understand the concerns and preferences of interested parties and the ratepayers. The results of the community workshop issue identification exercise are included in Appendix C. Through these outreach activities, community members have expressed their support for an interpretive center and/or elements at the WRRF that are integrated with and accessible from the Bob Jones bike trail. The siting of the interpretive elements will be performed in parallel with siting of the treatment upgrades, with treatment upgrades taking precedence. Additional factors that may be considered when siting the interpretive elements include project budget, available footprint, internal negotiations, safety and security, accessibility, and proximity to sources of noise and odor. Site Planning Study The site planning study consisted of an interactive workshop and site walk with City staff, followed by a site evaluation performed by the PM Team. The following sections describe the approach and results of the site planning study. Workshop Prior to discussing specific opportunities and constraints for individual Units, the Project Team discussed the City’s vision and goals for the site, and identified broad site considerations and project opportunities for the facility as a whole. The Project Team then moved through the facility, Unit by Unit to discuss specific opportunities, preferences and constraints. After the workshop, the Project Team participated in a site walk to review and discuss the opportunities, preferences and constraints for each Unit. Worksheets were distributed prior to the site walk for purposes of recording site conditions for each Unit and area. These worksheets were collected after the workshop and consolidated into the worksheets included in Appendix A. Site Evaluation The PM Team utilized the data and information provided by City staff and WRRF operators during the workshop and site walk to perform the site evaluation. For the facility as a whole, important site features were identified, including: major utilities; traffic and circulation routes; and telecommunications and/or network infrastructure. At the Unit level, the participants of the workshop assessed the infrastructure that could potentially remain, infrastructure that may be removed, and potential site opportunities that were identified specifically by WRRF staff and operators. Figure 4 and Figure 5 indicate which facilities were probable to remain (“Remain”), which may facilities be removed (“Remove”), and those that could be potentially repurposed or removed (“Tentative”), based on the consensus of the workshop participants. Figure 6 shows available space areas, potential available areas, traffic and circulation routes and parking areas. The signalized intersection associated with the proposed Prado Road improvements and a potential access alignment with the intersection are also illustrated in Figure 6. Figure 7 indicates the location of operator workstations, and the automatic, grab, constrained access and desired sample locations. A process flow schematic of the existing WRRF is provided in Figure 8 for reference. Appendix C contains figures that indicate the approximate location of underground utilities and site piping in Unit II and Unit III, based on GIS data provided by the City. Utility information for Unit IV was not available. The utility data shown for Unit II and Unit III has not been verified, thus the Project Team will need to evaluate the accuracy of this data and coordinate efforts with the basemap development. WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 9 of 47 Fi g u r e 4 Si t e av a i l a b i l i t y of Un i t s II , II I an d IV (p r e l i m i n a r y as s e s s m e n t ) WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 10 of 47 Fi g u r e 5 Si t e Av a i l a b i l i t y of Op e n Sp a c e Ar e a WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 11 of 47 Fi g u r e 6 Ma p of SL O WR R F il l u s t r a t i n g av a i l a b l e sp a c e ar e a s , po t e n t i a l av a i l a b l e ar e a s , tr a f f i c an d ci r c u l a t i o n routes, and parking locations WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 12 of 47 Fi g u r e 7 Ma p of SL O ‐WR R F il l u s t r a t i n g cu r r e n t sa m p l i n g si t e s , de s i r e d fu t u r e sa m p l i n g si t e s , an d operator workstations WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 13 of 47 Fi g u r e 8 Sc h e m a t i c of SL O WR R F pr o c e s s un d e r ty p i c a l op e r a t i o n WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 14 of 47 Site Opportunities and Constraints During the workshop and site walk, the Project Team identified several ideas for how operators, laboratory analysts and management staff envision specific upgrades or repurposing of available space. Table 2 through Table 5 list the opportunities and constraints identified in each Unit and the Open Space Area categorized by process type. WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 15 of 47 Table 2 Unit II: Solids opportunities and constraints Unit II: Opportunities Headworks Could enclose headworks with building equipped with air scrubbing equipment to reduce odor release from headworks. Potentially modify or replace aerated grit process that is not part of the Energy Efficiency Project to improve grit removal efficiency. Could modify or replace influent flow meters to allow measurement of peak flow intensity. Solids Thickening Solids and nutrient loading to the aeration basins could be significantly decreased if an alternate DAFT internatant process flow is identified. Currently, the nutrient‐rich DAFT internatant is diverted directly upstream of the aeration basins. Increased flexibility with this recycle stream would help operations avoid system shocks to the aeration basins at times of peak loading. Potentially replace the DAFT with screw thickeners to increase solids content sent to the digesters, improve system reliability and reduce energy costs. Provided an alternative solids thickening process is implemented, consider repurposing existing DAFT unit to receive FOG and/or liquefied food waste streams to augment digesters and enhance biogas production. Supernatant Lagoon Consider relocating and/or optimizing the supernatant lagoon. The design and configuration of the supernatant lagoon process limits operational flexibility and increases maintenance requirements. By potentially relocating the lagoon, this area of the site may be better suited for flow equalization, interpretive elements, public amenities or administrative and operations facilities. Optimizing the process could lessen maintenance requirements and improve flow control in and out of the lagoon. Solids Digestion Consider replacing Digester #3 with a digester of similar capacity to Digester #1. Sludge Drying Beds If another screw press is installed for redundancy, then a portion of sludge drying beds 1‐8, and possibly bed 9 and 9a, could be utilized to accommodate the expansion or compartmentalization of the existing equalization basin. General Although biosolids truck pickups will be infrequent following the conclusion of the Energy Efficiency project, access and egress to and from the area northeast of the equalization basin is limited. The new site layout around the solids processes should consider routes and space requirements of large vehicles and options to eliminate or reduce the need for biosolids trucks to drive in reverse. Unit II: Constraints Headworks Building a structure around the headworks would be costly, as the footprint of the headworks processes is significant (about 10,000ft2). Traffic and Circulation Truck access throughout the Unit is limited, especially near the current solids loading area (north of EQ basin) and near the digesters. Note that the solids loading area will be moved to the dewatering facility when it is upgraded with the Energy Efficiency Project. General Existing trunk lines are to remain in place. Sludge drying beds 10‐16 are currently used as disposal beds for vactor trucks. If these drying beds are removed, another location for these wastes would need to be identified. Prevailing westerly winds transport odors in the direction of nearby neighborhoods and businesses. Odors are typically observed at the equalization basin and the supernatant lagoon, which are located at the northeastern end of the plant. Location near supernatant lagoon can be very noisy due to operations of a neighboring business, therefore it may not be a favorable location for the interpretive center and/or educational elements. The neighboring commercial truck fueling and maintenance station often produces loud noises throughout the day. WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 16 of 47 Table 3 Unit III: Aerobic opportunities and constraints Unit III: Opportunities Equalization Basin Compartmentalize the equalization basin to separate stormwater and process flow equalization. The equalization basin is a single compartment which results in flow spreading out over the entire basin leading to odor issues and deterioration of the liner. Operators would prefer to have a more efficient and safe method to remove solids that accumulate within the basin. One example would be multiple water cannons similar to those used to clean the EQ tanks in Unit IV. Clarifiers Potentially eliminate the primary clarifier flow splitter box (also known as the peanut butter box). Because of its location and arrangement, grease buildup and unequal flow distribution are a concern. Address the operational burdens and treatment inefficiencies associated with the primary clarifiers. Primary clarifier #2 is sinking towards the northeast, the piping near the clarifiers is degraded and solids pumping to the DAFT lacks automation. Consider covering final clarifiers to mitigate algae growth. Consider adding an energy dissipating feed well (similar to LA‐EDI at Hyperion) to increase treatment performance and capacity. Increasing solids removal in the final clarifiers may decrease filter backwash frequency, which is desirable due to the current hydraulic bottleneck at the filters. Cal Poly Research Area Although the footprint currently occupied by the Cal Poly research area is likely to be used for additional secondary treatment infrastructure, the City wishes to designate a location on‐site specifically for research and pilot projects. Electrical Building Possibly preserve the existing electrical and generator building and consider the need for additional emergency power supply. General Improve flow monitoring capabilities through aerobic process. Potentially demolish and relocate existing maintenance buildings and consolidate with other facilities. Consider modifying the existing blower shade structure to create an enclosed structure for new blowers. Harvest and repurpose rock media from biofilters #1, #2 and #3 to use in landscaping, donate to other City uses and/or store in an accessible location for general reuse throughout the City. Facility Power New cogeneration system may provide additional backup power during power outages. Existing requirements from PG&E do not allow cogeneration system to operate during power outages. Discussions with PG&E are required to determine if new cogeneration system can be used as backup power source during outages. Unit III: Constraints Clarifiers Underground piping leading to and from primary clarifiers is degraded, therefore pipe removal in that location, or tie‐ins to the primary clarifiers possess some construction risk. Facility Power Current emergency power capacity is insufficient for full operation of the existing facility during power outages. General The space in between the electrical building and the final clarifiers contains a a vault that provides access to the major utility routings directly outside the electrical building. WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 17 of 47 Table 4 Unit IV: Disinfection opportunities and constraints Unit IV: Opportunities Cooling Towers Possibly reroute process flow such that cooling towers are downstream of tertiary treatment process and directly upstream from discharge to creek. A substantial amount of energy is wasted by cooling the water upstream of the filters since the water is reheated through the tertiary treatment process. This process change could also potentially reduce the amount of biofilm growth in the cooling towers. Additionally, recycled water does not need to be cooled. Disinfection Process Consider maintaining separation of the process flow and recycled water process flow to ensure energy is not wasted by cooling recycled water. This opportunity is warranted only if the cooling towers are rerouted downstream of the disinfection channels (see note above). Equalization Tanks Consider covering the equalization tanks to mitigate biomass growth. Administrative Facilities Maintaining Environmental Laboratory Accreditation Program (ELAP) certification can be accomplished if new facilities are built on available space, instead of retrofitting the existing administrative building. (See note in Constraints – Administrative Facilities) Consider relocating the administrative facilities in close proximity to the bike path and natural elements. General Consider providing an area to gather for barbeques, public gatherings, presentations and/or outdoor meetings. Remove or repurpose aqueous ammonia tanks. The process does not warrant the use of aqueous ammonia; the footprint occupied by the tank can be used for storage of a different chemical or can be deemed as potential construction space. Constraints Cooling Towers Existing process flow places the cooling towers upstream of the filters and disinfection processes. Significant piping modifications and/or relocation of cooling towers are required to reroute the cooling towers downstream of these facilities. Filter Towers Although the filter tower capacity is being upgraded to 8 MGD through the Energy Efficiency Project, the filter towers will be unable to handle peak flows during storm events. This hydraulic bottleneck limits operator’s flexibility in the disinfection process if blending is not an option during storm events. Administrative Facilities The existing administrative building houses the WRRF’s ELAP Certified water quality lab. This lab must be preserved during rehabilitation or demolition of the administrative building to ensure the lab does not lose its certification. Recycled Water Process No off‐site elevated storage tanks are currently available for recycled water storage. WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 18 of 47 Table 5 Open Space Area opportunities and constraints Open Space Area: Opportunities Diversion Ponds Landscape or clean perimeter of basins and include this area in public tours of the WWRF. Potentially discuss process control and/or outfall location and sampling. If the diversion ponds are rehabilitated, it would allow both ponds to be used to their full capacity. Currently one of the diversion ponds has less capacity than the other due to holes in the liner. If significant construction or demolition occurs at the decommissioned facilities, equalization retrofits to the nearby diversion ponds could be addressed. Currently, equalization between the ponds can only be controlled with a portable pump because the decommissioned disinfection channels are directly downstream of the existing effluent gates of the diversion ponds. Consider rehabilitating the gates located at the southern end of the diversion ponds to create the ability to equalize the flows between the two emergency storage ponds. Constructed Wetlands Consider enhancing the public benefit of the wetlands by adding bird watching information, viewing platforms and/or other amenities. Decommissioned Facilities Increase level of safety within the WRRF property by demolishing and removing decommissioned disinfection process. Evaluate the legality and safety of alternate methods of demolishing decommissioned facilities, such as partial removal and/or filling with structural bacfill. Potentially preserve objects from decommissioned facilities (e.g. screen) to use in the interpretive center as architectural/educational/historical features. Potentially rehabilitate building(s) to accommodate ongoing use by Park Rangers. Access and Circulation Improve access to outfall and diversion pond locations by landscaping or clearing open space area and designating a road specifically for SLO WRRF staff. Currently, staff use part of the bike path to get to the outfall location and diversion ponds; this poses a hazard for those on the bike path and for SLO WRRF staff in their vehicles. General Further evaluate opportunities for use of the Open Space Area with the Project Team. A substantial amount of open space is available for use and the incorporation of the bike path provides an opportunity for viewing platforms, bird watching or educational elements. The Open Space Area is in close proximity to community bike paths and homeless encampments, therefore low chain link fences around decommissioned facilities and the presence of hazards pose a safety risk and liability for the City. Site safety could be greatly improved by addressing safety concerns within the Open Space Area. Sampling Currently samples are obtained via an automatic samplers or grab samples. Additional sampling sites between processes and improved accessibility to sampling sites would allow the lab staff to collect more information. The information is valuable for maintaining compliance and allowing the operators to better monitor performance of processes. Open Space Area: Constraints WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 19 of 47 Diversion Ponds The valve used to divert process flow from the outfall to the diversion ponds is located a significant distance away from the nearest operator workstation. The delay between the disinfection system alarm and the time flow is diverted may result in a violation. Diversion ponds must remain in place to provide operational flexibility during disinfection process interruptions. If the gates at the southern end of the of the emergency storage ponds where opened, the flow from both emergency storage ponds would flow directly into the abandoned cholrine contact channels at the most southern part of the plant. The influent gate into the channels would need to be blocked in order to use the gates for equalizing flow between the ponds. Table 5 continued Open Space Area Constraints Decommissioned Facilities The facilities at the southernmost end of the site are currently not part of the treatment process, but are occupied by City Park Rangers. Coordination with the Park Rangers will be necessary to determine if the facilities should be rehabilitated for their ongoing use or fully decommissioned. Demolition and removal of decommissioned facilities may be costly due to the amount of infrastructure, the presence of hazardous materials and inaccessibility. Access and Circulation Currently, the bike path is the access and egress pathway to the outfall location and diversion ponds which limits operator response time to disinfection alarms and poses safety issues for both bike path users and WRRF staff. Outfall There are currently no communication lines or area lighting at the outfall area. Providing the capability to communicate with operators at the outfall area would improve safety during storm events or at night. Lighting would allow operators safer and more convenient access to the outfall area at night. Constructed Wetlands The constructed wetlands were built with grant funds, therefore modifications or additions to the constructed wetlands requires coordination with stakeholders that have an understanding of the wetlands project funding source. General The location of the Open Space Area does not lend itself to process related infrastructure, but rather to community integration and interpretive elements. There currently is no lighting or communication lines near the outfall sampling site or the emergency pond diversion gates. Sampling Safety while obtaining representative samples is a concern because accessibility is limited in specific areas. WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 20 of 47 Adjacent Areas In addition to the Open Space Area discussed in Table 5, the City considers the following areas available for potential future use: (1) SLO Transit bus yard, (2) the materials storage yard, and (3) the Prado Day Center lot and Gun Range. Figure 9 shows the approximate footprints of these Adjacent Areas. The access to these areas and potential uses of these areas may change with the new Highway 101 overpass at Prado Road. Preliminary plans for the overpass indicate the access road to the WRRF will need to be relocated to align with the proposed signalized intersection, as was illustrated in Figure 6. The lot where the existing Prado Day Center and Gun Range site will likely be utilized for relocation of the WRRF access road. This will be re‐evaluated as additional information about the overpass design becomes available. As the project progresses, the Project Team should consider the implications of WRRF access alignment according to the current Prado Road improvement plans which were shown in Figure 6. Figure 9 Aerial view of Adjacent Areas indicating their approximate footprints Prado Day Center, Gun Range and Vacant Lot ~1.9 acre footprint Materials Storage Yard ~1.4 acre footprint SLO Transit Bus Yard ~1.8 acre footprint WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 21 of 47 Appendix A – Site Walk Worksheets The Unit worksheets used to document the vision, preferences, constraints, considerations and opportunities during the workshop and site walk, were collected from each workshop participant and the information was consolidated into the appended documents. These documents represent the overarching, collective perspective of the City employees and PM Team staff that participated in the site planning study workshop. The notes documented in the following worksheets are a rough draft of the notes compiled during the workshop by the participants. The intention of the notes and ideas discussed during the workshop is described with more detail in Table 2, Table 3, Table 4, and Table 5. WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 22 of 47 Un i t II : So l i d s Av a i l a b i l i t y • Dr y i n g be d s 10 ‐16 ca n be re m o v e d bu t sp a c e is st i l l ne e d e d fo r va c t o r tr u c k s and street sweepers to dispose of solids. One of the remaining sl u d g e dr y i n g be d s (1 ‐8) co u l d be us e d fo r th i s pu r p o s e if ac c e s s is pe r m i t t e d • Ar e a cu r r e n t l y oc c u p i e d by th e su p e r n a t a n t la g o o n an d di r e c t l y to ea s t (b o u n d e d by Bob Jones bike trail) is a potential area for the interpretive ce n t e r • Su p e r n a t a n t la g o o n an d ea r t h e n la g o o n s ar e av a i l a b l e Wh e r e do we en v i s i o n th e r e wi l l be av a i l a b l e sp a c e fo r ne w pr o c e s s e s , fa c i l i t i e s or in t e r p r e t i v e el e m e n t s ? Pr e f e r e n c e s • In t e r p r e t i v e ce n t e r wi l l no t be an op e n do o r po l i c y . Id e a l l y , th e SL O WR R F staff will retain current roles and responsibilities at the plant but will be in cl o s e co m m u n i c a t i o n wi t h wh o m e v e r is ch o s e n to ma n a g e th e in t e r p r e t i v e center. The idea is to decouple the interpretive center from pl a n t in f r a s t r u c t u r e an d op e r a t i o n s (m u s t be a di v i d e be t w e e n in t e r p r e t i v e area and process areas so that safety issues are minimized). • Fi x am m o n i a re t u r n pr o b l e m (f r o m DA F T ) • El i m i n a t e od o r fr o m DA F T (c l o s e pr o x i m i t y to bi k e pa t h ) • Re m o v e su p e r n a t a n t la g o o n – op e r a t i o n a l he a d a c h e Wh a t is th e pr e f e r r e d co n f i g u r a t i o n or pr o c e s s ? Ar e th e r e an y sp e c i f i c pr e f e r e n c e s re l a t e d to op e r a t o r co n t r o l s , ac c e s s i b i l i t y , sa f e t y , et c . ? Co n s t r a i n t s an d Co n s i d e r a t i o n s • Ae r a t e d gr i t ta n k is a bi g en e r g y an d fo o t p r i n t ho g as we l l as an od o r so u r c e • Sc r e w pr e s s wi l l be in s t a l l e d in a ne w bu i l d i n g ad j a c e n t to th e ex i s t i n g be l t press structure. Belt press will remain in place for sludge dewatering re d u n d a n c y . • Ar e a ne a r su p e r n a t a n t la g o o n ha s st r o n g od o r s fr o m EQ ba s i n an d is ve r y loud – truck yard to the north is the source of noise. • If in t e r p r e t i v e ce n t e r is pl a c e d ne a r ex i s t i n g su p e r n a t a n t la g o o n , it ma y fe e l too secluded and have low traffic. • In t e r p r e t i v e ce n t e r sh o u l d no t be st a f f i n g ‐in t e n s i v e • Un d e r th e ex i s t i n g pr o c e s s fl o w op e r a t i o n s , th e in t e r n a t a n t fr o m th e DA F T contributes 1MGD of high BOD/COD/TAN flow to the aeration basins • No ro o m fo r tr u c k s to tu r n ar o u n d in ar e a no r t h of EQ ba s i n • EQ li n e r ha s be e n pe n e t r a t e d by go p h e r s C o n s i d e r pr e v a i l i n g wi n d s (w e s t e r l y ) • Co n s i d e r th e po t e n t i a l to re d u c e st o r m fl o w s (I & I ) wh e n an a l y z i n g EQ ca p a c i t y • Pr e s e r v e ex i s t i n g tr u n k li n e s • Co n s i d e r Pr a d o ov e r p a s s , si g n a l e d in t e r s e c t i o n an d ea s e of tr u c k ac c e s s • Pr e s e r v e bi o s w a l e s • CM T te a m : En g a g e in Pr a d o Ov e r p a s s pl a n n i n g an d in v e s t i g a t e th e sc h e d u l e Wh e r e ar e we li m i t e d ? Wh a t do we ha v e to ke e p in mi n d ? Is th e r e an y t h i n g wi t h i n th e bo u n d s of th e Un i t th a t li m i t s ou r op t i o n s ? Wh a t in f r a s t r u c t u r e wi l l re m a i n in pl a c e ? Op p o r t u n i t i e s • Tr i c k l i n g fi l t e r s an d pr i m a r i e s ar e cu r r e n t l y op e r a t o r in t e n s i v e ; im p r o v e m e n t in operator efficiency would be realized from optimizing that area. • En e r g y Ef f i c i e n c y Pr o j e c t up g r a d e s (s c r e w pr e s s ) wi l l al l e v i a t e ne e d to us e sludge drying beds due to redundancy between screw press and belt pr e s s ; ad d i t i o n a l l y , th e ar e a to th e no r t h of th e EQ ba s i n wi l l no lo n g e r be used since dewatered sludge will be emptied directly into bins, th e r e b y le s s e n i n g od o r is s u e s fr o m th e s e so u r c e s . • Co n s o l i d a t e ha z a r d o u s ma t e r i a l st o r a g e an d gr e e n wa s t e • Co n s i d e r lo n g te r m st a f f i n g pl a n fo r ne w pl a n t • De v e l o p ap p l i c a t i o n s or im p l e m e n t pr o c e s s e s wh i c h re d u c e od o r • Re p l a c e di g e s t e r fr o m 19 2 0 s • Re ‐ro u t e st o r m fl o w s if de s i r e d • Dr y i n g be d s 1‐8 ca n be re p u r p o s e d • Af t e r sc r e w pr e s s is in s t a l l e d th r o u g h th e WR R F En e r g y Ef f i c i e n c y Pr o j e c t , the existing belt press could be replaced with a redundant screw press, th u s el i m i n a t i n g th e ne e d fo r dr y i n g be d s 1‐8. Do e s th e ar e a or un i t po s s e s s a un i q u e op p o r t u n i t y fo r si m p l i f i e d co n s t r u c t i o n se q u e n c i n g , fl o w di v e r s i o n / e q u a l i z a t i o n , re p u r p o s i n g of ex i s t i n g in f r a s t r u c t u r e , et c . ? Wi l l an y in f r a s t r u c t u r e be re p l a c e d in th e un i t / a r e a ? WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 23 of 47 Un i t II I : Ae r o b i c Av a i l a b i l i t y • Fo o t p r i n t oc c u p i e d by bi o f i l t e r s an d re s e a r c h ar e a ar e av a i l a b l e ar e a s . • EQ ba s i n ca n be sh i f t e d to w a r d sl u d g e dr y i n g be d s , or co m p a r t m e n t a l i z e d , to create available area. • Sm a l l sp a c e av a i l a b l e to th e Ea s t of fi n a l cl a r i f i e r s . Wh e r e do we en v i s i o n th e r e wi l l be av a i l a b l e sp a c e fo r ne w pr o c e s s e s , fa c i l i t i e s or in t e r p r e t i v e el e m e n t s ? Pr e f e r e n c e s • Wo u l d li k e to ha v e sw e e p s ta k e n ou t of fi n a l cl a r i f i e r s • 60 ‐de g r e e ba f f l e s in fi n a l cl a r i f i e r s • Co v e r fi n a l cl a r i f i e r s • Co m p a r t m e n t a l i z e EQ ba s i n to se p a r a t e st o r m w a t e r an d pr o c e s s fl o w eq u a l i z a t i o n . • Ad d 3‐in 3‐wa t e r ca n n o n s ar o u n d th e EQ ba s i n to as s i s t wi t h od o r co n t r o l • Re m o v e or fi x pr i m a r y cl a r i f i e r fl o w sp l i t t e r bo x – cu r r e n t l y tr a p s a lo t of gr e a s e and does a poor job of equally splitting flows due to its location. • En c l o s e he a d w o r k s • Ge t ri d of ma i n t e n a n c e bu i l d i n g s an d to o l sh e d s an d co n s o l i d a t e in ne w fa c i l i t i e s Wh a t is th e pr e f e r r e d co n f i g u r a t i o n or pr o c e s s ? Ar e th e r e an y sp e c i f i c pr e f e r e n c e s re l a t e d to op e r a t o r co n t r o l s , ac c e s s i b i l i t y , sa f e t y , et c . ? Co n s t r a i n t s an d Co n s i d e r a t i o n s • Co n s i d e r an en e r g y ‐di s s i p a t i n g fe e d we l l si m i l a r to th e on e at Hy p e r i o n (L A ‐EDI) in order to increase capacity. • Pr i m a r y cl a r i f i e r #2 is si n k i n g to w a r d Bi o f i l t e r #3 • Pi p i n g su r r o u n d i n g pr i m a r i e s is in po o r co n d i t i o n • Se c o n d a r y cl a r i f i e r ba f f l e s , ca t w a l k an d sc u m be a c h ar e co r r o d e d . • Bi o f i l t e r we t we l l is a hy d r a u l i c bo t t l e n e c k • Po t a b l e wa t e r bo o s t e r lo c a t e d no r t h e a s t of Bi o f i l t e r #3 • If EQ ba s i n is to be us e d fo r bo t h st o r m w a t e r an d pr o c e s s eq u a l i z a t i o n , od o r and cleaning management must be of high priority • Ex i s t i n g ae r a t i o n ba s i n s an d bl o w e r sh a d e st r u c t u r e to re m a i n • El e c t r i c a l / G e n e r a t o r bu i l d i n g to re m a i n • Fi n a l cl a r i f i e r s to re m a i n • Ex i s t i n g LP ge n e r a t o r ru n s gr e a t • Co n s i d e r ne c e s s a r y re d u n d a n c i e s fo r cl a r i f i e r s • Co n s i d e r th e ne e d fo r ad d i t i o n a l po w e r ca p a c i t y fr o m ge n e r a t o r s • Co n s i d e r ha v i n g a di r e c t na t u r a l ga s li n e to th e ge n e r a t o r to re m o v e th e re q u i r e m e n t for above ground liquid propane tanks • Th e vo r t e x gr i t sy s t e m in s t a l l e d du r i n g WR R F En e r g y Ef f i c i e n c y Pr o j e c t co n s t r u c t i o n would need to be moved if the upper structure of the he a d w o r k s is de m o l i s h e d . • Th e ca p a c i t y of th e ex i s t i n g gr i t ta n k s is 22 MG D . Wh e r e ar e we li m i t e d ? Wh a t do we ha v e to ke e p in mi n d ? Is th e r e an y t h i n g wi t h i n th e bo u n d s of th e Un i t th a t li m i t s ou r op t i o n s ? Wh a t in f r a s t r u c t u r e wi l l re m a i n in pl a c e ? Op p o r t u n i t i e s • EQ ba s i n co u l d be co m p a r t m e n t a l i z e d (t o mi t i g a t e od o r an d se p a r a t e pr o c e s s flow equalization from stormwater equalization or expanded to in c l u d e sl u d g e dr y i n g be d s 9 & 9A . • Bi o f i l t e r #1 fo o t p r i n t co u l d be us e d fo r sl u d g e th i c k e n i n g pr o c e s s • Ut i l i z e op e n sp a c e to th e ea s t of th e ae r a t i o n ba s i n s fo r ne w pr o c e s s in f r a s t r u c t u r e . Currently, this is the footprint occupied by the AFS which has no un d e r g r o u n d pi p i n g or ut i l i t i e s . • Im p l e m e n t a hi g h ra t e , lo w HR T , lo w fo o t p r i n t pr o c e s s to ta k e pl a c e of pr i m a r i e s and biofilter to send high sBOD flow to existing aeration basins wh i l e us i n g se c o n d a r y cl a r i f i e r fo r so l i d s re m o v a l • Tr y to pr e s e r v e EQ ba s i n fo r st o r m w a t e r fl o w s an d cr e a t e fl o w eq u a l i z a t i o n near process using existing infrastructure • Du r i n g th e WR R F En e r g y Ef f i c i e n c y Pr o j e c t co n s t r u c t i o n , tw o Hu b e r gr i t sc r e e n i n g and washing systems will be installed. • Im p r o v e fl o w mo n i t o r i n g th r o u g h ae r o b i c pr o c e s s • Cr e a t e a de d i c a t e d de m o n s t r a t i o n ar e a fo r Ca l Po l y or ot h e r wa t e r re l a t e d research projects Do e s th e ar e a or un i t po s s e s s a un i q u e op p o r t u n i t y fo r si m p l i f i e d co n s t r u c t i o n se q u e n c i n g , fl o w di v e r s i o n / e q u a l i z a t i o n , re p u r p o s i n g of ex i s t i n g in f r a s t r u c t u r e , et c . ? Wi l l an y in f r a s t r u c t u r e be re p l a c e d in th e un i t / a r e a ? WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 24 of 47 Un i t IV : Di s i n f e c t i o n Av a i l a b i l i t y • Gr a s s ar e a ne x t to fl o w eq u a l i z a t i o n ce l l s • If co o l i n g to w e r s we r e to be mo v e d , th a t fo o t p r i n t co u l d be ut i l i z e d • An h y d r o u s am m o n i a ta n k ca n be re p u r p o s e d Wh e r e do we en v i s i o n th e r e wi l l be av a i l a b l e sp a c e fo r ne w pr o c e s s e s , fa c i l i t i e s or in t e r p r e t i v e el e m e n t s ? Pr e f e r e n c e s • Co o l i n g to w e r s sh o u l d be at th e en d of th e tr e a t m e n t tr a i n , im m e d i a t e l y before discharge to creek. Water is reheated through the tertiary tr e a t m e n t pr o c e s s . Co o l i n g do w n s t r e a m of fi l t r a t i o n an d di s i n f e c t i o n would conserve energy and reduce biofilm growth in cooling towers. • St o p co o l i n g re c y c l e d wa t e r to re d u c e en e r g y co n s u m p t i o n – re c y c l e d wa t e r does not need to be cooledRemove or repurpose aqueous ammonia ta n k • Ad d i t i o n of of f s i t e re c y c l e d wa t e r st o r a g e ta n k s • Bu i l d ad m i n i s t r a t i v e / O & M / l a b o r a t o r y fa c i l i t i e s on av a i l a b l e ar e a so te m p o r a r y offices and labs will not be needed; there is concern that the lab wi l l no lo n g e r be ce r t i f i e d if it is lo c a t e d in a tr a i l e r on si t e • Ke e p ad m i n i s t r a t i v e bu i l d i n g cl o s e to bi k e pa t h Wh a t is th e pr e f e r r e d co n f i g u r a t i o n or pr o c e s s ? Ar e th e r e an y sp e c i f i c pr e f e r e n c e s re l a t e d to op e r a t o r co n t r o l s , ac c e s s i b i l i t y , sa f e t y , et c . ? Co n s t r a i n t s an d Co n s i d e r a t i o n s • Cu r r e n t l y th e fo u r t h ch l o r i n e co n t a c t ch a n n e l (C C C ) di s i n f e c t s re c y c l e d wa t e r , but they have the option of using CCC #3. The first three CCC are us e d to di s i n f e c t ef f l u e n t th a t wi l l be di s c h a r g e d in t o th e cr e e k . • Fi l t e r up g r a d e s ar e ex p e c t e d to in c r e a s e ca p a c i t y to 8M G D (i n c r e a s e d fr o m 5.2 MGD), allowing for better control of disinfection system • Aq u e o u s am m o n i a ta n k ha s ne v e r be e n us e d • Fl o w me t e r in RW va u l t is fa u l t y • Eq u a l i z a t i o n ta n k s gr o w al g a e • Co n s i d e r re p u r p o s i n g or pr e s e r v i n g ex i s t i n g ad m i n i s t r a t i v e bu i l d i n g , as it is still in good shape • Fi l t e r s ar e to re m a i n • Ma i n t a i n op e r a t i n g la b , op e r a t o r lo c k e r s an d BB Q / p i c n i c ar e a du r i n g co n s t r u c t i o n Wh e r e ar e we li m i t e d ? Wh a t do we ha v e to ke e p in mi n d ? Is th e r e an y t h i n g wi t h i n th e bo u n d s of th e Un i t th a t li m i t s ou r op t i o n s ? Wh a t in f r a s t r u c t u r e wi l l re m a i n in pl a c e ? Op p o r t u n i t i e s • Ex i s t i n g ad m i n i s t r a t i v e bu i l d i n g co u l d be re t r o f i t t e d an d ad d e d to , ho w e v e r this option may become very costly • Cr e a t e pr o c e s s e s an d co n t r o l s th a t ar e op e r a t o r fr i e n d l y an d pr o v i d e fl e x i b i l i t y • In c r e a s e fl e x i b i l i t y in re c y c l e d wa t e r pr o d u c t i o n • A si n g l e di s i n f e c t i o n pr o c e s s fo r bo t h re c y c l e d wa t e r an d ef f l u e n t Do e s th e ar e a or un i t po s s e s s a un i q u e op p o r t u n i t y fo r si m p l i f i e d co n s t r u c t i o n se q u e n c i n g , fl o w di v e r s i o n / e q u a l i z a t i o n , re p u r p o s i n g of ex i s t i n g in f r a s t r u c t u r e , et c . ? Wi l l an y in f r a s t r u c t u r e be re p l a c e d in th e un i t / a r e a ? WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 25 of 47 Op e n Sp a c e Ar e a & Ad j a c e n t Ar e a s Av a i l a b i l i t y Op e n Sp a c e Ar e a • Av a i l a b l e sp a c e is to th e no r t h of th e we t l a n d s • If ol d fa c i l i t i e s an d di s i n f e c t i o n in f r a s t r u c t u r e is re m o v e d , th e so u t h e r n m o s t area of the open space would be available Ad j a c e n t Ar e a s • Pr a d o Da y Ce n t e r to be re l o c a t e d di r e c t l y ac r o s s Pr a d o Ro a d . • Ar e a cu r r e n t l y oc c u p i e d by th e bu s ya r d an d ad j a c e n t co r p ya r d wo u l d be very useful for the project. Wh e r e do we en v i s i o n th e r e wi l l be av a i l a b l e sp a c e fo r ne w pr o c e s s e s , fa c i l i t i e s or in t e r p r e t i v e el e m e n t s ? Pr e f e r e n c e s Op e n Sp a c e Ar e a • Au t o m a t e d va l v e co n t r o l fo r di v e r s i o n – cu r r e n t l y th e op e r a t o r s ha v e to dr i v e out there once they hear the alarm • Re h a b i l i t a t e di v e r s i o n po n d s • Pr e s e r v e at t r a c t i v e vi e w i n g si t e of so u t h e r n po r t i o n • De m o l i s h ol d di s i n f e c t i o n ch a n n e l s an d fa c i l i t i e s Ad j a c e n t Ar e a s • Ev a l u a t e th e be n e f i t s of us i n g th e ex i s t i n g bu s ya r d an d ad j a c e n t co r p ya r d area for interpretive center or additional process fa c i l i t i e s / i n f r a s t r u c t u r e Wh a t is th e pr e f e r r e d co n f i g u r a t i o n or pr o c e s s ? Ar e th e r e an y sp e c i f i c pr e f e r e n c e s re l a t e d to op e r a t o r co n t r o l s , ac c e s s i b i l i t y , sa f e t y , et c . ? Co n s t r a i n t s an d Co n s i d e r a t i o n s Op e n Sp a c e Ar e a • Di v e r s i o n po n d s ar e de s i g n a t e d we t l a n d s an d us e d wh e n th e r e is a di s i n f e c t i o n issue about (6 times/year) • Co n s t r u c t e d we t l a n d s ar e to th e no r t h of di v e r s i o n po n d s • Di v e r s i o n po n d li n e r is da m a g e d an d le a k i n g in t o cu l v e r t un d e r fr e e w a y • Ol d di s i n f e c t i o n in f r a s t r u c t u r e ne e d s to be re m o v e d , as it s lo w se c u r i t y an d close proximity to public use areas poses a safety issue • Op e r a t o r s cu r r e n t l y us e a po r t a b l e pu m p to eq u a l i z e th e di v e r s i o n po n d s Ad j a c e n t Ar e a s • Ar e a in be t w e e n Co r p Ya r d an d bu s ya r d ma y be ne e d e d by Co r p Ya r d • St a f f cu r r e n t l y us e s bi k e pa t h to ge t to ou t f a l l Wh e r e ar e we li m i t e d ? Wh a t do we ha v e to ke e p in mi n d ? Is th e r e an y t h i n g wi t h i n th e bo u n d s of th e Un i t th a t li m i t s ou r op t i o n s ? Wh a t in f r a s t r u c t u r e wi l l re m a i n in pl a c e ? Op p o r t u n i t i e s Op e n Sp a c e Ar e a • Ki o s k in we t l a n d ar e a co u l d be us e d fo r a vi e w i n g pl a t f o r m ar e a • Co n s t r u c t a vi e w i n g to w e r ne a r ex i s t i n g we t l a n d s • Re p u r p o s e ro t a t i n g al g a e sc r e e n fo r ar c h i t e c t u r a l fe a t u r e • Re p u r p o s e ol d di s i n f e c t i o n pr o c e s s ar e a , or us e th e la n d fo r ot h e r pu r p o s e s Ad j a c e n t Ar e a s • Ne w ac c e s s ro a d fo r pl a n t st a f f to av o i d tr a v e l i n g on bi k e pa t h • If bu s ya r d an d co r p ya r d ca n be ac q u i r e d , th e r e i n li e s an op p o r t u n i t y to co n s o l i d a t e the plant’s footprint. • Us e Pr a d o Da y Ce n t e r , Gu n Ra n g e an d Va c a n t Lo t ar e a to op t i m i z e ac c e s s and egress to and from the proposed signalized intersection. Do e s th e ar e a or un i t po s s e s s a un i q u e op p o r t u n i t y fo r si m p l i f i e d co n s t r u c t i o n se q u e n c i n g , fl o w di v e r s i o n / e q u a l i z a t i o n , re p u r p o s i n g of ex i s t i n g in f r a s t r u c t u r e , et c . ? Wi l l an y in f r a s t r u c t u r e be re p l a c e d in th e un i t / a r e a ? WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 26 of 47 Appendix B – WRRF Energy Efficiency Project Design Drawings The following is a subset of design drawings from the WRRF Energy Efficiency Project. WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 27 of 47 WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 28 of 47 WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 29 of 47 WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 30 of 47 WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 31 of 47 WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 32 of 47 WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 33 of 47 WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 34 of 47 WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 35 of 47 Ap p e n d i x C – G I S U n d e r g r o u n d U t i l i t i e s Fi g u r e 10 th r o u g h Fi g u r e 17 in d i c a t e th e lo c a t i o n of un d e r g r o u n d ut i l i t i e s an d si t e pi p i n g in Un i t II an d Un i t II I , ba s e d on GI S da t a pr o v i d e d by th e Ci t y . Ut i l i t y information for Unit IV was not available. The utility data shown for Unit II an d Un i t II I ha s no t be e n ve r i f i e d , th u s th e Pr o j e c t Te a m wi l l ne e d to ev a l u a t e th e ac c u r a c y of th i s da t a an d co o r d i n a t e ef f o r t s wi t h th e ba s e m a p de v e l o p m e n t . Fi g u r e 10 WR R F ai r pi p e s Figure 11 WRRF gas pipes WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 36 of 47 Fi g u r e 12 WR R F el e c t r i c a l co m p o n e n t s WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 37 of 47 Fi g u r e 13 WR R F dr a i n pi p e s WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 38 of 47 Fi g u r e 14 WR R F po t a b l e an d no n p o t a b l e wa t e r pi p e s WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 39 of 47 Fi g u r e 15 WR R F ra w wa s t e w a t e r pi p e s WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 40 of 47 Fi g u r e 16 WR R F li q u i d st r e a m pi p e s WR R F Pr o j e c t Te c h n i c a l Me m o r a n d u m #3 – Si t e Pl a n n i n g St u d y (F i n a l ) Pa g e 41 of 47 Fi g u r e 17 WR R F so l i d s st r e a m pi p e s WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 42 of 47 Appendix D – Community Workshop Issue Identification Results The attached tables are the results from the issue identification exercise performed at the community workshop on June 4, 2014. The number of green dots indicate items the community agreed with most strongly and the number of red dots indicate items the community disagreed with most strongly. WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 43 of 47 WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 44 of 47 WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 45 of 47 WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 46 of 47 WRRF Project Technical Memorandum #3 – Site Planning Study (Final) Page 47 of 47 Co m m e n t L o g Th e co m m e n t s re c e i v e d on th e Dr a f t Si t e Pl a n n i n g St u d y TM , al o n g wi t h th e as s o c i a t e d re s p o n s e s / c h a n g e s , ar e li s t e d be l o w . Co m m e n t No . La s t Fi r s t Da t e Re c e i v e d Co m m e n t Ad d r e s s e d ? Dr a f t TM Pa g e Se c t i o n Figure Table AppendixResponse 1 Br e w e n Ho w a r d 7/ 2 8 / 2 0 1 4 Ad d (M C C ) G Ye s 3 WR R F Ar e a Designations Added item 2 Br e w e n Ho w a r d 7/ 2 8 / 2 0 1 4 Ad d (M C C ) N an d (M C C ) M th e y ar e bo t h ho u s e d in (M C C ) J Ye s 4 WR R F Ar e a Designations Added item 3 Br e w e n Ho w a r d 7/ 2 8 / 2 0 1 4 Op e r a t o r wo r k s t a t i o n do e s no t ex i s t he r e / Op e r a t o r wo r k s t a t i o n sh o u l d be pl a c e he r e Ye s Si t e Ev a l u a t i o n 6 Corrected item 4 Hi x Da v e 8/ 1 / 2 0 1 4 We ne e d to cl o s e th e lo o p on th e ch l o r i n e st r u c t u r e in th e op e n sp a c e . It ’ s cu r r e n t l y ho u s i n g th e ra n g e r pr o g r a m , wh i c h ha s be e n be n e f i c i a l ha v i n g st a f f do w n th e r e . We do ne e d to de c o m m i s s i o n ma n y of th e st r u c t u r e do w n th e r e fo r sa f e t y re a s o n s Ye s 10 5 Added item in Table 5 Open Space Area opportunities and constraints (see response to comment no. 13) 5 Hi x Da v e 8/ 1 / 2 0 1 4 Th e he a d w o r k s ne e d s to be co n s i d e r e d fo r a mo d i f i c a t i o n , no t ju s t fo r en e r g y pr o j e c t eq u i p m e n t , bu t al s o fo r th e ag e d ae r a t e d gr i t pr o c e s s an d fl o w me t e r Ye s N/ A N/ A The Energy Efficiency project is supposed to provide new grit classifying equipment (Table 1). See TM #9A for details on influent flow meters. 6 Hi x Da v e 8/ 1 / 2 0 1 4 Th a n k s fo r ke e p i n g th e li s t of wo r k s h o p re s u l t s on th e do c ; we ma y wa n t to co n s i d e r at t a c h i n g th a t li s t on al l th e pe r t i n e n t pl a n n i n g do c s as we mo v e th r u th i s pr o g r a m Ye s N/ A N/ A D This list can be added to relevant TMs/documents. 7 Ma t t i n g l y Ca r r i e 7/ 2 4 / 2 0 1 4 Ad d "c o m m u n i t y " be t w e e n "s i g n i f i c a n t " an d "i n v e s t m e n t " Ye s 1 In t r o d u c t i o n Added item 8 Ma t t i n g l y Ca r r i e 7/ 2 4 / 2 0 1 4 Re p l a c e "w a s t e w a t e r ma n a g e m e n t " wi t h "r e s o u r c e ma n a g e m e n t " Ye s 1 In t r o d u c t i o n Replaced item 9 Ma t t i n g l y Ca r r i e 7/ 2 4 / 2 0 1 4 Ad d "u n d e r g r o u n d " be t w e e n "r e c y c l e d wa t e r " an d "s t o r a g e ta n k " Ye s 2 WR R F Ar e a Designations Added item 10 Ma t t i n g l y Ca r r i e 7/ 2 4 / 2 0 1 4 Re p l a c e "S S T " wi t h "E n e r g y Ef f i c i e n c y Pr o j e c t ( s ) " Ye s 4, 21 , 23 Th r o u g h o u t document Replaced item 11 Ma t t i n g l y Ca r r i e 7/ 2 4 / 2 0 1 4 Ad d "O b i s p o " be t w e e n "S a n Lu i s " an d "C r e e k " Ye s 6 Si t e Co n t e x t Added item 12 Ma t t i n g l y Ca r r i e 7/ 2 4 / 2 0 1 4 Ad d a sp a c e be t w e e n "F i g u r e 14 " an d "i n d i c a t e " Ye s 8 Si t e Ev a l u a t i o n Added item 13 Ma t t i n g l y Ca r r i e 7/ 2 4 / 2 0 1 4 It e m 41 : Th e pa r k ra n g e r s ar e cu r r e n t l y us i n g so m e of th i s pr o p e r t y so an y us e s pr o p o s e d (a n d de m o l i t i o n ac t i o n s ) sh o u l d co o r d i n a t e wi t h th e m Ye s 10 5 Added item in Table 5 Open Space Area opportunities and constraints 14 Ma t t i n g l y Ca r r i e 7/ 2 4 / 2 0 1 4 Fa c i l i t y Po w e r : Cu r r e n t em e r g e n c y po w e r ca p a c i t y is in s u f f i c i e n t fo r (f u l l ? ) op e r a t i o n of th e ex i s t i n g fa c i l i t y du r i n g po w e r ou t a g e s Ye s 22 Si t e Op p o r t u n i t i e s and Co n s t r a i n t s 3 Added item 15 Ma t t i n g l y Ca r r i e 7/ 2 4 / 2 0 1 4 Co n s t r a i n t s : De c o m m i s s i o n e d Fa c i l i t i e s : so m e fa c i l i t i e s to be re m o v e d (a r e a 41 ) ar e us e d by Pa r k Ra n g e r s . Ye s 24 Si t e Op p o r t u n i t i e s and Co n s t r a i n t s 5 Added item in Table 5 Open Space Area opportunities and constraints (see note 13) Co m m e n t No . La s t Fi r s t Da t e Re c e i v e d Co m m e n t Ad d r e s s e d ? Dr a f t TM Pa g e Se c t i o n Figure Table AppendixResponse 16 Ma t t i n g l y Ca r r i e 7/ 2 4 / 2 0 1 4 Ad d "G u n Ra n g e " af t e r "( 3 ) th e Pr a d o Da y Ce n t e r lo t " an d be t w e e n "e x i s t i n g Pr a d o Da y Ce n t e r " an d "s i t s ma y be a po t e n t i a l si t e fo r " Ye s 25 Ad j a c e n t Areas Added items 17 Ma t t i n g l y Ca r r i e 7/ 2 4 / 2 0 1 4 Re p l a c e "d i s c u s s e d ab o v e " wi t h "T a b l e 5" Ye s 25 Ad j a c e n t Areas Replaced item 18 Ma t t i n g l y Ca r r i e 7/ 2 4 / 2 0 1 4 Th i s me m o is us e f u l an d th e an a l y s i s of co n s t r a i n t s , co n s i d e r a t i o n s an d op p o r t u n i t i e s wi l l he l p me be t t e r co m m u n i c a t e fi n a l de c i s i o n s . It al s o br o u g h t to mi n d we ne e d to re m e m b e r th e Pa r k Ra n g e r s wh o ar e cu r r e n t l y in h a b i t i n g ar e a 41 in th e op e n sp a c e . Th e y ' v e ma d e so m e im p r o v e m e n t s to th e ar e a an d us e so m e of th e in d o o r sp a c e . Wh i l e th e y ' v e un d e r s t o o d th e y ma y ha v e to mo v e , th e y ' r e ki n d of ne s t i n g in th e r e . We sh o u l d in c l u d e th e m in ou r co n v e r s a t i o n s wh e n ap p r o p r i a t e . (i n Pr o c o r e mo d u l e co m m e n t se c t i o n ) Ye s N/ A N/ A Added item in Table 5 Open Space Area opportunities and constraints (see note 13) 19 Ou e l l e t t e Pa m 8/ 4 / 2 0 1 4 ID 1 Eq u a l i z a t i o n ba s i n wi l l ne e d to be re p l a c e d wi t h co n c r e t e co m p a r t m e n t a l i z e d ba s i n . Pa r t i a l l y 9 Si t e Ev a l u a t i o n 4 Added item to Table 2 Unit II: Solids opportunities and constraints. A number of people suggested having the EQ basin be modified (compartmentalized), but in general the feeling was that it was to remain. 20 Ou e l l e t t e Pa m 8/ 4 / 2 0 1 4 ID 9 Th i s is no t th e bi o f i l t e r di v e r s i o n bo x (t h e r e is no su c h th i n g ) . It is th e sl u d g e pu m p s fo r cl a r i f i e r 1 & 2. Th e y ar e We m c o ce n t r i f u g a l pu m p s fo r th e bo t t o m bl a n k e t s an d pu m p to th e DA F T . It wi l l re m a i n (h o p e f u l l y be re p l a c e d / m o d i f i e d ) Ye s 9 Si t e Ev a l u a t i o n 4 Changed item to "tentative" 21 Ou e l l e t t e Pa m 8/ 4 / 2 0 1 4 ID 14 Bl o w e r sh a d e st r u c t u r e wi l l ne e d to be mo d i f i e d to an en c l o s e d un i t fo r ne w bl o w e r s Ye s 9 Si t e Ev a l u a t i o n 4 Changed item to "tentative" 22 Ou e l l e t t e Pa m 8/ 4 / 2 0 1 4 ID 24 Di g e s t e r No . 3 wi l l be re p l a c e d wi t h a ne w un i t si m i l a r in ca p a c i t y as No . 1 Ye s 9 Si t e Ev a l u a t i o n 4 Added item to Table 2 Unit II: Solids opportunities and constraints. 23 Ou e l l e t t e Pa m 8/ 4 / 2 0 1 4 ID 26 Co g e n e r a t i o n sy s t e m wi l l be go n e by Tu e s d a y , Au g u s t 5. Ye s 9 Si t e Ev a l u a t i o n 4 Changed item to "remain" since it will be replaced soon. 24 Ou e l l e t t e Pa m 8/ 4 / 2 0 1 4 ID 27 Dr y i n g be d s 1‐8 ma y be pa r t i a l l y re m o v e d . (1 / 3 of th e m pe r h a p s ) In c o r p o r a t e d wi t h ea r t h e n be d 9 an d 9a to co n s t r u c t co n c r e t e co m p a r t m e n t a l i z e d EQ ba s i n st o r a g e . If th i s is bu i l t fi r s t an d ma d e op e r a t i o n a l , th e n EQ ba s i n ca n be mo d i f i e d af t e r . Th e to t a l ba s i n st o r a g e co u l d in c r e a s e to 8‐10 MG by do i n g th i s . Dr y i n g be d No . 2 ca n be fi l l e d in to ad d to sp a c e fo r tr u c k s de l i v e r i n g an d ha u l i n g de w a t e r e d bi o s o l i d s bi n s . Ye s 9 Si t e Ev a l u a t i o n 4 Added item to Table 2 Unit II: Solids opportunities and constraints. Figure 6 also indicates a third of the beds are a "potential available area" and beds 9 and 9a are "available space". 25 Ou e l l e t t e Pa m 8/ 4 / 2 0 1 4 ID 32 Co o l i n g to w e r s ma y be mo v e d to an o t h e r ar e a on s i t e Ye s 9 Si t e Ev a l u a t i o n 4 Changed item to "tentative" Co m m e n t No . La s t Fi r s t Da t e Re c e i v e d Co m m e n t Ad d r e s s e d ? Dr a f t TM Pa g e Se c t i o n Figure Table AppendixResponse 26 Ou e l l e t t e Pa m 8/ 4 / 2 0 1 4 ID 37 is th e La g u n a Li f t st a t i o n , no t re c y c l e d wa t e r pu m p st a t i o n . Re c y c l e d wa t e r pu m p st a t i o n is on to p of th e re c y c l e d wa t e r ta n k . Ye s 9 Si t e Ev a l u a t i o n 4 Changed item numbering in figure 27 Ou e l l e t t e Pa m 8/ 4 / 2 0 1 4 So l i d s lo a d i n g ar e a wi l l go aw a y . So l i d s wi l l be un d e r ro o f of bi o s o l i d s bu i l d i n g on fi l l e d in dr y i n g be d No 1 Ye s 11 Si t e Ev a l u a t i o n 6 Removed solids loading note in figure 28 Ou e l l e t t e Pa m 8/ 4 / 2 0 1 4 El i m i n a t e fl o w sp l i t t e r bo x to pr i m a r y cl a r i f i e r s . It is st i l l th e r e be c a u s e it wa s ne v e r re m o v e d du r i n g th e la s t up g r a d e in 19 9 4 . It is ju s t an op e n sp o t in th e li n e to cl a r i f i e r #2 . Th e ‘s p l i t t e r ’ li n e to cl a r i f i e r # 1 is ab a n d o n e d . Ye s 22 Ta b l e 3 Unit III 3 Changed item to state that it will be removed 29 Ou e l l e t t e Pa m 8/ 4 / 2 0 1 4 Fa c i l i t y Po w e r : Cu r r e n t l y PG & E do e s no t al l o w th e co g e n e r a t i o n sy s t e m to fu n c t i o n (f e e d ) po w e r in t o th e gr i d if th e r e is a po w e r ou t a g e . Di s c u s s i o n wi t h PG & E to al l o w th i s is ne c e s s a r y . Ye s 22 Un i t II I Ta b l e 3 Added item in table 30 Ou e l l e t t e Pa m 8/ 4 / 2 0 1 4 Un i t II : An o t h e r sc r e w pr e s s to be in s t a l l e d du r i n g th e WR R F up g r a d e to re p l a c e th e be l t pr e s s . Re d u n d a n c y of tw o ne w sc r e w pr e s s e s ve r s u s on e ne w sc r e w pr e s s (S S T ) an d a 60 ye a r ol d be l t pr e s s . (p a r t s re d u n d a n c y et c . ) Dr y i n g be d s 1‐8 sh o u l d be co n s i d e r e d , po s s i b l e re d u c i n g th e nu m b e r we ha v e fo r ot h e r th i n g s . Ye s 27 Ap p e n d i x A ‐ Site Walk Wo r k s h e e t s A Added item in Table 2 Unit II 31 Ou e l l e t t e Pa m 8/ 4 / 2 0 1 4 Un i t IV : Un d e r ‘c o n s t r a i n t s an d co n s i d e r a t i o n s ’ : fi r s t bu l l e t : Ch a n n e l s 1 & 2 ar e fr o m 19 9 4 . Ch a n n e l s 3& 4 ar e fr o m th e re u s e up g r a d e in 20 0 4 . Th e fo u r t h di s i n f e c t i o n ch a n n e l is us e d fo r ch l o r i n a t i n g RW (n o t us e d fo r st o r a g e as wr i t t e n ) . Ch a n n e l s 1, 2 (o r i g i n a l ) an d 3 (b o r r o w e d fr o m re ‐us e sy s t e m ) ar e al l us e d fo r di s i n f e c t i o n of ef f l u e n t wa s t e w a t e r to th e cr e e k . Th e re c y c l e d wa t e r st o r a g e ta n k is us e d fo r st o r i n g wa t e r . Se c o n d bu l l e t : fi l t e r up g r a d e s in c r e a s e fi l t r a t i o n fr o m 5. 2 mg d to 8 mg d Ye s 29 Ap p e n d i x A ‐ Site Walk Wo r k s h e e t s A Changed item 32 Le h m a n Ch r i s 8/ 1 0 / 2 0 1 4 We ha v e ma g n e s i u m Hy d r o x i d e , no t Ma g n e s i u m Ch l o r i d e Ye s 3 N/ A Changed item 33 Le h m a n Ch r i s 8/ 1 0 / 2 0 1 4 It e m WR R F 3: I st i l l th i n k th i s is a ba d id e a . Th e lo n g e r yo u le t a se t t l e d bl a n k e t si t , th e mo r e pa r t i c u l a t e BO D co n v e r t s to so l u b l e . Th i s so l u b l e BO D wi l l re q u i r e re m o v a l la t e r in an en e r g y in t e n s i v e pr o c e s s . In ad d i t i o n , co m p a c t i o n of pr i m a r y sl u d g e is mi n i m a l , so ma i n t a i n i n g a hi g h e r bl a n k e t le v e l wo n ' t ne c e s s a r i l y pr o d u c e me a n i n g f u l % so l i d s in c r e a s e . Ye s 5 WR R F En e r g y Efficiency Pr o j e c t 1 Added note to table that this improvement is tentative 34 Le h m a n Ch r i s 8/ 1 0 / 2 0 1 4 "R e m o v e sw e e p s fr o m fi n a l cl a r i f i e r s " ? Ye s 22 Si t e Op p o r t u n i t i e s and Co n s t r a i n t s 3 Item removed. Preference was inaccurately captured during discussion on site walk 35 Le h m a n Ch r i s 8/ 1 0 / 2 0 1 4 Un d e r Pr e f e r e n c e s ro w : Ag a i n , wh y wo u l d we re m o v e th e sw e e p s fr o m th e fi n a l cl a r i f i e r s ? Al s o , wh a t is th e "p r i m a r y cl a r i f i e r fl o w sp l i t t e r bo x " an d wh y wo u l d we re m o v e it ? Ye s 28 Ap p e n d i x A ‐ Site Walk Wo r k s h e e t s A See note 28 (splitter box) and 34 (sweeps) Co m m e n t No . La s t Fi r s t Da t e Re c e i v e d Co m m e n t Ad d r e s s e d ? Dr a f t TM Pa g e Se c t i o n Figure Table AppendixResponse 36 Le h m a n Ch r i s 8/ 1 0 / 2 0 1 4 Un d e r Co n s t r a i n t s an d Co n s i d e r a t i o n s ro w : Wh a t is th e se c o n d a r y cl a r i f i e r "g r e a s e tr a p " ? Th e sc u m tr o u g h / p i t ? In ad d i t i o n to th e co r r o s i o n on th e sc u m tr o u g h an d cl a r i f i e r ba f f l e it sh o u l d be no t e d th e ca t w a l k ha s co r r o s i o n al s o . Ye s 28 Ap p e n d i x A ‐ Site Walk Wo r k s h e e t s A Changed to scum trough and added corrosion to catwalk 37 Le h m a n Ch r i s 8/ 1 0 / 2 0 1 4 Re g a r d i n g th e ex i s t i n g LP Ge n e r a t o r : it wo u l d be ni c e to ha v e a di r e c t na t u r a l ga s li n e , wh i c h wo u l d re m o v e th e re q u i r e m e n t fo r an ab o v e gr o u n d LP ta n k . Ye s 28 Ap p e n d i x A ‐ Site Walk Wo r k s h e e t s A Added item 38 Re d m a n Er n i e 8/ 1 1 / 2 0 1 4 No sw e e p s on fi n a l cl a r i f i e r s ? Ev e n wi t h ba f f l i n g sc u m re m o v a l is im p o r t a n t Ye s See note 34 39 Re d m a n Er n i e 8/ 1 1 / 2 0 1 4 Wi t h he a v y ex p e n s e on co m p a r t m e n t a l i z a t i o n of th e EQ Ba s i n I su g g e s t ad d i t i o n a l 3 in c h 3 wa t e r ca n n o n s li k e we ha v e on EQ ta n k s ju s t fo r th e pu r p o s e of od o r co n t r o l , if we ca n ’ t ma k e an im p r o v e m e n t at le a s t le t ’ s lo o k in t o to o l s th a t wi l l he l p th e op e r a t o r he l p mi t i g a t e od o r co m p l a i n t s . (W e ha v e ha d on e ju s t re c e n t l y fr o m th e bu s i n e s s st r i p ma l l on Hi g u e r a . ) Ye s 28 Ap p e n d i x A‐ Site Walk Wo r k s h e e t s 3 Added item 40 Re d m a n Er n i e 8/ 1 1 / 2 0 1 4 3. Pr i m a r y cl a r i f i e r so l i d s re m o v a l , cu r r e n t l y We m c o ' s ru n 24 / 7 to ma i n t a i n bl a n k e t le v e l s , if we sw i t c h to au t o m a t e d on / o f f to se n d be t t e r so l i d s to ou r DA F T un i t We m c o ' s st r u g g l e on re s t a r t wi t h pr i m e du e to an y sh u t do w n , I un d e r s t a n d th i s is du e to he a d an d th e pu m p s in a b i l i t y to mo v e th i c k e n sl u d g e , th e pu m p s wi t h ha v e to be im p r o v e d if I un d e r s t a n d th e po i n t of au t o on / o f f to im p r o v e sl u d g e qu a l i t y to DA F T . Ye s 5 WR R F En e r g y Efficiency Pr o j e c t 1 See response for comment 33 41 Re d m a n Er n i e 8/ 1 5 / 2 0 1 4 Pu t t i n g ac t u a t o r s on in f l u e n t an d ef f l u e n t ga t e s fo r op e n an d cl o s u r e , we do ha v e so m e ga t e s th a t ar e di f f i c u l t . Pa r t i a l l y N/ A N/ A Item will be added to a Procore module in the near future 42 Ou e l l e t t e Pa m 8/ 1 3 / 2 0 1 4 Ha v i n g th e ab i l i t y to sa f e l y ma i n t a i n an d in s p e c t pi p e s Pa r t i a l l y N/ A N/ A Item will be added to a Procore module in the near future 43 Ou e l l e t t e Pa m 9/ 4 / 2 0 1 4 Po s s i b i l i t y of re p l a c i n g DA F T wi t h sc r e w th i c k e n e r s Ye s 15 (F i n a l TM ) Si t e Op p o r t u n i t i e s and Co n s t r a i n t s – Unit II Op p o r t u n i t i e s 2 Added item 44 Ou e l l e t t e Pa m 9/ 4 / 2 0 1 4 Po s s i b i l i t y of re p u r p o s i n g ex i s t i n g DA F T un i t fo r FO G an d / or li q u e f i e d fo o d wa s t e st r e a m s re c e i v i n g st a t i o n to au g m e n t Di g e s t e r s / en h a n c e d bi o g a s . Ye s 15 (F i n a l TM ) Si t e Op p o r t u n i t i e s and Co n s t r a i n t s – Unit II Op p o r t u n i t i e s 2 Added item 45 Ou e l l e t t e Pa m 9/ 4 / 2 0 1 4 Ha r v e s t an d re p u r p o s e ro c k ma t e r i a l fr o m bi o f i l t e r s 1, 2 & 3. Us e in co n s t r u c t i o n , us e in la n d s c a p i n g , st o r e fo r ge n e r a l pu r p o s e us e in th e Ci t y (i n co r p ya r d st o r a g e ? ) . It wo u l d be a re a l wa s t e to ha u l it aw a y fo r di s p o s a l . Wo r k wi t h ci t y pa r k s or ot h e r s to re p u r p o s e ro c k s . Ye s 16 (F i n a l TM ) Si t e Op p o r t u n i t i e s and Co n s t r a i n t s – Unit III Op p o r t u n i t i e s 3 Added item 46 Ou e l l e t t e Pa m 9/ 4 / 2 0 1 4 Pe r h a p s fi l l in de c o m m i s s i o n e d di s i n f e c t i o n pr o c e s s e s ra t h e r th a n de m o l i t i o n ? Wo u l d th a t be mo r e co s t ef f e c t i v e ? Is it le g a l ? Is it sa f e ? Ye s 18 (F i n a l TM ) Si t e Op p o r t u n i t i e s and Co n s t r a i n t s – Open Sp a c e Ar e a Op p o r t u n i t i e s 5 Added item Co m m e n t No . La s t Fi r s t Da t e Re c e i v e d Co m m e n t Ad d r e s s e d ? Dr a f t TM Pa g e Se c t i o n Figure Table AppendixResponse 47 Ou e l l e t t e Pa m 9/ 4 / 2 0 1 4 Th e on l y ti m e a po r t a b l e pu m p is us e d is wh e n th e so u t h po n d is fu l l an d we ne e d mo r e ro o m by em p t y i n g it in t o th e no r t h po n d . We ne v e r tr u l y at t e m p t to em p t y th e di v e r s i o n po n d s an y w h e r e be c a u s e th e r e is n ’ t an y pl a c e to pu t th e wa t e r as it is wi t h o u t tr e a t m e n t . Th e so u t h e a s t en d of th e di v e r s i o n po n d s ha v e ef f l u e n t ga t e s fr o m th e po n d s to th e ol d co n t a c t ch a n n e l s th a t do no t wo r k . (T h e y ar e cu r r e n t l y fe n c e d of f du e to it s pr o x i m i t y to th e ne w Bo b Jo n e s Tr a i l br i d g e ac c e s s . ) If th e eg r e s s to th e ch a n n e l s is ab a n d o n e d at th i s bo x an d th e ef f l u e n t ga t e s ar e re p l a c e d , th e y co u l d se r v e as eq u a l i z i n g ga t e s be t w e e n th e po n d s . We ha v e co n s i d e r e d in s t a l l i n g an ov e r f l o w pi p e co n n e c t i n g th e tw o po n d s vi a th e ‘r o a d ’ th a t di v i d e s th e m . Ye s 18 (F i n a l TM ) Si t e Op p o r t u n i t i e s and Co n s t r a i n t s – Open Sp a c e Ar e a Op p o r t u n i t i e s and Co n s t r a i n t s 5 Added item to Table 5 Opportunities and Constraints 48 Ou e l l e t t e Pa m 9/ 4 / 2 0 1 4 La n g u a g e is no t co n s i s t e n t wi t h be g i n n i n g of re p o r t . In ex a m p l e : Un d e r Co n s t r a i n t s , Dr y i n g be d s 1‐8 ma y no t be ma i n t a i n e d bu t co u l d be re p u r p o s e d . Ye s 22 (F i n a l TM ) Un i t II Si t e Walk Wo r k s h e e t A Modified statement and moved to “Opportunities” 49 Ou e l l e t t e Pa m 9/ 4 / 2 0 1 4 Co n s i d e r a t i o n of re p l a c i n g a 60 ye a r s ol d be l t pr e s s wi t h re d u n d a n t sc r e w pr e s s is no t no t e d he r e . A re d u n d a n t sc r e w pr e s s wi l l el i m i n a t e th e ne e d fo r dr y i n g be d s 1‐8. Ye s 22 (F i n a l TM ) Un i t II Si t e Walk Wo r k s h e e t A Added item 50 Ou e l l e t t e Pa m 9/ 4 / 2 0 1 4 Th e la n g u a g e fo r ad d i n g an o t h e r sc r e w pr e s s is lo c a t e d he r e (u n d e r pr e f e r e n c e s ) an d sh o u l d be on pa g e 22 un d e r Un i t II Co n s t r a i n t s . Th e la n g u a g e on pa g e 22 sh o u l d be am e n d e d as no t e d ab o v e . Ye s 23 (F i n a l TM ) Un i t II I Si t e Walk Wo r k s h e e t A Moved item and amended language 51 Ou e l l e t t e Pa m 9/ 4 / 2 0 1 4 Th e SS T is in s t a l l i n g tw o vo r t e x gr i t re m o v a l sy s t e m s (H u b e r ) . Th e cu r r e n t gr i t ta n k s wi l l st i l l fe e d th e ne w vo r t e x re m o v a l sy s t e m . Th e gr i t ta n k s ar e cu r r e n t l y ab l e to ha n d l e 22 mg d . Th e vo r t e x gr i t sy s t e m wi l l li k e l y ne e d to be mo v e d on c e th e de m o l i s h e d he a d w o r k s up p e r st r u c t u r e is go n e . Ye s 23 (F i n a l TM ) Un i t II I Si t e Walk Wo r k s h e e t A Added item 52 Ou e l l e t t e Pa m 9/ 4 / 2 0 1 4 Si n c e we ar e go i n g wi t h UV , th i s bu l l e t sh o u l d no lo n g e r be in c l u d e d [i n th e pr e f e r e n c e s se c t i o n ] . Ye s 24 (F i n a l TM ) Un i t IV Si t e Walk Wo r k s h e e t A Removed item 53 Ou e l l e t t e Pa m 9/ 4 / 2 0 1 4 [I n re s p e c t to th e fi f t h bu l l e t fo r co n s t r a i n t s an d co n s i d e r a t i o n s , th e ] po r t a b l e pu m p is us e d on l y fo r eq u a l i z a t i o n of di v e r s i o n po n d s . Ye s 25 (F i n a l TM ) Op e n Sp a c e Area & Ad j a c e n t Areas Site Wa l k Wo r k s h e e t A Modified item 54 Ma t t i n g l y Ca r r i e 9/ 1 0 / 2 0 1 4 Ch a n g e “P r a d o Da y Ce n t e r Lo t & Gu n Ra n g e ” to “P r a d o Da y Ce n t e r Lo t , Gu n Ra n g e an d Va c a n t Lo t ” . Ye s 9 (F i n a l TM ) Si t e Ev a l u a t i o n 4 Modified item 55 Ma t t i n g l y Ca r r i e 9/ 1 0 / 2 0 1 4 Th e co n s t r u c t e d we t l a n d s wa s bu i l t wi t h gr a n t fu n d s . If we ' r e co n s i d e r i n g do i n g so m e t h i n g wi t h th i s ar e a we ne e d to ta l k wi t h Bo b Hi l l so th i s is n ' t a su r p r i s e an d to en s u r e it do e s n ' t pu t th e ci t y in a po s i t i o n of ha v i n g to pa y ba c k th e gr a n t mo n e y . Ye s 10 (F i n a l TM ) Si t e Ev a l u a t i o n 5 Changed designation to “Remain” and added note to Table regarding coordination with stakeholders Co m m e n t No . La s t Fi r s t Da t e Re c e i v e d Co m m e n t Ad d r e s s e d ? Dr a f t TM Pa g e Se c t i o n Figure Table AppendixResponse 56 Hi x Da v e 9/ 1 2 / 2 0 1 4 I wo u l d li k e to ha v e [t h e fu t u r e ac c e s s ro a d al i g n m e n t fo r th e WR R F ] sh o w n on th e si t e pl a n be c a u s e th i s is cr i t i c a l to mo v i n g fo r w a r d wi t h th e pr o j e c t an d wi l l al l o w ot h e r s to be t t e r un d e r s t a n d th e ci r c u l a t i o n of no t ju s t th e WR R F bu t th e ot h e r fa c i l i t i e s af f e c t e d by th e ov e r p a s s . I' v e cr u d e l y dr a w n th e ac c e s s ro a d in ma n n e r th a t ma y al l o w th e be s t li n e of si g h t an d th e fe w e s t am o u n t of ch a n g e s . Le t ' s sh o w th i s on Fi g u r e 6, pa g e 11 an d in c l u d e in th e ot h e r co r r e s p o n d i n g fi g u r e s an d se c t i o n s fo r di s c u s s i o n . Ye s 11 (F i n a l TM ) Si t e Ev a l u a t i o n 6 Added to Figure 4 57 Hi x Da v e 9/ 1 2 / 2 0 1 4 Th e co n s t r u c t e d we t l a n d s ar e de s i g n a t e d as te n t a t i v e . Th e s e sh o u l d be de s i g n a t e d as "r e m a i n " . We [c a n ] la t e r di s c u s s en h a n c i n g th i s wi t h bi r d wa t c h i n g in f o r m a t i o n an d po s s i b l e vi e w i n g pl a t f o r m s or ot h e r am e n i t i e s . Ye s 10 (F i n a l TM ) Si t e Ev a l u a t i o n 5 Modified item; see response to comment 55 58 Hi x Da v e 9/ 1 2 / 2 0 1 4 Fo r ad j a c e n t ar e a s le t ' s fo c u s on th e ac c e s s ro a d th a t I de s c r i b e ab o v e wh e n di s c u s s i n g th e ar e a wh e r e th e Pr a d o da y ce n t e r is cu r r e n t l y . We ha v e st a t e d th a t we do n ’ t ne e d th e bu s ba r n an d co r p ya r d to do th i s pr o j e c t , so le t ' s so f t e n th e la n g u a g e re g a r d i n g th e s e pr o p e r t i e s . Ye s 25 (F i n a l TM ) Op e n Sp a c e Area & Ad j a c e n t Areas Site Wa l k Wo r k s h e e t A Language was altered and context was added 59 Hi x Da v e 9/ 1 2 / 2 0 1 4 Pl e a s e sh o w fl o w di r e c t i o n fo r th e s e pi p e s . Ge n e r a l l y , le t ’ s do th a t fo r al l ap p l i c a b l e dr a w i n g wh e r e th e di r e c t i o n so m e t h i n g mo v e s wi l l he l p th e re a d e r . Pa r t i a l l y 37 (F i n a l TM ) GI S Un d e r g r o u n d Ut i l i t i e s C Comment will be addressed in basemap files Appendix D TM No. 4 - Disinfection Study Date: 6/8/2015 Prepared by: June Leng, PhD; PE; Amelia Holmes, EIT Reviewed by: Holly Kennedy PE; Mallika Ramanathan, PE; Jeff Szytel, PE Project: WRRF Project SUBJECT: TM NO. 4 – DISINFECTION STUDY (FINAL) The purpose of this technical memorandum (TM) is to identify the recommended disinfection technology for use in the tertiary treatment processes at the San Luis Obispo Water Resource Recovery Facility (WRRF). Potential disinfection alternatives are presented and evaluated, and the design criteria for the recommended alternative are developed. Contents Background and Objectives .................................................................................................... 3 Basis of Evaluation .................................................................................................................. 3 Regulatory Disinfection Requirements ..................................................................................................... 3 Flow Routing ............................................................................................................................................. 4 Disinfection Water Quality ........................................................................................................................ 4 Site Specific Considerations ..................................................................................................................... 6 Project Area .......................................................................................................................................... 6 Hydraulics ............................................................................................................................................. 7 Standby Power ..................................................................................................................................... 7 Other Chlorine Uses ............................................................................................................................. 8 Algae Control ........................................................................................................................................ 8 Background Chlorination Byproducts ................................................................................................... 8 Evaluation Approach ................................................................................................................................. 9 Preliminary Evaluation ............................................................................................................ 9 Disinfection Alternatives ......................................................................................................................... 10 Chlorination and Dechlorination ......................................................................................................... 10 Chloramination ................................................................................................................................... 10 Chlorine Dioxide ................................................................................................................................. 11 Ozone ................................................................................................................................................. 11 Pasteurization ..................................................................................................................................... 12 Peracetic Acid ..................................................................................................................................... 13 UV Disinfection ................................................................................................................................... 14 Recommendation .................................................................................................................................... 16 UV Disinfection .......................................................................................................................17 Technology Alternatives ......................................................................................................................... 17 Lamps ................................................................................................................................................. 17 Reactor Configurations ....................................................................................................................... 18 Lamp Orientation ................................................................................................................................ 19 Recommended UV Technologies for Preliminary Evaluation ............................................................ 20 WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 2 of 30 Identification of Applicable UV Disinfection Systems ............................................................................. 20 UV Disinfection System Suppliers Identified ...................................................................................... 21 Disinfection Performance Requirements and Design Criteria for Preliminary Evaluation ...................... 23 Performance Requirements ............................................................................................................... 23 Design Criteria .................................................................................................................................... 23 Site Specific Considerations for UV Installation ..................................................................................... 24 Area for Installation............................................................................................................................. 24 Hydraulics ........................................................................................................................................... 25 Coagulation Flocculation .................................................................................................................... 25 Facility Requirements and Cost Estimate............................................................................................... 25 Life-Cycle Costs of UV Equipment ......................................................................................................... 28 Conclusions ............................................................................................................................................ 29 Recommendations .................................................................................................................................. 30 References ..............................................................................................................................30 List of Tables Table 1. Disinfection Final Effluent Limitations ............................................................................................. 4 Table 2. Liquid Stream THMs Profiling ......................................................................................................... 8 Table 3. Water Quality Parameter Fouling Potential .................................................................................. 15 Table 4. Comparison of Low-Pressure and Medium-Pressure Lamps ....................................................... 18 Table 5. Comparison of Submerged Reactors – Open Channel and Closed Vessel Reactors ................. 19 Table 6. Comparison of Horizontal and Vertical/Diagonal/Inclined UV Lamp Orientation in Open Channel Systems ............................................................................................................................... 20 Table 7. UV Disinfection System Alternatives Selected for Evaluation ...................................................... 21 Table 8. UV Disinfection Performance Requirements ................................................................................ 23 Table 9. UV Disinfection System Design Criteria........................................................................................ 24 Table 10. UV Disinfection Alternative Evaluation Design Summary ........................................................... 26 Table 11. Constructed Cost Estimates for the Largest, the Smallest UV Installations ............................... 27 Table 12. Summary of UV System Equipment, Annual O&M and Life-Cycle Costs .................................. 29 List of Figures Figure 1. Disinfection Water Quality - Historical Filter Effluent TSS Concentration ..................................... 5 Figure 2. Disinfection Water Quality – Filter Effluent Fecal Coliform Counts ............................................... 5 Figure 3. Disinfection Water Quality – Filter Effluent UVT ............................................................................ 6 Figure 4. Potential Disinfection Project Area ................................................................................................ 7 Figure 5. SLO WRRF PAA Testing Results – Fecal coliform Inactivetion .................................................. 14 Figure 6. SLO WRRF UV Testing Results – Fecal coliform Inactivation .................................................... 15 Figure 7. Conventional UV Systems Considered for SLO WRRF .............................................................. 22 Figure 8. High-Capacity UV System Considered for SLO WRRF .............................................................. 22 List of Attachments Attachment A – UV System Alternative Quotes Attachment B – UV System Construction Cost Estimate Attachment C – UV System Equipment Life Cycle Cost Analysis WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 3 of 30 Background and Objectives The Water Reclamation Facility Master Plan (May 2011, Brown and Caldwell) included the evaluation of seven disinfection technologies, including bulk delivered sodium hypochlorite; on-site generation of sodium hypochlorite; chloramination; ultraviolet disinfection; chlorine dioxide; ozone; and peracetic acid. As part of the 2011 Facility Master Plan, three disinfectant approaches were recommended based on an initial alternative screening and economic evaluation of the seven technologies. At the time of the analysis, the new effluent permit requirements for the WRRF had not yet been issued and more stringent regulatory requirements for chlorination byproducts were assumed. The 2011 Facility Master Plan concluded the following: • “Chlorine dioxide was considered as an alternative disinfectant for the WRRF. Pilot testing has demonstrated that chlorine dioxide is a practical disinfectant that does not form THMs.” • “UV disinfection does not produce THMs or residual chlorine and therefore should be considered in the study of process changes to meet the future limits on these constituents.” • “Ozone was considered and may be an effective disinfectant that does not produce THMs. Pilot testing is required to confirm its dose requirements and other design criteria.” This TM presents an update of the disinfection alternatives evaluation presented in the 2011 Facility Master Plan, including chlorination/dechlorination; chloramination, ultraviolet irradiation, chlorine dioxide, ozone and peracetic acid. In addition, pasteurization was also considered. The evaluation considered non-economic criteria and includes advantages and disadvantages of each disinfection technology based on up-to-date technology information and operational experiences. Based on the results of the non-economic evaluation, a recommended disinfection technology is presented. The recommended technology is then further developed, including disinfection system design features, construction cost estimates and a life cycle cost analysis of the disinfection equipment. Basis of Evaluation The basis of evaluation for the WRRF includes regulatory disinfection requirements, disinfection flows and water quality, and site-specific conditions that are related to the disinfection technology implementation. Not all information is available at this time; therefore, a number of assumptions have been made for preliminary facility sizing and cost estimates. A number of disinfection studies have been conducted, data collected and analyzed. The results from previous studies were used to support the technology evaluation. Regulatory Disinfection Requirements The WRRF has been issued a draft National Pollutant Discharge Elimination System (NPDES) Permit (R3-2014-0033) by the Central Coast Regional Water Quality Control Board (CCRWQCB). More stringent effluent limitations of disinfection byproducts (DBPs) and coliform limits are included in the draft NPDES permit which becomes effective on December 1, 2014. The final effluent limitations pertaining to the disinfection process are summarized in Table 1. WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 4 of 30 Table 1. Disinfection Final Effluent Limitations PARAMETER UNITS EFFLUENT LIMITATIONS Average Monthly Average Weekly Maximum Daily Chlorodibromomethane (CDBM) µg/L 0.40 -- 1.0 Dichlorobromomethane (DCBM) µg/L 0.56 -- 1.0 N-Nitrosodimethylamine (NDMA) µg/L 0.00069 -- 0.0014 Total Residual Chlorine µg/L -- -- ND Fecal coliform cfu/100mL average weekly, not to exceed 2.2, 7-day median Total coliform MPN/100 mL average weekly, not to exceed 23, in any 30-day period Total coliform MPN/100 mL not to exceed 240, any time The disinfection facilities at the WRRF will need to be designed for compliance with these regulatory requirements by the mandatory compliance date defined in the draft Time Schedule Order No. R3- 2014-0036. The Time Schedule Order provides interim THM limits (DCBM at 36 µg/L and CDBM at 42 µg/L), which are valid until November 30, 2019. After November 30, 2019, the final limits for CDBM and DCBM listed in Table 1 will take effect. Additionally, because recycled water is produced at the WRRF, the disinfection facilities will need to meet Title 22 disinfection requirements for unrestricted reuse. Flow Routing Secondary effluent is currently pumped via the Filter Influent Pump Station to the Filter Towers. A portion of the flow is pumped to the Cooling Towers prior to going to Filter Towers. From the filters, the tertiary effluent flows by gravity to the chlorine contact basins. Tertiary filtration currently operates during dry weather, but when the plant blends primary effluent with secondary effluent, filtration and cooling are bypassed and the blended flows are routed directly to the chlorine contact basins. The Secondary effluent flow being pumped from the Filter Influent Pump Station to the Under future conditions, it is assumed that blending will not be performed and the filters will operate continuously. Recent flow analyses have shown that peak hourly flows to the WRRF could be as high as 33 MGD. Influent flows greater than 17 MGD will be equalized upstream of secondary treatment. Secondary effluent will also be equalized (in the Filter Flow EQ Basin), such that the anticipated peak hour flow to be treated through tertiary filtration and disinfection will be 16 MGD. Disinfection Water Quality Disinfection influent water quality can have a significant impact on facility design, equipment performance, and operation and maintenance (O&M) costs. Water quality parameters of concern for the WRRF disinfection process are total suspended solids (TSS), fecal coliform counts and transmittance of ultraviolet light (UVT) at wavelength of 254 nanometers (nm). Figure 1 shows the historical (2011, 2012 and 2013) filter effluent TSS concentrations. In general, the filtered effluent TSS has been less than 5 mg/L, with an average of approximately 3 mg/L. The highest effluent TSS concentration during the period shown was 33 mg/L in January 2011. Since mid-2012, the filter effluent TSS concentration has been consistently below 10 mg/L, which is the regulatory compliance limit of final effluent TSS. WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 5 of 30 Figure 1. Disinfection Water Quality - Historical Filter Effluent TSS Concentration Figure 2 shows the filter effluent fecal coliform counts during the month of May 2014. The WRRF laboratory conducted a month long intensive testing including daily fecal coliform counts. Fecal coliform counts were analyzed in filter effluent samples with and without further lab filtration. Due to the low TSS concentration in the filter effluent, there is no significant differentiation of fecal coliform counts in-between lab filtered and unfiltered samples. In general, the fecal coliform in the filter effluent are at thousands or 100s of thousand counts, which is typically found in tertiary effluent. Figure 2. Disinfection Water Quality – Filter Effluent Fecal Coliform Counts 0 5 10 15 20 25 30 35 Jan-11Jul-11Jan-12Jul-12Jan-13Jul-13Jan-14 TS S ( m g / L ) 100 1,000 10,000 100,000 1,000,000 5/3/145/10/145/17/145/24/145/31/14 Fe c a l c o l i f o r m ( c f u / 1 0 0 m L ) Unfiltered Filtered WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 6 of 30 Figure 3 shows the filter effluent UVT during the months of January through May 2015 water quality monitoring and testing conducted by the WRRF laboratory. Figure 3. Disinfection Water Quality – Filter Effluent UVT UVTs were analyzed with a bench top spectrophotometer in filter effluent samples with and without further lab filtration. Similar to filter effluent TSS concentrations, there is no significant differentiation of UVT between the filtered and unfiltered samples. Filter effluent UVTs are slight higher when filter was chlorinated to reduce bio-growth. The 10th percentile of the “No chlorine” filter effluent UVTs is located at approximately 56 percent (%). The UVT of 55% will be used as the design criteria for UV system sizing and facility design. Site Specific Considerations Site specific conditions that will impact disinfection technology implementation must be considered in this evaluation. Those site conditions are discussed in the following subsections. Project Area The WRRF currently practices chlorination and dechlorination for final effluent disinfection prior to discharge to the nearby San Luis Obispo Creek. Figure 4 is the aerial image of the tertiary treatment area of the WRRF where the tertiary treatment processes are located. The tertiary treatment processes include tertiary equalization tanks, tertiary filters, cooling towers, hypochlorite and bisulfite storage and feed facilities, and four chlorine contact tanks in parallel configuration. As shown in Figure 4, there is adequate room in the tertiary treatment area to accommodate a new disinfection facility. A new disinfection facility could be constructed adjacent to the existing chlorine contact tanks with minimum interference of existing chlorination and dechlorination practice during construction. Three out of four contact tanks can be retained for chlorination and dechlorination without any facility modifications. The south side contact tank can be modified or demolished to 0 10 20 30 40 50 60 70 80 90 100 1/14/20152/14/20153/14/20154/14/20155/14/2015 UV T % UVT Unfiltered (No chlorine) UVT Filtered (No chlorine) UVT Filtered (Chlorinated) WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 7 of 30 provide space for the future disinfection facility. The ammonia storage and feed on the south of the existing CCTs are not in use and will not have any future potential uses; therefore the structure can be demolished to provide space for the future disinfection project. Figure 4. Potential Disinfection Project Area Hydraulics The hydraulic profile of the existing tertiary treatment processes was examined. The hydraulic profile water surface elevation was previously developed using a peak hourly flow of 15 MGD. The hydraulic profile shows that the available head in between the water level at the Parshall flume (disinfection influent) and the water level at the 3W pump station (disinfection effluent) effluent weir is approximately 10 inches under the flow of 15 mgd. The available head would be reduced as the final effluent flow increases above 15 mgd. Standby Power The WRRF is supplied from two independent power sources. For the purposes of this evaluation, it is assumed that a separate standby power source is not required. An electrical load study will need to be completed as part of the preliminary design effort to determine whether the main power feeds are sufficient to support a high power-demanding disinfection process such as a UV system. In case the standby generator is required, the plant existing standby generators capacity needs to be examined once the electrical load data has been attained from the electrical load study. The standby generator should be able to provide sufficient power for the disinfection process in case of power outages. WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 8 of 30 Other Chlorine Uses The existing sodium hypochlorite storage and feed system could be retained or at least partially retained if a disinfection technology other than chlorine is installed to replace the existing effluent disinfection system. Chlorine residual is required in plant effluent for reuse. Other potential uses of chlorine at the plant may include filamentous control of returned activated sludge (RAS); foaming control at aeration basins; and/or periodic filter maintenance cleaning. However, these uses should be under the trials and close monitoring to ensure that the chlorination byproducts generation will not challenge the THM limits in the plant permit. Algae Control Algae have a significant impact on disinfection performance. In chlorination practice, algae contribute to high total organic carbon concentration which exerts high chlorine demand and increases the potential for chlorination by-products formation. In UV disinfection, algae contribute to the solids content and provide shielding of microorganisms from exposure to UV light; and also seed UV reactors causing algae bloom in the reactors. At the WRRF typical algae sources include final clarifier launders and tertiary effluent equalization tanks (0.5 million gallons each; approximately 9,000 square feet surface area), which would be covered to reduce the potential for algae growth and transport to downstream tertiary treatment processes including disinfection. Background Chlorination Byproducts Raw sewage, or used potable water, typically contains chlorination byproducts such as THMs. As discussed previously, the THM limits in the NPDES permit are stringent with both DCBM and CDBM limits less than 1 µg/L becoming effective on November 30, 2019. It is crucial to know if the THMs will remain in the liquid stream throughout the WRRF treatment processes in the concentrations that would challenge the stringent THM limits for the final effluent. A THM profiling testing was carried out in a total of six (6) days during the week of March 29th and April 5th. During the profiling testing, samples for THMs were taken with the chlorine treatment or with the chlorinated return for three (3) days (March 31 through April 2); samples were taken without chlorine treatment or no chlorinated return for later three (3) days (April 5 through April 7). Prior to the sampling from multiple points in liquid stream in later three days, all chlorine uses were ceased and a minimum of three hydraulic retention times were given; as such, the testing results reflect the raw sewage or the “background” THM concentrations only. The testing results are summarized in Table 2. Table 2. Liquid Stream THMs Profiling THMs SAMPLING CONDITION HEADWORKS DOWNSTREAM OF PARSHALL FLUMES PRIMARY EFFLUENT AERATION BASIN FEED FINAL CLARIFIER EFFLUENT DCBM (g/L) with Chlorinated Returns 1.4 1.73 3.94 0.623 0.129 2.6 2.28 3.21 0.42 0.104 1.34 2.31 4.46 0.656 0.135 No Chlorinated Return 0.996 1.01 1.6 0.284 0.119 0.99 1.16 1.68 0.483 0.13 0.984 1.05 1.48 0.348 0.125 CDBM (g/L) with Chlorinated 1.26 1.29 1.94 0.251 ND 1.92 1.63 1.79 0.228 ND WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 9 of 30 THMs SAMPLING CONDITION HEADWORKS DOWNSTREAM OF PARSHALL FLUMES PRIMARY EFFLUENT AERATION BASIN FEED FINAL CLARIFIER EFFLUENT Returns 1.42 1.46 2.52 0.337 ND No Chlorinated Return 0.971 0.79 1.4 0.207 ND 0.834 1.03 1.38 0.307 ND 0.802 0.773 1.15 0.258 ND Note: ND = non detect The findings of THM profiling data are summarized as follows: • Raw sewage contains THMs, commonly from “used” drinking water. • Upstream chlorine treatments and chlorinated return increase THMs concentration in the liquid stream in general. • With and without upstream chlorine treatment and chlorinated return, effluent THM concentrations prior to disinfection are below the future regulatory limits. • There is significant THM “losses” through the WRRF’s biofiltration process. The background THM testing results have shown that THMs in the raw sewage dissipate through the WRRF’s primary and secondary treatment processes. No significant THM presence in the WRRF’s secondary effluent. The results indicate that, as long as there is no use of chlorine after secondary treatment, the THM in the WRRF’s final effluent will be in compliance with the stringent THM limits in the plant discharge permit. The major chlorine uses post the secondary treatment are filter cleaning and final effluent disinfection which are currently in practice. Evaluation Approach The evaluation of disinfection alternatives was conducted in a two-step approach: • Step 1 – Preliminary evaluation which includes a screening review of the disinfection alternatives. This preliminary evaluation is used to establish which alternative(s) is the most viable disinfection process and should be retained for further evaluation, and which alternative(s) should be eliminated from consideration beyond the preliminary evaluation. • Step 2 – Evaluation of the viable disinfection alternative(s) which includes technology comparison, facility description, capital cost estimate and life cycle cost analysis. Previous discussions of regulatory requirements, disinfection flow, disinfection water quality, and site specific considerations provide the basis for preliminary evaluation of the disinfection alternatives using past experience and professional judgment, as described further in the following section. Preliminary Evaluation The preliminary evaluation of the disinfection alternatives considered for the WRRF include discussion of each disinfection alternative and its applicability and viability towards the site specific WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 10 of 30 requirements with up-to-date technology information and operational experience. These discussions are in addition to the narrative evaluation presented in 2011 Facility Master Plan. In the preliminary evaluation, technologies that cannot meet the final effluent limitations presented in Table 1 were eliminated. Disinfection Alternatives The disinfection alternatives considered for preliminary evaluation include chlorination and dechlorination (existing), chloramination, chlorine dioxide, ozone, pasteurization, peracetic acid (PAA), and UV. Chlorination and Dechlorination Chlorination and dechlorination is the current disinfection practice at the WRRF. Bulk sodium hypochlorite and sodium bisulfite solutions are used. The primary advantage of continuing use of the existing chlorination and dechlorination system is that the facilities already exist and the process is well understood by treatment plant personnel. The equipment for dosing and controlling the process is readily available. However, the key concern regarding this alternative is the ability to meet the anticipated final permit limits for chlorination byproducts, such as DCBM and CDBM included in Table 1. Upgrades are planned for the secondary processes that will include biological nutrient removal including complete nitrification to eliminate ammonia in the secondary effluent. These upgrades will result in free chlorine being the primary disinfectant instead of combined chlorine in the presence of ammonia (e.g., chloramines). Free chlorine is known to generate THMs by reacting with organic precursors in the wastewater. The anticipated discharge permit includes THM limits where both CDBM and DCBM are limited to less than one microgram per liter at anytime. The WRRF monitoring data have shown that the monthly average concentration of CDBM has been greater than 40 µg/L and DCBM has been greater than 30 µg/L. The data indicated that the existing chlorine disinfection system will not comply with the new final effluent limitations. The stringent regulatory limitation on THMs effectively eliminates the existing chlorination practice as a viable disinfection process. Chloramination Chlorine, in the presence of ammonia will react almost instantaneously to form combined chlorine or chloramines. Chloramines are an effective disinfectant but are considered to be a weaker disinfectant in comparison to free chlorine. Unlike free chlorine, chloramines do not generate a significant amount of THMs. Under the laboratory testing condition, instantaneous mixing of chlorine with a wastewater stream that contains homogenized ammonia can be achieved with a bench top rapid mixing device. In the field when rapid mixing induction units are used, mixing a chlorine solution with a wastewater steam (with ammonia) can be challenging to avoid the presence of free chlorine and/or to avoid the presence of free ammonia. A sophisticated monitoring system that is reliable is needed. In addition to avoid permit violations for ammonia and/or THMs, a high level of operator attention is needed. To implement chloramination at the WRRF, ammonia would be added and mixed into tertiary effluent prior to chlorine addition at the existing chlorine contact tanks. Transporting, bulk storage and handling toxic ammonia solution is required. A high total chlorine residual (i.e. 5 mg/L) is also WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 11 of 30 typically required to meet the WRRF’s fecal coliform target of 2.2 cfu/100mL. To generate a high total chlorine residual, the potential exists for free chlorine to be present which can result in THM formation that could violate permit limitations. Field data have shown that there is significant generation of THMs even in a well-controlled chloramination process. Additionally, there is a potential for ammonia bleed-through to occur which could result in ammonia permit violations. Our past experiences have shown that the full scale practice of chloramination is challenging. In laboratory studies under ideal conditions, chloramines were found to not generate significant byproducts such as THMs. However, our past testing at the full scale chloramination facilities has shown THM generation. The full scale chloramination practice involves complicated process monitoring and controls. O&M requirements of chloramination facilities are complex when handling multiple toxic and corrosive chemicals. It is challenging to optimize the chloramination process to reduce the chance of free chlorine formation (results in THM formation) and/or the presence of free ammonia (results in potential ammonia permit violations). Recent results obtained from City of Stockton Wastewater Treatment Plant tertiary effluent disinfection study have shown that CDBM and DCBM concentrations in chloraminated wastewater could be controlled under the laboratory testing condition at a single digit in microgram per liter; however, the WRRF permit requirements are expected to be less than 1 microgram per liter for both CDBM and CDBM. NDMA is a chloramination byproduct. The anticipated WRRF discharge permit includes the NDMA limit of 0.00069 µg/L. While this limit is lower than the NDMA laboratory detection limit of 0.002 µg/L, it is not recommended that the WRRF adopt a process that could result in NDMA concentrations greater than the permit limit because the future detection limits could change as testing technology evolves. The stringent regulatory limitations on both THMs and NDMA effectively eliminates chloramination as a viable disinfection process for the WRRF. Chlorine Dioxide The 2011 Facility Master Plan identified chlorine dioxide as a viable option for final effluent disinfection at the WRRF. A series of chlorine dioxide pilot studies were conducted from November 2007 to September 2008 to determine the required dose to meet permit limits and to test for byproduct formation. The onsite chlorine dioxide study results have shown that a chlorine dioxide dose up to 5 mg/L could not meet the disinfection goal of fecal coliform 2.2 cfu/100mL over four days of testing. A higher chlorine dioxide dose up to 10 mg/L achieved the disinfection goal but the disinfected effluent sample showed the formation of disinfection byproducts. A DCBM concentration of 1.0 µg/L and total THM concentration greater than 5.5 µg/L were found in the effluent samples disinfected with chlorine dioxide. These effluent concentrations violate the limits presented in Table 1. The site specific pilot testing at the WRRF showed that chlorine dioxide cannot reliably achieve fecal coliform of 2.2 cfu/100mL and THMs were generated in concentrations higher than anticipated discharge limits. For these reasons, chlorine dioxide disinfection is not considered to be a viable option for disinfection at the WRRF. Ozone The 2011 Facility Master Plan identified ozonation as a viable option for final effluent disinfection at the WRRF. A pilot study was conducted in March 2013 to determine demand and viability of ozone WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 12 of 30 disinfection. An ozone dose as high as 12 mg/L was required to meet the disinfection goal of 2.2 MPN/100mL fecal coliform. This high dose would require ozone generation equipment of such magnitude that ozone is likely not an economical alternative for the WRRF unless other effluent limitations, such as endocrine disrupters or pharmaceutical/personal care products, become a concern. Ozone would also increase safety risks associated with ozone generation equipment using pure oxygen. Ozone generation is a complex, equipment intensive and labor intensive process. Ozone, once generated, is highly corrosive and toxic. Operating the ozone system, including generation, storage, handling and feed, takes great caution. Significant control effort is required for operational reliability of an ozone system. Formation of the disinfection byproduct NDMA during ozone disinfection is another concern. Ozonation has been shown to generate NDMA while simultaneously oxidizing NDMA. Ozone followed by biofiltration is reported to remove NDMA. However, ozonation as a final disinfection step without subsequent biofiltration has been shown to increase NDMA concentration in drinking water treatment (Asami et al., 2009) and has varied impacts on effluent quality such as reducing estrogenic activity while increasing toxicity and retarding growth in some test organisms (Stalter et al. 2010). Precursors, indicated by total organic carbon (TOC), to NDMA formation exist in much higher concentrations in the wastewater such as the WRRF tertiary effluent than in drinking water. Therefore, potential NDMA generation could be significant with ozone as the disinfectant. Because the draft NPDES permit includes an NDMA limit, ozone is not a viable disinfectant for the WRRF. Pasteurization Pasteurization has a history as a disinfection method in food processing. Pasteurization of wastewater is a new approach that relies on the fundamental concept of hot water sterilization. This physical treatment is designed to eliminate the use of chemicals in wastewater disinfection practice. Pasteurization has been granted conditional acceptance by the California Department of Public Health as a disinfection technology for non-restricted water reuse under Title 22 of the California Code of Regulations, which makes pasteurization the second physical disinfection technology validated to meet disinfection criteria for treating wastewater, following UV technology. Because there is no involvement of chemicals in the disinfection with pasteurization, no disinfection byproduct generation would be expected. Pasteurization Technology Group (PTG) owns the patent for the pasteurization technology for wastewater disinfection. The current available pasteurization system consists primarily of two heat exchangers and a gas turbine for an external heat source, with the wastewater effluent passing through the two heat exchangers in series. The first heat exchanger, a plate type regenerative exchanger, uses heat from pasteurized water to preheat wastewater from ambient temperature to approximately 177 degrees Fahrenheit. The second heat exchanger, an economizer type heat exchanger employing finned tubes, takes waste heat to further elevate the water temperature to the target value of 180 degrees Fahrenheit. The treated effluent then returns to the preheater for preheating the influent wastewater, and reducing the effluent temperature to just above ambient (3 degree Fahrenheit increase). WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 13 of 30 Pasteurization is an emerging technology in wastewater disinfection. Installations are limited in small scales with a maximum treatment capacity of 0.5 MGD in operation at the Ventura Water Reclamation Plant, California. A large amount of heat exchangers and ancillary equipment would be required for the WRRF to treat the peak hour flow of 20 MGD. Effluent cooling is one of the tertiary treatment processes at the WRRF and cooling occurs upstream of tertiary filtration. The current and anticipated discharge permit includes the temperature requirement for the plant discharge to the San Luis Obispo Creek. The permit mandates that the plant discharge shall not cause the San Luis Obispo Creek water temperature to increase more than 5 degree Fahrenheit above the creek water temperature and the discharge shall not cause the receiving water to exceed 72.5 degree Fahrenheit. To implement pasteurization, a post pasteurization cooling facility is likely required, in addition to or in lieu of the existing cooling towers, to ensure regulatory compliance of the discharge temperature requirements. The regulatory limitation on discharge temperature and the fact that there are no operating pasteurization installations at the scale of the WRRF eliminates pasteurization as a viable disinfection process for the WRRF. Peracetic Acid Peracetic acid (PAA) was one of the disinfection alternatives evaluated in the 2011 Facility Master Plan. Since then, the technology continues to be developed and implemented in full-scale wastewater applications. The recent success of using PAA at wastewater treatment facilities in Kentucky and Florida has stimulated the interest of this disinfectant and its applicability for the WRRF. While PAA does not form disinfection byproducts of concern, or have other toxic properties, it introduces acetic acid at its addition to wastewater, which can serve as a matrix for bacterial re- growth. In addition, the acetic acid has shown to increase total organic carbon and biochemical oxygen demand (BOD) in PAA treated wastewater when applied in high doses (i.e. 5 mg/L). The increase of BOD could potentially challenge the low BOD limit of 10 mg/L in the WRRF discharge permit. In the State of California, PAA is not yet an accepted wastewater disinfectant and as such, no guidelines currently exist for PAA residual concentration in plant discharges. The USEPA has set forth a discharge limit of 1 mg/L residual PAA at the St. Augustine wastewater treatment plant which is using PAA to disinfect its final effluent and disinfection is targeted at 200 cfu/100 mL fecal coliform as monthly geometric mean. A similar regulatory limit on residual PAA concentration would likely be imposed in California. During the month long disinfection study at the WRRF, PAA residuals were controlled to be less than 1 mg/L in a series of dose response tests. A PAA dose of 2 mg/L and 3 mg/L was used. Fecal coliform inactivation did not achieve the target of 2.2 cfu/100mL at PAA residual less than 1 mg/L. Figure 5 shows the fecal coliform inactivation with the testing PAA dosages. WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 14 of 30 Figure 5. SLO WRRF PAA Testing Results – Fecal coliform Inactivetion Future permit requirements may also hinder the use of PAA for disinfection at the WRRF. The EPA announced in April 2014 “the potential use of viral indicators” and is preparing Ambient Water Quality Criteria for Viruses. They have outlined a schedule for developing these water quality criteria over the next 1-2 years and noted that, “virus criteria will greatly improve knowledge of risk leaving WWTP.” HDR PAA testing results have shown that PAA is not effective on bacteriophage MS2, the indicator organism typically used for enteric viral pathogens. Therefore, disinfection using PAA will not meet the anticipated future permit limits for viruses. The onsite testing demonstrated that low residual PAA and fecal coliform compliance cannot be achieved at the same time using PAA as a disinfectant for the WRRF final effluent. In addition, PAA will not meet the potential regulatory requirements on virus. These issues eliminate disinfection with PAA as a viable disinfection process for SLO WRRF. UV Disinfection The 2011 Facility Master Plan identified UV as a viable option for final effluent disinfection at the WRRF. A disinfection study was conducted in May 2014 to determine the viability of UV disinfection for the WRRF. UV dose response testing was performed to examine the effectiveness of UV on WRRF tertiary effluent. UV dose response tests were conducted at the HDR Water Technology Laboratory with a collimated beam apparatus, a laboratory bench scale device that provides controlled UV light intensity to the wastewater sample under testing. Fecal coliform inactivation results are presented in Figure 6. A UV dose of 20 mJ/cm2 and higher reliably inactivated the fecal coliform to the compliance limit. As a reference, to meet the 2.2 cfu/100mL fecal coliform limit, the UV design guideline developed by National Water Research Institute (NWRI) and subsequently adopted by the California Department of Public Health (CDPH) recommends the UV dose of 100 mJ/cm2 for filtered effluent such as the filtered effluent produced in the WRRF tertiary treatment process. 1 10 100 1,000 10,000 100,000 1,000,000 10,000,000 051015202530354045505560 Fe c a l c o l i c o r m ( c f u / 1 0 0 m L ) Contact Time (minutes) PAA Test 1. PAA Dose = 2 mg/L PAA Test 2. PAA Dose = 3 mg/L Compliance Limit of fecal coliform 2.2 cfu/100mL WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 15 of 30 Figure 6. SLO WRRF UV Testing Results – Fecal coliform Inactivation Disinfection influent water quality has significant impact on UV performance. The most important quality parameter is UV transmittance. UVT data was collected in May 2014 and are presented in Figure 3. Suspended solids can shield organisms from exposure to UV, reducing its effectiveness as a disinfectant. TSS data from the past four years were presented in Figure 1 and discussed in the previous section. Other than UVT and TSS, water constituents that could cause UV lamp sleeve fouling were also tested during the month-long disinfection study in May 2014. High concentration of the fouling constituents is subject to high fouling potential. Sleeve fouling will discount the UV dose and hence reduce the effectiveness of UV. More frequent sleeve cleaning is required if the UV equipment is operated in high fouling potential wastewater. Testing results are summarized in Table 3. Table 3. Water Quality Parameter Fouling Potential TSS Hardness Calcium Magnesium Iron Manganese Total PO4-P mg/L mg/L mg/L mg/L g/L g/L mg/L 3.6 289 40 46 120 non-detect 4.7 2.0 287 41 45 160 non-detect 5.0 2.3 306 45 47 220 20 6.0 2.6 287 41 45 140 10 5.0 Moderate fouling potential would be expected from hardness. The results shown in Table 2 indicate that the tertiary effluent is high in hardness which could result in fouling on quartz sleeves if high operating temperature lamps were used. No significant impact from hardness is expected using low operating temperature lamp systems which are typical for wastewater disinfection. 0 0 0 1 10 100 1,000 10,000 100,000 1,000,000 10,000,000 0102030405060708090100 Fe c a l c o l i f o r m ( c o l o n i e s / 1 0 0 m L ) UV Dose (mJ/cm2) Compliancefecal coliform limit of 2.2 cfu/100mL WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 16 of 30 No significant impact from iron would be expected. Iron is a major concern for UV disinfection because iron in the wastewater not only absorbs UV light thereby discounting the UV dose, but it also forms iron scaling that is difficult to remove with automatic wiping. The iron concentration in the WRRF tertiary effluent is very low or less than the threshold limit of iron concentration (i.e. 300 µg/L) that would impact UV effectiveness and sleeve cleaning. UV disinfection does not generate any known toxic byproducts. The disinfection study results have shown that UV is effective in disinfecting WRRF tertiary effluent to meet the regulatory requirements. UV is a viable option for SLO WRRF disinfection process. Recommendation Seven disinfection alternatives were evaluated based on each alternative’s ability to meet the stringent disinfection byproducts limitations, disinfection effectiveness to meet fecal coliform 2.2 cfu/100mL, pathogen reduction requirements, and potential risk for compliance of final effluent temperature requirements. The evaluation eliminated chlorination and dechlorination (existing), chloramination, chlorine dioxide, ozone, pasteurization, and PAA as viable disinfection alternatives for further consideration. UV disinfection has shown its ability to effectively disinfect the WRRF tertiary effluent to the regulatory limit of fecal coliform 2.2 cfu/100mL. The benefits of implementing UV disinfection at the WRRF are summarized as follows: • UV disinfection is a mature technology for wastewater pathogen reduction. There are more than 100 installations in California with the compliance requirement of 2.2 cfu/100mL fecal coliform. • UV disinfection will not produce toxic byproducts of concern, including THMs and NDMA. • No chemical is required with UV disinfection; therefore, the WRRF could decommission the storage and feed facilities of the two corrosive chemicals that are currently used for final effluent disinfection, sodium hypochlorite and sodium bisulfite. There will be no large bulk chemical delivery and the potential risk during chemical transportation is eliminated. There will be no chemical procurement contracts to maintain and administer by WRRF staff. • There is no risk of potential permit violations of other regulatory compliance limits, such as BOD (potentially from PAA) and ammonia (potentially from chloramination), because chemical addition is not used with UV disinfection. • UV facilities typically have a small footprint. A preliminary evaluation indicates that one or two out of four existing chlorine contact tanks can accommodate a UV system sized for the peak hourly flow, which could maximize the use of existing facilities. UV disinfection is the recommended alternative for final effluent disinfection at the WRRF. A detailed evaluation of UV technologies, capital cost estimates and life cycle cost analysis of UV equipment are presented in the following sections. With UV as the main process technology for final effluent disinfection, sodium hypochlorite will not be eliminated entirely from the plant. Water recycling regulations require the plant effluent for reuse to have chlorine residuals. Sodium hypochlorite will also be used in several areas for house keeping WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 17 of 30 purpose, such as periodic filter maintenance cleaning and potential future sludge bulking control, etc. The overall volume of chlorine required will be significantly less with the addition of UV disinfection. However, the chlorine residual and THMs should be closely monitored to ensure that potential THMs will not exceed the limits set forth in the plant discharge permit. As an alternative, peracetic acid may be considered as an alternative to sodium hypochlorite for house keeping practices. UV Disinfection UV technologies have been used routinely in wastewater disinfection applications. With UV disinfection, specific electromagnetic wavelengths are used to inactivate microorganisms through denaturing of their DNA. Wavelengths ranging from 250 to 270 nm are readily absorbed by bacteria, effectively inactivating pathogens found in wastewater by rendering them unable to replicate. Technology Alternatives Lamps The major components of a UV system are the UV lamps arranged in a specific array. UV disinfection systems are categorized based on the source of UV light or the type of UV lamp used in the system. UV technology is available in three different lamp systems for wastewater treatment: • Low pressure low output (LPLO) lamp system • Medium pressure high output (MPHO) lamp system • Low pressure high output (LPHO) lamp system LPLO lamp systems are ineffective in treating wastewater of a quality less than filtered effluent water. The LPLO lamp system is no longer recommended for wastewater disinfection because it requires a large number of lamps. Thus, the LPLO lamp system is not being considered for this application. MPHO lamp systems operate with lamps at a much higher intensity than LPLO lamp systems. This results in the need for fewer lamps per system. However, the MPHO lamp systems have a shorter operating life and a lower efficiency for converting energy into the germicidal light. Additionally, the MPHO lamp systems have higher power requirements and experience more fouling due to high operating temperatures (600 and 800 degrees Celsius). MPHO lamp systems are polychromatic, producing UV light over a wider range of wavelengths in which the germicidal wavelength is a small portion of the entire generated light spectrum. These medium-pressure lamps are not as efficient as low-pressure lamps in terms of conversion of applied power to UV energy. Overall energy requirements for MPHO lamp systems are three to five times that of LPHO lamp systems. MPHO lamp systems were developed primarily to improve UV disinfection for drinking water treatment plants. LPHO lamp systems are more energy efficient and are a typical application for treated wastewater effluents. LPHO lamp systems combine the benefits of both LPLO and MPHO lamp systems. Since the LPHO lamp systems emit monochromatic germicidal light at higher intensity levels, the number of lamps needed for a given dose is reduced when compared to the LPLO lamp systems. The operating temperatures of LPHO lamp systems range from 140 to 180 degrees Celsius. The lower operating temperatures when compared to MPHO lamp systems result in the LPHO lamp systems WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 18 of 30 having a longer operational life than MPHO lamp systems. In addition, lower operating temperatures help limit fouling on the protective lamp sleeves, particularly in wastewater treatment applications. A comparison of the LPHO and MPHO lamp systems in terms of equipment, operation, maintenance, and cost is summarized in Table 4. Table 4. Comparison of Low-Pressure and Medium-Pressure Lamps LOW PRESSURE HIGH OUTPUT LAMPS MEDIUM PRESSURE HIGH OUTPUT LAMP Commonly used in wastewater disinfection Commonly used in drinking water disinfection More lamps Less lamps Lower lamp cost (~ $190/lamp) Higher lamp cost (~ $800/lamp) Longer lamp life (~ 12,000 hours) Shorter lamp life (~ 5,000 hours) Low power demand per lamp (~ 300 watts) High power demand per lamp (~ 4,100 watts) Low operating temperature (~ 140 to 180 degrees Celsius) High operating temperature (~ 600 to 800 degrees Celsius) Higher power to light conversion efficiency (~ 40% ) Lower power to light conversion efficiency (~ 15%) Lower overall system power consumption Higher overall system power consumption (more than three times) Low fouling potential High fouling potential Easy lamp replacement Complex lamp replacement No cool down before restart 15-minute cool down required before restart Reactor Configurations UV disinfection reactors are available in open channel and closed vessel configurations. The LPHO lamp systems are typically configured as modular arrangements in open, gravity-flow channels. The MPHO lamp is generally used in pressurized closed vessels where the system head loss is typically greater than open channel configurations. UV disinfection systems with open channel reactors are the most common UV disinfection installations in municipal wastewater treatment plants. Open channel reactors consist of modules of lamps with the modules spanning the width of the channel to form a bank. The reactor is typically configured as a long narrow channel with a number of UV banks arranged in series and the lamps completely submerged in the flowing effluent. Algae growth of various extents has been observed in open channel reactors. Cleaning of open channel reactors require the UV system be taken out of service for removal of a module/bank from the channel. In closed vessel reactors, the UV lamps are enclosed. Flanged pipes are typically connected to the inlet and outlet of the closed vessel. Multiple reactors can be arranged in series and in parallel to increase capacity and provide redundancy. Typically, wastewater flows full or pressurized through the closed vessels resulting in the lamps completely submerged. The lamps can be accessed through watertight ports on the side of the reactor, so that broken lamps can be removed and chemical cleaning can be completed in place. A comparison of the submerged reactors (open channel and closed vessel reactor configurations) in terms of equipment and operation is summarized in Table 5. WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 19 of 30 Table 5. Comparison of Submerged Reactors – Open Channel and Closed Vessel Reactors OPEN CHANNEL REACTOR CLOSED VESSEL REACTOR Algae growth in channel Algae growth in closed vessel Gravity flow through the system Pressurized or flow full Concrete channel configuration Pipe flanged reactors Need to lift lamps/modules/banks out of channel for periodic channel cleaning Cleaning in place Easy visual observation and manual cleaning Complex cleaning system required; difficult manual cleaning Potential of short circuiting Low potential of short circuiting Horizontal lamp systems need lifting devices for lamp replacement. No lifting devices required for lamp replacement; lamp replacement in-place. Lamp Orientation In open channel reactors, there are three typical lamp orientations: • Horizontal and parallel to flow • Vertical and perpendicular to flow • Diagonal/inclined to flow Equipment setting and operational and maintenance characteristics are very similar in between the vertical and diagonal/inclined lamp systems. Vertical or diagonal/inclined lamp systems consist of an open frame that rests on the bottom of the channel. A vertical module typically contains a large number of lamps (i.e. 40 lamps per module in Aquaray 40HO). A single module can form a bank in a vertical lamp system, while multiple modules form one bank in a horizontal lamp system. All electrical connectors in the vertical lamp system can be located above water, while lamp connectors are completely submerged in the horizontal lamp system. Water level control is critical to the horizontal lamp system. Typically, the allowable variation of the water level in channels with horizontal lamps is only two inches. If the water level is too low, it could expose the top row of lamps to air, likely causing lamp damage; and if the water level is too high, it could cause short-circuiting of the surface layer without receiving sufficient UV light exposure, hence, not enough dose to kill. Therefore, a reliable level control mechanism is important for design of horizontal lamp systems. Conversely, the open channel system with vertical or diagonal/inclined lamps is not as sensitive to the water level variation. Partial lamp exposure does not damage the lamps. The allowable water level change could be up to seven inches for an open channel system with vertical or diagonal/inclined lamps. Vertical lamp systems have higher head loss than horizontal lamp systems, and this must be taken into account when hydraulic constraints exist. A comparison of lamp orientations in terms of equipment and operation is summarized in Table 6. WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 20 of 30 Table 6. Comparison of Horizontal and Vertical/Diagonal/Inclined UV Lamp Orientation in Open Channel Systems HORIZONTAL LAMP SYSTEM VERTICAL/DIAGONAL/INCLINED LAMP SYSTEM Completely submerged electrical connectors All electrical connectors located above wastewater Lower hydraulic head loss Higher hydraulic head loss Smaller size module; multiple modules form a bank Larger size module; one module can form a bank Small davit crane for module lifting Minimum 1-ton crane required for module lifting Requires module removal from channel for lamp replacement Lamp replacement without module removal from channel Single lamp exposure; short circuiting with a single lamp out of service Multiple lamp exposure; no short circuiting even with multiple lamps out of service Sensitive to water level change; large fixed weir High allowable water level change; small fixed weir Flow pacing by on/off the entire bank Flow pacing by on/off row(s) of lamps Recommended UV Technologies for Preliminary Evaluation Based on the review of the UV technologies presented above, it is recommended that the preliminary evaluation of UV disinfection systems for the WRRF consider: • Low pressure high output (LPHO) lamps • Open channel configurations • Horizontal, vertical or diagonal/inclined lamp orientations Identification of Applicable UV Disinfection Systems Within the context of the WRRF UV disinfection evaluation, it is necessary to identify commercially available UV disinfection systems with the recommended UV technologies of LPHO lamp systems with open channel reactor configuration. Additional constraints established for identifying available UV systems included: • UV system suppliers shall have UV system(s) validated in the US, with an applicable dose- based sizing algorithm. The UV system validation shall be via USEPA UV Design Guidance Manual (UVDGM), International UV Association (IUVA) low-dose protocols, and National Water Research Institute (NWRI) Ultraviolet Disinfection Guidelines for Drinking Water and Water Reuse (2012) to allow direct comparisons of UV disinfection systems; • The system has been approved or is in the process of getting approval for California Title 22 non-restricted reuse application; • The system shall be compatible with the water quality expected in the tertiary filter effluent and the expected flow operating ranges; • The system shall be commercially available and in practice in North America; • Suppliers shall have past history of systems sized similarly to the WRRF capacity levels. WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 21 of 30 • The system shall operate under gravity flow conditions with low-head configuration; • System footprint, inclusive of the approach and exit channels, UV modules and power/control centers, shall be capable of fitting within the practical constraints of the proposed WRRF site. UV Disinfection System Suppliers Identified Three suppliers with the recommended UV technologies (LPHO lamps with open channel reactor configurations) were selected for the evaluation process. The three suppliers were selected on the basis of their ability to meet the constraints listed above. These suppliers are representative of UV disinfection systems that address conventional and high-capacity commercial products. CONVENTIONAL SYSTEMS Several suppliers are available that offer conventional open channel systems with LPHO lamps and meet the design requirements and constraints delineated above. These UV disinfection systems are characterized by lamp wattages up to 400-watt, greater than 12,000 hours operating life, validated sizing algorithms, automatic quartz sleeve cleaning devices, and systems in operation with disinfection capacities up to 55 MGD tertiary effluent. HIGH-CAPACITY SYSTEMS Recent advances in high-wattage lamp technologies have been introduced by several suppliers, using lamps up to 1,000-watt in input power. Fewer lamps are needed with these systems. The key benefits would be fewer lamps to maintain and a smaller site footprint. Table 7 summarizes the three suppliers and their respective products. Table 7. UV Disinfection System Alternatives Selected for Evaluation UV ALTERNATIVE SYSTEM TYPE UV SUPPLIER MODEL LAMP SYSTEM CONFIGURATION 1 Conventional Ozonia Aquaray® 3X Vertical – Open channel 2 Conventional Trojan UV3000 Plus™ Horizontal – Open channel 3 High Capacity Wedeco Duron Diagonal/Inclined – Open channel Figure 7 illustrates the conventional systems. Ozonia North America provides its Aquaray® 3X unit with 406-watt lamps oriented vertically and configured in 36-lamp modules that are arrayed in series in an open channel. Trojan Technologies (Trojan UV3000Plus) has powered UV lamps oriented horizontally and configured as banks of lamps in series. WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 22 of 30 Ozonia Aquaray 3X Trojan Technologies UV3000Plus Figure 7. Conventional UV Systems Considered for SLO WRRF Figure 8 illustrates the recently introduced high-capacity system. The Wedeco Duron uses 600-watt lamps. The Duron unit is configured as banks in series, but with a diagonal/inclined lamp orientation. Wedeco Duron Figure 8. High-Capacity UV System Considered for SLO WRRF The purpose of the evaluation process is to recommend a UV technology and not a specific product. All three UV alternatives listed in Table 6 could achieve disinfection performance levels with different cost and space requirements. Conventional and high-capacity systems were evaluated since these UV systems use UV lamp technologies that are typical in wastewater treatment installations and WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 23 of 30 there is a significant database of operational experience to derive information related to design criteria, anticipated treatment performance, and facility and site requirements, as well as cost estimates. A specific UV system vendor can be selected once the site has been selected at a later stage of project definition. Disinfection Performance Requirements and Design Criteria for Preliminary Evaluation In order to obtain preliminary system quotations from the three disinfection suppliers (Ozonia, Trojan, and WEDECO), it was necessary to establish consistent performance requirements and design criteria. Performance Requirements The required hydraulic capacity of 16 mgd for the UV disinfection system was determined using the potential future filter influent pumping capacity and the equalized peak hourly flow rate. This capacity requirement will be further refined as part of the overall Facilities Planning effort. The influent TSS and BOD to the disinfection process were based on anticipated treatment performance of the tertiary processes and the historical compliance data. The maximum possible TSS and BOD would both be 10 mg/L, which are the regulatory discharge requirements of these two parameters. Fecal coliform standard is the same as the disinfection limitations for California Title 22 non- restricted reuse criteria, which is the 7-day median 2.2 MPN/100mL total coliform. Table8 summarizes the performance requirements for the UV disinfection process. Table 8. UV Disinfection Performance Requirements PARAMETER CRITERIA NOTES Peak Flow (mgd) 16 Maximum filter influent pumping rate Disinfection Influent TSS (mg/L) 10 Maximum based on discharge requirement Disinfection Influent BOD (mg/L) 10 Maximum based on discharge requirement Fecal coliform (cfu/100mL) 2.2 Average weekly not to exceed 7-day median Total coliform (MPN/100mL) 23 Average weekly not to exceed in any 30-day period Total coliform (MPN/100mL) 240 not to exceed any time Disinfection Influent Temperature 40°F / 75°F minimum/maximum Design Criteria In addition to the performance requirements, UV design criteria need to be established for system sizing and cost estimating. Two critical UV design parameters, UV transmittance (UVT) and UV dose to achieve the fecal coliform limit, need to be determined for UV system sizing. As previously described, a disinfection study was performed in May 2014 including UVT monitoring and UV dose response testing, or collimated beam test. The study results have shown that UVT of 55% represents the tertiary filter effluent water quality and a minimum UV dose of 20 mJ/cm2 is required to achieve fecal coliform inactivation to 2.2 cfu/100mL under laboratory testing condition. The WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 24 of 30 targeted minimum dose of 100 mJ/cm2 for full scale installation is the recommended UV dose for tertiary filter effluent according to UV Design Guideline issued by the National Water Research Institute (NWRI 2012). The targeted minimum dose of 100 mJ/cm2 is referred to as the “credited” UV dose to reflect the subsequent application of a validation factor that is generated from required validation testing. This validation is expected from the UV equipment supplier, and will need to be reviewed to assure that it follows standard protocols. It should incorporate a surrogate similar to fecal and total coliforms, such as MS2 coliphage. The validation factor accounts for experimental uncertainty and provides a “safety factor” to the design sizing of the system. Table 9 summarizes the design criteria for the UV disinfection system. Table 9. UV Disinfection System Design Criteria PARAMETER CRITERIA NOTES UV Dose (mJ/cm2) 100 minimum at peak flow and the end of lamp life MS2 bacteriophage bioassay based UVT % 55 minimum at 254 nm End of Lamp Life Factor (EOLL) 0.5 (technology dependent, maximum at 0.9) Sleeve Fouling Factor (FF) 0.8 (technology dependent, maximum at 0.9) The proposed system design is based on multiple banks per channel and multiple channels, which affords flexibility and consequent efficiency in operating the system. Available head loss is a key parameter and can be a reason to use open channel configurations as opposed to closed vessel configurations that are characterized by higher head losses. For the WRRF, it is estimated that the head loss through a UV disinfection system with an open channel reactor configuration would be 3 feet or less. Performance requirements are based on the anticipated discharge permit. Minimum dose delivery to assure compliance with these limits must be accomplished at the peak flow with all duty channels and lamp banks in operation at 100 percent input power and minimum UVT of 55 percent. The lamp output under these design conditions must reflect the UV intensity attenuation factors (EOLL and FF) guaranteed by the UV equipment supplier. Site Specific Considerations for UV Installation In addition to the UV performance requirements and design criteria, site specific conditions that will impact UV implementation should be considered. Those site conditions are discussed in the following subsections. Area for Installation The Potential Disinfection Project Area was shown in Figure 4. UV system maybe installed inside one or two of the existing chlorine contact tanks and modified as necessary. WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 25 of 30 Hydraulics Previous discussion (Basis of Evaluation) has indicated that the available hydraulic head for the new disinfection system is less than a foot, which constrains UV installation. The headloss through the entire UV system, including flow control mechanism, UV equipment and level control mechanism, is typically about three feet under peak flow condition. However, the potential exists to lower the effluent weir at the 3W pump station to provide more hydraulic head for UV designed for gravity flow. Refinements to the system hydraulics will be completed as part of the hydraulic modeling task. Coagulation Flocculation Coagulation and Flocculation process will only be considered if the suspended solids concentration in the plant effluent would be the potential hindrance of UV performance. Suspended solids in final effluent have a significant impact on disinfection effectiveness, in particular, UV effectiveness. An efficient and proven cost-effective way to reduce the suspended solids is to employ a coagulation and flocculation process. Coagulation and flocculation is a process where chemicals (coagulants and/or polymers) are added, with mixing, to a stream of wastewater to increase settleability of suspended particulate matter or colloidal material. Common coagulants are aluminum sulfate (alum), ferric chloride or sulfate, and various polymers that sometimes are incorporated into coagulants. In future operations if improved solids reduction is found to be necessary, alum, poly aluminum chloride (PACl) or cationic polymers may be used as coagulant. Ferric chloride should be avoided because iron, even in a very low concentrations (i.e., 0.3mg/L), would adversely impact UV operation. Iron absorbs UV light, and therefore decreases the effectiveness of a UV dose; and iron is also a strong fouling agent on UV lamp sleeves. Flocculation refers to the process of agglomeration of the particulate matter into larger particles (floc) that are then removed through sedimentation and/or filtration. For the WRRF, the final clarifiers could be used for flocculation and settling. A coagulation/flocculation system typically consists of metering pumps, coagulant storage tank(s) and a rapid mixing mechanism. During plant operation, coagulant can be injected immediately upstream of the final clarifiers where the highest flow turbulence occurs or an inline mixer can be installed in the distribution line to enhance the coagulant and water mixing. A coagulation/flocculation process would be operated only to mitigate high suspended solids that may result due to secondary treatment process upsets or storm events. Facility Requirements and Cost Estimate Requests for preliminary system quotations were submitted to the three UV disinfection suppliers identified previously (Ozonia, WEDECO, and Trojan). Each supplier was provided with a summary of the preliminary performance requirements and design criteria for the WRRF UV disinfection system (Table 7 and Table 8). Each supplier provided technical information, preliminary equipment sizing, equipment costs and associated replacement costs, and equipment information for their conventional and high-capacity systems. Attachment A includes equipment information and quotes from the suppliers of each UV disinfection system evaluated. Table 10 provides a summary of the UV disinfection systems proposed by each supplier, including preliminary information on system head losses. WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 26 of 30 Table 10. UV Disinfection Alternative Evaluation Design Summary UV DISINFECTION SYSTEM CONVENTIONAL HIGH CAPACITY Supplier OZONIA TROJAN WEDECO Model Aquaray 3X UV3000Plus Duron UV Channel Number of Channels 2 2 2 Channel Equipment Section Length (feet) 37 66 49 Channel Width (in) 59 52 115 Channel Depth, min (in) 84 62 75 Minimum Straight Channel Upstream (feet) 10 10 10 Minimum Straight Channel Downstream (feet) 10 10 10 UV Module Total Number of Banks per Channel 5 5 6.5 Total Number of Lamps per Bank 72 104 48 Total Number of UV Lamps Installed 720 1,040 624 Input Power per Lamp (W) 406 250 600 Max Power Consumption (kW) (Duty) 292 260 374 Head Loss Across UV Banks at Peak Flow (in) 1 1 2 Approximate System Head Loss (in)* 21 21 22 Power Requirements Power Distribution Center 480V/3PH/4 wire System Control Center 120V/1PH/2 wire Online UVT Monitor 120V/1PH/2 wire * System Head loss including baffle, stilling plate, UV banks, gates and freefall required for flow distribution and level control. The conventional systems are open-channel processes with two identical parallel channels proposed by the vendors. The conventional systems are traditional horizontal (Trojan) or vertical (Ozonia) type arrangements with staggered lamp arrays and rated input power per lamp ranging from 250 to 406 watts. The total number of lamps for the conventional systems range from 720 to 1,040 lamps with maximum power consumptions approximately at 300 kW. The newer diagonal/inclined system (WEDECO) consists of high output amalgam UV lamps with UV254 output approximately 2 to 3 times higher than the conventional LPHO lamp systems, resulting in fewer UV lamps required. The Duron systems also fit into 2-channel configurations. The number of lamps required for the high-capacity system is 624 lamps with maximum power consumptions approximately at 380 kW. Each system is equipped with substantial turndown capability, using power input (i.e. dim lamps from 100 percent to 50 percent power input), number of channels and banks per channel as the accessible variables to control dose. Opinions of probable construction costs were also prepared for two UV disinfection systems: • The system with the largest footprint and highest equipment cost. • The system with the smallest footprint and lowest equipment cost. WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 27 of 30 The construction costs were determined using the general methodology following EJCDC format. The contractor overhead and profit markups were assumed to be 10 percent and 5 percent, respectively. The contractor mobilization/demobilization markup of 6 percent was used in calculating the construction cost. The construction contingency and overall project contingency are assumed at 5 percent and 20 percent, respectively. These costs are for relative comparison only and do not provide the accuracy or capture overall project costs that will be provided by construction cost estimates performed at design stage. Supporting information of construction cost estimates is included in Attachment B. The main purpose of the construction cost estimate is to provide a preliminary range of construction costs (UV disinfection system and associated facility cost). These cost estimates are presented in Table 11. The largest and the most costly system (Duron) had an estimate of $8 million. The smallest and the least costly system (Ozonia Aquaray 3X) had an estimate of $7 million. Table 11. Constructed Cost Estimates for the Largest, the Smallest UV Installations PLANNING LEVEL COST ESTIMATE Largest Footprint and Highest Equipment Cost System Wedeco Duron Smallest Footprint and Lowest Equipment Cost System Ozonia Aquaray 3X Sitework - Div. 2 Total $703,600 $703,600 Concrete - Div. 3 Total $389,000 $347,000 Metals - Div. 5 Total $95,200 $86,200 Wood & Plastics - Div. 6 Total $14,500 $13,100 Thermal & Moist. Protc. - Div. 7 Total $10,000 $10,000 Finishes - Div. 9 Total $5,000 $5,000 Specialties - Div. 10 Total $9,500 $9,500 Equipment - Div. 11 Total $2,409,200 $1,798,500 Special Construction - Div. 13 Total $450,000 $424,000 Conveying Systems - Div. 14 Total $- $50,000 Mechanical - Div. 15 Total $220,000 $238,000 Electrical - Div. 16 Total $855,100 $743,300 Subtotal $5,161,100 $4,428,200 Construction Contingency (5%) $258,100 $221,400 Subtotal – Direct Costs $5,419,200 $4,649,600 Contractor Mobilization/Demobilization (6%) $325,200 $279,000 Contractor’s Overhead (10%) $574,400 $492,900 Contractor’s Profit (5%) $287,200 $246,400 Subtotal $6,606,000 $5,667,900 Project Contingency (20%) $1,321,200 $1,133,600 Total Estimated Construction Cost $7,930,000 $6,810,000 WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 28 of 30 Life-Cycle Costs of UV Equipment Life-cycle costs for the UV equipment were developed for all three UV alternatives. In addition to providing equipment costs, each supplier provided costs and life-cycle information for the major UV equipment replacement components to enable an itemized present worth cost to be calculated for: lamps, ballasts, lamp sleeves, wipers, and UV intensity sensors. UV equipment quotes included UV lamp modules, ballasts and enclosures, power distribution, electrical panels, control panel and instrumentation. Life-cycle cost estimates were prepared for UV equipment, power consumption, UV lamp replacement, ballast replacement, sleeve replacement, wiper replacement and intensity sensor replacement. Life-cycle costs were prepared for each alternative based on the following assumptions: • Life-Cycle Term – Life-cycle costs were estimated over a 20-year equipment life which is typical for UV equipment life. • Average Flow Factor – UV lamps are paced on and off with tertiary effluent flow to the UV disinfection system. An average flow of 5.5 mgd is assumed for average filter influent pumping rate. An average flow factor (= 5.5mgd/16mgd) was used for UV equipment life calculation. • Power – The major operating cost of a UV disinfection system is power. UV disinfection is an equipment intensive treatment process. Power is consumed by UV lamps, ballasts, and auxiliary equipment (wiping system, online monitoring device, flow meter(s), out-of-channel cleaning system, etc). • Staffing – For comparison purposes, general staff requirements were assumed to be common for all UV alternatives, and thus, were not included in the life cycle analysis. • Replacement Labor Hours – The major labor requirement of a UV disinfection system is for the replacement of lamps, ballasts, sleeves, wipers, and intensity sensors. The replacement labor hours required are different for the various UV alternatives evaluated. The replacement labor hours were estimated based on past experience and complexity of replacement for the UV equipment in this evaluation. The life-cycle cost summary is based on total equipment pricing. Attachment C contains details of the life-cycle cost analysis. Table 12 summarizes the relative equipment cost, annual O&M cost, and life-cycle cost for the UV alternatives evaluated. WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 29 of 30 Table 12. Summary of UV System Equipment, Annual O&M and Life-Cycle Costs UV DISINFECTION SYSTEM CONVENTIONAL HIGH CAPACITY Supplier OZONIA TROJAN WEDECO Model Aquaray 3X UV3000Plus Duron UV Equipment Cost a $1,450,000 $1,830,000 $1,981,000 Annual Energy Cost b $120,000 $100,000 $150,000 Annual O&M Cost c $190,000 $240,000 $250,000 Present Value O&M Cost d 2,270,000 2,960,000 3,110,000 Life-Cycle Cost e $3,720,000 $4,790,000 $5,080,000 a provided by UV equipment suppliers b Energy costs are included in the O&M costs but are shown separately for comparison purposes. c Today’s dollar. Labor hours were estimated for lamps, ballasts, sleeves (or tubes), wipers and intensity sensors replacement for each UV disinfection system. d Present value is based on 20 year period and a 5 percent discount rate e Present value including equipment cost and O&M costs The Ozonia Aquaray 3X has the lowest equipment cost among the three UV alternatives and the lowest overall life-cycle cost, at $1.45 million and $3.72 million, respectively. The Trojan UV3000Plus system equipment cost is $1.83 million. Trojan equipment replacement costs are much higher than Ozonia’s which resulted in approximately $4.79 million present worth cost compared to Ozonia’s $3.72 million. The annual power costs of these two alternatives are similar. The Wedeco equipment cost is approximately $2 million, the highest among the three alternatives. In addition to the equipment cost, the annual power consumption as well as the overall annual O&M cost of the Duron system are much higher than those of the other two alternatives. The present worth life-cycle cost of the Wedeco Duron system is approximately $5.08 million. Conclusions The following conclusions are made based on this evaluation: • Results from the UV technology comparison show that a UV disinfection system with open channel reactor(s) equipped with LPHO lamps is the most suitable UV technology for disinfection at the WRRF. • UV technology is proprietary and the UV equipment or systems vary among suppliers in terms of lamp technology, ballast location, reactor configuration and control strategy, etc. • Results indicate that the initial construction cost of the UV disinfection system range from approximately $7 to $8 million. • Footprint requirements, a key element of siting, range from approximately 3,000 square feet to 3,500 square feet for the WRRF UV disinfection system. The vertical UV disinfection WRRF Project TM No. 4 – Disinfection Study (FINAL) Page 30 of 30 system (Ozonia Aquaray 3X) has a smaller footprint than the horizontal (Trojan UV3000Plus) and the diagonal (Wedeco Duron) systems. • Results indicate that the present worth of UV equipment (does not include concrete channels, enclosures/covers, and auxiliary facilities) based on the life-cycle cost analysis range from $3.7 to $5 million for the three UV alternatives evaluated. • The annual power cost, which is the major O&M cost associated with the UV system, is approximately $100,000 to $150,000. Recommendations Given the above conclusions, an open channel UV disinfection system with LPHO lamps is the recommended disinfection technology for SLO WRRF. Once the site is selected, further selection and optimization of the technology can be conducted. If an open channel UV disinfection system is selected for implementation, a competitive pre- selection process may be warranted, using an “evaluated bid” approach. In this approach, the system with the best value based on an acceptable combination of life-cycle costs and non- economic factors would be selected, and the UV disinfection facility would be designed around the equipment of the selected vendor. References Asami, M.; Oya, M.; Kosaka., K. (2009) “A nationwide survey of NDMA in raw and drinking water in Japan.” Science of the total environment, 407(11):3540-3545. Brown and Caldwell (2011) Water reclamation facility master plan. City of San Luis Obispo: San Luis Obispo, CA. NWRI (National Water Research Institute) in collaboration with Water Research Foundation (2012) Ultraviolet disinfection guidelines for drinking water and water reuse. Third ed. Stalter, D.; Magdeburg, A.; Oehlmann, J. (2010) “Comparative toxicity assessment of ozone and activated carbon treated sewage effluents using an in vivo test battery.” Water research, 44(8):2610- 2620. Attachment A UV System Alternative Quotes Ozonia North America LLC 600 Willow Tree Rd. | Leonia | NJ 07605 | USA Tel : 201-676-2525 | Fax : 201-346- 5460 | www.ozonia.com San Luis Obispo WWRF, CA (System C – 16 MGD Peak Disinfection) Aquaray 3X Vertical Lamp UV Disinfection System AQUARAY 3X 2 CHANNELS Peak Flow, MGD 20 MGD % UV Transmission 55% Minimum Bioassay UV Dosage at Peak Flow, mJ/cm2 100 mJ/cm2 Number of Channels 2 Number of Modules Across (Number of modules per bank) 2 Number of Modules in Series (Number of Banks) 5 Channel Width, in. 58.5 inches Channel Length, ft. 37 feet Channel Depth, in. 84 inches Aquaray® Modules/Channel 10 Total Number of Modules 20 Number of Lamps/Module 36 Total Number of Lamps 720 Power Consumption per Lamp 406 watts Total Installed Power 292.04 kW Power Consumption at 16 MGD 282.11 kW Power Consumption at 5.5 MGD 111.85 kW Power Consumption at 0.7 MGD 29.20 kW Headloss at 35 MGD 5.17 inches Headloss at 16 MGD 0.96 inches BUDGET PRICE $ 1,450,000 PROPOSAL FOR THE CITY OF SAN LUIS OBISPO, CA QUOTE: LJK1910B 10/21/2014 The TrojanUV3000Plus™ is operating in over 1300 municipal wastewater plants around the world. Disinfecting over 17 billion gallons a day, the TrojanUV3000Plus™ has become the reference standard in the industry. San Luis Obispo LJK1910 10/21/2014 - 2 - October 21, 2014 In response to your request, we are pleased to provide the following TrojanUV3000Plus™ proposal for the San Luis Obispo project. The TrojanUV3000PlusTM has been shown in over 1300 installations to provide dependable performance, simplified maintenance, and superior electrical efficiency. As explained in this proposal, the system incorporates innovative features to reduce O&M costs, including variable output electronic ballasts to provide dimming capability and Trojan’s revolutionary ActiClean-WWTM system – the industry’s only online chemical and mechanical quartz sleeve cleaning system. All Trojan installations are supported by a global network of certified Service Representatives providing local service and support. Please do not hesitate to call us if you have any questions regarding this proposal. Thank you for the opportunity to quote the TrojanUV3000Plus™ and we look forward to working with you on this project. With best regards, Jordan Fournier 3020 Gore Road London, Ontario N5V 4T7 Canada (519) 457 – 3400 ext. 2193 jfournier@trojanuv.com Local Representative: Dean Boode The Coombs-Hopkins Company 2855 Mitchell Drive Suite 215, Walnut Creek, CA 94598 USA (925) 947-6733 DESIGN CRITERIA SAN LUIS OBISPO Peak Design Flow: 16 MGD Peak Hydraulic Flow: 35 MGD UV Transmittance: 55% (minimum) Total Suspended Solids: 10 mg/l (Maximum, grab sample) Disinfection Limit: 2.2 total coliform per 100 ml, based on a 7 day Median, 23 total coliform per 100 ml, Maximum Design Dose: 100,000 µWs/cm2, MS2 bioassay validated Validation Factors: 0.95 end of lamp life factor (Low-Pressure Amalgam Lamps) 0.90 fouling factor (ActiClean-WW™ Chemical / Mechanical Cleaning System) San Luis Obispo LJK1910 10/21/2014 - 3 - DESIGN SUMMARY QUOTE: LJK1910 Based on the above design criteria, the TrojanUV3000Plus™ proposed consists of: CHANNEL (Please reference Trojan layout drawings for details.) Number of Channels: 2 Approximate Channel Length Required: 66 ft Channel Width Based on Number of UV Modules: 52 in Channel Depth Recommended for UV Module Access: 62 in UV MODULES Total Number of Banks: 10 Number of Modules per Bank: 13 Number of Lamps per Module: 8 Total Number of UV Lamps: 1,040 Maximum Power Draw: 260 kW UV PANELS Power Distribution Center Quantity: 10 System Control Center Quantity: 1 MISCELLANEOUS EQUIPMENT Level Controller Quantity: 2 Type of Level Controller: Motorized Weir Gate Automatic Chemical / Mechanical Cleaning: Trojan ActiClean-WW™ UV Module Lifting Device: Davit Crane On-line UVT Monitor: Hach UVAS sc Sensor Standard Spare Parts / Safety Equipment: Included Other Equipment: ELECTRICAL REQUIREMENTS 1. Each Power Distribution Center requires an electrical supply of one (1) 480 Volts, 3 phase, 4 wire (plus ground), 26.5 kVA. 2. The Hydraulic System Center requires an electrical supply of one (1) 480 Volts, 3 phase, 3 wire (plus ground), 2 kVA. 3. The System Control Center requires an electrical supply of one (1) 120 Volts, 1 phase, 2 wire (plus ground), 15 Amps. 4. The Online UVT Monitor requires an electrical supply of one (1) 120 Volts, 1 phase, 2 wire (plus ground), 1 Amp. 5. Electrical disconnects required per local code are not included in this proposal. San Luis Obispo LJK1910 10/21/2014 - 4 - COMMERCIAL INFORMATION Total Capital Cost: $1,830,000 (US$) This price excludes any taxes that may be applicable and is valid for 90 days from the date of this letter. OPERATING COST ESTIMATE Operating Conditions Average Flow: 5.5 MGD Yearly Usage: 8760 hours UV Transmittance: 55% Power Requirements Lamp Replacement Average Power Draw: 99.8 kW Number lamps per year: 304 Cost per kW hour: $0.10 Price per lamp: $250 Annual Power Cost: $87,425 Annual Lamp Replacement Cost: $76,000 Total Annual O&M Cost: $163,425 This cost estimate is based on the average flow and UV transmittance listed above. Actual operating costs may be lower due to the TrojanUV3000Plus™ automatic dose pacing control system. As UV demand decreases, by a change in operating conditions, the power level of the lamps decreases accordingly. The dose pacing system minimizes equipment power levels while the target UV dose is maintained to ensure disinfection at all times. EQUIPMENT WARRANTEES 1. Trojan Technologies warrants all components of the system (excluding UV lamps) against faulty workmanship and materials for a period of 12 months from date of start-up or 18 months after shipment, which ever comes first. 2. UV lamps purchased are warranted for 12,000 hours of operation or 3 years from shipment, whichever comes first. The warranty is pro-rated after 9,000 hours of operation. This means that if a lamp fails prior to 9,000 hours of use, a new lamp is provided at no charge. 3. Electronic ballasts are warranted for 5 years, pro-rated after 1 year. Page1of4 XylemWaterSolutionsUSA,Inc. 14125SouthBridgeCircle Charlotte,NC28273 USA October22,2014 JuneLeng,P.E. HDRInc. 2365IronPointRoad,Suite300 Folsom,CA95360 Subject:SanLuisObispo,CA–SystemC UltravioletDisinfectionEquipment Attn:JuneLeng, WEDECOispleasedtosubmitthefollowingpreliminaryproposalfortheSanLuisObispo,CA ultravioletdisinfectionequipment.ThisproposalisinresponsetoarecentlyaddedSystemC optionandisinaccordancewiththetwo(2)previousSystemAandSystemBproposals WEDECOhassubmittedforthisproject.TheDuronsystemisanopenchannelprocesswhich providesmanybenefitsthatcanimprovetheperformanceofthesystemandincreasethe lifespanoftheequipment. Efficient45degreedesign.WEDECOhasusedourmanyyearsofexperienceintheUV industrytodevelopthis45degreeanglesystemwithstaggeredlampdesignwhich combinestheadvantagesofverticalandhorizontaldesigns.Thisdesignresultsin betterhydraulicsandperformance. Easeofmaintenance.WiththeDuronsystem,lampsandsleevescanbereplacedright inthechannel.TheDuronsystemalsoincludesauniquecompactautomaticlifting mechanismwhichofferseaseofinstallationandmaintenanceaseachmoduleisableto beliftedautomaticallyfromthechannelwithnoadditionalliftingmechanismrequired. Thisliftingdeviceallowsforeasyaccessforwiperringreplacement,visualinspection, andsensorexchange. Latestlamptechnology.Oursystemincludesourlatestlow-pressure,high-intensity Ecoraylampswhichhaveaguaranteedlifeof14,000hoursandareamoreefficient lamp.Witheachlampbeinghighpoweredat600watts,theDuronsystemalsorequires fewerlampsandotherreplacementcomponents. True"intensitybased"closedloopdosepacingcontrol.AUVintensitysensorlocated withineachmodulemeasuresrealtimeUVintensity.TheWEDECOUVsystemwas validatedusingthecalibratedsensorallowingforrealtimemeasurementoflampaging, fouling,andwaterqualityparameters.Knowingthatflowsandwaterqualityconstantly vary,havingarealtime(andaccurate)UVintensitysensortocontrolthelampsprovides theenduserwithpowersavingsandpreventsover-dosing,givinganassurancewhichis notalwaysavailableonotherUVmanufacturers’systems. Electricmotordrivenautomaticwipingsystemthatpreventsfoulingofthequartzsleeve withveryeasyreplacementofwipers. Remoteenclosures.WEDECO’sballastsarelocatedinseparateenclosure(s)remote fromthechannelwhichallowsforeasyaccessibilityformaintenanceandnoriskof floodingoftheUVchannel(s). DuronUVSystemBudgetProposal Xylem - WEDECO Products ∙ 14125 South Bridge Circle ∙ Charlotte, NC 28273 Page2of4 TotalCare.WEDECOhasrecentlydevelopedourTotalCareProgramwhichprovidesour customerswithproactiveservicesalldesignedtominimizethecostofownershipto operateandmaintaintheUVsystem.TotalCareservicescanprovideourcustomers withsystemhealthchecks,efficiencyaudits,trainingandpreventativemaintenance contracts.Wewouldbehappytodiscussthiswithyouinmoredetail. Wewouldliketoclarifythattheproposedsystemmeetsthedoserequirementsof100mJ/cm2 MS2basedonNWRI2012validationatthePeakflowrateof16MGDasspecifiedbyHDR,Inc. PleasedonothesitatetocontactusorourlocalrepresentativeDwightCraigofMisco,(925) 225-1900foranyclarificationofourproposal.Welookforwardtohavingtheopportunityto workwithyouinthenearfutureonthisveryimportantproject. Sincerely, KevinFlisJosephJordan TerritoryManagerApplicationsEngineer WEDECOaXylembrandWEDECOaXylembrand (704)351-3219 DuronUVSystemBudgetProposal Xylem - WEDECO Products ∙ 14125 South Bridge Circle ∙ Charlotte, NC 28273 Page3of4 BudgetProposalforWastewaterUVDisinfectionEquipment–SystemC Projectname SanLuisObispo,CA Proposalno.PPN14JJ0801 Rev 0 Date:October22,2014 Designapproach:NWRI2012(BioassayDose) EffluentTotalColiformsMax:23MPN/100ml @ 30daysgeometricmean EffluentTotalColiformsMax:2.2MPN/100ml @ 7daysgeometricmean UVdosemin:100mJ/cm²@ endoflamplifetime UVEquipmentStandardDetails DuronModelDuron312i4-6.5x2 Numberofchannels 2 Numberofbanksperchannel 6.5 UVlampsperbank (fullmodule/halfmodule)12/6 TotalnumberofUVlamps 624 Maximumheadloss,includingfreefall 11.4inches (=1.1”banks+6.3”levelcontrol+4”freefall) Maximumpowerconsumption816kW(lampsandballastsonly) WidthatUVbanks 114.4inches Widthatlevelcontrol 114.4inches Waterdepth 42.13inches Channeldepth 74.76inches Approx.Length578.3(6.5banks/channel)inches AllrequiredUVmodulesincl.lampsandsupportframeworkforinstallationoftheUVmodulesinthe channels 82ft(25m)powercablingfromlampstoballastcabinets Electricalenclosureshousingtheelectricalequipment: Enclosurematerialandrating:PaintedSteelEnclosuresType12withfan-cooling ControllerType:PLCAllenBradleyandHMIPanelViewPlus Powersupplyrequirements:480V,3phase,4wire+ground Labelingofcomponents Electricmotordrivenautomaticwipingsystem Fullautomaticliftingsystem UV-intensitymonitoringandcontrolsystem[oneperbank] Lowlevelprobes[oneperchannel] Downwardopeninggate[oneperchannel] UVtransmittancemonitor:YSI DosePacingandVariablePower RemoteServiceSupport Three(3)operatingandmaintenancemanualsinEnglishlanguage Preparedfor Representativesalesassociate:DwightCraig Representativecompany:Misco UVSystemDesignCriteria Peakdesignflow:16MGD Peakhydraulicflow:35MGD UVtransmittance(1cm),min:55 % Suspendedsolids,max:<10mg/l DuronModule DuronUVSystemBudgetProposal Xylem - WEDECO Products ∙ 14125 South Bridge Circle ∙ Charlotte, NC 28273 Page4of4 Factorytestingofallpartsandequipmentpriortoshipment PackagingofUVequipment Manufacturer’sfieldservicesonsite[2trips/15days] UVEquipmentOptions StainlesssteelelectricalenclosureType4Xforoutdoorinstallationwithair-conditioning Recommendedspareparts:10%Lamps,10%wipers,3%ballasts CommercialDetails Submittaltime:8weeksafterapprovedpurchaseorder Deliverytime:18weeksafterapprovedsubmittals TermsofDelivery:FOBFactory/Ex-works(Freightnotincluded) TermsofPayment: ThisproposalisbaseduponWEDECO’sGeneralTermsof Business.Priceisbaseduponthefollowingpaymentterms(net30 days): 15%uponapproveddrawings 75%upondeliveryofequipmenttosite,unlessdelayedby purchaserthenuponnotificationofreadytoship 10%uponstart-uporwithinsix(6)monthsfromdateof delivery,whicheveroccursfirst Warranties: LampWarranty:Guaranteed14,000hoursofoperation,prorated after9,000hours. SystemWarranty:18monthsfromdateofdeliveryor12months fromdateofsubstantialcompletionofUVequipmentwhichever comesfirst. BudgetPrice Duronstandardequipmentsale price:INCLUDED Total$1,981,000 OptionalAdders OptionalAddersListedAbove:PRICEAVAILABLEUPONREQUEST Pleasecontactusifyouhaveanyquestionsorcomments. TerritoryManager:KevinFlis-(704)351-3219 Email:Kevin.Flis@xyleminc.com ApplicationsEngineer:JosephJordan Attachment B UV System Construction Cost Estimate San Luis Obispo Water Resource Recovery Facility UV System Alternatives Evaluation Summary of Opinion of Probable Construction Cost16MGD UV Planing Level Sitework - Div. 2 Total 703,600$ 703,600$ Concrete - Div. 3 Total 389,000$ 347,000$ Metals - Div. 5 Total 95,200$ 86,200$ Wood & Plastics - Div. 6 Total 14,500$ 13,100$ Thermal & Moist. Protc. - Div. 7 Total 10,000$ 10,000$ Finishes - Div. 9 Total 5,000$ 5,000$ Specialties - Div. 10 Total 9,500$ 9,500$ Equipment - Div. 11 Total 2,409,200$ 1,798,500$ Special Construction - Div. 13 Total 450,000$ 424,000$ Conveying Systems - Div. 14 Total -$ 50,000$ Mechanical - Div. 15 Total 220,000$ 238,000$ Electrical - Div. 16 Total 855,100$ 743,300$ Subtotal 5,161,100$ 4,428,200$ Construction Contingency 5%258,100$ 221,400$ Subtotal - Direct Costs 5,419,200$ 4,649,600$ Contractor mobilization/demobilization markup 6%325,200$ 279,000$ Contractor's Overhead 10%574,400$ 492,900$ Contractor's Profit Markups 5%287,200$ 246,400$ Subtotal 6,606,000$ 5,667,900$ Project Contingency 20%1,321,200$ 1,133,600$ Total 7,930,000$ 6,810,000$ Summary of Estimate Largest System Division Totals Smallest System Division Totals Page 1 SLO UV Cost Analysis San Luis Obispo Water Resource Recovery Facility UV System Alternatives Evaluation Opinion of Probable Construction Cost 16MGD UV Planning Level Largest System Duron Division Summary of Estimate Totals Sitework - Div. 2 Total 703,600$ Concrete - Div. 3 Total 389,000$ Metals - Div. 5 Total 95,200$ Wood & Plastics - Div. 6 Total 14,500$ Thermal & Moist. Protc. - Div. 7 Total 10,000$ Finishes - Div. 9 Total 5,000$ Specialties - Div. 10 Total 9,500$ Equipment - Div. 11 Total 2,409,200$ Special Construction - Div. 13 Total 450,000$ Conveying Systems - Div. 14 Total -$ Mechanical - Div. 15 Total 220,000$ Electrical - Div. 16 Total 855,100$ Subtotal 5,161,100$ Construction Contingency5%258,100$ Subtotal - Direct Costs 5,419,200$ Contractor mobilization/demobilization markup 6%325,200$ Contractor's Overhead 10%574,400$ Contractor's Profit Markups 5%287,200$ Subtotal 6,606,000$ Project Contingency20%1,321,200$ Total 7,930,000$ Description QuantityUnit Unit Price ($/unit)Total ($) Division #2 - Site Work Drain and Stormwater 300LF200$ 60,000$ Clearing and Grubbing 0.3AC15,000$ 4,500$ Excavation for UV Structure (Includes Shoring)3,000CY30$ 90,000$ Structural Backfill 2,750CY8$ 22,000$ Structural Bedding 95CY55$ 5,200$ Material Disposal 1,500CY8$ 12,000$ Concrete Pavement 700SF75$ 52,500$ Final Grading & Seeding 0.3AC8,000$ 2,400$ Demolition 1LS250,000$ 250,000$ Connection 1LS50,000$ 50,000$ Conduit Fittings 1LS50,000$ 50,000$ Influent Conduit/Piping 70LF1,500$ 105,000$ Div. #2 Total 703,600$ Division #3 - Concrete Influent Channel 50CY700$ 35,000$ Effluent Channel 50CY700$ 35,000$ UV Channel and Deck 450CY700$ 315,000$ Access Walkway Slabs & Stairs 5CY800$ 4,000$ Div. #3 Total 389,000$ Division #4 - Masonry CMU Exterior Walls 0SF25$ -$ Div. #4 Total -$ Divison #5 - Metals Ladders and Stairs 25VLF75$ 1,900$ Miscellaneous Structural Steel 500LBS3$ 1,300$ Bollards 4EA1,000$ 4,000$ Grating 1,800SF30$ 54,000$ Fixed Weir 200LF120$ 24,000$ Stilling Plates 2EA5,000$ 10,000$ Div. #5 Total 95,200$ Division #6 - Wood & Plastics FRP Handrail 100LF35$ 3,500$ Aluminum Guardrail 100LF110$ 11,000$ Div. #6 Total 14,500$ Division 7 - Thermal and Moisture Protection Sealants 1LS10,000$ 10,000$ Div. #7 Total 10,000$ Division #8 - Doors and Windows Hardware 0EA850$ -$ Div. #8 Total -$ Division #9 - Finishes Paint 1LS5,000$ 5,000$ Div. #9 Total 5,000$ Division # 10 Specialties Equipment Tagging 1LS5,000$ 5,000$ Signage 1LS1,500$ 1,500$ Fire Extinguishers 3EA1,000$ 3,000$ Div. #10 Total 9,500$ Division # 11 - Equipment UV Equipment (including installation)1EA2,278,150$ 2,278,200$ Influent Isolation Gates 2EA20,000$ 40,000$ Influent Weir 2EA15,000$ 30,000$ Effluent Isolation Gates 2EA20,000$ 40,000$ Effluent Stop Logs 3EA2,000$ 6,000$ Sump Pump 1EA15,000$ 15,000$ Div. #11 Total 2,409,200$ Division # 12 - Furnishings -$ Div. #12 Total -$ Division # 13 - Special Construction Integration 1LS50,000$ 50,000$ Canopy 4500SF40$ 180,000$ Siding 3500SF20$ 70,000$ Open Channel Flow Meter 3EA50,000$ 150,000$ Div. #13 Total 450,000$ Division #14 - Conveying Systems Bridge Crane 0EA50,000$ -$ Div. #14 Total -$ Division # 15 - Mechanical Valves, Miscellaneous 1LS50,000$ 50,000$ Channel Liners 1LS100,000$ 100,000$ Plumbing 1LS50,000$ 50,000$ Potable Water Lines 500LF40$ 20,000$ Emergency Eyewash and Shower 0EA9,000$ -$ Div. #15 Total 220,000$ Division # 16 - Electrical UV System 1LS775,080$ 775,100$ Transfer Switch 1LS80,000$ 80,000$ Div. #16 Total 855,100$ Page 2 SLO UV Cost Analysis San Luis Obispo Water Resource Recovery Facility UV System Alternatives Evaluation Opinion of Probable Construction Cost 16MGD UV Planning Level Smallest System Aquaray® 3X Division Summary of Estimate Totals Sitework - Div. 2 Total 703,600$ Concrete - Div. 3 Total 347,000$ Metals - Div. 5 Total 86,200$ Wood & Plastics - Div. 6 Total 13,100$ Thermal & Moist. Protc. - Div. 7 Total 10,000$ Finishes - Div. 9 Total 5,000$ Specialties - Div. 10 Total 9,500$ Equipment - Div. 11 Total 1,798,500$ Special Construction - Div. 13 Total 424,000$ Conveying Systems - Div. 14 Total 50,000$ Mechanical - Div. 15 Total 238,000$ Electrical - Div. 16 Total 743,300$ Subtotal 4,428,200$ Construction Contingency5%221,400$ Subtotal - Direct Costs 4,649,600$ Contractor mobilization/demobilization markup 6%279,000$ Contractor's Overhead 10%492,900$ Contractor's Profit Markups 5%246,400$ Subtotal 5,667,900$ Project Contingency20%1,133,600$ Total 6,810,000$ Description QuantityUnit Unit Price ($/unit)Total ($) Division #2 - Site Work Drain and Stormwater 300LF200$ 60,000$ Clearing and Grubbing 0.3AC15,000$ 4,500$ Excavation for UV Structure (Includes Shoring)3,000CY30$ 90,000$ Structural Backfill 2,750CY8$ 22,000$ Structural Bedding 95CY55$ 5,200$ Material Disposal 1,500CY8$ 12,000$ Concrete Pavement 700SF75$ 52,500$ Final Grading & Seeding 0.3AC8,000$ 2,400$ Demolition 1LS250,000$ 250,000$ Connection 1LS50,000$ 50,000$ Conduit Fittings 1LS50,000$ 50,000$ Influent Conduit/Piping 70LF1,500$ 105,000$ Div. #2 Total 703,600$ Division #3 - Concrete Influent Channel 45CY700$ 31,500$ Effluent Channel 45CY700$ 31,500$ UV Channel and Deck 400CY700$ 280,000$ Access Walkway Slabs & Stairs 5CY800$ 4,000$ Div. #3 Total 347,000$ Division #4 - Masonry CMU Exterior Walls 0SF25$ -$ Div. #4 Total -$ Divison #5 - Metals Ladders and Stairs 25VLF75$ 1,900$ Miscellaneous Structural Steel 500LBS3$ 1,300$ Bollards 4EA1,000$ 4,000$ Grating 1,500SF30$ 45,000$ Fixed Weir 200LF120$ 24,000$ Stilling Plates 2EA5,000$ 10,000$ Div. #5 Total 86,200$ Division #6 - Wood & Plastics FRP Handrail 90LF35$ 3,200$ Aluminum Guardrail 90LF110$ 9,900$ Div. #6 Total 13,100$ Division 7 - Thermal and Moisture Protection Sealants 1LS10,000$ 10,000$ Div. #7 Total 10,000$ Division #8 - Doors and Windows Hardware 0EA850$ -$ Div. #8 Total -$ Division #9 - Finishes Paint 1LS5,000$ 5,000$ Div. #9 Total 5,000$ Division # 10 Specialties Equipment Tagging 1LS5,000$ 5,000$ Signage 1LS1,500$ 1,500$ Fire Extinguishers 3EA1,000$ 3,000$ Div. #10 Total 9,500$ Division # 11 - Equipment UV Equipment (including installation)1EA1,667,500$ 1,667,500$ Influent Isolation Gates 2EA20,000$ 40,000$ Influent Weir 2EA15,000$ 30,000$ Effluent Isolation Gates 2EA20,000$ 40,000$ Effluent Stop Logs 3EA2,000$ 6,000$ Sump Pump 1EA15,000$ 15,000$ Div. #11 Total 1,798,500$ Division # 12 - Furnishings -$ Div. #12 Total -$ Division # 13 - Special Construction Integration 1LS50,000$ 50,000$ Canopy 4000SF40$ 160,000$ Siding 3200SF20$ 64,000$ Open Channel Flow Meter 3EA50,000$ 150,000$ Div. #13 Total 424,000$ Division #14 - Conveying Systems Bridge Crane 1EA50,000$ 50,000$ Div. #14 Total 50,000$ Division # 15 - Mechanical Valves, Miscellaneous 1LS50,000$ 50,000$ Channel Liner 1LS100,000$ 100,000$ Plumbing 1LS50,000$ 50,000$ Potable Water Lines 500LF40$ 20,000$ Emergency Eyewash and Shower 2EA9,000$ 18,000$ Div. #15 Total 238,000$ Division # 16 - Electrical UV System 1LS663,282$ 663,300$ Transfer Switch 1LS80,000$ 80,000$ Div. #16 Total 743,300$ Page 3 SLO UV Cost Analysis Attachment C UV System Equipment Life Cycle Cost Analysis San Luis Obispo Water Resource Recovery Facility UV System Alternatives Evaluation Life Cycle Cost Analysis 16MGD UV Planning Level Basis of Calculation Present Worth Factor: 20 yrs @ 5% discount rate12.4622 Cost of Energy: $/kW-hr 0.12 Hours Per Year 8,760 Days Per Year 365 Avg Flow Factor 0.34Peak Wet Weather 16 MGD, Average 5.5 MGD Labor cost per hour $70 Ultraviolet Disinfection Systems HIGH CAPACITY SYSTEM Supplier OZONIATROJANWEDECO Model Aquaray® 3X UV3000 Plus™Duron Power Consumption Cost Installed Max Power Consumption (Kilowatts) 292260374 Max Operational Power (Kilowatts)321260412 Average Utilized Power (Kilowatts)11089142 Total UV System Power Consumption (kWh/year - maximum)967,214782,9251,240,153 Annual Power Cost $116,066$93,951$148,818 Present Worth of Power Cost $1,446,434$1,170,837$1,854,606 Lamp Replacement Cost Number of UV Lamps Installed 7201,040624 Number of UV Lamps in Service at Average Annual Flow Rate248358215 Number of Lamps Replaced per Year at Average Annual Flow Rate248358215 Lamp Replacement (hours)4117954 Guaranteed Replacement Price per Lamp at Date of Bid $175$250$300 Annual Cost of Lamp Replacement $46,200$101,888$68,104 Present Worth of Lamp Replacement $575,754$1,269,743$848,723 Ballast Replacement Cost Number of UV Ballasts Installed 360520312 Number of Ballasts Replaced per Year 253621 Ballast Replacement (hours)4364 Guaranteed Replacement Price per Ballast at Date of Bid $300$495$800 Annual Cost of Ballast Replacement $7,714$20,199$17,410 Present Worth of Ballast Replacement $96,130$251,721$216,970 Lamp Sleeve Replacement Cost Number of Lamp Sleeves Installed 7201,040624 Number of Lamp Sleeves Replaced per Year 507243 Lamp Sleeve Replacement (hours per year)507243 Guaranteed Lamp Sleeve Replacement Price at Date of Bid $75$110$164 Annual Cost of Lamp Sleeve Replacement:$7,178$12,870$10,039 Present Worth of Lamp Sleeve Replacement $89,448$160,389$125,103 Wiper Replacement Cost Number of Wipers Installed 7201,040624 Number of Wipers Replaced per Year 507243 Wiper Replacement (hours per year)507243 Guaranteed Wipers Replacement Price at Date of Bid ($ per Wiper)$8$25$17 Annual Cost of Wiper Replacement $3,861$6,793$3,732 Present Worth of Wiper Replacement $48,117$84,650$46,513 UV Intensity Sensors Number of UV Intensity Sensors Installed 101013 Number of UV Intensity Sensors Replaced per Year 0.70.70.9 UV Intensity Sensor Replacement (hours per year)1.41.41.8 Guaranteed UV Intensity Sensor Replacement Price at Date of Bid $950$2,500$924 Annual Cost of UV Intensity Sensor Replacement $749$1,815$951 Present Worth of UV Intensity Sensor Replacement$9,339$22,619$11,851 Life Cycle Cost Ultraviolet Disinfection Systems Supplier OZONIATROJANWEDECO Model Aquaray® 3X UV3000 Plus™Duron Total UV Equipment Price (provided by vendor)$1,450,000 $1,830,000 $1,981,000 Calculated Present Worth Costs: Present Worth of Power Consumption $1,446,434 $1,170,837 $1,854,606 Present Worth of Lamp Replacement Cost $575,754 $1,269,743 $848,723 Present Worth of Ballast Replacement Cost $96,130 $251,721 $216,970 Present Worth of Lamp Sleeve Replacement Cost $89,448 $160,389 $125,103 Present Worth of Wiper Replacement Cost $48,117 $84,650 $46,513 Present Worth of UV Intensity Sensor Replacement Cost $9,339 $22,619 $11,851 Total Present Worth Cost (20 yrs, 5%)$3,720,000 $4,790,000 $5,080,000 CONVENTIONAL SYSTEMS CONVENTIONAL SYSTEMS Appendix E TM No. 5 - Asset Planning and Rehabilitation Date: 12/1/2014 Prepared by: Ted Kontonickas, PE Reviewed by: Mallika Ramanathan, PE, Holly Kennedy, PE, Lianne Westberg, PE, Jasmine Diaz, EIT Project: WRRF Project SUBJECT: TM NO. 5 – ASSET PLANNING AND REHABILITATION STUDY The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long-term strategy for resource management. The purpose of this technical memorandum (TM) is to document the condition of existing mechanical equipment at the WRRF and provide recommendations for equipment replacement for the proposed upgrades. Contents Introduction .............................................................................................................................. 2 Equipment Evaluation ............................................................................................................. 2 Equalization Basin .................................................................................................................................... 2 Headworks (Screening and Pumping) ...................................................................................................... 2 Aerated Grit .............................................................................................................................................. 3 Primary Clarifiers ...................................................................................................................................... 4 Trickling Biofilters ...................................................................................................................................... 5 Secondary Clarifier 3 ................................................................................................................................ 5 Aeration Basins (Diffusers and Air Control Valves) .................................................................................. 5 Aeration Blowers ....................................................................................................................................... 6 Final Clarifiers 4 and 5 .............................................................................................................................. 6 RAS/WAS Pumps ..................................................................................................................................... 6 Chemical Feed Systems ........................................................................................................................... 7 Ferrous Chloride Metering Pumps ....................................................................................................... 7 Sodium Hydroxide/ Magnesium Hydroxide Metering System .............................................................. 7 Filtration System ....................................................................................................................................... 7 Unit 4 Tank Drain Sump ........................................................................................................................... 8 Cooling Towers ......................................................................................................................................... 8 Disinfection Chemical Storage Facility ..................................................................................................... 9 Three Water (3W) System ........................................................................................................................ 9 Reuse System .......................................................................................................................................... 9 Dissolved Air Flotation (DAF) Thickener ................................................................................................ 10 Anaerobic Digesters ............................................................................................................................... 10 Solids Dewatering ................................................................................................................................... 11 Supernatant Lagoon ............................................................................................................................... 11 Summary of Recommendations .............................................................................................12 List of Tables Table 1. Recommendations by Process Area............................................................................................. 12 WRRF Project TM No. 5 – Asset Planning and Rehabilitation Study Page 2 of 14 Introduction This technical memorandum (TM) describes existing process equipment at the WRRF, and documents the condition of mechanical equipment based on visual inspections and interviews held with operations and maintenance (O&M) staff during site visits conducted on October 16 and 17, 2014. Recommendations for mechanical equipment replacement and upgrades needed at the WRRF are provided in this TM. Electrical equipment was also evaluated and the condition assessment and recommendations for electrical equipment replacement are provided in TM 10.2 – Electrical and I&C TM. Equipment Evaluation Existing equipment at the WRRF was evaluated during site visits conducted on October 16 and 17, 2014. The program management (PM) team met with WRRF staff at the plant to discuss equipment condition, age, maintenance practices and issues as well as equipment preferences for future upgrades. The following subsections identify mechanical equipment by process area and documents the findings of the site visit. Equalization Basin The Equalization Basin provides emergency storage of raw influent wastewater during peak flow events and is also used by staff to provide diurnal equalization of primary effluent during average flow conditions. Raw influent wastewater can be routed to the Equalization Basin from the Equalization Pond Control Structure at the Headworks or from the Primary Effluent Diversion Box (PEDB). The basin has a return pumping structure to route flows back to the PEDB for treatment. There is only a single pump with a spare motor and therefore no redundancy. The return pump was dismantled in 2000 due to grease buildup and the motor was re-wound in 2003 due to lightning damage. The pump appears to be in good condition. Due to the recent work on the pump and motor, replacement is not necessary at this time. Installation of a redundant pump or provision for a shelf spare is recommended. Additional control upgrades have also been identified to improve operational flexibility and provide automation of the pump operation. Control upgrades are described in detail in TM No. 10.2 Electrical and I&C. The existing pond liner is compromised allowing vegetation to grow. Headworks (Screening and Pumping) The headworks consist of screening followed by pumping, followed by grit removal. As part of the Energy Efficiency Project, the existing bar screens are being replaced with Huber ¼-inch chain rake screens. An auger system will replace the existing screenings grinders, pumps and a washer compactor added. Thus, the condition of the existing bar screens and screenings equipment was not assessed. The influent pump station is downstream of the screens and consists of four influent pumps and a flush-water chopper pump (Vaughan). The influent pumps consist of two vertical turbine pumps sized for 22 mgd each and two horizontal, centrifugal pumps sized for 5 mgd each. The horizontal centrifugal pumps are typically in operation and the vertical turbine pumps are normally only used for WRRF Project TM No. 5 – Asset Planning and Rehabilitation Study Page 3 of 14 peak wet-weather flows. The pumps operate on a lead-lag arrangement and are equipped with VFDs. The 5 MGD pumps have a stainless volute wear ring and the impeller has a bronze wear ring. The vertical turbine pumps and flush water pump were installed as part of the Unit III Improvements in approximately 1995 and the horizontal centrifugal pumps were installed in approximately the late 1980s. The vertical turbine pumps are operated monthly for testing of seal-water operation and system/pump performance. Vibration analysis is performed twice a year on all influent pumps. The horizontal centrifugal pumps were taken apart about six to eight months ago to clear rags. All four pumps appear to be in good condition and routine maintenance is performed on all the pumps. WRRF staff indicated that they would prefer the horizontal pumps be replaced with vertical, centrifugal pumps to help prevent excessive grit damage to the wear rings. and increase O&M efficiency. Based on discussions with WRRF management, the horizontal pumps will be replaced in the next calendar year as part of ongoing O&M. The influent pump station wet well is largely not accessible to perform periodic condition assessment and was not inspected as part of this effort. Access points should be evaluated and added where feasible. The hydraulics of using the wet-weather equalization pond to allow enough time to enter and inspect the wet-well should be considered in the expansion project. Aerated Grit Grit is removed from screened wastewater in aerated grit basins. Positive displacement blowers provide diffused air into the basins which allows grit to settle out but keeps organics in suspension. Settled grit is pumped with horizontal recessed impeller pumps (WEMCO) to grit washing and dewatering equipment. As part of the Energy Efficiency Project, new grit washing and dewatering equipment is being installed. The four grit pumps are recessed impeller type manufactured by Wemco and operate 24 hours per day, 7 days per week. Grit Pump 3 used to have clogging issues, but has not experienced any problems in the last 3 to 4 years. The wear plates on the pumps were removed approximately 10 years ago and the impellers were deemed to be in good shape. The volutes were not inspected at that time and their condition is unknown. The grit pumps appear to be in good condition and are not recommended to be replaced at this time. After the new grit washing system is installed, the pumps should be assessed to determine if new belts and sheaves are needed to handle the flow and pressure required for the new grit system. It should also be noted that the grit piping is not glass lined and has short radius elbows which creates more pressure drop through the system. It is recommended that the short radius elbows be replaced with long radius elbows to prevent clogging and shortened life on the piping. This modification will also reduce the pressure drop across the system and may improve operation with the new grit washing and dewatering equipment. Seal water from the grit pumps drain to a sump. The pumps are submersible type manufactured by EBARA and are 20 years old. The existing pumps are not on rails and need to be manually lifted out if servicing is required. The impellers were changed about 15 years ago and the check valves were recently replaced. The condition of the pumps is not known, but given the age of the pumps, it is recommended that they be replaced. A rail system for the pumps should also be installed to facilitate O&M. WRRF Project TM No. 5 – Asset Planning and Rehabilitation Study Page 4 of 14 Based on discussions with WRRF management, there are plans to replace the aerated grit removal system with a forced vortex grit removal system. The primary reason for the change is to reduce energy consumption at the plant. It is assumed that the WRRF upgrades detailed in the Facilities Plan will include provisions for a change to forced vortex grit removal. Despite the WRRF’s intent to change the grit removal system, the condition of the aeration blowers was assessed. The aeration blowers are operated in a duty/standby configuration and routine maintenance is performed on these blowers. They appear to be in good condition and it is not recommended to replace them at this time. There is also a blower that supplies air to the influent grit basin channel, but it is not currently used because it does not suspend the grit well. Primary Clarifiers Screened and degritted influent wastewater is routed to two primary clarifiers. The two influent flow meters (Parshall flumes) split the flow to the two primary clarifiers. Primary effluent is routed to the primary effluent diversion box (PEDB). Primary sludge is pumped with horizontal, recessed impeller pumps (manufactured by WEMCO) to the anaerobic digesters and/or the dissolved air flotation thickener (DAFT). Primary sludge is not thickened in the clarifiers and is pumped at a total solids concentration of 0.5 percent or less. Primary scum can also be conveyed to the anaerobic digesters and/or the DAFT. The primary sludge pumps were installed in the 1990s and are approximately 24 years old. They are operated on a timer system but typically pump primary sludge 24 hours per day, seven days per week. The sludge blanket in the clarifiers is maintained at approximately three to four inches. The pumps have experienced air binding issues in the past and cannot pull from the lower sludge blanket. The pump impellers were inspected in 2000 and were deemed to be in good condition. Due to the limitations of pulling from the lower sludge blanket, these pumps should be replaced with pumps with better suction lift capability such as positive displacement gear type pumps or self- priming centrifugal pumps. Primary scum is typically pumped using piston pumps to the DAF, and can also be directly pumped to the anaerobic digesters. Two piston pumps were installed in the 1940’s. Currently only one pump is connected to the primary scum piping and is typically used. There is a second, operational pump that can be used after opening and closing appropriate valving. The primary piston pump is operated for about 20-minutes each day at a rate of approximately 40 gpm. Both pumps were pulled apart about 10 years ago to change the seals and bearings. High pressure shutoff switches were added about 15 to 20 years ago. These pumps have exceeded their useful life and it is recommended that they be replaced. The primary sludge collection mechanisms are scraper blade type and date back to the 1960’s. The turntable of Primary Clarifier 1 was rebuilt in 2000. The motors have been re-wound once and there are no spare motors. The primary clarifiers are taken down once per year for inspection and maintenance. The current condition of the mechanisms is unknown, although observations during a clarifier recoating project within the past five-years indicated some potential “integrity” issues. Due to the routine maintenance and yearly inspections, replacement of the existing mechanisms is not recommended at this time. During the next scheduled maintenance, the mechanisms should be inspected to determine if coating is needed. A shelf spare motor is also recommended to provide adequate redundancy. WRRF Project TM No. 5 – Asset Planning and Rehabilitation Study Page 5 of 14 Trickling Biofilters Trickling Biofilter 1 and 2 are no longer in service. Primary effluent is pumped to Trickling Biofilter 3 with the recirculation pumps located to the east of Secondary Clarifier 3. The operating biofilter turntable was rebuilt in 2003 and appears to be in good condition. Once the plant upgrades are implemented, the biofilters will no longer be operated and therefore no replacement is required at this time. The recirculation pumps are vertical turbine type. Routine maintenance is performed on the pumps, although the shaft and impellers have not been inspected. Once the plant upgrades are implemented, the biofilters will no longer be operated, therefore the pumps will not be needed and replacement is not required at this time. Secondary Clarifier 3 Secondary Clarifier No. 3 has a scraper sludge collection mechanism and receives flow from Trickling Biofilter 3. Solids are settled out and pumped to the DAFT as secondary sludge. The scum is collected and is also pumped to the DAFT. The secondary clarifier effluent is either sent to the Secondary Effluent Diversion Box (SEDB) where it is conveyed to the aeration basins or can be routed directly to the Nitrified Effluent Junction Box. Diversion to the Nitrified Effluent Junction Box is typically used during wet weather flow events. The turntable of the secondary was rebuilt in 2003. The paint on portions of the mechanism and structure is starting to fail in places. As part of the upgrades, the secondary clarifier structure will be retained and used for flow equalization. Therefore it is recommended to only re-condition portions of the sludge collection mechanism and turntable to keep it serviceable until the upgrades are constructed. The scum pump operates once per day and has been in operation for more than 17 years. New Chevron type packing has been installed on the scum pump. This pump is nearing the end of its useful life and is probably not as efficient as newer pumps. The pump also gets air locked. Because the clarifier will be repurposed as an equalization tank (for primary effluent) the scum collection system will no longer be needed. Therefore it is recommended that the cause for the air binding be reviewed and retrofits be performed to keep the system operational until the upgrades are constructed. The sludge pump for the secondary clarifier operates 24 hours per day, 7 days per week. It has been in operation for 15 years. It has a variable speed drive. The pump was pulled apart about 10 years ago and at that time it was deemed to be in good condition. No upgrades are recommended for the sludge pump. Aeration Basins (Diffusers and Air Control Valves) The aeration basins currently receive secondary effluent from the SEDB. Secondary effluent is split to the two aeration basins with a weir on the inlet of each basin. Return activated sludge (RAS) from the final clarifiers is pumped to the inlet channel of the aeration basins and is split to the two basins. The RAS is pumped to an inlet channel that is separate from the secondary effluent inlet channel. The RAS is fed to each aeration basin via three gates on each basin the gravity flow the RAS inlet channel to the aeration tanks. Mixed liquor from the aeration basins is split using two Parshall flumes, and conveyed to Final Clarifiers 4 and 5. Under the future upgrades, the aeration basins will receive primary effluent because the trickling filters will be taken out of service, additional aeration WRRF Project TM No. 5 – Asset Planning and Rehabilitation Study Page 6 of 14 basins will be constructed and two additional final clarifiers will be constructed. The existing aeration basins and final clarifiers will be used for treatment. The aeration basins are equipped with fine bubble diffusers that have been in operation a little more than a year. The diffuser membranes are constructed of an EPDM membrane with Teflon coating. The fine bubble diffuser system is relatively new and in good condition. The diffuser layout in the basins will need to be modified as part of the WRRF upgrades. There are two manually operated butterfly valves for air distribution to the aeration basins. The valves are more than 20 years old and are nearing the end of their useful life. It is recommended that these valves be replaced with the same type. New Auma valve actuators were installed in 2007 on the air distribution control valves in the basins. These actuators appear to be in good condition and do not require immediate replacement staff indicated that they intend to have two new turbo aeration blowers installed prior to the WRRF upgrades; a new control panel will also be installed with the blowers to provide dissolved oxygen (DO) control. The DO instruments will be replaced along with the new blowers; as such, the WRRF upgrades will not need to include replacement of the DO instrumentation and butterfly valve actuators. If the instruments and actuators are not replaced, it is recommended that they be replaced during the WRRF upgrades to provide common equipment and controls for all aeration basins. Aeration Blowers There are currently three centrifugal aeration blowers (2 Lamson, and 1 Turblex), that are installed under a canopy to the south of the aeration blowers. Blower 1 is a multi-stage centrifugal blower manufactured by Lamson. This blower is not operational due to issues with the end bearing. Blower 2 was recently replaced with a spare Lamson blower and motor. Blower 3 is a single stage centrifugal blower manufactured by Turblex. This blower is not typically operated due to surge issues. Currently, there is no redundancy for the blowers. There is an existing plan to install two new, high-speed turbo blowers in 2015 and WRRF staff is currently working on developing a scope of services to be distributed to blower manufacturers Additional blowers will be installed when the basins are expanded in the future. Final Clarifiers 4 and 5 Final Clarifiers No. 4 and 5 have a suction header sludge collection mechanism. The nitrified effluent is sent to the Nitrified Effluent Junction Box prior to tertiary treatment. Two RAS pumps are dedicated to each final clarifier and pump the RAS back to the front of the aeration basins. Scum is collected and pumped to the DAFT. Speed reducers on the sludge collection mechanisms failed about five years ago and have been replaced. Periodic routine maintenance is performed. The wipers are changed as needed. The coatings are in good shape. One clarifier is cleaned each summer. It is not recommended to replace the mechanisms at this time. RAS/WAS Pumps Waste activated sludge is currently pumped from the mixed liquor channel of the aeration basins. The two WAS pumps are centrifugal pumps that have been in operation for approximately 10 to 15 years and are routinely maintained. There are currently no issues with these pumps and replacement is not needed at this time. WRRF Project TM No. 5 – Asset Planning and Rehabilitation Study Page 7 of 14 The four RAS pumps (two per clarifier) are non-clog vertical turbine type. The pumps operate in a lead-lag configuration and are switched each month. The bowl assemblies were replaced about a year ago. All other parts are deemed to be in good condition. As part of the Energy Efficiency Project, the WRRF replaced the current constant speed motors with VFDs which, when programming is completed, will enable the pumps to be flow-paced with influent flows. Chemical Feed Systems Ferrous Chloride Metering Pumps Ferrous chloride is stored near the headworks and solids handling area of the plant. Two diaphragm type chemical metering pumps are used to dose the anaerobic digesters for hydrogen sulfide control. The ferrous chloride metering pumps operate on a lead-lag configuration. They visually appear to be in good condition and replacement is not recommended at this time. Sodium Hydroxide/ Magnesium Hydroxide Metering System Currently the WRRF uses magnesium hydroxide, Mg(OH)2, for alkalinity and pH control. The chemical storage tanks appear to be in good condition and replacement is not recommended. The Mg(OH)2 lines tend to plug and are flushed routinely. Parts are taken apart and cleaned regularly. The gear pump and peristaltic pump appear to be in good condition and it is not recommended to replace them at this time. Filtration System The filters were installed as part of the 1994 plant upgrades. Nitrified effluent is routed to the flow equalization tanks by gravity and then pumped to the filter influent channel. The filter influent channel feeds the four mono-media filters and also feeds the cooling towers. Filtered water flows by gravity to the Nitrified Effluent Junction Box and then to the chlorine contact basins. Filtered water is also routed to a backwash water tank from where it is pumped for use during filter backwash. The backwash waste stream is then pumped to the influent flow meter box. Air blowers provide scour air for the backwash process. New filter media and underdrain system was installed in 2014. The filter valve actuators are manufactured by Limitorque. Since the current actuators use older technology it is recommended that they are replaced. The plant is standardizing around Auma actuators, therefore these actuators should be evaluated during the replacement. There are three filter influent pumps that are located adjacent to the flow equalization tanks. The pumps were installed as part of the Unit 4 Improvements in 1994. The VFDs to the pumps were replaced in 2005. Two of the three pumps are used to pump up to five mgd of flow to the filters; the third is provided for redundancy. The filter influent pumps will need to be replaced or additional pumps will need to be installed to increase the filtration capacity. There are two, vertical turbine backwash pumps that were originally installed in 1994. One of the pumps was replaced with an ABS pump in 2008. Both pumps operate at the same time against a closed butterfly valve and after a set time the valve starts to open. For lower flows the valve opens to minimum position. The backwash supply pumps are undersized and both can only pump limited flow for backwashing, and therefore the plant has to limit the number of backwashes that are performed. The size of the pumps should be evaluated after the filters operate with the new media to confirm if the pump capacity needs to be increased. If the backwash pumps need to be replaced with WRRF Project TM No. 5 – Asset Planning and Rehabilitation Study Page 8 of 14 larger pumps, they should be sized to provide a duty/standby configuration so only one pump is needed to supply the total backwash flow. The pumps were determined to be in good condition and do not need to be replaced, unless their capacity is determined to be insufficient. There are two, submersible waste backwash water pumps. These pumps return the backwash waste back to the influent flow meter box (upstream of the primary clarifiers). The pumps were noted to be in good condition and do not need replacement at this time. The two backwash blowers are positive displacement type. One air blower is needed to provide the air to the filters during a backwash. Routine maintenance is performed on the blowers and there are currently no issues with the equipment. It is recommended that the blower size be evaluated based on the new filter media. The control system should also be evaluated to allow automatic operation and to prevent surge. The new monomedia requires additional head to maximize efficiency such that the added water level in the filters is now above than the air blower header pipe, Leaking air valves on the air blower header system allow water to backflow into the air blower header, filling the piping and the air blower discharge vessel. Operators are currently keeping the original filter level in the filter cells and not utilizing the full capacity of the mono media as a result. The hydraulics should be evaluated and potentially the header should be relocated as part of the future filter expansion. Unit 4 Tank Drain Sump Two submersible pumps receive waste flow from the various basins within the Unit 4 area (e.g., filter drains). The pumps return the waste streams to influent meter box (upstream of the primary clarifiers). Both pumps were replaced with ABS pumps around 2002 to 2003. One pump was again replaced in July 2014 and is making noise. The pump that is having noise issues should be checked and replaced if it is failing. The other pump appears to not have issues and replacement is not needed at this time. Cooling Towers Three cooling towers were installed in 1994 and are used to cool the nitrified effluent to meet temperature requirements in the WRRF’s NPDES discharge permit. The cooling towers are fed from the filter influent channel (by gravity). The cooling tower effluent is pumped back to the filter influent channel and filtered prior to disinfection. Due to the configuration of the filter influent channel some fraction of the cooled water is returned to the cooling towers. Motor actuated inlet valves regulate the flow into the cooling towers. Manual grab samples are taken at the outfall structure for temperature measurement and used to manually control the cooling towers. The automatic controls do not work at this time. The isolation butterfly valves upstream of the actuators are throttled for flow control. The cooling tower effluent pumps are horizontal centrifugal type. The pump bowls were fusion epoxy coated in 2000. One pump has been re-built. Vibration analysis on the pumps was recently performed and there were no issues. The programming for the pump controls has been revised and the pumps are currently working well. The pumps appear to be in good condition and it is not recommended to replace them at this time. The cooling towers currently have snail issues likely coming from the trickling biofilters. After the upgrades, the trickling biofilters will not be in operation, which will address the current snail issues. A chiller system is currently proposed cooling for the expansion project. The cooling towers would WRRF Project TM No. 5 – Asset Planning and Rehabilitation Study Page 9 of 14 used in a closed condenser water circuit that will resolve any water quality or fouling issues. The media was replaced in 2014 and may need to be modified depending on the future configuration Disinfection Chemical Storage Facility The Chemical Storage Facility contains storage tanks and two metering pumps for sodium hypochlorite and two sodium bisulfite metering pumps in a fully contained area. All the pumps, except sodium bisulfite are peristaltic type. The sodium bisulfite pumps are diaphragm type and staff intends to replace them with peristaltic pumps in the near term. The pumps and tanks appear to be in good condition and it is not recommended to replace them at this time. Filters are installed on all the tank fill lines to minimize particulate in the pumps and piping. The chemical feed piping does not appear to be in good condition. After the WRRF upgrades, sodium bisulfite will no longer be needed at the plant. In the interim, the sodium bisulfite piping has been recently replaced and should be in good condition. Due to tight THM limits in the NPDES permit it recommended to eliminate all use of sodium hypochlorite on the WRRF. If it is determined that small amounts may continue to be used, it is recommended that as part of the WRRF upgrades, that the condition of the sodium hypochlorite piping be confirmed and if necessary replaced. Three Water (3W) System The 3W system provides pressurized water throughout the plant for washdown and process water. The system was installed in 1994. There are two, vertical turbine 3W pumps located downstream of the sodium bisulfite mixing chamber (downstream of the chlorine contact basin). One of the 3W pump seals was leaking at the time of the site visit and should be repaired. The bowl on one of the pumps was changed in 2000 due to impacts related to air from the mixer. Replacement of the 3W pumps should be considered as part of the upgrades, particularly if 3W demands will increase. Additionally, staff has indicated they may look at pulling 3W off of the recycled water system to increase the pressure of the 3W system. Alternatively, the 3W pumps could be replaced with the upgrades to address higher demands and higher pressure requirements. Effluent Dechlorination Sodium Bisulfite is added and mixed with effluent using a submersible mixer. The submersible mixer is manufactured by Gas Master and runs 24 hours per day and seven days per week. The mixer impeller was replaced about two years ago. There is a spare mixer on the shelf that can be used if needed. Routine maintenance is performed on the mixer and although there have been seal failures and some corrosion, plant staff indicated it is in good condition. It is not recommended to replace the mixer at this time. Sodium Bisulfite will not be used in the future Reuse System The reclamation storage and distribution system has been in operation since 2006. There are a total of five vertical turbine pumps (three larger and two smaller pumps) that pump recycled water from the holding tank to the recycled water customers. All the pumps are on VFDs. The small jockey pumps are in a lead-lag configuration and the first to be energized. As demand increases, the large pumps are then energized. New level control has been provided for the sump pumps. The check valves on the main pumps have been modified. WRRF Project TM No. 5 – Asset Planning and Rehabilitation Study Page 10 of 14 All pumps are the original pumps, except for one that was replaced in 2013. One pump VFD failed and was replaced in 2014. Routine maintenance is performed on the pumps and they appear to be in good condition and replacement is not recommended at this time. Dissolved Air Flotation Thickener (DAFT) Primary sludge, WAS, and scum (primary, secondary and chlorine contact tank scum) are thickened in the DAFT and thickened sludge is then pumped to the digesters. Two grinders were installed on the DAFT feed stream in 1991. The grinders have been rebuilt every 2 years, and are overhauled every 6 months. A spare grinder is kept in stock to always maintain 2 grinders in service. More failures tend to occur due to wipes jamming the grinder. It is not recommended to replace the grinders at this time as long as routine maintenance is performed. The installation of the new headworks screens will likely improve rags and wipe removals at the front of the plant, which may reduce future maintenance activities associated with the grinder. The DAFT was rebuilt seven years ago. The two DAFT dissolution pumps are configured as duty/standby and their operation is alternated monthly. Routine maintenance is performed on the pumps. One pump failed approximately seven to eight years ago. The pumps appear to be in good condition and it is not recommended to replace them at this time. There is no redundant thickener to the DAFT. The WRRF would like to install a new, energy efficient thickening technology. As part of the WRRF upgrades a rotary drum thickener or screw thickener are being considered. The DAFT tank could be repurposed to serve as a primary sludge and WAS blend tank to feed the thickener system; alternatively a new blend tank could be constructed. The TWAS pumps were installed in 1991 and are progressive cavity pumps. The stators are replaced periodically including one in 2014. TWAS Pump 1 is serviced three times more than TWAS Pump 2. The pumps appear to be in good condition and it is not recommended to replace them at this time. The DAFT is covered and foul air is routed to a carbon unit for odor control. The carbon is replaced annually. It is recommended that odor control be maintained after the upgrades. Anaerobic Digesters Anaerobic Digester 1 (Digester 1) was built in 1962, Anaerobic Digester 2 (Digester 2) was built in 1940, and Anaerobic Digester 3 (Digester 3) was built in 1923. The digesters are cleaned periodically; Digester 1 was last cleaned in 2012, Digesters 2 and 3 were last cleaned in 2013. Digesters 1 and 2 were recoated after they were cleaned. Digester 3 is used for storage upstream of dewatering and is not heated or mixed. As part of the WRRF upgrades, Digester 2 and 3 will no longer be operated as digesters, but will instead be repurposed as sidestream treatment reactors. It is recommended that in subsequent project phases that a structural analysis of the tanks be performed. A new digester will be constructed that has the same volume as Digester 1. The digesters are mixed with gas mixing systems that include gas compressors that pull gas from the digesters and recirculates the gas into sparger tubes. Digester 1 gas mixer was replaced a few years ago, but the belt has failed every two years. Digester 2 gas compressor was replaced with a new compressor in 2013. The existing compressor was rehabilitated and is used as a spare. In general the compressors need to be rebuilt once every 3 years due to seal failure. The formation of WRRF Project TM No. 5 – Asset Planning and Rehabilitation Study Page 11 of 14 struvite is a problem in piping and has to be routinely cleaned out of the piping as part of the maintenance program. Gas mixing systems have fallen out of favor at most treatment plants due to the equipment problems that tend to occur in these systems. It is recommended that the gas mixing system be replaced with a new system such as pump or draft tube mixing. Heating of the digesters consist of a natural gas fired boiler supplying hot water in a recirculation system to a piping manifold inside each digester. The boiler is 10 years old and is routinely maintained. It is relatively new, in good condition and it is not recommended to be replaced it at this time. The hot water pumps were replaced this last year due to wear and do not need to be replaced at this time. The heat exchangers of digester No. 1 were blasted and scraped to remove buildup around the tubes and reinstalled. There was not any evidence of pitting and they appeared to be in good condtion. The new cogeneration system will reduce the use of the existing boiler. A progressive cavity pump manufactured by Moyno that was used to transfer digested sludge to the sludge drying beds is used as needed to unplug lines and send sludge to upper drying beds if needed.. Solids Dewatering Digested sludge is dewatered in a belt filter press (BFP). The BFP was originally installed in 1993 and was rebuilt in 1997. The BFP operates six to eight hours per day. The belts are replaced every two years and the variable speed drive has been converted to a constant speed drive. The rollers have failed in the past and since the model of this unit is no longer manufactured, the rollers have to be specially fabricated, which can take up to a week or more and the unit has to be taken out of service. There is currently no redundant BFP and the sludge drying beds provide redundancy to the BFP. The BFP produces dewatered cake of approximately 15 to 16 percent solids. A shaftless screw conveyor conveys the dewatered cake from the BFP up to the truck bed. The lining on the conveyor was replaced 5 years ago and the screw conveyor appears to be in good condition. A polymer system supplies polymer to the sludge feed to aid in the dewatering. This system needs to be cleaned every two to three years due to clogging. As part of the Energy Efficiency Project, a screw press will be installed and the BFP will serve as a redundant dewatering system. The digested sludge feed pump that feeds the BFP was originally installed in 1993, but has been rebuilt within the last 10 years. Pump lubrication has been added. A new dewatering screw press and associated equipment is being provided as part of the Energy Efficiency Project. The BFP, pump, polymer system, and conveyor can be used as a backup system and it is recommended to continue to provide routine maintenance, but it is not recommended to replace any equipment at this time. Supernatant Lagoon The Supernatant Lagoon provides equalization of the WRRF’s dewatering return streams. Currently filtrate from the belt filter press is stored in the lagoon and then returned to the front of the plant (downstream of the influent flow meters) when flows and loads are low. The lagoon additionally receives stormwater captured in the sludge drying beds. The lagoon provides operational flexibility WRRF Project TM No. 5 – Asset Planning and Rehabilitation Study Page 12 of 14 because it allows operations to control when they return the high-strength ammonia loads to the front of the plant. The Supernatant Lagoon is equipped with a surface aerator that was installed approximately 8 to 10 years ago. The surface aerator replaced a paddle mixer. Routine maintenance is performed on the aerator and it visually appeared to be in good condition. Staff noted the aerator to be in good condition. The Supernatant Lagoon is equipped with two submersible Von Chopper pumps that were installed as part of the Unit III Improvements (in approximately 1995). The pumps return the equalized filtrate to the front of the plant and are controlled by a timer system in a lead-lag configuration. The pumps are also installed with moisture indication. Routine maintenance is performed on the pumps and they visually appear to be in good condition. Staff concurred with this assessment and replacement of these pumps is not recommended at this time. Sludge Drying Beds The sludge drying are being replaced by a screw press for dewatering and are not expected to be used in the future. They were not evaluated as part of the planning effort. Summary of Recommendations Table 1 provides a summary of recommendations for equipment replacement and upgrades at the WRRF. The recommendations are based on observations during the site walk conducted on October 16 and 17, 2014 and based on discussions with Staff on routine maintenance activities, and observed equipment condition and performance. The recommendations provided in this TM will be incorporated into the Facilities Plan. Table 1. Summary of Recommendations by Process Area Process Area Recommendation Equalization Basin • Replacement not needed at this time. • Provision for a redundant or shelf spare pump. • Provide control upgrades/automation. Headworks(a) • 2, Vertical Turbine pumps in good condition and replacement is not recommended at this time. • 2, Horizontal, centrifugal pumps in good condition. Staff preference for vertical, centrifugal pumps. • Install magmeters on each of the pump discharges to replace the influent flow measuring function of the Parshall flumes. Retain the flumes for hydraulic flow splitting function only. • Improve access to wetwell to allow for periodic inspections. Aerated Grit (b) • Grit pumps in good condition. Confirm pumps are compatible with new grit washing system. If pumps can meet pressure and flow requirements of new system – replacement is not recommended at this time. • Replace grit piping with glass lined pipe and with long radius elbows to minimize clogging/pressure loss. • Install new submersible pump seal pumps with rail system. Primary Clarifiers • Replace primary sludge pumps. • Replace primary scum pumps. • Condition of mechanisms unknown. Inspection during next scheduled maintenance is recommended. WRRF Project TM No. 5 – Asset Planning and Rehabilitation Study Page 13 of 14 Process Area Recommendation • Provide shelf spare motor for mechanism. Trickling Filter 3(c) • Trickling Filter 3 will be decommissioned as part of the upgrades and was not inspected. Secondary Clarifier 3 • Secondary clarifier 3 will be decommissioned as part of the upgrades. Paint on portions of the mechanism are starting to fail. The mechanism should be re-conditioned in failing areas to keep it in service until the upgrades are operational. • Air binding issues with the scum pump should be addressed to keep the pump operational until the upgrades are complete. • Sludge pump is in good condition and replacement is not recommended at this time. Aeration Basins(d) • Diffusers are in good condition –replacement is not recommended at this time. • Replace butterfly valves for air distribution. • Actuators for butterfly valves should be replaced unless replacement is performed during new blower installation Final Clarifiers 4 and 5 • Mechanisms are in good condition – replacement is not necessary. RAS/WAS Pumps • RAS and WAS pumps are in good condition - replacement is not recommended at this time. Ferrous Chloride Metering Pumps • Pumps appear to be in good condition – replacement is not recommended at this time. Magnesium Hydroxide Metering Pumps • Pumps appear to be in good condition – replacement is not recommended at this time. Filtration System • Replacement and/or expansion of filter influent pump station is needed to accommodate higher filtration rates in the future. • Filter media and underdrain system replaced in 2014 and was not evaluated. • Replacement of filter valve actuators is recommended. • Additional evaluation of backwash pumps is needed to determine if they are adequate with the new media. If capacity is inadequate, pumps should be replaced. The pumps are in good condition and do not need to be replaced if the capacity is sufficient. • Waste backwash water pumps are in good condition – replacement is not necessary at this time. • Backwash air blowers are in good condition. The size/capacity of the blowers should be further evaluated with the new media. • Raise are header piping to prevent inundation from potentially higher operating heads in the filter cells. Unit 4 Tank Drain Sump • One of two submersible pumps is having noise issues. The noise issue should be further investigated and replaced if the pump is failing. • The second submersible pump is in good condition and replacement is not necessary. Cooling Towers • Cooling tower effluent pumps are in good condition – replacement is not recommended at this time. • Cooling tower media was replaced in 2014 and therefore replacement is not recommended at this time. Disinfection Chemical Storage • The upgrades will convert disinfection to UV; sodium bisulfite and aqueous ammonia will no longer be needed onsite. Smaller quantities of sodium hypochlorite will still be retained onsite for use with the recycled water system. • Sodium hypochlorite and sodium bisulfite pumps appear to be in good condition and replacement is not recommended at this time. • Chemical feed piping is not in good condition and should be replaced for continued use through the upgrades. 3W System • One 3W pump is leaking and requires repairs. • Replacement or expansion of the 3W pumps should be considered as part of the upgrades to address higher 3W demands and/or higher pressure requirements. WRRF Project TM No. 5 – Asset Planning and Rehabilitation Study Page 14 of 14 Process Area Recommendation Reuse System • The reuse pumps appear to be in good condition and replacement is not recommended at this time. DAF Thickener • Replacement of the grinder for influent flows to the DAFT is not recommended at this time. • The DAFT pumps are in good condition and replacement is not recommended at this time. The upgrades should consider replacement of the DAFT with a new, energy efficient thickening system. A redundant unit should be provided. • The thickened sludge pumps are in good condition and replacement is not recommended at this time. Anaerobic Digesters • The digester gas mixing system should be replaced with a new pump or draft tube mixing system. • The boiler is in good condition and replacement is not recommended at this time. • The hot water pumps are in good condition and replacement is not recommended at this time • Condition of heat exchangers is unknown at this time – it is recommended that during next planned maintenance, the heat exchangers condition be assessed. Solids Dewatering • The BFP, polymer system, feed pump and conveyor are in good condition and replacement is not recommended at this time because the BFP will be used as a redundant unit after completion of the Energy Efficiency Upgrade Project. Supernatant Lagoon • Surface Aerator in good condition. • Return pump replacement not replacement is not recommended at this time. Notes: (a) Screens, screening washer compactor, and screenings conveyor to be replaced as part of Energy Efficiency Project. Therefore, existing screens and screenings equipment were not evaluated. (b) Existing grit washing and compaction equipment to be replaced under the Energy Efficiency Project, and therefore was not evaluated. (c) Trickling Filters 1 and 2 have been decommissioned. (d) Aeration blowers were not included in list because two, new blowers are being installed by the City in 2015. Appendix F TM No. 6 - Renewable Energy Generation Study Date: 5/29/2015 To: Carrie Mattingly Phone: (805) 781-7205 Utilities Director 879 Morro St. San Luis Obispo, CA 93401 CC: Dave Hix; Howard Brewen Prepared by: Lianne Westberg, P.E., Kaylie Ashton, E.I.T. Reviewed by: Jeffrey Szytel, P.E., Holly Kennedy, P.E. Project: WRRF Project SUBJECT: TECHNICAL MEMORANDUM #6 – RENEWABLE ENERGY GENERATION UPDATE The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long-term strategy for resource management. This technical memorandum (TM) summarizes the previous renewable energy studies performed for the WRRF and presents the updated economic evaluation of solar, wind and micro-hydropower as a source of renewable energy at the WRRF. The memorandum is organized into the following sections: Contents Section 1 Introduction .............................................................................................................................. 2 Section 2 Background ............................................................................................................................... 2 Section 3 Solar PV Generation .................................................................................................................. 5 Section 4 Wind Energy .............................................................................................................................. 9 Section 5 Micro-Hydropower ................................................................................................................. 11 Section 6 Recommendations .................................................................................................................. 12 WRRF Project Technical Memorandum #6 – Renewable Energy Generation Update Page 2 of 12 Section 1 Introduction The WRRF Project will provide significant investment in treatment process upgrades and site improvements at the WRRF. In addition to process upgrades at the WRRF, the City is interested in developing renewable energy projects at the WRRF to reduce the cost of purchased electricity and increase the value of the WRRF as a community asset. Renewable energy is consistent with the following triple bottom line objectives and performance measures from the Program Charter: Economic Environmental Social Optimize capital investment and life cycle cost Maximize value for ratepayers’ investment Develop and implement a holistic strategy to maximize sustainable resource recovery and manage salts, nutrients and environmental pollutants in the Basin Incorporate sustainability practices in planning, design, construction and operation Create and sustain diverse partnerships that add value to the community Be a good neighbor Section 2 Background The WRRF receives electricity from Pacific Gas and Electric Company (PG&E) and natural gas from Southern California Gas Company (SoCalGas). Electricity is provided through three PG&E electrical services. The main PG&E service (Plant Service 1) is located at the plant electrical building and is on electrical rate schedule E-19P. The Water Reuse facilities are served by a separate service (Plant Service 2) and there is also a PG&E service that serves the abandoned chlorination facilities at the southern end of the site (Plant Service 3). A summary of the PG&E services and recent billing data is shown in Table 1. For more information on the electrical services and existing infrastructure, refer to TM #10.2 – Infrastructure Planning, Electrical and I&C (HDR, 2014). Table 1. Summary of Existing Electrical Meters and Use PG&E Service Plant Service 1 Plant Service 2 Plant Service 3 Area Served Main Plant Water Reuse Abandoned Chlorination Facilities Rate Schedule E-19P A-10 A-6 Annual Energy Usage1 4,510,000 kWh 250,000 kWh 7,000 kWh Maximum Billing Demand1 650 kW 131 kW 4 kW Annual PG&E Cost1 $596,000 $50,000 $1,600 Average PG&E Rate1 $0.132/kWh $0.199/kWh $0.228/kWh 1 Based on 12-months of electricity billing data from May 2014 through April 2015. As part of the WRRF Energy Efficiency Project, the City has recently installed a new cogeneration system. The 150 kW cogeneration system is an internal combustion engine that will produce electricity from WRRF Project Technical Memorandum #6 – Renewable Energy Generation Update Page 3 of 12 digester gas. The waste heat will be used to heat the digesters. The cogeneration system will be put online once the interconnection agreement with PG&E is finalized. The improvements proposed in the Facilities Plan include new disinfection technology and significant upgrades to the secondary treatment process, as well as upgrades to filtration, cooling and solids handling. In addition to the process upgrades, the WRRF Project includes a new Water Resource Center, Learning Center and Maintenance Shop. These upgrades will increase the electrical usage at the WRRF. Estimates show the upgraded WRRF will require approximately 2,600 kWh per MG treated. With an average annual flow of 6.1 MGD, this results in an average annual energy usage of 5,800 MWh/year (not including the energy use of the Water Resource Center, Learning Center and Maintenance Shop). The estimated electrical usage of the upgraded WRRF (excluding the buildings listed above) is 30% greater than the energy usage of the existing plant. With rising electricity costs and increasing electrical usage, the City is interested in economically viable renewable energy opportunities. The City has evaluated renewable energy opportunities in the past to offset energy costs at the WRRF. A summary of past studies and relevant findings is provided in Table 2. Other than cogeneration, which is discussed below, the City has historically found other renewable energy technologies to be infeasible and/or not cost-effective for the WRRF. As part of the WRRF Project, the Program Management (PM) Team has performed an updated renewable energy assessment to analyze the current economic feasibility of three renewable energy technologies: solar photovoltaic (PV), wind power, and micro- hydropower. WRRF Project Technical Memorandum #6 – Renewable Energy Generation Update Page 4 of 12 Table 2. Summary of Previous Renewable Energy Studies Study Title Year Author Renewable Energy Measures Estimated Generation Estimated Cost Savings Estimated Capital Cost Notes Preliminary Energy Assessment 2013 PG&E and AECOM 750 kW Solar PV system 1.2 million kWh/yr Not provided $3.8 million • Study did not evaluate Net Present Value. • System would require 5-6 acres; south end of plant was proposed. • Potential complication for Net Energy Metering (NEM) due to PV system and cogeneration on one meter; would need to coordinate with PG&E on Rule 21 interconnection requirements. Preliminary Energy Assessment 2013 PG&E and AECOM 7.3 kW Low Head Hydropower 64 kWh/yr $8,900/yr Not provided • O&M costs were estimated at $4,600/yr and administration costs at $2,300/yr, resulting in a net financial benefit of $2,300/yr. • Project was not recommended due to the low potential savings and high payback. Investment Grade Analysis Report 2013 PG&E and AECOM 150 kW cogeneration system 601,000 kWh/yr 29,000 therms/yr $98,800/yr (total) $1.7 million • Electricity savings were estimated at $72,700 for electricity and $26,700 for natural gas. • This project has being implemented with the WRRF Energy Efficiency Project. Report of the Preliminary Survey of the City of San Luis Obispo Water Reclamation Facility 2011 Chevron Energy Solution Hydro-Turbine at Plant Outfall; 1 MW ground mounted solar PV system; Combined Heat and Power; Geothermal effluent cooling system Not provided Not provided Not provided • Recommended renewable energy options were listed in the study but were not fully analyzed. • Estimated costs and savings were not provided. City of San Luis Obispo Wastewater Treatment Plant Efficiency Evaluation 2010 Waterworks Engineers Reciprocating engine cogeneration System 2.05 million kWh/yr $221,700/yr $1.35 million • Project was estimated to have a 6.1 year simple payback. WRRF Project Technical Memorandum #6 – Renewable Energy Generation Update Page 5 of 12 Section 3 Solar PV Generation Potential Locations Based on the proposed site plan for the WRRF, the rooftops of new and existing buildings and the new parking areas were identified as most suitable for solar PV. The open space on the southern end of the plant was not considered available for solar PV based on the City’s desire to preserve the existing natural environment and wetlands. Additionally, the paved area north of the equalization pond, which is currently used to store biosolids, was not evaluated due to the planned Prado Road overpass and associated widening of Prado Road. While solar PV on new facilities is most cost-effective, the City is interested in planning for solar PV on existing rooftops as well; therefore solar on both new and existing buildings was evaluated. Included in the existing buildings is the recycled water clearwell which has a concrete cover. Figure 1 shows the proposed sites for solar PV. The area available for solar at each identified site differs based on the existing and planned equipment on the roof/clearwell and roof aspect. Table 3 provides the estimated area available for solar at each proposed location. Table 3. Estimated Area for Solar at Proposed Sites Location Mounting Type Estimated Roof Area (sf) Assumed Area Available for Solar (%) Assumed Area Available for Solar (sf) New Facilities Water Resource Center Roof 12,000 50% 6,000 Carport - Guest Parking Carport 3,500 100% 3,500 Carport - Employee Parking Carport 3,600 100% 3,600 Maintenance Shop Roof 6,000 50% 3,000 Blower Building Roof 1,3801 90% 1,240 Subtotal – New Facilities 17,340 Existing Facilities Dewatering Building Roof 9,000 90% 8,100 Learning Center (current Admin Building) Roof 2,850 70% 1,995 Plant Electrical Building Roof 1,750 90% 1,575 Recycled Water Clearwell Roof 6,300 90% 5,670 Subtotal – Existing Facilities 17,340 Total 34,680 1 Estimated roof area for blower building is south facing roof area only. WRRF Project Technical Memorandum #6 – Renewable Energy Generation Update Page 6 of 12 Solar Panels on Existing Facility Solar Panels on Proposed Facility PLANT SERVICE 1 (E-19) PLANT SERVICE 2 (A-10) RECYCLED WATER CLEARWELL PLANT ELECTRICAL BUILDING Plant Electrical Service Figure 1. Proposed Locations for Solar PV WRRF Project Technical Memorandum #6 – Renewable Energy Generation Update Page 7 of 12 Energy Generation The following assumptions were made to estimate the annual solar electricity production: 1. 7.5 watts of solar PV installed per sf available 2. 1,600 kWh of electricity generation per kW installed for the first year 3. 0.5% annual degradation in energy production Based on these assumptions, the total annual energy generation from solar PV in the first year is approximately 416,000 kWh, which equates to roughly 7% of the estimated future electricity use of the WRRF (excluding buildings). Table 4 summarizes estimated electricity production from solar PV and shows that electricity production from solar PV on new and existing facilities is roughly equal. Table 4. Estimated Solar PV Generation Assumed Area Available for Solar (sf) Electricity Generation First Year (kWh) New Facilities 17,340 208,100 Existing Facilities 17,340 208,100 Total 34,680 416,200 Economics The project economics were evaluated by calculating the net present value (NPV) for three (3) different purchasing methods: (1) cash purchase, (2) loan purchase, and (3) power purchase agreement (PPA). For the financial analysis, the following assumptions were made: 1. The approximate installed cost of a PV system is assumed to be $3.80/W installed for new facilities and $4.40/W installed for existing facilities. This cost includes PV modules, mounting structure, inverter, balance of systems, and installation labor. 2. All PV systems except the Recycled Water Clearwell are assumed to be net metered through Plant Service 1 (E-19 rate schedule) and to generate an average electricity credit of $0.132/kWh produced. 3. The PV system at the Recycled Water Clearwell is assumed to be net metered through Plant Service 2 (A-10 rate schedule) and to generate an average electricity credit of $0.199/kWh produced. 4. The annual PG&E electricity escalation rate is assumed to be 4%. Rates are expected to increase more significantly than they have historically as PG&E works towards meeting California’s renewable energy goal of 50% by 2030. Published rate forecasts suggest PG&E rates will increase by 4 to 6% annually. To be conservative, an annual escalation of 4% is assumed. 5. Annual operation and maintenance costs (O&M) are assumed to be $18 per kW during the first year and escalate at 3% per year. 6. The inverters are assumed to be replaced at year 15 and to have a cost of $0.20/W at Year 0; cost at Year 15 is calculated assuming 3% per year escalation. 7. Loans are assumed to have a 20 year term. WRRF Project Technical Memorandum #6 – Renewable Energy Generation Update Page 8 of 12 8. The PV system life is assumed to be 30 years. At 30 years, the PV system is assumed to reach the end of its useful life and have zero salvage value. 9. For new facilities, the upfront cost of the PPA option is assumed to be zero. For existing facilities, the upfront cost of the PPA option is assumed to be 10% of the installed cost of an equivalent sized PV system to account for any potential required electrical upgrades. 10. PPAs are assumed to be fixed. Although the initial term is assumed to be 20 years, PPA payments for the NPV analysis were extended through Year 30 to account for the City’s options to extend the PPA or purchase at fair market value. 11. The discount rate is assumed to be 5%. The estimated NPV for the proposed projects using various purchasing methods is presented in Table 5. Solar systems are grouped by those being installed on new facilities and those being installed on existing facilities due to the difference in estimated installed cost. The Recycled Water Clearwell system is shown separately because it is assumed to be net metered through Plant Service 2, which has a higher value for the electricity (see assumption 3 above). In addition to estimating NPV for a cash purchase, the life cycle cost was calculated for several loan rates and PPA rates. In Table 5, three loan options are presented, which correspond to the current financing rates available (California Energy Commission loans – 1%, Clean Water State Revolving Fund – 1.5%, and private financing – 3%), and two PPA rates. Actual loan rates and PPA rates available at the time the WRRF Project is ready for construction may differ and should be evaluated at that time. Table 5. Life Cycle Cost Summary Facility New Facilities Existing Facilities, Except Recycled Water Clearwell Recycled Water Clearwell Total Rated DC Power (kW) 130 87.5 42.5 Estimated Area Occupied by Solar (sf) 17,340 11,670 5,670 Estimated Annual Energy (kWh/yr) 208,100 140,000 68,000 Estimated Capital Cost $494,000 $385,000 $187,000 Estimated Annual O&M Cost $2,300 $1,500 $800 Inverter Replacement at Year 15 $39,000 $26,500 $12,900 Estimated NPV (5%, 30 years) Cash Purchase $75,000 -$1,000 $104,000 Loan – 1% interest $248,000 $132,000 $168,000 Loan – 1.5 % interest $212,000 $106,000 $156,000 Loan – 3 % interest $178,000 $77,000 $142,000 PPA - $0.14/kWh $215,000 $106,000 $157,000 PPA - $0.17/kWh $124,000 $45,000 $128,000 WRRF Project Technical Memorandum #6 – Renewable Energy Generation Update Page 9 of 12 Based on the analysis presented above, the proposed solar projects have a positive NPV for all cases except the cash purchase of the PV systems for the existing facilities. Financing the systems through a 1% loan through the California Energy Commission (CEC) appears to be the most cost-effective option at this time. It is recommended that the City pursue CEC financing for the solar PV projects and any other energy efficiency projects (a loan of up to $3 million can be obtained from the CEC pending funding availability). Incentives and Tax Credits Incentives through the California Solar Initiative are no longer available for PG&E customers and therefore were not included in this analysis. Federal investment tax credits (ITC) of 30% are available through 2016 for solar installations. As a municipality the City would not be able to take advantage of the tax credits. If the City chooses the PPA option, the solar provider will utilize the tax credits to reduce the PPA rate to the City; however the ITC is set to expire at the end of 2016 so may result in an increase in PPA rates. Interconnection Considerations Because the WRRF has a cogeneration system which produces electricity, the City will have to apply for interconnection through the Net Metering Multiple Tariff schedule (NEM-MT). This allows a NEM generator, like solar PV systems, to be tied to the same PG&E meter as a cogeneration system. Metering is required to ensure the customer is only credited for excess production from the solar PV system and does not receive credits from excess production from the cogeneration system. If the City desires to pursue a larger solar PV system in the future, up to 1 MW of solar can be implemented with net metering. A single 1 MW solar PV facility would require approximately 5 acres and could be located on an owned or leased parcel adjacent to the WRRF (separated only by roads) and net metered through the Net Energy Metering Aggregation (NEMA) rate tariff. A single large facility would reduce the installation cost due to economies of scale. Based on understanding of the City’s preferences for smaller solar PV throughout the WRRF, this option was not evaluated in this study but could be evaluated in the future if preferences change and/or lease opportunities arise (for example, across Highway 101). Section 4 Wind Energy The City is interested in wind energy opportunities at the WRRF. Electricity generated from wind could further offset electricity costs of the WRRF. According to the online wind data, average wind speeds at the San Luis Obispo Regional Airport weather station range from 4 mph in the winter to 8 mph in the spring and early summer (source: weatherspark.com). The winds are generally in a northwest direction as shown in the wind rose in Figure 2. WRRF Project Technical Memorandum #6 – Renewable Energy Generation Update (Draft) Page 10 of 12 Figure 2. Wind Rose for San Luis Obispo (source: windfinder.com) Assuming the wind velocity at the Airport is being measured at the standard height of 10 meters (32 ft) above the surface, wind velocities at higher elevations can be approximated using the following formula: V2 = (H2/H1)t x V1 where: V1 = measured wind speed, V2 = estimated wind speed, H1 = measured height, H2 = desired height, and t = terrain wind shear exponent (assumed to be 0.25 for buildings). Using the formula above, average wind speeds at the WRRF at 100 ft are estimated to range between 5.3 mph and 10.6 mph. At 230 ft, average wind speeds are estimated to range from 6.5 mph to 13.1 mph. Table 6 provides wind requirements for small wind turbines based on a report prepared for the California Energy Commission by Local Power, Inc. in 2013. Based on the data shown in Table 6, the wind speeds at the WRRF do not appear sufficient for operation of a small residential wind turbine (less than 15 kW) or an urban/commercial wind turbine (300 kW to 1 MW). This means that a very small wind turbine would have to be used at the WRRF, which would result in low energy generation. Table 6. Wind Requirements for Small Turbines (source: California Energy Commission, 2013) Turbine Scale Power Rating (kW) Minimum Wind Power Requirement Average Wind Speed (mph) Dimensions Hub Height Rotor Diameter Residential Less than 15 15.2 – 16.8 mph at 100 ft 13 + 30 to 140 ft 10 to 30 ft Urban / Commercial 300 to 1,000 16.8 – 18.1 mph at 230 ft 16 + 200 to 300 ft 100 to 250 ft In addition to limitations of wind speed, the WRRF is in the flight path of the Airport and is within Airport Safety Zone S-1b according to the Airport Land Use Plan. In order to construct a wind turbine at the WRRF Project Technical Memorandum #6 – Renewable Energy Generation Update Page 11 of 12 WRRF, the City would need to file a FAR Part 77 form with the Federal Aviation Administration (FAA) to determine whether the wind turbine would be considered an obstruction for aircraft operations. Due to the low energy generation potential of wind power at the WRRF and the complexities with FAA approval, a wind turbine at the WRRF is not recommended with the WRRF Project. The City may consider a small roof mounted or similar turbine for demonstration purposes if desired. Section 5 Micro-Hydropower They City discharges tertiary treated water to the San Luis Obispo Creek through the creek outfall structure. It is estimated that the current average annual flow (AA) is 3.9 mgd and projected AA is 6.1 mgd. The City previously evaluated low head hydropower at the WRRF outfall in the Preliminary Energy Assessment (PEA) phase of the WRRF Energy Efficiency Project. The PEA estimated a 7.3 kW low head hydropower system could be installed at the outfall and it would generate approximately $8,900 in savings per year. However, O&M and administration costs were estimated at $ 6,900, thereby reducing the annual cost savings to $2,300 and resulting in a payback greater than 20 years. Due to the high payback, hydropower was not further evaluated during the Investment Grade Audit (IGA). As part of the WRRF Project, the PM Team prepared updated energy generation estimates for micro- hydro at the WRRF outfall. Power was calculated using the following equation: Power (kW) = Head (ft) x Flow (cfs) x Efficiency / 11.8 Assuming 15 ft of available head at the outfall and a projected AA of 6.1 mgd (9.4 cfs), a 70% efficient turbine could generate 8.4 kW of power. The annual energy production would be approximately74,000 kWh and the cost savings would be approximately $9,700 (assuming $0.132/kWh). As estimated in the PEA, the cost savings potential is low and the annual O&M costs may offset a majority of these costs savings. If the City desires to implement micro-hydro at the WRRF outfall, a cross-flow turbine should be considered and grants should be pursued to offset costs of the turbine. These turbines can operate at low flow and low head, and are able to extract most of the energy out of the water. Additionally, they have a lower upfront cost and are easy to install. The Ossberger Turbine manufactured by Ossberger has been used successfully for these types of applications. Several requests for cost estimates were made to Ossberger to help with estimating costs for this turbine, but no response has been received. Updates on the cost will be provided as they become available. While the cost savings potential from micro-hydro is low, the City may be able to obtain a grant to fund the project and make it economically viable. Depending on the City’s desire to further pursue micro- hydro, grant funding for this project component could be further evaluated and pursued in Phase 2. WRRF Project Technical Memorandum #6 – Renewable Energy Generation Update Page 12 of 12 Section 6 Recommendations Based on the results of the renewable energy assessment, the City should consider implementing solar PV on the following nine (9) facilities as part of the WRRF Project: Water Resource Center Carport - Guest Parking Carport - Employee Parking Maintenance Shop Blower Building Dewatering Building Learning Center (current Admin Building) Plant Electrical Building Recycled Water Clearwell The solar PV projects are economically viable based on current cost estimates, with the CEC loan being the most favorable financing mechanism. Due to declining solar PV costs and increasing PG&E rates, solar PV is expected to remain economical in the future but the life cycle cost estimates should be revisited at the time of construction to verify the project economics. Wind power and micro-hydro are less favorable renewable energy opportunities for the City and do not appear to provide meaningful energy generation potential to offset WRRF electricity costs. However, if the City wishes to implement these technologies for demonstration purposes or if a grant can be obtained, they can be revisited. Appendix G TM No. 8 - Regulatory Compliance Date: 10/16/2014 Prepared by: Irina Luckicheva, PhD, Mike Falk, PhD, PE Reviewed by: Mallika Ramanathan, PE, Holly Kennedy, PE Project: WRRF Project SUBJECT: TM NO. 8 – REGULATORY COMPLIANCE The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long-term strategy for resource management. This technical memorandum summarizes the City of San Luis Opisbo’s (City) renewed National Pollutant Discharge Elimination System (NPDES) permit. The permit limits provide the basis of the process evaluation and selection for upgrades for the City’s Water Resource Recovery Facility (WRRF). Contents Introduction .............................................................................................................................. 3 Background .............................................................................................................................. 3 Previous NPDES Permit (Order R3-2002-0043) ...................................................................... 5 Averaging Periods .................................................................................................................................... 5 Reasonable Potential Analysis Findings .................................................................................................. 7 Previous NDPES Permit (Order R3-2014-0033) ...................................................................... 7 Averaging Periods .................................................................................................................................... 7 Rated Capacity ......................................................................................................................................... 7 Dissolved Oxygen ..................................................................................................................................... 9 Mass Based Limits .................................................................................................................................... 9 Biochemical Oxygen Demand and Total Suspended Solids .................................................................... 9 Nutrients.................................................................................................................................................... 9 Disinfection ............................................................................................................................................. 10 Disinfection By-Products......................................................................................................................... 10 Metals ..................................................................................................................................................... 11 Nitrosodimethylamine ............................................................................................................................. 11 pH ........................................................................................................................................................... 12 Future Limits ...........................................................................................................................13 Averaging Periods .................................................................................................................................. 13 Role of Water Conservation.................................................................................................................... 13 Role of Recycled Water .......................................................................................................................... 14 Contaminants of Emerging Concern ...................................................................................................... 14 Human Health Criteria ............................................................................................................................ 15 Nutrients.................................................................................................................................................. 15 Disinfection Indicators ............................................................................................................................. 16 WRRF Project TM No. 8 – Regulatory Compliance Page 2 of 22 Biosolids ................................................................................................................................................. 17 Air Emissions .......................................................................................................................................... 17 References ..............................................................................................................................19 List of Tables Table 1. Summary of Earlier NPDES Discharge Limits for Selected Pollutants (R3-2002-0043) ................ 6 Table 2. Renewed NPDES Discharge Limits for Selected Pollutants (R3-2014-0043) ................................ 8 Table 3. Contaminants of Emerging Concern Classifications ..................................................................... 15 List of Figures Figure 1. SLO WRRF Existing Process Schematic (includes WRRF Energy Efficiency Project) ................ 4 Figure 2. Historical Effluent pH Values ....................................................................................................... 12 Figure 3. Historical Raw Influent Ammonia Concentrations ....................................................................... 13 Figure 4. Historical Recycled Water Volume .............................................................................................. 14 Figure 5. GHG Emissions Distribution per Treatment Level for a 10 mgd Nominal Plant (Falk et al., 2013) ............................................................................................................................................. 17 List of Appendices Appendix A – Renewed NPDES Permit CA 0049224 (R3-2014-0033) and Time Schedule Order Appendix B – City Comments on Draft Tentative NPDES Permit Appendix C – Tables from Larry Walker and Associates on Potential Future Nutrient Limits WRRF Project TM No. 8 – Regulatory Compliance Page 3 of 22 Introduction The WRRF’s NPDES discharge permit (Order R3-2014-0033; Permit Number CA0049224) was renewed in September 2014. This permit supersedes the previous NPDES discharge permit (Order R3-2002-0043; Permit Number CA0049224). The key changes in the renewed permit are more stringent discharge limits for nitrogen species and trihalomethanes (THMs). The renewed NPDES becomes effective on December 1, 2014. A Time Schedule Order (TSO) (R3-2014-0036) was also issued that prescribes interim effluent limitations for THMs and nitrates with final limitations going into effect on November 30, 2019. This technical memorandum (TM) summarizes modifications in discharge limitations in the renewed permit and also identifies conditions in the TSO. This information will provide the basis of the process evaluation and selection for the WRRF Facilities Plan. Background The WRRF treats municipal wastewater flow from the City, California Polytechnic State University (Cal Poly), and the San Luis Obispo County Airport. The WRRF is permitted to treat an average dry weather flow (ADWG) of 5.1 million gallons per day (mgd). Currently, the WRRF treats an ADWF (with Cal Poly) of approximately 3.5 mgd (TM 1: Wastewater Characteristics, HDR 2014). Treated effluent is either discharged to the San Luis Obispo Creek or recycled to various users. A process schematic of the WRRF is provided in Figure 1. The WRRF treatment facilities include the following liquid and solids processes: • Liquid Treatment: - Wet weather flow equalization - Headworks – screening, grinding, and aerated grit removal - Primary settling using primary clarifiers - Diurnal flow equalization - Biofiltration with trickling filters and clarifiers - Air activated sludge and final clarifiers - Cooling using evaporative cooling towers - Filtration with mono media filtration - Disinfection with chlorination and dechlorination • Solids Treatment: - Thickening using dissolved air flotation thickeners (DAFTs) - Stabilization using anaerobic digestion - Dewatering of digested solids using either belt presses, drying beds, or a new screen press (future) The following sections summarize the existing and tentative NPDES permits. WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e 4 o f 2 2 Fi g u r e 1 . S L O W R R F E x i s t i n g P r o c e s s S c h e m a t i c ( i n c l ud e s W R R F E n e r g y E f f i c i e n c y P r o j e c t ) WRRF Project TM No. 8 – Regulatory Compliance Page 5 of 22 Previous NPDES Permit (Order R3-2002-0043) Discharge requirements for selected pollutants are summarized in Table 1 for the earlier NPDES permit (Order R3-2002-0043; Permit Number CA0049224). A description of the averaging periods used for each selected pollutant and a discussion of the reasonable potential analysis (RPA) is provided in the following subsections. Averaging Periods The earlier NPDES permit had limits based on various averaging periods as shown in Table 1 (e.g., average monthly). Descriptions of the averaging periods for the selected pollutants are as follows: • Average Annual (AA): AA is defined as the average over a calendar year. For the NPDES permit, AA compliance is based on an annual running average of the past four quarterly sampling events. This averaging period is applicable only to un-ionized ammonia discharge limits to San Luis Obispo Creek. • Average Monthly: The average monthly effluent limitation is defined as the maximum allowable average of daily discharges over a calendar month. • Average Weekly: The average weekly effluent limitation is defined as the maximum allowable average of daily discharges over a calendar week (i.e., Sunday through Saturday). • Maximum Day: The maximum day effluent limitation is defined as the maximum allowable discharge over a calendar day. • Instantaneous Minimum: Instantaneous Minimum is defined as the minimum value taken for any grab sample. This averaging period applies to pH only. • Instantaneous Maximum: Instantaneous Maximum is defined as the maximum value taken for any grab sample. This averaging period applies to pH and total coliforms of the selected pollutants. WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e 6 o f 2 2 Ta b l e 1 . S u m m a r y o f E a r l i e r N P D E S D i s c h a r g e L i m i t s fo r S e l e c t e d P o l l u t a n t s ( R 3 - 2 0 0 2 - 0 0 4 3 ) Pa r a m e t e r U n i t Av e r a g e D r y We a t h e r F l o w Av e r a g e A n n u a l Av e r a g e Mo n t h l y Av e r a g e We e k l y Ma x i m u m Da i l y In s t a n t a n e o u s Mi n i m u m Instantaneous Maximum Ra t e d C a p a c i t y m g d 5 . 2 - - - - - - - - - - - - Bi o l o g i c a l O x y g e n D e m a n d , 5 - d a y (B O D ) mg / L - - - - 1 0 3 0 5 0 - - - - To t a l S u s p e n d e d S o l i d s ( T S S ) m g / L - - - - 1 0 3 0 7 5 - - -- Un - i o n i z e d A m m o n i a m g N / L - - 0 . 0 2 5 ( A n n u a l Ru n n i n g M e a n ) (a ) -- - - - - - - - - Co l i f o r m (b ) M P N / 1 0 0 m L - - - - 2 3 2 . 2 - - 2 4 0 pH (c ) s . u . - - - - - - - - - - 6 . 5 8 . 3 Se l e n i u m g / L - - - - 4 . 1 - - 8 . 2 - - - - Br o m o f o r m g / L - - - - 4 . 3 - - 8 . 6 - - - - Cy a n i d e g / L - - - - 4 . 3 - - 8 . 6 - - - - In t e r i m C h l o r o d i b r o m o m e t h a n e (d ) g / L - - - - - - - - - - - - 4 2 In t e r i m D i c h l o r o b r o m o m e t h a n e (d ) g / L - - - - - - - - - - - - 2 7 Fi n a l C h l o r o d i b r o m o m e t h a n e (e ) g / L - - - - 0 . 4 0 - - 0 . 8 - - - - Fi n a l D i c h l o r o b r o m o m e t h a n e (e ) g / L - - - - 0 . 6 0 - - 1 . 1 - - - - No t e : B a s e d o n N P D E S P e r m i t N o . C A 0 0 4 9 2 2 4 i s s u e d i n M a y 2 0 0 2 ( M o d i f i e d i n 2 0 0 5 ) (a ) I n - s t r e a m c r i t e r i a ( i . e . , n o n - d i s c h a r g e l i m i t ) (b ) T h e m e d i a n n u m b e r o f f e c a l c o l i f o r m s s h a l l n o t ex c e e d 2 . 2 M P N / 1 0 0 m L O R t h e m e d i a n n u m b e r o f t o t a l c o l i f o r m s s h a l l n o t e x c e e d 2 3 M P N / 1 0 0 m L . C o l i f o r m n u m b e r s s h a l l b e d e t e r m i n e d f o r t h e l a s t 7 - d a y s s a mples were taken. The ma x i m u m n u m b e r o f t o t a l c o l i f o r m s i n a n y s a m p l e s h a ll n o t e x c e e d 2 4 0 M P N / 1 0 0 m L . (d ) R e c e i v i n g w a t e r p H m u s t n o t f a l l b e l o w 7 . 0 o r e xc e e d 8 . 3 , o r t o c h a n g e b y m o r e t h a n 0 . 5 u n i t s (d ) I n t e r i m l i m i t s u s e d t h r o u g h F e b r u a r y 2 8 , 2 0 1 0 (e ) F i n a l l i m i t s c o m p l i a n c e b y M a r c h 1 , 2 0 1 0 . WRRF Project TM No. 8 – Regulatory Compliance Page 7 of 22 Reasonable Potential Analysis Findings The previous NPDES permit was modified in 2005 to include additional limitations based on the reasonable potential analysis (RPA) that statistically determined which California Toxics Rule (CTR) and California Code of Regulations (CCR) Title 22 pollutants have reasonable potential to exceed their respective water quality objectives and require effluent limitations. Of the pollutants analyzed by RPA, selenium, cyanide, bromoform, chlorodibromomethane, and dichlorobromomethane exhibited reasonable potential and thus required effluent limitations. Refer to the earlier NPDES permit (R3- 2002-0043) for a statistical description supporting the RPA exceedances. Typically, the Regional Water Quality Control Board (CCRWQCB) provides a TSO compliance schedule for any pollutants that exceed the RPA analysis. In the case of selenium, bromoform, and cyanide, the CCRWQCB believed that the WRRF should be able to achieve immediate compliance with CTR criteria and thus included immediate monthly average final effluent limitations for these constituents (as shown in Table 1). As for chlorodibromomethane and dichlorobromomethane, an earlier TSO compliance schedule was initiated that provided both interim and final effluent limits (as shown in Table 1). The WRRF has yet to meet the chlorodibromomethane and dichlorobromomethane limits and the renewed TSO schedule has been integrated into the renewed NDPES Permit that will be discussed in the next section. Previous NDPES Permit (Order R3-2014-0033) The WRRF’s renewed NPDES Permit was finalized after the September 25, 2014 board hearing. A copy of the permit is provided as Appendix A. Prior to the final permit, a draft was issued to the City for review and comment (Order R3-2013-0043). Appendix B provides a summary of the City’s comments on the Tentative NPDES permit as submitted to the CCRWQCB. The following sections detail the limitations and details in the final version of the renewed permit. Averaging Periods The legal description for the averaging periods is the same as the WRRF’s previous permit (refer to the Previous Permit section above). Rated Capacity The draft permit included a maximum daily flow limit of 5.1 mgd. This was noted by the City to be incorrect and was corrected in the renewed permit. The renewed permit states that the maximum effluent average dry weather flow rate that is discharged shall not exceed 5.1 mgd. WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e 8 o f 2 2 Ta b l e 2 . R e n e w e d N P D E S D i s c h a r g e L i m i t s f o r S e l e c t e d P o l l u t a n t s ( R 3 - 2 0 1 4 - 0 0 4 3 ) Pa r a m e t e r U n i t Av e r a g e D r y We a t h e r F l o w Av e r a g e An n u a l Av e r a g e Mo n t h l y Av e r a g e We e k l y Ma x i m u m Da i l y Instantaneous Minimum Instantaneous Maximum Ma x i m u m E f f l u e n t D i s c h a r g e F l o w m g d 5 . 1 - - - - - - - - - - - - Bi o l o g i c a l O x y g e n D e m a n d , 5 - d a y ( B O D ) m g / L - - - - 1 0 3 0 5 0 - - - - lb / d 4 2 5 1 , 2 7 5 2 , 1 2 5 To t a l S u s p e n d e d S o l i d s ( T S S ) m g / L - - - - 1 0 3 0 7 5 - - -- lb / d 4 2 5 1 , 2 7 5 3 , 1 9 0 Un - i o n i z e d A m m o n i a m g N / L - - - - - - - - 0 . 0 2 5 (b ) - - - - In t e r i m N i t r a t e (c ) m g N / L - - - - 4 2 . 6 - - - - - - - - Ni t r a t e m g N / L - - - - 1 0 - - - - - - - - Co l i f o r m (b ) M P N / 1 0 0 m L - - - - 2 3 2 . 2 - - 2 4 0 Di s s o l v e d O x y g e n m g / L 4 . 0 pH s. u . - - - - - - - - - - 6 . 5 8 . 3 In t e r i m C h l o r o d i b r o m o m e t h a n e (c ) g / L - - - - - - - - - - - - 4 2 In t e r i m D i c h l o r o b r o m o m e t h a n e (c ) g / L - - - - - - - - - - - - 3 6 Fi n a l C h l o r o d i b r o m o m e t h a n e (d ) g / L - - - - 0 . 4 0 - - 1 . 0 - - - - Fi n a l D i c h l o r o b r o m o m e t h a n e (d ) g / L - - - - 0 . 5 6 - - 1 . 0 - - - - N- N i t r o s o d i m e t h y l a m i n e ( N D M A ) g / L 0 . 0 0 0 6 9 0 . 0 0 1 4 (a ) I n - s t r e a m c r i t e r i a ( i . e . , n o n - d i s c h a r g e l i m i t ) (b ) T h e m e d i a n n u m b e r o f f e c a l c o l i f o r m s s h a l l n o t ex c e e d 2 . 2 M P N / 1 0 0 m L f o r t h e l a s t 7 - d a y s s a m p l e s w er e t a k e n . N o m o r e t h a n o n e s a m p l e s h a l l e x c e e d 2 3 MP N / 1 0 0 m L t o t a l c o l i f o r m i n a n y 3 0 - d a y p e r i o d . T h e maximum number of to t a l c o l i f o r m s i n a n y s a m p l e s h a l l n o t e x c e e d 2 4 0 MP N / 1 0 0 m L . (c ) I n t e r i m l i m i t s l i s t e d i n r e n e w e d T S O R 3 - 2 0 1 4 - 0 0 36 v a l i d t h r o u g h N o v e m b e r 3 0 , 2 0 1 9 . (d ) F i n a l l i m i t s c o m p l i a n c e b y N o v e m b e r 3 0 , 2 0 1 9 . WRRF Project TM No. 8 – Regulatory Compliance Page 9 of 22 Dissolved Oxygen The renewed permit contains a discharge limit (4.0 mg/L instantaneous minimum) and a year round receiving water dissolved oxygen (DO). The previous permit did not have an instantaneous minimum discharge limit. The year round receiving water limit is more stringent than the previous permit. The City commented on the seasonal DO limits in Appendix B. The previous permit contained seasonal DO limits that require DO greater than 5 mg/L from May through September and DO greater than 7 mg/L from October through April. The City requested that the seasonal DO limits be carried over from the previous permit. The basis of this relates to the language in the Central Coast Region Basin Plan, which states that DO should not drop below 5 mg/L at any time. Additionally, for cold waters used for spawning fish it recommends DO levels not drop below 7 mg/L. For either case, the seasonal DO limits in the previous permit satisfy both requirements. The City request was not addressed and the renewed permit contains a provision that the receiving water DO shall not be lower than 7 mg/L at any time. Mass Based Limits The renewed permit contains concentration and mass based effluent limits for BOD and TSS (Table 2). The City commented on the inclusion of mass based limits (Appendix B) stating that the water quality criteria used to establish discharge limits are based on concentration. Mass based limits provide no additional assurance that beneficial uses are being protected and could result in the discharge effectively violating two effluent limits based on one actual exceedance. The City requested that mass limits be eliminated for all constituents, except for BOD and TSS which are technology based effluent limits. A technology based limit is the limit that can be reliably achieved over time to meet permit limits. A full description on the statistics associated with technology based effluents is described in a WERF report by Bott and Parker (2011). This request was carried through and only BOD and TSS have mass based effluent limits in the renewed permit. Biochemical Oxygen Demand and Total Suspended Solids The BOD and TSS concentration limits are similar to the previous NPDES permit (R3-2002-0043). The WRRF has reliably met these limits and should continue to be able to meet the limits in the renewed permit. The stringent nature of these limits impacts the technology selection for any expansion at the WRRF. For example, one of the potential disinfectants considered, Peracetic Acid (PAA), produces BOD which could lead to a discharge violation. Nutrients The nutrient limits that are included in the renewed permit are limited to nitrogen species, specifically un-ionized ammonia and nitrate. The ammonia limit is similar to the permit, where the limit is based on not causing the un-ionized ammonia in the receiving water to become greater than 0.025 mg-N/L. The WRRF’s previous permit specified that compliance shall be measured by comparison to an annual running mean of the past four quarterly sampling events. Historically, the WRRF has reliably met this limit. The previous permit does not include the averaging language, and is more restrictive compared to previous permit. WRRF Project TM No. 8 – Regulatory Compliance Page 10 of 22 In subsequent discussions with the CCRWQCB, it is recommended that the City consider requesting the following: • A table from the CCRWQCB to assist with determining the discharge ammonia limits. Otherwise, an uncontrolled variable (i.e., the creek) is introduced into operating the WRRF. • Modification of sample from a grab sample to a composite sample. A composite is preferred as raw influent ammonia concentrations are highly variable over a 24-hour cycle. This eliminates the likelihood of grabbing a sample when maximum ammonia concentrations occur over a 24-hour cycle. This strategy will increase the ability to reliably comply with discharge limits. The renewed permit requires a weekly grab sample for ammonia. The un-ionized ammonia concentration is then calculated based on pH and temperature of the effluent at the time of sample collection. The limitation states that the effluent may not result in the creek un-ionized ammonia concentration to exceed 0.025 mg-N/L. The WRRF upgrades will need to address ammonia compliance, recognizing that averaging is no longer valid. The nitrate limit is new to the WRRF. Similar to ammonia, the sampling requirements include a grab sample taken once per week. The nitrate limits are based on average monthly conditions. Upgrades are needed to achieve nitrate removal. Typically, nitrate is removed biologically while under the appropriate environmental conditions (i.e., available carbon, anoxic conditions, and nitrate present). Interim limitations have been established in the renewed TSO to provide adequate time for the WRRF to complete the necessary designs and facility upgrades. To develop alternatives and configurations to remove nitrate will require additional sampling to understand the various forms of carbon (e.g., BOD and COD) through the liquid stream process. The WRRF staff is already collecting such data to assist in technology selection and preliminary design. Disinfection The previous and renewed permits use a combination of fecal and total coliforms that consider average weekly and instantaneous maximum limits. Disinfection By-Products In the 1970s, it was recognized that chlorine disinfection may produce disinfection byproducts (DBPs) that can cause health concerns, if ingested or inhaled, or impose other environmental impacts. DBPs are produced when disinfectants, and specifically chlorine, readily react with certain natural organic matter (NOM) present in water and wastewater. NOM present in water and wastewater is the primary precursor for the formation of DBPs and typically consists of residual soluble microbial products (SMPs), proteins, polysaccharides, humic acids, fulvic acids, and DNA. In addition, certain organic chemicals introduced into wastewater treatment facilities as settling aids or for nuisance foam control, or for thickening and dewatering, have been implicated in DBP formation. Interim discharge limitations were established for the WRRF in the earlier TSO R3-2010-0013 for the DBPs known as trihalomethanes (THMs). The THMs of interest are chlorodibromomethane (CDB) and dichlorobromomethane (DCB). The interim THM discharge limits were valid until March 31, 2015, after which the discharge limits were prescribed to be consistent with the TSO. Since the WRRF Project TM No. 8 – Regulatory Compliance Page 11 of 22 WRRF is still undertaking the necessary steps to comply with the permit limits, the earlier TSO was renewed and the interim effluent limitations were extended to be valid until November 30, 2019. DBPs do not relate to pathogen levels, but they impact disinfection equipment selection. Similar to nitrate, interim limitations have been established to provide adequate time for the WRRF to complete the necessary designs and facility upgrades. To develop alternatives and configurations to meet the THM discharge limits will require evaluation of existing disinfection equipment and other potential alternatives (e.g., UV disinfection, PAA, etc.). Metals The previously issued tentative permit required the City to comply with copper and lead limits based on the RPA study results, however the City commented on the copper and lead limits in Appendix B. The concern by the City was the hardness assumption used to quantify the copper and lead limits. In short, the CCRWQCB assumed a hardness value of 100 mg/L. Historical hardness is typically about 250 to 400 mg/L. By assuming a lower value, the copper and lead limits become more stringent. The City has requested that the CCRWQCB revisit this assumption as this directly impacts the copper and lead limits. The CCRWQCB assumed a hardness of 330 mg/L for the renewed permit which resulted in removal of copper and lead limits following the City’s request. Nitrosodimethylamine Nitrosomines are a group of compounds that are among the most potent carcinogens known (Snyder, 1995). The most studied nitrosamine is N-nitrosodimethylamine (NDMA), which can be generated when chloramines react with dimethylamine (DMA) in water and wastewater (Choi and Valentine, 2002; Mitch and Sedlak, 2002). Given the carcinogenic potential of NDMA, the discharge limits are low (Renewed Permit limit = 0.00069 µg/L for maximum month effluent limits and 0.0014 µg/L for maximum daily effluent limits). A key concern regarding these limits is the ability to confidently measure NDMA to such low limits. The method proposed for measuring NDMA in the renewed permit (EPA Method 625) has a method detection limit of 50 to 25,000 µg/L, which is several magnitudes greater than the proposed limits. Another concern is the raw influent having NDMA values larger than the discharge limits. This would require source control of NDMA precursors, which would be a complex task as NDMA precursors are commonly found in clothing, residential building materials, chemicals, rubber, plasticizers, etc. In fact, wastewater treatment plants use various materials that are NDMA precursors which can react with chlorine to form NDMA: • Chloramines and dimethylamine - a component in cationic polymers used to enhance settling. • Rubber materials in valves, gaskets, pipelines, and other process equipment - can be a source of nitrosamines. From a technology removal standpoint, the initial step is to not use chlorine or chloramines to disinfect. The most promising technology at this stage to remove NDMA is UV disinfection or an advanced oxidation processes (AOPs). Membranes are not effective at removing NDMA given its molecular size. UV has been found to effectively breakup NDMA compounds. However, the UV dose required to breakup NDMA compounds is on the order of 1,000 MJ/cm2 which is about 10 times greater than most UV dose applications for wastewater treatment. WRRF Project TM No. 8 – Regulatory Compliance Page 12 of 22 Other prospective technologies of interest are advanced oxidation processes (AOPs), such as ozone. Ozonation has been shown to generate NDMA (and bromates) while simultaneously oxidizing NDMA (albeit at low reaction rates compared to other compounds of emerging concerns (CECs)). Ozone followed by biofiltration is reported to remove NDMA. However, ozonation as a final disinfection step without subsequent biofiltration has been shown to increase NDMA concentration in drinking water treatment (Asami et al., 2009) and has varied impacts on effluent quality such as reducing estrogenic activity while increasing toxicity and retarding growth in some test organisms (Stalter et al. 2010). Ozone and hydrogen peroxide is reported to remove NDMA but there is limited information. The average monthly NDMA limitation of 0.00069 µg/L and the maximum daily limitation of 0.0014 µg/L were retained in the renewed permit. The City should continue to discuss the NDMA limits with the CCRWQCB to determine if an amendment could be issued to waive the NDMA limitations due to the lack of reliable analytical methods. pH The renewed permit pH limits (6.5 to 8.3) remained the same as in the earlier permit. Figure 2 demonstrates that the WRRF would not struggle to reliably meet the pH limits in the renewed permit. Figure 2. Historical Effluent pH Values The incorporation of a nitrate and/or NOx limit in the Final NPDES permit should benefit the effluent pH. The removal of nitrate and/or NOx produces alkalinity: 6 +5 +→3 +6 +7 (1) 6.50 6.70 6.90 7.10 7.30 7.50 7.70 7.90 8.10 8.30 8.50 Jan-11Jul-11Jan-12Jul-12Jan-13Jul-13Jan-14 pH , s . u . Renewed pH Range WRRF Project TM No. 8 – Regulatory Compliance Page 13 of 22 Despite the alkalinity gains associated with nitrate and/or NOx removal, it is unclear if there would be sufficient alkalinity recovered in the future. The impact on effluent pH should be evaluated as part of the nitrate and/or NOx removal evaluation. Future Limits The following subsections describe key parameters to consider for future limits. Of particular concern are managing averaging periods, the impact of water conservation, the role of water recycling, contaminants of emerging concern, phosphorus, and air emissions. Averaging Periods Appropriate NPDES discharge permit structures for nutrients should be based on long averaging periods linked to the specific water body response to nutrient enrichment. Unlike BOD, ammonia nitrogen, and some toxic pollutants can have acute effects in the aquatic environment; total nitrogen and phosphorus have seasonal impacts on receiving waters. Short-term limitations, such as maximum daily and average weekly limits, should not be imposed for nutrients. Imposition of short averaging periods for nutrient removal facilities will result in unnecessarily over-designed facilities which provide little, or no, additional water quality benefit and may exceed the capabilities of nutrient removal treatment technologies (WERF, 2010). Role of Water Conservation The City has successfully implemented water conservation measures within its service area and as a result the City has observed increases in influent concentrations (Figure 3). The most recent increases in concentrations may also be attributed to drought conditions which result in additional water conservation as well as reduced groundwater infiltration into the collection system. Figure 3. Historical Raw Influent Ammonia Concentrations 0 10 20 30 40 50 60 70 80 90 100 Jan-11Jul-11Jan-12Jul-12Jan-13Jul-13Jan-14 Am m o n i a C o c n e n t r a t i o n , m g N / L WRRF Project TM No. 8 – Regulatory Compliance Page 14 of 22 While this is beneficial in terms of water consumption, there is an unintended consequence at the WRRF. The rated capacity at the WRRF is based on flow, not loads. By having concentrations increase over time, the load associated with the rated capacity increases over time. The implications are that unit processes might not have as much rated flow capacity and the amount of consumables per unit flow increases directly with water conservation. For example, the amount of energy demand, chemical demand, and unit biosolids production per unit flow increases with water conservation. Role of Recycled Water The City is intending to increase the volume of recycled water in upcoming years. A plot of recycled water usage over the last few years is provided in Figure 4. Figure 4. Historical Recycled Water Volume A benefit of recycled water is that the constituent loads discharged to the creek are reduced. This does not provide a reprieve for discharge limits based on concentration. Contaminants of Emerging Concern Contaminants or compounds from pharmaceuticals and/or personal care products are being discovered in watersheds at very low concentrations (e.g., ppb or ppt). Some of these contaminants have been determined to be endocrine disrupters (Kolpin et al, 2002). The contaminants mimic estrogen and, therefore, may disrupt the endocrine (hormone) system of both animals and humans. These contaminants are known in the water industry as contaminants of emerging concern (CEC). In response to concerns about the possible impacts of these CECs (pharmaceuticals, detergents, hormones and other chemicals) on human health and aquatic organisms, in 2010, the US EPA 0 100,000 200,000 300,000 400,000 500,000 600,000 Jan-11Jul-11Jan-12Jul-12Jan-13Jul-13Jan-14 Re c y c l e d W a t e r , g a l WRRF Project TM No. 8 – Regulatory Compliance Page 15 of 22 conducted a literature search of numerous articles that referenced treatment of CECs. The EPA has classified the CECs as shown in Table 3. It is well documented that as treatment plants improve treatment performance, specifically those that transition from secondary treatment to nitrogen removal by increasing the solids residence time (SRT), the ability to remove overall CECs also increases. This increase in removal is highly dependent on the CEC constituent of interest. The longer SRT for ammonia removal translates to an increased surface area on mixed liquor for sorption, elevated biomass concentration, and the enzymes that carry out nitrification (Horz et al., 2004). The enzyme responsible for the oxidation of ammonia to nitrite, ammonia monooxygenase, is commonly referred to as ‘promiscuous’ because it has the ability to assist in the biodegradation of a wide-range of compounds such as CECs (Vader et al., 2000). Table 3. Contaminants of Emerging Concern Classifications Class Class Abbreviation Nonlyphenols, octylphenol, and alkylphenol ethoxylate (APEs) compounds NP/APEs Polynuclear aromatic hydrocarbons PAH Polybrominated biphenyl ethers PBDEs Pesticide Pesticide Pharmaceuticals and personal care products PPCP Steroids and Hormones S/H Other Other There is uncertainty on which CECs will be regulated in the future (if any). However, the existing unit processes at the WRRF provide a level of treatment for removing CECs that would match other public owned treatment works (POTWs) (except those with membrane removal processes). Human Health Criteria The United States Environmental Protection Agency (USEPA) is recommending a modification on the human health criteria they established decades ago. The proposed criteria result in modifications to the assumptions used to calculate the criteria (e.g., changes in body weight, fish consumption amount and frequency, water consumption, etc.). The implications of such modifications are more stringent limits. Larry Walker and Associates provided a comparative table as shown in Appendix B that presents the previous versus the recommended criteria as ambient water quality criteria. The impact varies per compound. Whether the State Water Resources Control Board decides to take action to update the statewide criteria (e.g., California Toxins Rule) to reflect the updated criteria is unclear. Regardless, it is important that any proposed modifications or updates to the WRRF consider such modifications to the rule making. Nutrients The key nutrients of interest for regulatory purposes are typically nitrogen and phosphorus. The concern over nitrogen and phosphorus discharge loadings is based on downstream ecological and aquatic impacts from nutrients. Ammonia is considered a toxin, whereas the other nitrogen species WRRF Project TM No. 8 – Regulatory Compliance Page 16 of 22 (e.g., nitrate) and all phosphorus species promote aquatic growth. The Basin Plan for the Central Coast Water Board contains a narrative objective for biostimulatory substances that states "water shall not contain biostimulatory substances which promote aquatic growths in concentrations that cause nuisance or adversely affect beneficial uses (Central Coast Basin Plan)." To better understand the impact of biostimulatory substances, state and regional water board staffs are working collaboratively with the USEPA. They have developed a draft science-based approach known as the nutrient numeric endpoint (NNE) to translate a water quality objective’s narrative for biostimulatory substances. If the NNE and other on-going studies lead to a statewide nutrient policy, the CCRWQCB shall use the policy results to develop final numeric effluent limitations (nitrogen and phosphorus). In the case that no statewide policy is in place, the CCRWQCB might consider developing their own site specific conceptual model and use the NNE framework to calculate final nitrogen and phosphorus numeric effluent limitations. Besides the on-going NNE framework efforts, it is important to recognize that some water bodies in the Central Coast (CC) Region are already recognized as impaired and thus have or are in the process of implementing total maximum daily loads (TMDLs) for various nitrogen and/or phosphorus species. Larry Walker and Associates provided information that addresses the existing and prospective nutrient limits in Appendix C. The first table in Appendix C provides a complete list of the Central Coast Region TMDLs along with information on the affected water bodies (e.g., limits, load allocations, wasteload allocations, responsible particles, etc.). The second table highlights the waste load allocations (WLAs) of TMDLs which address biostimulatory substance impairments and the corresponding numeric targets. It is apparent from this table that the limits have the potential to get below the municipal target of 10 mg NO3-N/L. The key point from both tables in Appendix C is that there is potential for phosphorus and more stringent nitrogen nutrient limits and upgrades at the WRRF should be implemented with the ability to accommodate future upgrades, as needed, for additional nutrient removal. From a nutrient removal technology standpoint, the WRRF already removes ammonia with little or no total nitrogen or total phosphorus removal. The ammonia limits might become more restrictive as the USEPA is recommending the use of mussels as the indicator organism which is more stringent than the status quo. The order identifies an average monthly nitrate limit that will be addressed with this permit cycle. The technologies selected for nitrate removal (Modified Ludzack-Ettinger with the ability to convert to a High Rate A/B Process) have the flexibility to meet more restrictive limits, such as those values listed in Appendix C. The ability to remove phosphorus can be achieved biologically or with chemical addition. Enhanced biological phosphorus removal (EBPR) can be achieved cost effectively by expanding the aeration basins to provide anaerobic zones upstream of anoxic zones. The WRRF already has in place filters which could be used with chemical addition to remove phosphorus. Disinfection Indicators The USEPA is in the process of developing Ambient Water Quality Criteria to protect human health based on virus quantitation. The USEPA has outlined a schedule for developing virus criteria and indicated that this will be done in the next 1 to 2 years. Details are not available as of today regarding the virus indicator and numeric limits for wastewater dischargers. It is likely that bacteriophage will be adopted as the viral indicator. WRRF Project TM No. 8 – Regulatory Compliance Page 17 of 22 Regardless of which virus indicator type is selected by the USEPA, it is anticipated that the WRRF will be able to meet the updated USEPA limits. The previous and renewed permits both have Fecal and Total Coliform limits that are considerably more stringent than limits seen nationally. Additionally, the WRRF UV disinfection system will be designed to meet unrestricted Title 22 requirements, which will be more stringent than any nationally imposed limits. It is recommended that the WRRF track and monitor the USEPA virus indicator limits, but they are not anticipated to be more difficult to meet than the renewed permit limits. Biosolids Currently the WRRF is producing Class B biosolids that are hauled offsite to a privately owned composting facility and/or landfill. The growing public concern associated with Class B biosolids, increasing stringent future regulations with land application and/or alternative daily cover (ADC) at landfills, as well as the high costs associated with biosolids hauling could potentially lead the City to move towards Class A production in the future. It is recommended that the City consider conversion to Class A biosolids in the future. Air Emissions The implementation of more stringent nutrient limits has the potential to result in adverse environmental impacts, such as an in increase in energy demand, greenhouse gas (GHG) production, land requirements and treatment residuals disposal. For example, the adverse environmental impact on GHG emissions for variable nutrient discharge limits is presented in Figure 5. Figure 5. GHG Emissions Distribution per Treatment Level for a 10 mgd Nominal Plant (Falk et al., 2013) -2,000 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 CO 2 eq u i v a l e n t t o n n e s / y r N2OEmissions (w/Data Range as Bars) Biosolids Hauling and CH4 Emissions DeepWell Injection Aeration ChemicalsPumping/ Mixing Miscellaneous Cogeneration WRRF Project TM No. 8 – Regulatory Compliance Page 18 of 22 The energy demand increases with each treatment level and it is the dominant parameter for GHG emissions. The City needs to understand this relationship and communicate it to the CCRWQCB as the potential limits trend lower over time. WRRF Project TM No. 8 – Regulatory Compliance Page 19 of 22 References Asami, M.; Oya, M.; Kosaka, K. (2009) A nationwide survey of NDMA in raw and drinking water in Japan. Science of The Total Environment, 407(11):3540-3545. Basin Plan, p. III-3.00; Central Coast Region Basin Water Quality Control Plan, p. 3-3. Bott, C. and Parker, D. (2011) WEF/WERF Study Quantifying Nutrient Removal Technology Performance. WERF Research Project under Nutrient Challenge, NUTR1R06h. Choi, J.H. and Valentine, R.L. (2002) Formation of N-nitrosodimethylamine (NDMA) by reaction of monochloramine in a model water: A new disinfection by-product. Wat. Res. 36(4):817–824. Falk, M.W., Reardon, D.J., Neethling, J.B., Clark, D.L., Pramanik, A. (2013) Striking the Balance between Nutrient Removal, Greenhouse Gas Emissions, Receiving Water Quality, and Costs. Wat. Environ. Res., 85(12):2307-2316. Horz, H.-P., Barbrook, A., Field, C.B., Bohannan, B.J.M. (2004) Ammonia-oxidizing bacteria respond to multifactorial global change. Proceedings of the Nat. Acad. Sci., 101(42):15136-15141. Kolpin, D.W., Furlong, E.T., Meyer, M.T., Thurman, E.M.; Zaugg, S.D.; Barber, L.B.; Buxton, H.T. (2002) Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000: a national reconnaissance. Environ. Sci. Technol., 36(6):1202-1211. Mitch, W.A. and Sedlak, D.L. (2002) Formation of Nnitrosodimethylamine (NDMA) from dimethylamine during chlorination. Environ. Sci. Technol. 36: 588–595. Stalter, D.; Magdeburg, A.; Oehlmann, J. (2010) Comparative toxicity assessment of ozone and activated carbon treated sewage effluents using an in vivo test battery. Water Research, 44(8):2610-2620. Vader, J.S., van Ginkel, C.G., Sperling, F., de Jong, J., de Boer, W., de Graaf, J. S., van der Most, M., Stokman, P.G.W. (2000) Degradation of ethinyl estradiol by nitrifying activated sludge. Chemosphere 41(8): 1239-1243. WERF (2010) Nutrient Management: Regulatory Approaches to Protect Water Quality, Volume 1 – Review of Existing Practices, HDR Engineering, Inc., Project #NUTR1R06i. WRRF Project TM No. 8 – Regulatory Compliance Page 20 of 22 Page intentionally blank. WRRF Project TM No. 8 – Regulatory Compliance Appendix A Renewed NPDES Permit CA 0049224 and Time Schedule Order WRRF Project TM No. 8 – Regulatory Compliance Page intentionally blank. ORDER NO. R3-2014-0033 NPDES NO. CA0049224 The following Discharger is subject to waste discharge requirements (WDRs) set forth in this Order: Table 1. Discharger Information Table 2. Discharge Location Table 3. Administrative Information I, Kenneth A. Harris Jr., Executive Officer, do hereby certify that this Order with all attachments is a full, true, and correct copy of an order adopted by the California Regional Water Quality Control Board, Central Coast Region on September 25, 2014. ________________________________________ Kenneth A. Harris Jr., Executive Officer Discharger City of San Luis Obispo Name of Facility Water Resource Recovery Facility Facility Address 35 Prado Road San Luis Obispo, CA 93401 San Luis Obispo County Discharge Point Effluent Description Discharge Point Latitude (North) Discharge Point Longitude (West) Receiving Water 001 Advanced tertiary treated effluent 35º 14ʹ 40ʺ N 120º 40ʹ 45ʺ W San Luis Obispo Creek This Order was adopted on: September 25, 2014 This Order shall become effective on: December 1, 2014 This Order shall expire on: November 30, 2019 The Discharger shall file a Report of Waste Discharge as an application for reissuance of WDRs in accordance with title 23, California Code of Regulations, and an application for reissuance of a National Pollutant Discharge Elimination System (NPDES) permit no later than: June 3, 2019 The U.S. Environmental Protection Agency (U.S. EPA) and the California Regional Water Quality Control Board, Central Coast Region have classified this discharge as follows: Major Discharge CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ORDER 2 Contents I. Facility Information ........................................................................................................................ 3 II. Findings ........................................................................................................................................ 3 III. Discharge Prohibitions .................................................................................................................. 3 IV. Effluent Limitations and Discharge Specifications ......................................................................... 4 A. Effluent Limitations – Discharge Point 001 ............................................................................. 4 1. Final Effluent Limitations – Discharge Point 001 ................................................................ 4 2. Interim Effluent Limitations – Not Applicable ...................................................................... 5 B. Land Discharge Specifications – Not Applicable .................................................................... 5 C. Recycling Specifications ........................................................................................................ 5 V. Receiving Water Limitations .......................................................................................................... 5 A. Surface Water Limitations ...................................................................................................... 5 B. Groundwater Limitations ........................................................................................................ 8 VI. Provisions ..................................................................................................................................... 9 A. Standard Provisions ............................................................................................................... 9 B. Monitoring and Reporting Program (MRP) Requirements ...................................................... 9 C. Special Provisions.................................................................................................................. 9 1. Reopener Provisions ......................................................................................................... 9 2. Special Studies, Technical Reports and Additional Monitoring Requirements .................... 9 3. Best Management Practices and Pollution Prevention ..................................................... 11 4. Construction, Operation and Maintenance Specifications ................................................ 13 5. Special Provisions for Municipal Facilities (POTWs Only) ................................................ 13 6. Other Special Provisions ................................................................................................. 15 7. Compliance Schedules – Not Applicable ......................................................................... 15 VII. Compliance Determination .......................................................................................................... 15 Tables Table 1. Discharger Information ............................................................................................................. 1 Table 2. Discharge Location .................................................................................................................. 1 Table 3. Administrative Information ........................................................................................................ 1 Table 4. Effluent Limitations ................................................................................................................... 4 Table 6. Organic Substances Water Quality Objectives ........................................................................ 7 Table 7. Surface Water Quality Objectives ............................................................................................ 7 Table 8. Groundwater Objectives .......................................................................................................... 8 Table 9. Toxicity Reduction Evaluation Schedule ................................................................................ 10 Attachments Attachment A – Definitions .................................................................................................................. A-1 Attachment B – Map ........................................................................................................................... B-1 Attachment C – Flow Schematic .........................................................................................................C-1 Attachment D – Standard Provisions ..................................................................................................D-1 Attachment E – Monitoring and Reporting Program ............................................................................ E-1 Attachment F – Fact Sheet ................................................................................................................. F-1 CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 LIMITATIONS AND DISCHARGE REQUIREMENTS 3 I. FACILITY INFORMATION Information describing the City of San Luis Obispo Water Reclamation Facility (Facility) is summarized in Table 1 and in sections I and II of the Fact Sheet (Attachment F). Section I of the Fact Sheet also includes information regarding the Facility’s permit application. II. FINDINGS The California Regional Water Quality Control Board, Central Coast Region (Central Coast Water Board) finds: A. Legal Authorities. This Order serves as WDRs pursuant to article 4, chapter 4, division 7 of the California Water Code (commencing with section 13260). This Order is also issued pursuant to section 402 of the federal Clean Water Act (CWA) and implementing regulations adopted by the U.S. EPA and chapter 5.5, division 7 of the Water Code (commencing with section 13370). It shall serve as an NPDES permit for point source discharges from this facility to surface waters. B. Background and Rationale for Requirements. The Central Coast Water Board developed the requirements in this Order based on information submitted as part of the application, through monitoring and reporting programs, and other available information. The Fact Sheet (Attachment F), which contains background information and rationale for the requirements in this Order, is hereby incorporated into and constitutes Findings for this Order. Attachments A through E are also incorporated into this Order. C. Provisions and Requirements Implementing State Law. The provisions/requirements in subsections IV.B, IV.C, V.B, and VI.C are included to implement state law only. These provisions/requirements are not required or authorized under the federal CWA; consequently, violations of these provisions/requirements are not subject to the enforcement remedies that are available for NPDES violations. D. Notification of Interested Parties. The Central Coast Water Board has notified the Discharger and interested agencies and persons of its intent to prescribe WDRs for the discharge and has provided them with an opportunity to submit their written comments and recommendations. Details of the notification are provided in the Fact Sheet. E. Consideration of Public Comment. The Central Coast Water Board, in a public meeting, heard and considered all comments pertaining to the discharge. Details of the public hearing are provided in the Fact Sheet. THEREFORE, IT IS HEREBY ORDERED that this Order supersedes Order No. R3-2002-0043, modified March 25, 2005, except for enforcement purposes, and, in order to meet the provisions contained in division 7 of the Water Code (commencing with section 13000) and regulations adopted thereunder and the provisions of the CWA and regulations and guidelines adopted thereunder, the Discharger shall comply with the requirements in this Order. This action in no way prevents the Central Coast Water Board from taking enforcement action for past violations of the previous Order. III. DISCHARGE PROHIBITIONS A. The discharge of treated wastewater at a location other than 35º 14' 40" N. Latitude, 120º 40' 45" W. Longitude, unless permitted by other waste discharge requirements or NPDES permit, is prohibited. B. Discharge to San Luis Obispo Creek of wastewaters containing bentazon, molinate, or thiobencarb is prohibited. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 LIMITATIONS AND DISCHARGE REQUIREMENTS 4 IV. EFFLUENT LIMITATIONS AND DISCHARGE SPECIFICATIONS A. Effluent Limitations – Discharge Point 001 1. Final Effluent Limitations – Discharge Point 001 a. The Discharger shall maintain compliance with the following effluent limitations at Discharge Point 001, with compliance measured at Monitoring Location EFF-001 as described in the Monitoring and Reporting Program (MRP) Attachment E: Table 4. Effluent Limitations Parameter Units Effluent Limitations Average Monthly Average Weekly Maximum Daily Instantaneous Minimum Instantaneous Maximum Biochemical Oxygen Demand 5-day @ 20°C [1] mg/L 10 30 50 -- -- lbs/day 425 1,275 2,125 -- -- Total Suspended Solids [1] mg/L 10 30 75 -- -- lbs/day 425 1,275 3,190 -- -- Oil and Grease mg/L 5 -- 10 -- -- pH standard units -- -- -- 6.5 8.3 Chlorodibromomethane µg/L 0.40 -- 1.0 -- -- Dichlorobromomethane µg/L 0.56 -- 1.0 -- -- N-Nitrosodimethylamine µg/L 0.00069 -- 0.0014 -- -- Dissolved Oxygen mg/L -- -- -- 4.0 -- Nitrate (as N) mg/L 10 -- -- -- -- Settleable Solids mL/L 0.1 -- -- -- -- Chlorine Residual mg/L -- -- ND [3] -- -- [1] The average monthly percent removal for BOD and TSS shall not be less than 85 percent. [2] When the Discharger continuously monitors effluent pH, levels shall be maintained within specified ranges 99 percent of the time. To determine 99 percent compliance, the following conditions shall be met: • The total time during which pH is outside the range of 6.5 – 8.3 shall not exceed 7 hours and 26 minutes in any calendar month; • No single excursion from the range of 6.5 – 8.3 shall exceed 30 minutes; • No single excursion shall fall outside the range of 6.0 – 9.0; and • When continuous monitoring is not being performed, standard compliance guidelines shall be followed (i.e., between 6.5 – 8.3 at all times, measured daily) [3] ND = less than 0.1 mg/L. Compliance determination for total chlorine residual shall be based on 99 percent compliance. To determine 99 percent compliance, the following conditions shall be met: • The total time during which the total chlorine residual values are above 0.1 mg/L (instantaneous maximum value) shall not exceed 7 hours and 26 minutes in any calendar month; • No single excursion from 0.1 mg/L shall exceed 30 minutes; • No single excursion shall exceed 2 mg/L. • When continuous monitoring is not being performed, standard compliance guidelines shall be followed. b. Toxicity: Discharges at Discharge Point 001, with compliance measured at Monitoring Location EFF-001 as described in the Monitoring and Reporting Program (Attachment E), shall not contain chronic toxicity at a level that would cause or contribute to toxicity in the receiving water. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, or any other relevant measure of the health of an organism population or community. Compliance with this limit shall be determined by analysis of indicator organisms and toxicity tests as described in the MRP. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 LIMITATIONS AND DISCHARGE REQUIREMENTS 5 c. Coliform: i. The fecal colif orm concentrations shall not exceed a median of 2.2 MPN/100 mL as determined from the last 7 days of sampling results for which analyses have been completed; ii. No more than one sample shall exceed 23 MPN/100 mL total coliform in any 30-day period; iii. No sample shall exceed 240 MPN/100 mL total coliform. d. Effluent flow: The average dry weather daily discharge flow shall not exceed 5.1 million gallons per day (MGD). 2. Interim Effluent Limitations – Not Applicable B. Land Discharge Specifications – Not Applicable C. Recycling Specifications The Discharger currently produces and distributes tertiary treated recycled water within the City of San Luis Obispo. Recycled water is regulated under the City’s existing Master Reclamation Permit Order No. R3-2003-081, and therefore no additional specifications are applicable under this permit. V. RECEIVING WATER LIMITATIONS A. Surface Water Limitations Receiving water limitations are based on water quality objectives contained in the Basin Plan, are consistent with the State Implementation Policy, and are a required part of this Order. The discharge shall not cause a violation of the following receiving water limitations in San Luis Obispo Creek. The Central Coast Water Board may require the Discharger to investigate the cause of exceedance(s) in the receiving water to determine whether the Discharger caused any water condition that exceeds the following receiving water limitations. 1. Waters shall be free of coloration that causes nuisance or adversely affects beneficial uses. Coloration attributable to materials of waste origin shall not be greater than 15 units or 10 percent above natural background color, whichever is greater. 2. Waters shall not contain taste or odor-producing substances in concentrations that impart undesirable tastes or odors to fish flesh or other edible products of aquatic origin, that cause nuisance, or that adversely affect beneficial uses. 3. Waters shall not contain floating material, including solids, liquids, foams, and scum, in concentrations that cause nuisance or adversely affect beneficial uses. 4. Waters shall not contain suspended material in concentrations that cause nuisance or adversely affect beneficial uses. 5. Waters shall not contain settleable material in concentrations that result in deposition of material that causes nuisance or adversely affects beneficial uses. 6. Waters shall not contain oils, greases, waxes, or other similar materials in concentrations that result in a visible film or coating on the surface of the water or on objects in the water, that cause nuisance, or that otherwise adversely affect beneficial uses. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 LIMITATIONS AND DISCHARGE REQUIREMENTS 6 7. Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. 8. The suspended sediment load and suspended sediment discharge rate to surface waters shall not be altered in such a manner as to cause nuisance or adversely affect beneficial uses. 9. Concentrations of toxic metals and inorganic chemicals in waters shall not be increased in such a manner that may adversely affect beneficial uses. 10. Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Increase in turbidity attributable to controllable water quality factors shall not exceed the following limits: a. Where natural turbidity is between 0 and 50 Natural Turbidity Units (NTUs), increases shall not exceed 20 percent. b. Where natural turbidity is between 50 and 100 NTUs, increases shall not exceed 10 NTU. c. Where natural turbidity is greater than 100 NTUs, increases shall not exceed 10 percent. d. Turbidity to exceed 5 NTU when the Creek contains no natural flow. 11. The pH value shall not be depressed below 7.0 nor raised above 8.3. The change in normal ambient pH levels shall not exceed 0.5 units. 12. Dissolved oxygen concentrations in receiving waters shall not be reduced below 7.0 mg/L at any time. 13. Effluent discharged shall not cause the receiving water temperature to increase more than 5° F above receiving water temperature. If, due to the Creek’s low temperature as determined by early-morning monitoring, the discharge causes the Creek’s temperature increase to exceed the limit, the Discharger must ensure the discharge shall not cause the receiving water to exceed 72.5° F (22.5° C). The Discharger shall monitor the Creek again four hours after discovering the exceedance and shall report both results to the Executive Officer in the monthly self-monitoring report. 14. Waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Survival of aquatic life in surface waters subjected to a waste discharge or other controllable water quality conditions shall not be less than that for the same water body in areas unaffected by the waste discharge. 15. The discharge of wastes shall not cause concentrations of un-ionized ammonia (NH3) to exceed 0.025 mg/L (as N) in the receiving water. 16. No individual pesticide or combination of pesticides shall reach concentrations that adversely affect the beneficial uses of the receiving water. There shall be no increase in pesticide concentrations found in bottom sediments or aquatic life. For waters where existing concentrations are presently nondetectable or where beneficial uses would be impaired by concentrations in excess of nondetectable levels, total identifiable chlorinated hydrocarbon pesticides shall not be present at concentrations detectable within the accuracy of analytical methods as prescribed in Standard Methods for the Examination of Water and Wastewater, latest edition, or other equivalent methods approved by the Executive Officer. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 LIMITATIONS AND DISCHARGE REQUIREMENTS 7 17. Waters shall not contain organic substances in concentrations greater than the following: Table 6. Organic Substances Water Quality Objectives Parameter Water Quality Objective Methylene Blue Activated Substances 0.2 mg/L Phenols 1.0 µg/L PCBs [1] 0.3 µg/L Phthalate Esters 0.002 µg/L [1] PCBs refer to the sum of PCB 1016, 1221, 1232, 1242, 1248, 1254, and 1260. 18. Radionuclides shall not be present in concentrations that are deleterious to human, plant, animal, or aquatic life or that result in the accumulation of radionuclides in the food web to an extent that presents a hazard to human, plant, animal, or aquatic life. In no circumstance shall receiving waters contain concentrations of radionuclides in excess of the maximum contaminant levels (MCLs) for radioactivity presented in Table 4 of Title 22 California Code of Regulations, Division 4, Chapter 15, Article 5. 19. Receiving waters shall not contain concentrations of chemical constituents in excess of the primary MCLs specified for drinking water in Table 64431-A (Primary MCLs for Inorganic Chemicals) and Table 64444-A (Primary MCLs for Organic Chemicals) of Title 22 California Code of Regulations, Division 4, Chapter 15. 20. Receiving waters shall not contain concentrations of chemical constituents in amounts that adversely affect the agricultural beneficial use. Interpretation of adverse effects shall be derived from guidelines of the University of California Agricultural Extension Service guidelines presented in Section III, Table 3-3 of the Basin Plan. 21. Receiving waters shall not contain concentrations of chemical constituents in excess of those levels specified for irrigation and livestock watering in Section III, Table 3-4 of the Basin Plan. Salt concentrations for irrigation waters shall be controlled through implementation of the anti-degradation policy to the effect that mineral constituents of currently or potentially usable waters shall not be increased. 22. Receiving waters shall not contain concentrations of chemical constituents known to be deleterious to fish or wildlife in excess of the levels presented in Section III, Table 3- 5 of the Basin Plan. 23. Fecal coliform concentration, based on a minimum of not fewer than five samples for any 30-day period, shall not exceed a log mean of 200 organisms/100 mL, nor shall more than 10 percent of samples collected during any 30-day period exceed 400 organisms/100 mL. 24. Discharges shall not cause receiving water to exceed the following water quality objectives specifically identified for the San Luis Obispo Creek sub-area (Estero Bay sub- basin) by Table 3-7 of the Basin Plan, shown below in Table 7. Table 7. Surface Water Quality Objectives Constituent Annual Running Mean(1), mg/L Total Dissolved Solids 650 Chloride 100 Sulfate 100 Boron 0.2 Sodium 50 CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 LIMITATIONS AND DISCHARGE REQUIREMENTS 8 (1) Compliance shall be measured by comparison to an annual running mean of the past four quarterly sampling events. B. Groundwater Limitations Activities at the Facility shall not cause exceedance/deviation from the following water quality objectives for groundwater established by the Basin Plan. The Central Coast Water Board may require the Discharger to investigate the cause of exceedances in the groundwater before determining whether the Discharger caused any water condition that exceeds the following groundwater limitations. 1. Groundwater shall not contain taste- or odor-producing substances in concentrations that adversely affect beneficial uses. 2. The Discharger shall not cause a statistically significant increase of mineral constituent concentrations in underlying groundwaters as determined by comparison of samples collected from wells located up-gradient and down-gradient of the waters affected by the discharge. 3. Radionuclides shall not be present in concentrations that are deleterious to human, plant, animal, or aquatic life or that result in the accumulation of radionuclides in the food web to an extent that presents a hazard to human, plant, animal, or aquatic life. In no circumstances shall groundwater contain concentrations of radionuclides in excess of the MCLs for radioactivity presented in Table 4 of Title 22 California Code of Regulations, Division 4, Chapter 15, Article 5. 4. The median concentration of coliform organisms in groundwater, over any seven-day period, shall be less than 2.2 organisms/100 mL. 5. Groundwater shall not contain concentrations of chemical constituents in excess of the primary MCLs specified for drinking water in Table 64431-A (Primary MCLs for Inorganic Chemicals) and Table 64444-A (Primary MCLs for Organic Chemicals) of Title 22 California Code of Regulations, Division 4, Chapter 15. 6. Groundwater shall not contain concentrations of chemical constituents in amounts that adversely affect the agricultural supply beneficial use. Interpretation of adverse effects shall be as described in University of California Agricultural Extension Service guidelines provided in Table 3-3 of the Basin Plan. 7. Groundwater used for irrigation and livestock watering shall not exceed concentrations of chemical constituents in excess of those levels specified for irrigation and livestock watering in Section III, Table 3-4 of the Basin Plan. 8. Groundwater shall not contain pollutants at concentrations greater than the following established in Table 3-8 of the Basin Plan for groundwaters within the San Luis Obispo Creek sub-area (Estero Bay sub-basin). Table 8. Groundwater Objectives Constituent Median[1], mg/L Total Dissolved Solids 900 Chloride 200 Sulfate 100 Boron 0.2 Sodium 50 Nitrogen (as N) 5 [1] Objectives shown are median values based on data averages; objectives are based on preservation of existing water quality enhancement believed attainable following control of point sources. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 LIMITATIONS AND DISCHARGE REQUIREMENTS 9 VI. PROVISIONS A. Standard Provisions 1. The Discharger shall comply with all Standard Provisions included in Attachment D of this Order. 2. The Discharger shall comply with the following provision: a. Before changing the point of discharge, place of use, or purpose of use of treated wastewater that results in a decrease of flow in any portion of an inland watercourse, in any way, the Discharger shall file a petition with the State Water Resources Control Board (State Water Board), Division of Water Rights, and receive approval for such a change. (Water Code section 1211.) B. Monitoring and Reporting Program (MRP) Requirements Pursuant to CWC sections 13267 and 13383, the Discharger shall comply with the Monitoring and Reporting Program (MRP), and future revisions thereto, in Attachment E of this Order, and all notification and general reporting requirements throughout this Order and Attachment D. Where notification or general reporting requirements conflict with those stated in the MRP (e.g., annual report due date), the Discharger shall comply with the MRP requirements. All monitoring shall be conducted according to 40 C.F.R. part 136, Guidelines Establishing Test Procedures for Analysis of Pollutants. The Discharger is required to provide these technical or monitoring reports because it is the owner and operator responsible for the waste discharge and compliance with this Order. The Central Coast Water Board needs the information to determine the Discharger’s compliance with this Order, assess the need for further investigation and/or enforcement action, and to protect public health and safety and the environment. C. Special Provisions 1. Reopener Provisions This permit may be reopened and modified in accordance with NPDES regulations at 40 C.F.R. parts 122 and 124, as necessary, to include additional conditions or limitations based on newly available information or to implement any USEPA approved, new, State WQO. 2. Special Studies, Technical Reports and Additional Monitoring Requirements a. Toxicity Reduction Requirements As indicated in section V.D of the MRP, when acute toxicity is detected in the effluent or chronic toxicity is detected greater than a chronic toxicity trigger of 1 TUc, and the discharge is continuing, the Discharger shall resample immediately, retest, and report the results to the Executive Officer, who will determine whether to initiate an enforcement action, require a Toxicity Reduction Evaluation (TRE) in accordance with the Discharger’s TRE Workplan, or implement other measures. A TRE is a study conducted in a step-wise process designed to identify the causative agents of effluent or ambient toxicity, isolate the sources of toxicity, evaluate the effectiveness of toxicity control options, and then confirm the reduction in toxicity. The first steps of the TRE consist of the collection of data relevant to the toxicity, including additional toxicity testing, an evaluation of facility operations and maintenance practices, and best management practices. A Toxicity Identification Evaluation (TIE) may be required as part of the TRE, if appropriate. A CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 LIMITATIONS AND DISCHARGE REQUIREMENTS 10 TIE is a set of procedures to identify the specific chemical(s) responsible for toxicity. These procedures are performed in three phases - characterization, identification, and confirmation using aquatic organism toxicity tests. The TRE shall include all reasonable steps to identify the source of toxicity. The Discharger shall take all reasonable steps to reduce toxicity to the required level once the source of toxicity is identified. The Discharger shall maintain a TRE Workplan, which describes steps that the Discharger intends to follow in the event that a toxicity effluent limitation or toxicity trigger established by this Order is exceeded in the discharge. The workplan shall be prepared in accordance with current technical guidance and reference material, including EPA/600/2-88/062, and shall include, at a minimum: i. Actions that will be taken to investigate/identify the causes/sources of toxicity; ii. Actions that will be evaluated to mitigate the impact of the discharge, to correct the noncompliance, and/or to prevent the recurrence of acute or chronic toxicity (this list of action steps may be expanded, if a TRE is undertaken); and iii. A schedule under which these actions will be implemented. When monitoring measures toxicity in the effluent above a limitation or toxicity trigger established by this Order, if the discharge is continuing, the Discharger shall resample immediately, and retest for acute or chronic toxicity. Results of an initial failed test and results of subsequent monitoring shall be reported to the Executive Officer as soon as possible following receipt of monitoring results. The Executive Officer will determine whether to initiate enforcement action, whether to require the Discharger to implement a TRE, or to implement other measures. When the Executive Officer requires the Discharger to conduct a TRE, the TRE shall be conducted giving due consideration to guidance provided by the USEPA’s Toxicity Reduction Evaluation Procedures, Phases 1, 2, and 3 (USEPA document Nos. EPA 600/R-91/003, 600/R-92/080, and 600/R-92/081, respectively). A TRE, if necessary, shall be conducted in accordance with the following schedule. Table 9. Toxicity Reduction Evaluation Schedule Action Step When Required Take all reasonable measures necessary to immediately reduce toxicity, where the source is known. Within 24 hours of identification of noncompliance. Submit to the Executive Officer a TRE study plan describing the toxicity reduction procedures to be employed Within 60 days of identification of noncompliance. Initiate the TRE in accordance with the Workplan Within 7 days of notification by the Executive Officer. Conduct the TRE following the procedures in the Workplan. Within the period specified in the Workplan (not to exceed one year, without an approved Workplan). Submit the results of the TRE, including summary of findings, required corrective action, and all results and data. Within 60 days of the completion of the TRE. Implement corrective actions to meet Permit limits and conditions. To be determined by the Executive Officer. Return to regular monitoring after implementing corrective measures and approval by the Executive Officer. To be determined by the Executive Officer. b. Facilities Evaluation CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 LIMITATIONS AND DISCHARGE REQUIREMENTS 11 Based on Discharger reports, the Facility is operating at 88% of its design capacity for flow. Based on that data, it appears that the monthly average daily flow will or may reach design capacity during the term of this permit. Pursuant to Central Coast Standard Provisions, the Discharger shall evaluate the need for future expansion of the Facility to accommodate future growth within the City of San Luis Obispo. The evaluation shall quantify future flows to the plant from indirect dischargers, California State Polytechnic University and San Luis Obispo County Airport, and future annexations to the City of San Luis Obispo. This evaluation shall be completed as part of the Facilities Plan during the term of this permit and submitted to the Central Coast Water Board. c. Effluent pH Evaluation The Discharger shall complete an Effluent pH Evaluation by February 1, 2016 to assess opportunities for effluent pH adjustments consistent with more stringent Basin Plan water quality objectives for receiving water (i.e., 7.0-8.3 standard units), impact on receiving water and environment, cost to pH adjust, and expected frequency and duration that effluent pH would drop below 7.0 s.u. under current operations. Central Coast Water Board staff will review the data to consider whether a more stringent pH effluent limit would indeed be more protective of water quality objectives, or if existing pH effluent limits are adequately protective of receiving water quality objectives. 3. Best Management Practices and Pollution Prevention a. Salt and Nutrient Management Program i. The Discharger shall develop and implement an ongoing Salts Management Program dedicated to minimizing the discharge of salts to and attainment of applicable WQOs for salts in San Luis Obispo Creek sub-basin of the Estero Bay Drainage Basin. Additionally, the Discharger shall develop and implement a Nutrient Management Program, with the intent of reducing mass loading of nutrients in treated effluent and attainment of applicable WQOs for nutrients in the same basin. ii. Salt reduction measures shall focus on all potential salt contributors to the collection system, including water supply, commercial, industrial, and residential dischargers. iii. Nutrient reduction measures shall focus on optimizing wastewater treatment processes for nitrification and denitrification, or other means of nitrogen removal. Reduction measures may also include source control (non-human waste from commercial and industrial sources) as appropriate. iv. As part of the salts and nutrients management program, the Discharger shall submit an annual report of salts and nutrients reduction efforts. This salts and nutrients management report shall be included as part of the annual report described in the MRP (Attachment E). The report shall be submitted by February 15, and shall include, as appropriate: (a) Salt Component (1) Calculations of annual salt mass discharged to (influent) and from (effluent) the wastewater treatment or recycling facility with a description of contributing sources; CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 LIMITATIONS AND DISCHARGE REQUIREMENTS 12 (2) Analysis of wastewater evaporation/salt concentration effects; (3) Analysis of groundwater monitoring results for salts constituents and associated trends; (4) Analysis of potential impacts of salt loading on the groundwater basin (focusing on the relationship between salt concentration in the discharge and the Basin Plan water quality objectives); (5) A summary of existing salt reduction measures; and (6) Recommendations and time schedules for implementation of any additional salt reduction measures; (b) Nutrient Component (1) Calculations of annual nitrogen mass (for all identified species) discharged to (influent) and from (effluent) the wastewater treatment or recycling facility with a description of contributing sources; (2) Analysis of wastewater treatment facility ability to facilitate nitrification and denitrification, or other means of nitrogen removal; (3) Analysis of groundwater monitoring results for nitrogen constituents and trends; (4) Analysis of potential impacts of nitrogen loading on the groundwater basin (focusing on the relationship between salt concentration in the discharge and the Basin Plan water quality objectives); (5) A summary of existing nitrogen loading reduction measures; and (6) Recommendations and time schedules for implementation of any additional nitrogen loading reduction measures. v. As an alternative to the Salt and Nutrient Management Program requirements described above, upon Executive Officer approval, the Discharger may submit documentation and summary of participation in a regional salts and nutrients management plan implemented under the provisions of State Water Board Resolution No. 2009-0011 (Recycled Water Policy). b. Pollutant Minimization Program The Discharger shall develop and conduct a Pollutant Minimization Program (PMP) as further described below when there is evidence (e.g., sample results reported as DNQ when the effluent limitation is less than the MDL, sample results from analytical methods more sensitive than those methods required by this Order, presence of whole effluent toxicity, health advisories for fish consumption, results of benthic or aquatic organism tissue sampling) that a priority pollutant is present in the effluent above an effluent limitation and either: i. A sample result is reported as DNQ and the effluent limitation is less than the RL; or ii. A sample result is reported as ND and the effluent limitation is less than the MDL, using definitions described in Attachment A and reporting protocols described in MRP section X.B.4. The PMP shall include, but not be limited to, the following actions and submittals acceptable to the Central Coast Water Board: CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 LIMITATIONS AND DISCHARGE REQUIREMENTS 13 iii. An annual review and semi-annual monitoring of potential sources of the reportable priority pollutant(s), which may include fish tissue monitoring and other bio-uptake sampling; iv. Quarterly monitoring for the reportable priority pollutant(s) in the influent to the wastewater treatment system; v. Submittal of a control strategy designed to proceed toward the goal of maintaining concentrations of the reportable priority pollutant(s) in the effluent at or below the effluent limitation; vi. Implementation of appropriate cost-effective control measures for the reportable priority pollutant(s), consistent with the control strategy; and vii. An annual status report that shall be sent to the Central Coast Water Board including: (a) All PMP monitoring results for the previous year; (b) A list of potential sources of the reportable priority pollutant(s); (c) A summary of all actions undertaken pursuant to the control strategy; and (d) A description of actions to be taken in the following year. 4. Construction, Operation and Maintenance Specifications The Facility shall be operated as specified under Standard Provision I.A.4 of Attachment D. 5. Special Provisions for Municipal Facilities (POTWs Only) a. Biosolids Management i. The handling, treatment, use, management, and disposal of sludge and solids derived from wastewater treatment must comply with applicable provisions of CWA Section 405 and USEPA regulations at 40 C.F.R. p arts 257, 258, 501, and 503, including all monitoring, record keeping, and reporting requirements. ii. Sludge and wastewater solids must be disposed of in a municipal solid waste landfill, reused by land application, or disposed of in a sludge-only landfill in accordance with 40 C.F.R. parts 258 and 503 and Title 23, Chapter 15 of the CCR. If the Discharger desires to dispose of solids and/or sludge in a different manner, a request for permit modification must be submitted to the USEPA and to the Central Coast Water Board at least 180 days prior to beginning the alternative means of disposal. iii. Sludge that is disposed of in a municipal solid waste landfill must meet the requirements of 40 C.F.R. part 258 pertaining to providing information to the public. In the annual self-monitoring report, the Discharger shall include the amount of sludge placed in the landfill as well as the landfill to which it was sent. iv. All requirements of 40 C.F.R. part 503 and 23 CCR Chapter 15 are enforceable whether or not the requirements of those regulations are stated in an NPDES permit or any other permit issued to the Discharger. v. The Discharger shall take all reasonable steps to prevent and minimize any sludge use or disposal in violation of this Order that has a likelihood of adversely affecting human health or the environment. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 LIMITATIONS AND DISCHARGE REQUIREMENTS 14 vi. Solids and sludge treatment, storage, and disposal or reuse shall not create a nuisance, such as objectionable odors or flies, and shall not result in groundwater contamination. vii. The solids and sludge treatment and storage site shall have adequate facilities to divert surface water runoff from adjacent areas to protect the boundaries of the site from erosion, and to prevent drainage from the treatment and storage site. Adequate protection is defined as protection, at the minimum, from a 100-year storm and protection from the highest possible tidal stage that may occur. viii. The discharge of sewage sludge and solids shall not cause waste material to be in position where it is, or can be, conveyed from the treatment and storage sites and deposited in waters of the State. ix. The Discharger shall submit an annual report to the USEPA and the Central Coast Water Board containing monitoring results and pathogen and vector attraction reduction requirements, as specified by 40 C.F.R. part 503. The Discharger shall also report the quantity of sludge removed from the Facility and the disposal method. This self-monitoring report shall be postmarked by February 19th of each year and report for the period of the previous calendar year. b. Pretreatment The Discharger shall be responsible for the performance of all pretreatment requirements contained in 40 C.F.R. and shall be subject to enforcement actions, penalties, fines, and other remedies by the USEPA, or other appropriate parties, as provided in the CWA, as amended (33 USA 1351 et seq.). The Discharger shall implement and enforce its Approved Publicly Owned Treatment Works (POWT) Pretreatment Program. Implementation of the Discharger’s Approved POTW Pretreatment Program is hereby made an enforceable condition of this permit. USEPA may initiate enforcement action against an industrial user for non- compliance with applicable standards and requirements as provided in the CWA. The Discharger shall enforce the requirements promulgated under Sections 307 (b), (c), & (d) and 402 (b) of the CWA. The Discharger shall cause industrial users subject to Federal Categorical Standards to achieve compliance no later than the date specified in those requirements, or, in the case of a new industrial user, upon commencement of the discharge. The Discharger shall perform the pretreatment functions as required in 40 C.F.R. 403, including, but not limited to: i. Implement necessary legal authorities as provided in 40 C.F.R 403.8 (f)(1); ii. Enforcement of pretreatment requirements under 40 C.F.R. 403.5 and 403.6; iii. Implement the programmatic functions as provided in 40 C.F.R. 403.8 (f)(2); and iv. Provide the requisite funding and personnel to implement the pretreatment program as provided in 40 C.F.R. 403.8 (f)(3). The Discharger shall submit annually a report to the USEPA – Region 9, the Central Coast Water Board, and the State Water Board describing the Discharger’s pretreatment activities over the previous twelve months. If the Discharger violates this Order’s pretreatment conditions or requirements, it shall also include reasons CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 LIMITATIONS AND DISCHARGE REQUIREMENTS 15 for noncompliance, and a statement how and when it shall comply. This annual report is due by February 1st of each year and shall contain, but not be limited to, the contents described in the “Pretreatment Reporting Requirements” contained in the Monitoring and Reporting Program (Attachment E). The Discharger shall comply, and ensure affected “indirect dischargers” comply with Paragraph II.D.1 of the “Standard Provisions and Reporting Requirements.” 6. Other Special Provisions a. Discharges of Storm Water. For the control of storm water discharged from the site of the wastewater treatment and disposal facilities, if applicable, the Discharger shall seek authorization to discharge under and meet the requirements of the State Water Board’s Water Quality Order 97-03-DWQ, NPDES General Permit No. CAS0000001, Waste Discharge Requirements for Discharges of Storm Water Associated with Industrial Activities Excluding Construction Activities. b. Statewide General Waste Discharge Requirements for Sanitary Sewer Systems (State Water Board Order 2006-0003-DWQ). This General Permit, adopted on May 2, 2006, is applicable to all “federal and State agencies, municipalities, counties, districts, and other public entities that own or operate sanitary sewer systems greater than one mile in length that collect and/or convey untreated or partially treated wastewater to a publically owned treatment facility in the State of California.” The purpose of the General Permit is to promote the proper and efficient management, operation, and maintenance of sanitary sewer systems and to minimize the occurrences and impacts of sanitary sewer overflows. The Discharger has obtained coverage under the General Permit. 7. Compliance Schedules – Not Applicable VII. COMPLIANCE DETERMINATION Compliance with the effluent limitations contained in Section IV of this Order will be determined as specified below: A. General. Compliance with effluent limitations for reportable pollutants shall be determined using sample reporting protocols defined in the MRP and Attachment A of this Order. For purposes of reporting and administrative enforcement by the Central Coast Water Board and State Water Boards, the Discharger shall be deemed out of compliance with effluent limitations if the concentration of the reportable pollutant in the monitoring sample is greater than the effluent limitation and greater than or equal to the reported Minimum Level (ML). B. Multiple Sample Data. When determining compliance with an average monthly effluent limit and more than one sample result is available in a month, the Discharger shall compute the arithmetic mean unless the data set contains one or more reported determinations “Detected, but Not Quantified” (DNQ) or “Not Detected” (ND). In those cases, the Discharger shall compute the median in place of the arithmetic mean in accordance with the following procedure: 1. The data set shall be ranked from low to high, ranking the reported ND determinations lowest, DNQ-determinations next, followed by quantified values (if any). The order of the individual ND or DNQ determinations is unimportant. 2. The median value of the data set shall be determined. If the data set has an odd number of data points, then the median is the middle value. If the data set has an even number CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 LIMITATIONS AND DISCHARGE REQUIREMENTS 16 of data points, then the median is the average of the two values around the middle unless one or both of the points are ND or DNQ, in which case the median value shall be the lower of the two data points where DNQ is lower than a value and ND is lower than DNQ. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT A – DEFINITIONS A-1 A. ATTACHMENT A – DEFINITIONS Arithmetic Mean (µ) Also called the average, is the sum of measured values divided by the number of samples. For ambient water concentrations, the arithmetic mean is calculated as follows: Arithmetic mean = µ = Σx / n where: Σx is the sum of the measured ambient water concentrations, and n is the number of samples. Average Monthly Effluent Limitation (AMEL) The highest allowable average of daily discharges over a calendar month, calculated as the sum of all daily discharges measured during a calendar month divided by the number of daily discharges measured during that month. Average Weekly Effluent Limitation (AWEL) The highest allowable average of daily discharges over a calendar week (Sunday through Saturday), calculated as the sum of all daily discharges measured during a calendar week divided by the number of daily discharges measured during that week. Bioaccumulative Those substances taken up by an organism from its surrounding medium through gill membranes, epithelial tissue, or from food and subsequently concentrated and retained in the body of the organism. Carcinogenic Pollutants are substances that are known to cause cancer in living organisms. Coefficient of Variation (CV) CV is a measure of the data variability and is calculated as the estimated standard deviation divided by the arithmetic mean of the observed values. Daily Discharge Daily Discharge is defined as either: (1) the total mass of the constituent discharged over the calendar day (12:00 am through 11:59 pm) or any 24-hour period that reasonably represents a calendar day for purposes of sampling (as specified in the permit), for a constituent with limitations expressed in units of mass or; (2) the unweighted arithmetic mean measurement of the constituent over the day for a constituent with limitations expressed in other units of measurement (e.g., concentration). The daily discharge may be determined by the analytical results of a composite sample taken over the course of one day (a calendar day or other 24-hour period defined as a day) or by the arithmetic mean of analytical results from one or more grab samples taken over the course of the day. For composite sampling, if 1 day is defined as a 24-hour period other than a calendar day, the analytical result for the 24-hour period will be considered as the result for the calendar day in which the 24-hour period ends. Detected, but Not Quantified (DNQ) DNQ are those sample results less than the RL, but greater than or equal to the laboratory’s MDL. Sample results reported as DNQ are estimated concentrations. Dilution Credit Dilution Credit is the amount of dilution granted to a discharge in the calculation of a water quality- based effluent limitation, based on the allowance of a specified mixing zone. It is calculated from the CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT A – DEFINITIONS A-2 dilution ratio or determined through conducting a mixing zone study or modeling of the discharge and receiving water. Effluent Concentration Allowance (ECA) ECA is a value derived from the water quality criterion/objective, dilution credit, and ambient background concentration that is used, in conjunction with the coefficient of variation for the effluent monitoring data, to calculate a long-term average (LTA) discharge concentration. The ECA has the same meaning as waste load allocation (WLA) as used in U.S. EPA guidance (Technical Support Document For Water Quality-based Toxics Control, March 1991, second printing, EPA/505/2-90-001). Enclosed Bays Enclosed Bays means indentations along the coast that enclose an area of oceanic water within distinct headlands or harbor works. Enclosed bays include all bays where the narrowest distance between the headlands or outermost harbor works is less than 75 percent of the greatest dimension of the enclosed portion of the bay. Enclosed bays include, but are not limited to, Humboldt Bay, Bodega Harbor, Tomales Bay, Drake’s Estero, San Francisco Bay, Morro Bay, Los Angeles-Long Beach Harbor, Upper and Lower Newport Bay, Mission Bay, and San Diego Bay. Enclosed bays do not include inland surface waters or ocean waters. Estimated Chemical Concentration The estimated chemical concentration that results from the confirmed detection of the substance by the analytical method below the ML value. Estuaries Estuaries means waters, including coastal lagoons, located at the mouths of streams that serve as areas of mixing for fresh and ocean waters. Coastal lagoons and mouths of streams that are temporarily separated from the ocean by sandbars shall be considered estuaries. Estuarine waters shall be considered to extend from a bay or the open ocean to a point upstream where there is no significant mixing of fresh water and seawater. Estuarine waters included, but are not limited to, the Sacramento-San Joaquin Delta, as defined in Water Code section 12220, Suisun Bay, Carquinez Strait downstream to the Carquinez Bridge, and appropriate areas of the Smith, Mad, Eel, Noyo, Russian, Klamath, San Diego, and Otay rivers. Estuaries do not include inland surface waters or ocean waters. Inland Surface Waters All surface waters of the state that do not include the ocean, enclosed bays, or estuaries. Instantaneous Maximum Effluent Limitation The highest allowable value for any single grab sample or aliquot (i.e., each grab sample or aliquot is independently compared to the instantaneous maximum limitation). Instantaneous Minimum Effluent Limitation The lowest allowable value for any single grab sample or aliquot (i.e., each grab sample or aliquot is independently compared to the instantaneous minimum limitation). Maximum Daily Effluent Limitation (MDEL) The highest allowable daily discharge of a pollutant, over a calendar day (or 24-hour period). For pollutants with limitations expressed in units of mass, the daily discharge is calculated as the total mass of the pollutant discharged over the day. For pollutants with limitations expressed in other units of measurement, the daily discharge is calculated as the arithmetic mean measurement of the pollutant over the day. Median CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT A – DEFINITIONS A-3 The middle measurement in a set of data. The median of a set of data is found by first arranging the measurements in order of magnitude (either increasing or decreasing order). If the number of measurements (n) is odd, then the median = X(n+1)/2. If n is even, then the median = (Xn/2 + X(n/2)+1)/2 (i.e., the midpoint between the n/2 and n/2+1). Method Detection Limit (MDL) MDL is the minimum concentration of a substance that can be measured and reported with 99 percent confidence that the analyte concentration is greater than zero, as defined in in 40 C.F.R. part 136, Attachment B, revised as of July 3, 1999. Minimum Level (ML) ML is the concentration at which the entire analytical system must give a recognizable signal and acceptable calibration point. The ML is the concentration in a sample that is equivalent to the concentration of the lowest calibration standard analyzed by a specific analytical procedure, assuming that all the method specified sample weights, volumes, and processing steps have been followed. Mixing Zone Mixing Zone is a limited volume of receiving water that is allocated for mixing with a wastewater discharge where water quality criteria can be exceeded without causing adverse effects to the overall water body. Not Detected (ND) Sample results which are less than the laboratory’s MDL. Persistent Pollutants Persistent pollutants are substances for which degradation or decomposition in the environment is nonexistent or very slow. Pollutant Minimization Program (PMP) PMP means waste minimization and pollution prevention actions that include, but are not limited to, product substitution, waste stream recycling, alternative waste management methods, and education of the public and businesses. The goal of the PMP shall be to reduce all potential sources of a priority pollutant(s) through pollutant minimization (control) strategies, including pollution prevention measures as appropriate, to maintain the effluent concentration at or below the water quality-based effluent limitation. Pollution prevention measures may be particularly appropriate for persistent bioaccumulative priority pollutants where there is evidence that beneficial uses are being impacted. The Central Coast Water Board may consider cost effectiveness when establishing the requirements of a PMP. The completion and implementation of a Pollution Prevention Plan, if required pursuant to Water Code section 13263.3(d), shall be considered to fulfill the PMP requirements. Pollution Prevention Pollution Prevention means any action that causes a net reduction in the use or generation of a hazardous substance or other pollutant that is discharged into water and includes, but is not limited to, input change, operational improvement, production process change, and product reformulation (as defined in Water Code section 13263.3). Pollution prevention does not include actions that merely shift a pollutant in wastewater from one environmental medium to another environmental medium, unless clear environmental benefits of such an approach are identified to the satisfaction of the State Water Board or Central Coast Water Board. Reporting Level (RL) The RL is the ML (and it s associated analytical method) chosen by the Discharger for reporting and compliance determination from the MLs included in this Order, including an additional factor if CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT A – DEFINITIONS A-4 applicable as discussed herein. The MLs included in this Order correspond to approved analytical methods for reporting a sample result that are selected by the Central Coast Water Board either from Appendix 4 of the SIP in accordance with section 2.4.2 of the SIP or established in accordance with section 2.4.3 of the SIP. The ML is based on the proper application of method-based analytical procedures for sample preparation and the absence of any matrix interferences. Other factors may be applied to the ML depending on the specific sample preparation steps employed. For example, the treatment typically applied in cases where there are matrix-effects is to dilute the sample or sample aliquot by a factor of ten. In such cases, this additional factor must be applied to the ML in the computation of the RL. Source of Drinking Water Any water designated as municipal or domestic supply (MUN) in the Central Coast Water Board Basin Plan. Standard Deviation (σ) Standard Deviation is a measure of variability that is calculated as follows: σ = (∑[(x - µ)2]/(n – 1))0.5 where: x is the observed value; µ is the arithmetic mean of the observed values; and n is the number of samples. Toxicity Reduction Evaluation (TRE) TRE is a study conducted in a step-wise process designed to identify the causative agents of effluent or ambient toxicity, isolate the sources of toxicity, evaluate the effectiveness of toxicity control options, and then confirm the reduction in toxicity. The first steps of the TRE consist of the collection of data relevant to the toxicity, including additional toxicity testing, and an evaluation of facility operations and maintenance practices, and best management practices. A Toxicity Identification Evaluation (TIE) may be required as part of the TRE, if appropriate. (A TIE is a set of procedures to identify the specific chemical(s) responsible for toxicity. These procedures are performed in three phases (characterization, identification, and confirmation) using aquatic organism toxicity tests.) CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT B –MAP B-1 B. ATTACHMENT B – MAP Drawing Reference: SAN LUIS OBISPO (CA) U.S.G.S TOPOGRAPHIC MAP 7.5 MINUTE QUADRANGLE Date: 1981 SITE LOCATION MAP CITY OF SAN LUIS OBISPO WATER RECLAMATION FACILITY SAN LUIS OBISPO COUNTY Facility Location CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT C – WASTEWATER FLOW SCHEMATIC C-1 C. ATTACHMENT C – FLOW SCHEMATIC CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-1 D. ATTACHMENT D – STANDARD PROVISIONS I. FEDERAL STANDARD PROVISIONS – PERMIT COMPLIANCE A. Federal Standard Provisions – Permit Compliance 1. Duty to Comply a. The Discharger must comply with all of the conditions of this Order. Any noncompliance constitutes a violation of the Clean Water Act (CWA) and the California Water Code and is grounds for enforcement action, for permit termination, revocation and reissuance, or modification; or denial of a permit renewal application. (40 C.F.R. § 122.41(a).) b. The Discharger shall comply with effluent standards or prohibitions established under Section 307(a) of the CWA for toxic pollutants and with standards for sewage sludge use or disposal established under Section 405(d) of the CWA within the time provided in the regulations that establish these standards or prohibitions, even if this Order has not yet been modified to incorporate the requirement. (40 C.F.R. § 122.41(a)(1).) 2. Need to Halt or Reduce Activity Not a Defense. It shall not be a defense for a Discharger in an enforcement action that it would have been necessary to halt or reduce the permitted activity in order to maintain compliance with the conditions of this Order. [40 C.F.R. § 122.41(c)]. 3. Duty to Mitigate. The Discharger shall take all reasonable steps to minimize or prevent any discharge or sludge use or disposal in violation of this Order that has a reasonable likelihood of adversely affecting human health or the environment. [40 C.F.R. § 122.41(d)]. 4. Proper Operation and Maintenance. The Discharger shall at all times properly operate and maintain all facilities and systems of treatment and control (and related appurtenances) which are installed or used by the Discharger to achieve compliance with the conditions of this Order. Proper operation and maintenance also includes adequate laboratory controls and appropriate quality assurance procedures. This provision requires the operation of backup or auxiliary facilities or similar systems that are installed by a Discharger only when necessary to achieve compliance with the conditions of this Order [40 C.F.R. § 122.41(e)]. 5. Property Rights a. This Order does not convey any property rights of any sort or any exclusive privileges [40 C.F.R. § 122.41(g)]. b. The issuance of this Order does not authorize any injury to persons or property or invasion of other private rights, or any infringement of state or local law or regulations [40 C.F.R. § 122.5(c)]. 6. Inspection and Entry. The Discharger shall allow the Central Coast Water Board, State Water Board, United States Environmental Protection Agency (USEPA), and/or their authorized representatives (including an authorized contractor acting as their representative), upon the presentation of credentials and other documents, as may be required by law, to [40 C.F.R. § 122.41(i); Water Code §13383]: CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-2 a. Enter upon the Discharger's premises where a regulated facility or activity is located or conducted, or where records are kept under the conditions of this Order [40 C.F.R. § 122.41(i)(1)]; b. Have access to and copy, at reasonable times, any records that must be kept under the conditions of this Order [40 C.F.R. § 122.41(i)(2)]; c. Inspect and photograph, at reasonable times, any facilities, equipment (including monitoring and control equipment), practices, or operations regulated or required under this Order [40 C.F.R. § 122.41(i)(3)]; and d. Sample or monitor, at reasonable times, for the purposes of assuring Order compliance or as otherwise authorized by the CWA or the Water Code, any substances or parameters at any location [40 C.F.R. § 122.41(i)(4)]. 7. Bypass a. Definitions i. “Bypass” means the intentional diversion of waste streams from any portion of a treatment facility [40 C.F.R. § 122.41(m)(1)(i)]. ii. “Severe property damage” means substantial physical damage to property, damage to the treatment facilities, which causes them to become inoperable, or substantial and permanent loss of natural resources that can reasonably be expected to occur in the absence of a bypass. Severe property damage does not mean economic loss caused by delays in production [40 C.F.R. § 122.41(m)(1)(ii)]. b. Bypass not exceeding limitations. The Discharger may allow any bypass to occur which does not cause exceedances of effluent limitations, but only if it is for essential maintenance to assure efficient operation. These bypasses are not subject to the provisions listed in Federal Standard Provisions – Permit Compliance I.A.7.c, I.A.7.d, and I.A.7.e below [40 C.F.R. § 122.41(m)(2)]. c. Prohibition of bypass. Bypass is prohibited, and the Central Coast Water Board may take enforcement action against a Discharger for bypass, unless [40 C.F.R. § 122.41(m)(4)(i)]: i. Bypass was unavoidable to prevent loss of life, personal injury, or severe property damage [40 C.F.R. § 122.41(m)(4)(i)(A)]; ii. There were no feasible alternatives to the bypass, such as use of auxiliary treatment facilities, retention of untreated wastes, or maintenance during normal periods of equipment downtime. This condition is not satisfied if adequate back-up equipment should have been installed in the exercise of reasonable engineering judgment to prevent a bypass that occurred during normal periods of equipment downtime or preventive maintenance [40 C.F.R. § 122.41(m)(4)(i)(B)]; and iii. The Discharger submitted notice to the Central Coast Water Board as required under Federal Standard Provisions – Permit Compliance I.A.7.e below [40 C.F.R. § 122.41(m)(4)(i)(C)]. d. The Central Coast Water Board may approve an anticipated bypass, after considering its adverse effects, if the Central Coast Water Board determines that it will meet the three conditions listed in Federal Standard Provisions – Permit Compliance I.A.7.c above [40 C.F.R. § 122.41(m)(4)(ii)]. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-3 e. Notice. i. Anticipated bypass. If the Discharger knows in advance of the need for a bypass, it shall submit a notice, if possible at least 10 days before the date of the bypass [40 C.F.R. § 122.41(m)(3)(i)]. ii. Unanticipated bypass. The Discharger shall submit notice of an unanticipated bypass as required in Federal Standard Provisions - Reporting I.E.5 below (24- hour notice) [40 C.F.R. § 122.41(m)(3)(ii)]. 8. Upset. Upset means an exceptional incident in which there is unintentional and temporary noncompliance with technology based permit effluent limitations because of factors beyond the reasonable control of the Discharger. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation [40 C.F.R. § 122.41(n)(1)]. a. Effect of an upset. An upset constitutes an affirmative defense to an action brought for noncompliance with such technology based permit effluent limitations if the requirements of Federal Standard Provisions – Permit Compliance I.A.8.b below are met. No determination made during administrative review of claims that noncompliance was caused by upset, and before an action for noncompliance, is final administrative action subject to judicial review [40 C.F.R. § 122.41(n)(2)]. b. Conditions necessary for a demonstration of upset. A Discharger who wishes to establish the affirmative defense of upset shall demonstrate, through properly signed, contemporaneous operating logs or other relevant evidence that [40 C.F.R. § 122.41(n)(3)]: c. Burden of proof. In any enforcement proceeding, the Discharger seeking to establish the occurrence of an upset has the burden of proof [40 C.F.R. § 122.41(n)(4)]. B. Federal Standard Provisions – Permit Action 1. General. This Order may be modified, revoked and reissued, or terminated for cause. The filing of a request by the Discharger for modification, revocation and reissuance, or termination, or a notification of planned changes or anticipated noncompliance does not stay any Order condition [40 C.F.R. § 122.41(f)]. 2. Duty to Reapply. If the Discharger wishes to continue an activity regulated by this Order after the expiration date of this Order, the Discharger must apply for and obtain a new permit [40 C.F.R. § 122.41(b)]. 3. Transfers. This Order is not transferable to any person except after notice to the Central Coast Water Board. The Central Coast Water Board may require modification or revocation and reissuance of the Order to change the name of the Discharger and incorporate such other requirements as may be necessary under the CWA and the Water Code [40 C.F.R. § 122.41(l)(3); §122.61]. C. Federal Standard Provisions – Monitoring 1. Samples and measurements taken for the purpose of monitoring shall be representative of the monitored activity [40 C.F.R. § 122.41(j)(1)]. 2. Monitoring results must be conducted according to test procedures under 40 C.F.R. part 136 or, in the case of sludge use or disposal, approved under 40 C.F.R. part 136 unless otherwise specified in 40 C.F.R. part 503 unless other test procedures have been specified in this Order [40 C.F.R. § 122.41(j)(4); § 122.44(i)(1)(iv)]. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-4 D. Federal Standard Provisions – Records 1. Records Retention. Except for records of monitoring information required by this Order related to the Discharger's sewage sludge use and disposal activities, which shall be retained for a period of at least five years (or longer as required by 40 C.F.R. part 503), the Discharger shall retain records of all monitoring information, including all calibration and maintenance records and all original strip chart recordings for continuous monitoring instrumentation, copies of all reports required by this Order, and records of all data used to complete the application for this Order, for a period of at least three (3) years from the date of the sample, measurement, report or application. This period may be extended by request of the Central Coast Water Board Executive Officer at any time. (40 C.F.R. § 122.41(j)(2).) 2. Records of monitoring information shall include: a. The date, exact place, and time of sampling or measurements [40 C.F.R. § 122.41(j)(3)(i)]; b. The individual(s) who performed the sampling or measurements [40 C.F.R. § 122.41(j)(3)(ii)]; c. The date(s) analyses were performed [40 CF.R. § 122.41(j)(3)(iii)]; d. The individual(s) who performed the analyses [40 C.F.R. § 122.41(j)(3)(iv)]; e. The analytical techniques or methods used [40 C.F.R. § 122.41(j)(3)(v)]; and f. The results of such analyses [40 C.F.R. § 122.41(j)(3)(vi)]. 3. Claims of confidentiality for the following information will be denied [40 C.F.R. § 122.7(b)]: a. The name and address of any permit applicant or Discharger [40 C.F.R. § 122.7(b)(1)]; and b. Permit applications and attachments, permits and effluent data [40 C.F.R. § 122.7(b)(2)]. E. Federal Standard Provisions – Reporting 1. Duty to Provide Information. The Discharger shall furnish to the Central Coast Water Board, State Water Board, or USEPA within a reasonable time, any information which the Central Coast Water Board, State Water Board, or USEPA may request to determine whether cause exists for modifying, revoking and reissuing, or terminating this Order or to determine compliance with this Order. Upon request, the Discharger shall also furnish to the Central Coast Water Board, State Water Board, or USEPA copies of records required to be kept by this Order [40 C.F.R. § 122.41(h); Water Code §13267]. 2. Signatory and Certification Requirements a. All applications, reports, or information submitted to the Central Coast Water Board, State Water Board, and/or USEPA shall be signed and certified in accordance with Federal Standard Provisions – Reporting I.E.2.b, I.E.2.c, I.E.2.d and I.E.2.e below [40 C.F.R. § 122.41(k)]. b. All permit applications shall be signed by a responsible corporate officer. For the purpose of this section, a responsible corporate officer means: (i) A president, secretary, treasurer, or vice-president of the corporation in charge of a principal business function, or any other person who performs similar policy- or decision- making functions for the corporation, or (ii) the manager of one or more CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-5 manufacturing, production, or operating facilities, provided, the manager is authorized to make management decisions which govern the operation of the regulated facility including having the explicit or implicit duty of making major capital investment recommendations, and initiating and directing other comprehensive measures to assure long term environmental compliance with environmental laws and regulations; the manager can ensure that the necessary systems are established or actions taken to gather complete and accurate information for permit application requirements; and where authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures [40 C.F.R. § 122.22(a)(1)]. c. All reports required by this Order and other information requested by the Central Coast Water Board, State Water Board, or USEPA shall be signed by a person described in Federal Standard Provisions – Reporting I.E.2.b above, or by a duly authorized representative of that person. A person is a duly authorized representative only if: i. The authorization is made in writing by a person described in Federal Standard Provisions – Reporting I.E.2.b above [40 C.F.R. § 122.22(b)(1)]; ii. The authorization specifies either an individual or a position having responsibility for the overall operation of the regulated facility or activity such as the position of plant manager, operator of a well or a well field, superintendent, position of equivalent responsibility, or an individual or position having overall responsibility for environmental matters for the company. (A duly authorized representative may thus be either a named individual or any individual occupying a named position.) [40 C.F.R. § 122.22(b)(2)]; and iii. The written authorization is submitted to the Central Coast Water Board and State Water Board [40 C.F.R. § 122.22(b)(3)]. d. If an authorization under Federal Standard Provisions – Reporting I.E.2.c above is no longer accurate because a different individual or position has responsibility for the overall operation of the facility, a new authorization satisfying the requirements of Standard Provisions – Reporting V.B.3 above must be submitted to the Central Coast Water Board and State Water Board prior to or together with any reports, information, or applications, to be signed by an authorized representative [40 C.F.R. § 122.22(c)]. e. Any person signing a document under Federal Standard Provisions – Reporting I.E.2.b or I.E.2.c above shall make the following certification: “I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.” [40 C.F.R. § 122.22(d)]. 3. Monitoring Reports a. Monitoring results shall be reported at the intervals specified in the Monitoring and Reporting Program (Attachment E) in this Order [40 C.F.R. § 122.41(l)(4)]. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-6 b. Monitoring results must be reported on a Discharge Monitoring Report (DMR) form or forms provided or specified by the Central Coast Water Board or State Water Board for reporting results of monitoring of sludge use or disposal practices [40 C.F.R. § 122.41(l)(4)(i)]. c. If the Discharger monitors any pollutant more frequently than required by this Order using test procedures approved under 40 C.F.R. part 136 or, in the case of sludge use or disposal, approved under 40 C.F.R. part 136 unless otherwise specified in 40 C.F.R. part 503, or as specified in this Order, the results of this monitoring shall be included in the calculation and reporting of the data submitted in the DMR or sludge reporting form specified by the Central Coast Water Board [40 C.F.R. § 122.41(l)(4)(ii)]. d. Calculations for all limitations, which require averaging of measurements, shall utilize an arithmetic mean unless otherwise specified in this Order [40 C.F.R. § 122.41(l)(4)(iii)]. 4. Compliance Schedules. Reports of compliance or noncompliance with, or any progress reports on, interim and final requirements contained in any compliance schedule of this Order, shall be submitted no later than 14 days following each schedule date [40 C.F.R. § 122.41(l)(5)]. 5. Twenty-Four Hour Reporting a. The Discharger shall report any noncompliance that may endanger health or the environment. Any information shall be provided orally within 24 hours from the time the Discharger becomes aware of the circumstances. A written submission shall also be provided within five (5) days of the time the Discharger becomes aware of the circumstances. The written submission shall contain a description of the noncompliance and its cause; the period of noncompliance, including exact dates and times, and if the noncompliance has not been corrected, the anticipated time it is expected to continue; and steps taken or planned to reduce, eliminate, and prevent reoccurrence of the noncompliance [40 C.F.R. § 122.41(l)(6)(i)]. b. The following shall be included as information that must be reported within 24 hours under this paragraph [40 C.F.R. § 122.41(l)(6)(ii)]: i. Any unanticipated bypass that exceeds any effluent limitation in this Order [40 C.F.R. § 122.41(l)(6)(ii)(A)]. ii. Any upset that exceeds any effluent limitation in this Order [40 C.F.R. § 122.41(l)(6)(ii)(B)]. c. The Central Coast Water Board may waive the above-required written report under this provision on a case-by-case basis if an oral report has been received within 24 hours [40 C.F.R. § 122.41(l)(6)(iii)]. 6. Planned Changes. The Discharger shall give notice to the Central Coast Water Board as soon as possible of any planned physical alterations or additions to the permitted facility. Notice is required under this provision only when [40 C.F.R. § 122.41(l)(1)]. a. The alteration or addition to a permitted facility may meet one of the criteria for determining whether a facility is a new source in § 122.29(b) [40 C.F.R. § 122.41(l)(1)(i)]; or b. The alteration or addition could significantly change the nature or increase the quantity of pollutants discharged. This notification applies to pollutants that are not subject to effluent limitations in this Order [40 C.F.R. § 122.41(l)(1)(ii)]. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-7 c. The alteration or addition results in a significant change in the Discharger's sludge use or disposal practices, and such alteration, addition, or change may justify the application of permit conditions that are different from or absent in the existing permit, including notification of additional use or disposal sites not reported during the permit application process or not reported pursuant to an approved land application plan [40 C.F.R. § 122.41(l)(1)(iii)]. 7. Anticipated Noncompliance. The Discharger shall give advance notice to the Central Coast Water Board or State Water Board of any planned changes in the permitted facility or activity that may result in noncompliance with General Order requirements. [40 C.F.R. § 122.41(l)(2)]. 8. Other Noncompliance. The Discharger shall report all instances of noncompliance not reported under Federal Standard Provisions – Reporting I.E.3, I.E.4, and I.E.5 above at the time monitoring reports are submitted. The reports shall contain the information listed in Federal Standard Provisions – Reporting I.E.5 above. [40 C.F.R. § 122.41(l)(7)]. 9. Other Information. When the Discharger becomes aware that it failed to submit any relevant facts in a permit application, or submitted incorrect information in a permit application or in any report to the Central Coast Water Board, State Water Board, or USEPA, the Discharger shall promptly submit such facts or information [40 C.F.R. § 122.41(l)(8)]. F. Federal Standard Provisions – Enforcement 1. The Central Coast Water Board is authorized to enforce the terms of this permit under several provisions of the Water Code, including, but not limited to, §§13385, 13386, and 13387. G. Additional Federal Provisions – Notification Levels 1. Non-Municipal Facilities. Existing manufacturing, commercial, mining, and silvicultural Dischargers shall notify the Central Coast Water Board as soon as they know or have reason to believe [40 C.F.R. § 122.42(a)]: a. That any activity has occurred or will occur that would result in the discharge, on a routine or frequent basis, of any toxic pollutant that is not limited in this Order, if that discharge will exceed the highest of the following "notification levels" [40 C.F.R. § 122.42(a)(1)]: i. 100 micrograms per liter (μg/L) [40 C.F.R. § 122.42(a)(1)(i)]; ii. 200 μg/L for acrolein and acrylonitrile; 500 μg/L for 2,4-dinitrophenol and 2-methyl-4, 6-dinitrophenol; and 1 milligram per liter (mg/L) for antimony [40 C.F.R. § 122.42(a)(1)(ii)]; iii. Five (5) times the maximum concentration value reported for that pollutant in the Report of Waste Discharge [40 C.F.R. § 122.42(a)(1)(iii)]; or iv. The level established by the Central Coast Water Board in accordance with 40 C.F.R. § 122.44(f) [40 C.F.R. § 122.42(a)(1)(iv)]. b. That any activity has occurred or will occur that would result in the discharge, on a non-routine or infrequent basis, of any toxic pollutant that is not limited in this Order, if that discharge will exceed the highest of the following “notification levels" [40 C.F.R. § 122.42(a)(2)]: i. 500 micrograms per liter (μg/L) [40 C.F.R. § 122.42(a)(2)(i)]; ii. 1 milligram per liter (mg/L) for antimony [40 C.F.R. § 122.42(a)(2)(ii)]; CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-8 iii. Ten (10) times the maximum concentration value reported for that pollutant in the Report of Waste Discharge [40 C.F.R. § 122.42(a)(2)(iii)]; or iv. The level established by the Central Coast Water Board in accordance with 40 C.F.R. § 122.44(f) [40 C.F.R. § 122.42(a)(2)(iv)]. 2. Publicly Owned Treatment Works (POTWs). All POTWs shall provide adequate notice to the Central Coast Water Board of the following [40 C.F.R. § 122.42(b)]: a. Any new introduction of pollutants into the POTW from an indirect discharger that would be subject to sections 301 or 306 of the CWA if it were directly discharging those pollutants [40 C.F.R. § 122.42(b)(1)]; and b. Any substantial change in the volume or character of pollutants being introduced into that POTW by a source introducing pollutants into the POTW at the time of adoption of the Order. [40 C.F.R. § 122.42(b)(2)] c. Adequate notice shall include information on the quality and quantity of effluent introduced into the POTW as well as any anticipated impact of the change on the quantity or quality of effluent to be discharged from the POTW. [40 C.F.R. § 122.42(b)(3)] CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-9 II. CENTRAL COAST REGION’S STANDARD PROVISIONS (JANUARY 2013) A. Central Coast General Permit Conditions 1. Introduction of "incompatible wastes" to the treatment system is prohibited. 2. Discharge of high-level radiological waste and of radiological, chemical, and biological warfare agents is prohibited. 3. Discharge of "toxic pollutants" in violation of effluent standards and prohibitions established under Section 307(a) of the Clean Water Act is prohibited. 4. Discharge of sludge, sludge digester or thickener supernatant, and sludge drying bed leachate to drainageways, surface waters, or the ocean is prohibited. 5. Introduction of pollutants into the collection, treatment, or disposal system by an "indirect discharger” that: a. Inhibit or disrupt the treatment process, system operation, or the eventual use or disposal of sludge; or, b. Flow through the system to the receiving water untreated; and, c. Cause or "significantly contribute" to a violation of any requirement of this Order, is prohibited. 6. Introduction of "pollutant free" wastewater to the collection, treatment, and disposal system in amounts that threaten compliance with this order is prohibited. B. Central Coast Standard Provisions – Provisions 1. Collection, treatment, and discharge of waste shall not create a nuisance or pollution, as defined by Section 13050 of the California Water Code. 2. All facilities used for transport or treatment of wastes shall be adequately protected from inundation and washout as the result of a 100-year frequency flood. 3. Operation of collection, treatment, and disposal systems shall be in a manner that precludes public contact with wastewater. 4. Collected screenings, sludges, and other solids removed from liquid wastes shall be disposed in a manner approved by the Executive Officer. 5. Wastewater treatment plants shall be supervised and operated by persons possessing certificates of appropriate grade pursuant to Title 23 of the California Code of Regulations. 6. After notice and opportunity for a hearing, this order may be terminated for cause, including, but not limited to: a. violation of any term or condition contained in this order; b. obtaining this order by misrepresentation, or by failure to disclose fully all relevant facts; c. a change in any condition or endangerment to human health or environment that requires a temporary or permanent reduction or elimination of the authorized discharge; and, d. a substantial change in character, location, or volume of the discharge. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-10 7. Provisions of this permit are severable. If any provision of the permit is found invalid, the remainder of the permit shall not be affected. 8. After notice and opportunity for hearing, this order may be modified or revoked and reissued for cause, including: a. Promulgation of a new or revised effluent standard or limitation; b. A material change in character, location, or volume of the discharge; c. Access to new information that affects the terms of the permit, including applicable schedules; d. Correction of technical mistakes or mistaken interpretations of law; and e. Other causes set forth under Subpart D of 40 C.F.R. 122. 9. Safeguards shall be provided to assure maximal compliance with all terms and conditions of this permit. Safeguards shall include preventative and contingency plans and may also include alternative power sources, stand-by generators, retention capacity, operating procedures, or other precautions. Preventative and contingency plans for controlling and minimizing the effect of accidental discharges shall: a. Identify possible situations that could cause "upset", "overflow" or "bypass”, or other noncompliance. (Loading and storage areas, power outage, waste treatment unit outage, and failure of process equipment, tanks and pipes should be considered.) b. Evaluate the effectiveness of present facilities and procedures and describe procedures and steps to minimize or correct any adverse environmental impact resulting from noncompliance with the permit. 10. Physical Facilities shall be designed and constructed according to accepted engineering practice and shall be capable of full compliance with this order when properly operated and maintained. Proper operation and maintenance shall be described in an Operation and Maintenance Manual. Facilities shall be accessible during the wet-weather season. 11. The discharger shall at all times properly operate and maintain all facilities and systems of treatment and control (and related appurtenances) that are installed or used by the discharger to achieve compliance with the conditions of this order. Electrical and mechanical equipment shall be maintained in accordance with appropriate practices and standards, such as NFPA 70B, Recommended Practice for Electrical Equipment Maintenance; NFPA 70E, Standard for Electrical Safety in the Workplace; ANSI/NETA MTS Standard for Maintenance: Testing Specifications for Electrical Power Equipment and Systems, or procedures established by insurance companies or other industry resources. 12. If the discharger’s facilities are equipped with SCADA or other systems that implement wireless, remote operation, the discharger should implement appropriate safeguards against unauthorized access to the wireless systems. Standards such as NIST SP 800- 53, Recommended Security Controls for Federal Information Systems, can provide guidance. 13. Production and use of recycled water is subject to the approval of the Board. Production and use of recycled water shall be in conformance with reclamation criteria established in Chapter 3, Title 22, of the California Code of Regulations and Chapter 7, Division 7, of the California Water Code. An engineering report pursuant to section 60323, Title 22, of the California Code of Regulations is required and a waiver or water reclamation requirements from the Board is required before reclaimed water is supplied for any use, CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-11 or to any user, not specifically identified and approved either in this Order or another order issued by this Board. C. Central Coast Standard Provisions – General Monitoring Requirements 1. If results of monitoring a pollutant appear to violate effluent limitations based on a weekly, monthly, 30-day, or six-month period, but compliance or non-compliance cannot be validated because sampling is too infrequent, the frequency of sampling shall be increased to validate the test within the next monitoring period. The increased frequency shall be maintained until the Executive Officer agrees the original monitoring frequency may be resumed. For example, if copper is monitored annually and results exceed the six-month median numerical effluent limitation in the permit, monitoring of copper must be increased to a frequency of at least once every two months (Central Coast Standard Provisions – Definitions II.F.13.). If suspended solids are monitored weekly and results exceed the weekly average numerical limit in the permit, monitoring of suspended solids must be increased to at least four (4) samples every week (Central Coast Standard Provisions – Definitions II.F.14.). 2. Water quality analyses performed in order to monitor compliance with this permit shall be by a laboratory certified by the State Department of Public Health (DPH) for the constituent(s) being analyzed. Bioassay(s) performed in order to monitor compliance with this permit shall be in accord with guidelines approved by the State Water Resources Control Board and the State Department of Fish and Game. 3. Samples and measurements taken for the purpose of monitoring shall be representative of the monitored activity. Samples shall be taken during periods of peak loading conditions. Influent samples shall be samples collected from the combined flows of all incoming wastes, excluding recycled wastes. Effluent samples shall be samples collected downstream of the last treatment unit and tributary flow and upstream of any mixing with receiving waters. 4. All monitoring instruments and devices used by the discharger to fulfill the prescribed monitoring program shall be properly maintained and calibrated as necessary to ensure their continued accuracy. D. Central Coast Standard Provisions – General Reporting Requirements 1. Reports of marine monitoring surveys conducted to meet receiving water monitoring requirements of the Monitoring and Reporting Program shall include at least the following information: a. A description of climatic and receiving water characteristics at the time of sampling (weather observations, floating debris, discoloration, wind speed and direction, swell or wave action, time of sampling, tide height, etc.). b. A description of sampling stations, including differences unique to each station (e.g., station location, grain size, rocks, shell litter, calcareous worm tubes, evident life, etc.). c. A description of the sampling procedures and preservation sequence used in the survey. d. A description of the exact method used for laboratory analysis. In general, analysis shall be conducted according to (Central Coast Standard Provisions – Definitions II.B.1 above, and Federal Standard Provision – Monitoring I.C.1. However, CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-12 variations in procedure are acceptable to accommodate the special requirements of sediment analysis. All such variations must be reported with the test results. e. A brief discussion of the results of the survey. The discussion shall compare data from the control station with data from the outfall stations. All tabulations and computations shall be explained. 2. Reports of compliance or noncompliance with, or any progress reports on, interim and final requirements contained in any compliance schedule shall be submitted within 14 days following each scheduled date unless otherwise specified within the permit. If reporting noncompliance, the report shall include a description of the reason, a description and schedule of tasks necessary to achieve compliance, and an estimated date for achieving full compliance. A second report shall be submitted within 14 days of full compliance. 3. The “Discharger” shall file a report of waste discharge at least 180 days before making any material change or proposed change in the character, location, or plume of the discharge. 4. Within 120 days after the discharger discovers, or is notified by the Central Coast Water Board, that monthly average daily flow will or may reach design capacity of waste treatment and/or disposal facilities within four (4) years, the discharger shall file a written report with the Central Coast Water Board. The report shall include: a. the best estimate of when the monthly average daily dry weather flow rate will equal or exceed design capacity; and, b. a schedule for studies, design, and other steps needed to provide additional capacity for waste treatment and/or disposal facilities before the waste flow rate equals the capacity of present units. In addition to complying with Federal Standard Provision – Reporting I.E.2, the required technical report shall be prepared with public participation and reviewed, approved and jointly submitted by all planning and building departments having jurisdiction in the area served by the waste collection, treatment, or disposal facilities. 5. All “Dischargers” shall submit reports electronically to the: California Regional Water Quality Control Board Central Coast Region centralcoast@waterboards.ca.gov 895 Aerovista Place, Suite 101 San Luis Obispo, CA 93401-7906 In addition, "Dischargers" with designated major discharges shall submit a copy of each document to: Regional Administrator USEPA, Region 9 Attention: CWA Standards and Permits Office (WTR-5) 75 Hawthorne Street San Francisco, California 94105 6. Transfer of control or ownership of a waste discharge facility must be preceded by a notice to the Central Coast Water Board at least 30 days in advance of the proposed transfer date. The notice must include a written agreement between the existing CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-13 “Discharger” and proposed “Discharger” containing specific date for transfer of responsibility, coverage, and liability between them. Whether a permit may be transferred without modification or revocation and reissuance is at the discretion of the Board. If permit modification or revocation and reissuance are necessary, transfer may be delayed 180 days after the Central Coast Water Board's receipt of a complete permit application. Please also see Federal Standard Provision – Permit Action IB.3. 7. Except for data determined to be confidential under Section 308 of the Clean Water Act (excludes effluent data and permit applications), all reports prepared in accordance with this permit shall be available for public inspection at the office of the Central Coast Water Board or Regional Administrator of EPA. Please also see Federal Standard Provision – Records I.D.3. 8. By February 1st of each year, the discharger shall submit an annual report to the Central Coast Water Board. The report shall contain the following: a. Both tabular and graphical summaries of the monitoring data obtained during the previous year. b. A discussion of the previous year’s compliance record and corrective actions taken, or which may be needed, to bring the discharger into full compliance. c. An evaluation of wastewater flows with projected flow rate increases over time and the estimated date when flows will reach facility capacity. d. A discussion of operator certification and a list of current operating personnel and their grades of certification. e. The date of the facility’s Operation and Maintenance Manual (including contingency plans as described in Provision B.9), the date the manual was last reviewed, and whether the manual is complete and valid for the current facility. f. A discussion of the laboratories used by the discharger to monitor compliance with effluent limits and a summary of performance relative to Section C, General Monitoring Requirements. g. If the facility treats industrial or domestic wastewater and there is no provision for periodic sludge monitoring in the Monitoring and Reporting Program, the report shall include a summary of sludge quantities, analyses of its chemical and moisture content, and its ultimate destination. h. If appropriate, the report shall also evaluate the effectiveness of the local source control or pretreatment program using the State Water Resources Control Board's "Guidelines for Determining the Effectiveness of Local Pretreatment Program." E. Central Coast Standard Provisions – General Pretreatment Provisions 1. Discharge of pollutants by "indirect dischargers” in specific industrial sub-categories (appendix C, 40 C.F.R. part 403), where categorical pretreatment standards have been established, or are to be established, (according to 40 C.F.R. Chapter 1, Subchapter N), shall comply with the appropriate pretreatment standards by the date specified therein or, if a new indirect discharger, upon commencement of discharge. F. Central Coast Standard Provisions – Enforcement CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-14 1. Any person failing to file a report of waste discharge or other report as required by this permit shall be subject to a civil penalty not to exceed $5,000 per day. 2. Upon reduction, loss, or failure of the treatment facility, the "Discharger" shall, to the extent necessary to maintain compliance with this permit, control production or all discharges, or both, until the facility is restored or an alternative method of treatment is provided. G. Central Coast Standard Provisions – Definitions (Not otherwise included in Attachment A to this Order) 1. A “composite sample" is a combination of no fewer than eight (8) individual samples obtained at equal time intervals (usually hourly) over the specified sampling (composite) period. The volume of each individual sample is proportional to the flow rate at the time of sampling. The period shall be specified in the Monitoring and Reporting Program ordered by the Executive Officer. 2. “Daily Maximum” limit means the maximum acceptable concentration or mass emission rate of a pollutant measured during a calendar day or during any 24-hour period reasonably representative of the calendar day for purposes of sampling. It is normally compared with results based on "composite samples” except for ammonia, total chlorine, phenolic compounds, and toxicity concentration. For all exceptions, comparisons will be made with results from a “grab sample”. 3. “Discharger", as used herein, means, as appropriate: (l) the Discharger, (2) the local sewering entity (when the collection system is not owned and operated by the Discharger), or (3) "indirect discharger" (where "Discharger" appears in the same paragraph as "indirect discharger”, it refers to the discharger.) 4. “Duly Authorized Representative" is one where: a. the authorization is made in writing by a person described in the signatory paragraph of Federal Standard Provision I.E.2; b. the authorization specifies either an individual or the occupant of a position having either responsibility for the overall operation of the regulated facility, such as the plant manager, or overall responsibility for environmental matters of the company; and, c. the written authorization was submitted to the Central Coast Water Board. 5. A "grab sample" is defined as any individual sample collected in less than 15 minutes. "Grab samples” shall be collected during peak loading conditions, which may or may not be during hydraulic peaks. It is used primarily in determining compliance with the daily maximum limits identified in Central Coast Standard Provision – Provision II.F.2 and instantaneous maximum limits. 6. "Hazardous substance” means any substance designated under 40 C.F.R. 116 pursuant to Section 311 of the Clean Water Act. 7. "Incompatible wastes” are: a. Wastes which create a fire or explosion hazard in the treatment works; b. Wastes which will cause corrosive structural damage to treatment works, or wastes with a pH lower than 5.0 unless the works is specifically designed to accommodate such wastes; CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-15 c. Solid or viscous wastes in amounts which cause obstruction to flow in sewers, or which cause other interference with proper operation of treatment works; d. Any waste, including oxygen demanding pollutants (BOD, etc), released in such volume or strength as to cause inhibition or disruption in the treatment works and subsequent treatment process upset and loss of treatment efficiency; and, e. Heat in amounts that inhibit or disrupt biological activity in the treatment works or that raise influent temperatures above 40°C (104°F) unless the treatment works is designed to accommodate such heat. 8. "Indirect Discharger” means a non-domestic discharger introducing pollutants into a publicly owned treatment and disposal system. 9. "Log Mean” is the geometric mean. Used for determining compliance of fecal or total coliform populations, it is calculated with the following equation: Log Mean = (C1 x C2 x...x Cn)1/n in which “n" is the number of days samples were analyzed during the period and any "C" is the concentration of bacteria (MPN/100 ml) found on each day of sampling. "n” should be five or more. 10. “Mass emission rate" is a daily rate defined by the following equations: mass emission rate (lbs/day) = 8.34 x Q x C; and, mass emission rate (kg/day) = 3.79 x Q x C, where “C" (in mg/l) is the measured daily constituent concentration or the average of measured daily constituent concentrations and “Q” (in MGD) is the measured daily flow rate or the average of measured daily flow rates over the period of interest. 11. The "Maximum Allowable Mass Emission Rate," whether for a month, week, day, or six- month period, is a daily rate determined with the formulas in paragraph F.10, above, using the effluent concentration limit specified in the permit for the period and the average of measured daily flows (up to the allowable flow) over the period. 12. “Maximum Allowable Six-Month Median Mass Emission Rate" is a daily rate determined with the formulas in Central Coast Standard Provision – Provision II.F.10, above, using the "six-month Median" effluent limit specified in the permit, and the average of measured daily flows (up to the allowable flow) over a 180-day period. 13. "Median" is the value below which half the samples (ranked progressively by increasing value) fall. It may be considered the middle value, or the average of two middle values. 14. "Monthly Average" (or "Weekly Average”, as the case may be) is the arithmetic mean of daily concentrations or of daily mass emission rates over the specified 30-day (or 7-day) period Average = (Xl + X2 + ... + Xn) / n in which “n" is the number of days samples were analyzed during the period and “X" is either the constituent concentration (mg/l) or mass emission rate (kg/day or lbs/day) for each sampled day. “n" should be four or greater. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT D – STANDARD PROVISIONS D-16 15. "Municipality" means a city, town, borough, county, district, association, or other public body created by or under state law and having jurisdiction over disposal of sewage, industrial waste, or other waste. 16. "Overflow" means the intentional or unintentional diversion of flow from the collection and transport systems, including pumping facilities. 17. "Pollutant-free wastewater" means inflow and infiltration, storm waters, and cooling waters and condensates which are essentially free of pollutants. 18. "Primary Industry Category" means any industry category listed in 40 C.F.R. 122, Appendix A. 19. "Removal Efficiency" is the ratio of pollutants removed by the treatment unit to pollutants entering the treatment unit. Removal efficiencies of a treatment plant shall be determined using “Monthly averages" of pollutant concentrations (C, in mg/l) of influent and effluent samples collected about the same time and the following equation (or its equivalent): CEffluent Removal Efficiency (%) = l00 x (l – Ceffluent / Cinfluent) 20. "Severe property damage" means substantial physical damage to property, damage to treatment facilities which causes them to become inoperable, or substantial and permanent loss to natural resources which can reasonably be expected to occur in the absence of a "bypass”. It does not mean economic loss caused by delays in production. 21. "Sludge" means the solids, residues, and precipitates separated from, or created in, wastewater by the unit processes of a treatment system. 22. To "significantly contribute" to a permit violation means an "indirect discharger" must: a. Discharge a daily pollutant loading in excess of that allowed by contract with the "Discharger" or by Federal, State, or Local law; b. Discharge wastewater which substantially differs in nature or constituents from its average discharge; c. Discharge pollutants, either alone or in conjunction with discharges from other sources, which results in a permit violation or prevents sewage sludge use or disposal; or d. Discharge pollutants, either alone or in conjunction with pollutants from other sources that increase the magnitude or duration of permit violations. 23. "Toxic Pollutant" means any pollutant listed as toxic under Section 307 (a) (1) of the Clean Water Act or under 40 C.F.R. 122, Appendix D. Violation of maximum daily discharge limitations are subject to 24-hour reporting (Federal Standard Provisions I.E.5.). 24. “Zone of Initial Dilution" means the region surrounding or adjacent to the end of an outfall pipe or diffuser ports whose boundaries are defined through calculation of a plume model verified by the State Water Resources Control Board. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-1 E. ATTACHMENT E – MONITORING AND REPORTING PROGRAM Contents I. General Monitoring Provisions ................................................................................................... E-2 II. Monitoring Locations .................................................................................................................. E-3 III. Influent Monitoring Requirements ............................................................................................... E-4 A. Monitoring Location INF-001 ............................................................................................... E-4 IV. Effluent Monitoring Requirements .............................................................................................. E-4 A. Monitoring Location EFF-001 .............................................................................................. E-4 V. Whole Effluent Toxicity Testing Requirements ........................................................................... E-6 A. Whole Effluent Acute Toxicity – Monitoring Location EFF-001 ............................................ E-6 B. Whole Effluent Chronic Toxicity – Monitoring Location EFF-001 ......................................... E-6 C. Quality Assurance ............................................................................................................... E-8 D. Accelerated Monitoring Requirements ................................................................................ E-8 E. Conducting Toxicity Identification Evaluation (TIE) and Toxicity Reduction Evaluation (TRE) ........................................................................................................................................... E-8 VI. Land Discharge Monitoring Requirements – Not Applicable ....................................................... E-9 VII. Recycling Monitoring Requirements – Not Applicable ................................................................ E-9 VIII. Receiving Water Monitoring Requirements ................................................................................ E-9 A. Monitoring Location RSW -001, RSW-002, RSW -003, RSW-004, RSW-005, RSW-006, RSW - 007, RSW-008 .................................................................................................................... E-9 IX. Other Monitoring Requirements ............................................................................................... E-10 A. Solids/Biosolids Monitoring, Notification, and Reporting .................................................... E-10 B. Pretreatment Monitoring.................................................................................................... E-13 X. Reporting Requirements .......................................................................................................... E-16 A. General Monitoring and Reporting Requirements ............................................................. E-16 B. Self-Monitoring Reports (SMRs) ....................................................................................... E-16 C. Discharge Monitoring Reports (DMRs) .............................................................................. E-18 D. Other Reports ................................................................................................................... E-19 Tables Table E-1. Monitoring Station Locations........................................................................................... E-3 Table E-2. Influent Monitoring .......................................................................................................... E-4 Table E-3. Effluent Monitoring .......................................................................................................... E-4 Table E-4. Short-Term Methods for Estimating Chronic Toxicity – Fresh Water ............................... E-7 Table E-5. Receiving Water Monitoring Requirements ..................................................................... E-9 Table E-6. Monitoring Periods and Reporting Schedule ................................................................. E-17 CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-2 ATTACHMENT E – MONITORING AND REPORTING PROGRAM (MRP) The Code of Federal Regulations (40 C.F.R. § 122.48) requires that all NPDES permits specify monitoring and reporting requirements. Water Code sections 13267 and 13383 also authorize the Central Coast Water Board to require technical and monitoring reports. This MRP establishes monitoring and reporting requirements that implement federal and California regulations. I. GENERAL MONITORING PROVISIONS A. Laboratories analyzing monitoring samples shall be certified by the California Department of Public Health (DPH), in accordance with Water Code section 13176, and must include quality assurance/quality control data with their reports. B. Samples and measurements taken as required herein shall be representative of the volume and nature of the monitored discharge. All samples shall be taken at the monitoring locations specified below and, unless otherwise specified, before the monitored flow joins or is diluted by any other waste stream, body of water, or substance. Monitoring locations shall not be changed without notification to and approval of the Central Coast Water Board. C. Appropriate flow measurement devices and methods consistent with accepted scientific practices shall be selected and used to ensure the accuracy and reliability of measurements of the volume of monitored discharges. The devices shall be installed, calibrated, and maintained to ensure that the accuracy of the measurements is consistent with the accepted capability of that type of device. Devices selected shall be capable of measuring flows with a maximum deviation of less than ±10 percent from true discharge rates throughout the range of expected discharge volumes. Guidance in selection, installation, calibration, and operation of acceptable flow measurement devices can be obtained from the following references. 1. A Guide to Methods and Standards for the Measurement of Water Flow, U.S. Department of Commerce, National Bureau of Standards, NBS Special Publication 421, May 1975, 96 pp. (Available from the U.S. Government Printing Office, Washington, D.C. 20402. Order by SD Catalog No. C13.10:421.) 2. Water Measurement Manual, U.S. Department of Interior, Bureau of Reclamation, Second Edition, Revised Reprint, 1974, 327 pp. (Available from the U.S. Government Printing Office, Washington D.C. 20402. Order by Catalog No. 172.19/2:W29/2, Stock No. S/N 24003- 0027.) 3. Flow Measurement in Open Channels and Closed Conduits, U.S. Department of Commerce, National Bureau of Standards, NBS Special Publication 484, October 1977, 982 pp. (Available in paper copy or microfiche from National Technical Information Services (NTIS) Springfield, VA 22151. Order by NTIS No. PB-273 535/5ST.) 4. NPDES Compliance Sampling Manual, U.S. Environmental Protection Agency, Office of Water Enforcement, Publication MCD-51, 1977, 140 pp. (Available from the General Services Administration (8FFS), Centralized Mailing Lists Services, Building 41, Denver Federal Center, CO 80225.) D. All monitoring instruments and devices used by the Discharger to fulfill the prescribed monitoring program shall be properly maintained and calibrated as necessary to ensure their continued accuracy. All flow measurement devise shall be calibrated at least once per year to ensure continued accuracy of the devices. E. Monitoring results, including noncompliance, shall be reported at intervals and in a manner specified in this MRP. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-3 F. Unless otherwise specified by this MRP, all monitoring shall be conducted according to test procedures established at 40 C.F.R. 136, Guidelines Establishing Test Procedures for Analysis of Pollutants. All analyses shall be conducted using the lowest practical quantitation limit achievable using the specified methodology. Where effluent limitations are set below the lowest achievable quantitation limits, pollutants not detected at the lowest practical quantitation limits will be considered in compliance with effluent limitations. Analysis for toxics listed by the California Toxics Rule (CTR) shall also adhere to guidance and requirements contained in the Policy for Implementation of Toxics Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California (2005) (SIP). II. MONITORING LOCATIONS The Discharger shall establish the following monitoring locations to demonstrate compliance with the effluent limitations, discharge specifications, and other requirements in this Order: Table E-1. Monitoring Station Locations Type of Sampling Location Monitoring Location Name Monitoring Location Description Influent INF-001 A location where a representative sample of the influent into the facility can be collected prior to any plant return flows or treatment processes Effluent EFF-001 A location where a representative sample of the effluent from the facility can be collected after all treatment processes and prior to commingling with other waste streams or being discharged into San Luis Obispo Creek Receiving Water RSW -001 At Fox Canyon Road Receiving Water RSW -002 At Mission Receiving Water RSW -003 At Marsh Street Bridge Receiving Water RSW -004 50 feet upstream of effluent structure discharge point on San Luis Obispo Creek Receiving Water RSW -005 A location in San Luis Obispo Creek immediately upstream of the confluence with Prefumo Canyon Creek Receiving Water RSW -006 A location in Prefumo Canyon Creek 50 feet upstream of the confluence with San Luis Obispo Creek Receiving Water RSW -007 Approximately 0.5 miles downstream from effluent structure discharge point on San Luis Obispo Creek Receiving Water RSW -008 At Higuera Street Bridge, near US 101 Biosolids BIO-001 Representative sample location for biosolids at the last point in the biosolids handling process (i.e., the drying beds just before removal). CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-4 III. INFLUENT MONITORING REQUIREMENTS A. Monitoring Location INF-001 1. The Discharger shall monitor influent to the facility at INF-001 as follows: Table E-2. Influent Monitoring Parameter Units Sample Type Minimum Sampling Frequency Biochemical Oxygen Demand, 5-day @ 20°C (BOD5) mg/L 24-hr. composite 1/Month Total Suspended Solids (TSS) mg/L 24-hr. composite 1/Month IV. EFFLUENT MONITORING REQUIREMENTS A. Monitoring Location EFF-001 1. The Discharger shall monitor effluent at EFF-001 as follows. Table E-3. Effluent Monitoring Parameter Units Sample Type Minimum Sampling Frequency Daily Flow MG Metered 1/Day Instantaneous Maximum Flow Rate MGD Metered 1/Day Maximum Daily Flow MGD Calculated 1/Month Mean Daily Flow MGD Calculated 1/Month BOD Mass Emissions Rate lbs/day Calculated 1/Month pH s.u. Grab 1/Day [1], [2] Chlorine Residual mg/L Continuous or Grab [1] Grab samples shall be taken a minimum of twice per day, and within 30 minutes of any excursion above 0.1 mg/L Total Chlorine lbs/day Instantaneous 1/Day Temperature °C Grab [2] 5/Week Fecal Coliform Organisms MPN/100 mL Grab 5/Week Total Coliform Organisms MPN/100 mL Grab 5/Week Settleable Solids ml/L 24-hr. composite 5/Week Ammonia (as N) mg/L Grab 1/Week Total Suspended Solids mg/L 24-hr. composite 1/Week Turbidity NTU 24-hr. composite 1/10 days BOD, 5-day mg/L Grab 1/Month Dissolved Oxygen mg/L Grab 1/Month Color mg/L Grab 1/Month Oil and Grease mg/L Grab 1/Month Total Kjeldahl Nitrogen (TKN) (as N) mg/L Grab 1/Month CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-5 Parameter Units Sample Type Minimum Sampling Frequency Chlorodibromomethane µg/L 24-hr. composite 1/Month Dichlorobromomethane µg/L 24-hr. composite 1/Month Nitrite (as N) mg/L Grab 1/Month Nitrate (as N) mg/L Grab 1/Month Dissolved Orthophosphate (as P) mg/L Grab 1/Month Total Phosphate (as P) mg/L Grab 1/Month Total Dissolved Solids mg/L Grab 1/Quarter Pentachlorophenol µg/L 24-hr. composite 1/Quarter N-Nitrosodimethylamine µg/L 24-hr. composite 1/Quarter Sodium mg/L Grab 1/Quarter Chloride mg/L Grab 1/Quarter Chronic Toxicity [3] TUc Grab 1/Year (in October) Acute Toxicity [3] TUa Grab 1/Year (in October) MBAS mg/L Grab 1/Year (in October) Boron mg/L Grab 1/Year (in October) Cobalt mg/L Grab 1/Year (in October) Iron mg/L Grab 1/Year (in October) Lithium mg/L Grab 1/Year (in October) Manganese mg/L Grab 1/Year (in October) Molybdenum mg/L Grab 1/Year (in October) Vanadium mg/L Grab 1/Year (in October) CTR Pollutants [4], [5] µg/L 24-hr. composite 1/Year (in October) Title 22 Pollutants [6], [7] µg/L 24-hr. composite 1/Year (in October) [1] Report minimum and maximum pH values and maximum chlorine residual value. Also report if there is natural flow in San Luis Obispo Creek. [2] Temperature and pH shall be measured simultaneously with the sample taken for measurement of total ammonia. Results shall be used to calculate un-ionized ammonia concentration. [3] Whole effluent acute and chronic toxicity monitoring shall be conducted according to the requirements established in section V of this Monitoring and Reporting Program. [4] The CTR Priority Pollutants are those listed by the California Toxics Rule at 40 C.F.R. § 131.38(b)(1). These pollutants shall be monitored one time per year. Analyses, compliance determination, and reporting for these pollutants shall adhere to applicable provisions of the Policy for Implementation of Toxics Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California (SIP). The Discharger shall instruct its analytical laboratory to establish calibration standards so that the Minimum Levels (MLs) presented in Appendix 4 of the SIP are the lowest calibrate standards. The Discharger and its analytical laboratory shall select MLs, which are below applicable water quality criteria of the CTR; and when applicable water quality criteria are below all MLs, the Discharger and is analytical laboratory shall select the lowest ML. [5] Monitoring for the CTR pollutant in the effluent shall occur simultaneously with monitoring required for the CTR pollutants in the receiving water. [6] The Title 22 Pollutants are those for which primary Maximum Contaminant Levels (MCLs) have been established by the Department of Public Health and which are listed in Tables 64431-A and 64444-A of the California Code of Regulations, Title 22, Division 4, Chapter 15. Where these pollutants are included in other groups of pollutants (CTR Priority Pollutants), monitoring does not need to be duplicated. Analytical methods shall adhere to the Detection Limits for Purposes of Reporting (DLRs) established by Title 22 of the California Code of Regulations, Division 4, Chapter 15, section 64432 and 64445.1. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-6 [7] Monitoring for the Title 22 pollutants in the effluent shall occur simultaneously with monitoring required for the Title 22 pollutants in the receiving water. V. WHOLE EFFLUENT TOXICITY TESTING REQUIREMENTS A. Whole Effluent Acute Toxicity – Monitoring Location EFF-001 1. Acute toxicity shall be evaluated by measuring survival of test organisms exposed to 96-hour static renewal toxicity tests. 2. Test organisms shall be fathead minnow unless the Executive Officer specifies in writing otherwise. The Discharger may be required by the Executive Officer to retest sensitivity upon changes to the facility or operations which may affect effluent toxicity. 3. All bioassays shall be performed using the most sensitive species based on the most recent screening test results and in accordance with the most up-to-date protocols in 40 C.F.R. part 136, currently in Methods for Measuring the Acute Toxicity of Effluents and Receiving Water to Freshwater and Marine Organisms, 5th Edition. 4. If the Discharger can demonstrate that specific identifiable substances in the discharge are rapidly rendered harmless upon discharge to the receiving water, compliance with the acute toxicity limitation may be determined after the test samples are adjusted to remove the influence of those substances. The Discharger must obtain written approval from the Executive Officer to authorize such an adjustment. 5. The sample shall be taken from treated effluent after disinfection. Monitoring of the bioassay water shall include, on a daily basis, the following parameters: pH, dissolved oxygen, ammonia (if toxicity is observed), temperature, hardness, and alkalinity. These results shall be reported in the monthly SMRs or as specified by the Central Coast Water Board. 6. The presence of acute toxicity shall be determined as significantly reduced survival of test organisms at 100 percent effluent compared to a control using a statistical t-test. The Discharger shall include with the SMR the percent survival of the organisms for both the effluent and control, and the results of the t-test (“statistically different” or “not statistically different”). If the control fish survival rate is less than 90 percent, the bioassay test shall be restarted with new fish and shall continue as soon as practical until an acceptable test is completed (i.e., control fish survival rate is 90 percent or greater). B. Whole Effluent Chronic Toxicity – Monitoring Location EFF-001 1. Chronic Toxicity Monitoring Requirements a. Toxicity Trigger. A toxicity trigger of 1 TUc is established for the discharge of effluent through Discharge Point 001. b. Sampling. The Discharger shall collect grab samples of the effluent at EFF-001, as specified in Table E-3 above, for critical life stage toxicity testing as indicated below. c. Test Species. The test species for chronic toxicity screening shall include a vertebrate, invertebrate, and an aquatic plant as identified in Table E-4 below. The Executive Officer may change the test species if data suggest that another test species is more sensitive to the discharge. After a three-month screening period, monitoring may be reduced to the most sensitive species. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-7 Table E-4. Short-Term Methods for Estimating Chronic Toxicity – Fresh Water Species Scientific Name Effect Test Duration (days) Fathead Minnow Pimephales promelas Larval Survival and Growth 7 Water Flea Ceriodaphnia dubia Survival; number of young 6 to 8 days Green Alga Selenastrum capricornutum Growth Rate 4 days d. Methodology. Sample collection, handling, and preservation shall be in accordance with USEPA protocols. In addition, bioassays shall be conducted in compliance with the most recently promulgated test methods, as shown in Appendix E-1 and Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Marine and Estuarine Organisms, currently third edition (EPA-821-R-02- 014) and Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms, currently fourth Edition (EPA-821-R- 02-013), with exceptions granted the Discharger by the Executive Officer and the Environmental Laboratory Accreditation Program (ELAP). e. Dilution Series. The Discharger shall conduct tests at 100%, 85%, 70%, 50%, and 25%. The “%” represents percent effluent as discharged. The Discharger may use the biological buffer MOPS (3-(N-Morpholino)propanesulfonic Acid) to control pH drift and ammonia toxicity caused by increasing pH during the test. 2. Chronic Toxicity Reporting Requirements a. Routine Reporting. Toxicity test results for the current reporting period shall include, at a minimum, for each test: i. Sample dates ii. Test initiation date iii. Test species iv. End point values for each dilution (e.g., number of young, growth rate, percent survival) v. NOEC values in percent effluent vi. IC15, IC25, IC40, and IC50 values (or EC15, EC25 ... etc.) in percent effluent vii. TUc values (100/NOEC, 100/IC25, or 100/EC25) viii. Mean percent mortality (±s.d.) after 96 hours in 100% effluent (if applicable) ix. NOEC and LOEC values for reference toxicant tests x. IC50 or EC50 values for reference toxicant test xi. Available water quality measurements for each test (pH, dissolved oxygen, temperature, conductivity, hardness, salinity, ammonia) b. Compliance Summary. The results of the chronic toxicity testing shall be provided in the next Self-Monitoring Report and shall include a summary table of chronic toxicity data from at least eleven of the most recent samples. The information in the table shall include the items listed above under 2.a. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-8 C. Quality Assurance 1. For the acute toxicity testing using a t-test, two dilutions shall be used, i.e., 100 percent effluent and a control (when a t-test is used instead of an LC50). 2. If organisms are not cultured in-house, concurrent testing with a referenced toxicant shall be conducted. Where organisms are cultured in-house, monthly reference toxicant testing is sufficient. Reference toxicant tests also shall be conducted using the same test conditions as the effluent toxicity tests (e.g., same test duration, etc.). 3. If either the reference toxicant test or effluent test does not meet all test acceptability criteria (TAC) as specified in the toxicity test references, then the Discharger must resample and retest within 15 working days or as soon as possible. The retesting period begins when the Discharger collects the first sample required to complete the retest. 4. The reference toxicant and effluent tests must meet the upper and lower bounds on test sensitivity as determined by calculating the percent minimum significant difference (PMSD) for each test result. The test sensitivity bound is specified for each test method in the respective methods manuals. D. Accelerated Monitoring Requirements 1. When acute toxicity is detected in the effluent or when the chronic toxicity trigger of 1 TUc is exceeded during regular toxicity monitoring, and the testing meets all test acceptability criteria, the Discharger shall initiate accelerated monitoring to confirm the effluent toxicity. 2. The Discharger shall implement an accelerated monitoring frequency consisting of performing three toxicity tests in a six-week period following the first failed test results. 3. If implementation of the Discharger’s Toxicity Reduction Evaluation (TRE) work plan indicates the source of the exceedance of the effluent limitation or toxicity trigger (for instance, a temporary plant upset), then only one additional test is necessary. If exceedance of the effluent limitation or toxicity trigger is detected in this test, the Discharger will continue with accelerated monitoring requirements or implement the Toxicity Identification and Toxicity Reduction Evaluations. 4. If none of the three tests indicated exceedance of the effluent limitation or toxicity trigger, then the Discharger may return to the normal bioassay testing frequency. E. Conducting Toxicity Identification Evaluation (TIE) and Toxicity Reduction Evaluation (TRE) 1. A Toxicity Identification Evaluation (TIE) shall be triggered if testing from the accelerated monitoring frequency indicates any of the following: a. Two of the three accelerated toxicity tests are reported as failed tests meeting any of the conditions specified in Attachment E, section V.D. b. The TIE shall be initiated within 15 days following failure of the second accelerated monitoring test. c. If a TIE is triggered prior to the completion of the accelerated testing, the accelerated testing schedule may be terminated, or used as necessary in performing the TIE. 2. The TIE shall be conducted to identify and evaluate toxicity in accordance with procedures recommended by the United States Environmental Protection Agency (USEPA) which include the following: CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-9 a. Toxicity Identification Evaluation: Characterization of Chronically Toxic Effluents, Phase I, (USEPA, 1992a); b. Methods for Aquatic Toxicity Identification Evaluations: Phase I Toxicity Characterization Procedures, Second Edition (USEPA, 1991a); c. Methods for Aquatic Toxicity Identification Evaluations: Phase II Toxicity Identification Procedures for Sampling Exhibiting Acute and Chronic Toxicity (USEPA, 1993a); and d. Methods for Aquatic Toxicity Identification Evaluations: Phase III Toxicity Confirmation Procedures for Samples Exhibiting Acute and Chronic Toxicity (USEPA, 1993b). 3. As part of the TIE investigation, the Discharger shall be required to implement its TRE work plan. The Discharger shall take all reasonable steps to control toxicity once the source of the toxicity is identified. A failure to conduct required toxicity tests or a TRE within a designated period shall result in the establishment of numerical effluent limitations for chronic toxicity in a permit or appropriate enforcement action. Recommended guidance in conducting a TRE includes the following: a. Toxicity Reduction Evaluation Guidance for Municipal Wastewater Treatment Plants, August 1999, EPA/833B-99/002; and b. Clarifications Regarding Toxicity Reduction and Identification Evaluations in the National Pollutant Discharge Elimination System Program dated March 27, 2001, USEPA Office of Wastewater Management, Office of Regulatory Enforcement. VI. LAND DISCHARGE MONITORING REQUIREMENTS – NOT APPLICABLE VII. RECYCLING MONITORING REQUIREMENTS – NOT APPLICABLE VIII. RECEIVING WATER MONITORING REQUIREMENTS A. Monitoring Location RSW-001, RSW-002, RSW-003, RSW-004, RSW-005, RSW-006, RSW-007, RSW-008 1. The Discharger shall monitor the receiving water at Monitoring Locations RSW -001, RSW -002, RSW -003, RSW -004, RSW -005, RSW -006, RSW -007, AND RSW -008 as follows: Table E-5. Receiving Water Monitoring Requirements Parameter Units Sample Type [1] Sampling Station Minimum Sampling Frequency Flow [2] cfs Instantaneous 4, 5, 7, 8 1/Week, Apr – Oct Flow MGD Instantaneous 4, 5, 7, 8 1/Week, Apr – Oct [3] Turbidity [2] NTU Grab 4, 5 1/Week Color [2] Units Grab 4, 5 1/Week pH [2] [4] s.u. Grab 4, 5 1/Week Dissolved Oxygen mg/L Grab 4, 5 1/Week Temperature [4] °C Grab 4, 5 1/Week Un-Ionized mg/L calculated 4, 5 1/Month CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-10 Ammonia [4] Total Dissolved Solids mg/L Grab 4, 5 1/Quarter Sodium mg/L Grab 4, 5 1/Quarter Chloride mg/L Grab 4, 5 1/Quarter pH [4] s.u. Grab 5, 7, 8 1/Month Nitrate as N mg/L Grab 5, 7, 8 1/Month Dissolved Oxygen mg/L Grab 5, 7, 8 1/Month Total Phosphate as P mg/L Grab 5, 7, 8 1/Month Algal description [5] Visual observation Grab 5, 7, 8 1/Month Nitrite as N mg/L Grab 5, 7, 8 1/Month Ammonia as N mg/L Grab 5, 7, 8 1/Month TKN as N mg/L Grab 5, 7, 8 1/Month Dissolved Orthophosphate as P mg/L Grab 5, 7, 8 1/Month [1] Samples shall be obtained only when safe to do so. [2] The San Luis Obispo Creek flow rate shall determine the upstream and downstream stations where these constituents shall be monitored, as follows. If the creek flows underground between Monitoring Location RSW-002 and the discharge point, samples shall be obtained from Monitoring Location RSW-002. If the creek flows aboveground from Monitoring Location RSW-002 to the discharge point, samples shall be obtained from Monitoring Location RSW-004. In either case, Monitoring Location RSW-005 shall be the downstream location. [3] Sampling shall be concurrent with sampling of effluent for ammonia. [4] Temperature and pH are to be measured at the same time the Total Ammonia sample is collected. Results shall be used to calculate and report Un-Ionized Ammonia concentrations. [5] Narrative description of algae present at the monitoring location shall include: algal color, location with respect to stream banks and depth of water, and appearance (filamentous, matting, attached, etc., percent coverage of water surface). IX. OTHER MONITORING REQUIREMENTS A. Solids/Biosolids Monitoring, Notification, and Reporting 1. Biosolids Monitoring a. Biosolids shall be tested for the metals required in 40 C.F.R. § 503.16 (for land application) or 40 C.F.R. § 503.26 (for surface disposal), using the methods in Test Methods for Evaluating Solid Waste, Physical/Chemical Methods (SW -846), as required in 40 C.F.R. § 503.8(b)(4), at the following minimum frequencies: Volume (dry metric tons) [1] Sampling and Analysis Frequency [2] 0-290 Once per year 290-1500 Once per quarter 1500-15000 Once per 60 days > 15000 Once per month [1] For accumulated, previously untested biosolids, the Discharger shall develop a representative sampling plan, including number and location of sampling points, and collect representative samples. [2] Test results shall be expressed in mg pollutant per kg biosolids on a 100% dry weight basis. Biosolids to be land applied shall be tested for organic-N, ammonium-N, and nitrate-N at the frequencies required above CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-11 b. Prior to land application, the Discharger shall demonstrate that the biosolids meet Class A or Class B pathogen reduction levels by one of the methods listed in 40 C.F.R. § 503.32. Prior to disposal in a surface disposal site, the Discharger shall demonstrate that the biosolids meet Class B levels or shall ensure that the site is covered at the end of each operating day. If pathogen reduction is demonstrated using a “Process to Significantly/Further Reduce Pathogens”, the Discharger shall maintain daily records of the operating parameters used to achieve this reduction. If pathogen reduction is demonstrated by testing for fecal coliforms and/or pathogens, samples must be drawn at the frequency in 11(a) above. For fecal coliform, at least seven grab samples must be drawn during each monitoring event and a geometric mean calculated from these seven samples. c. For biosolids that are land applied or placed in a surface disposal site, the Discharger shall track and keep records of the operational parameters used to achieve Vector Attraction Reduction requirements in 40 C.F.R. § 503.33(b). d. Class 1 facilities (facilities with pretreatment programs or others designated as Class 1 by the Regional Administrator) and Federal facilities with greater than five million gallons per day (MGD) influent flow shall sample biosolids for pollutants listed under Section 307(a) of the Clean Water Act (as required in the pretreatment section of the permit for POTW’s with pretreatment programs). Class 1 facilities and Federal facilities greater than five MGD shall test dioxins/dibenzofurans using a detection limit of less than one pg/g at the time of their next priority pollutant scan if they have not done so within the past five years, and once per five years thereafter. e. The biosolids shall be tested annually, or more frequently if necessary, to determine hazardousness in accordance 40 C.F.R. part 261. f. If biosolids are placed in a surface disposal site (dedicated land disposal site or monofill), a qualified groundwater scientist shall develop a groundwater monitoring program for the site, or shall certify that the placement of biosolids on the site will not contaminate an aquifer. g. Biosolids placed in a municipal landfill shall be tested by the Paint Filter Liquids Test (EPA Method 9095) at the frequency in 11 (a) above or more often if necessary to demonstrate that there are no free liquids. 2. Biosolids Notification The Discharger, either directly or through contractual arrangements with their biosolids management contractors, shall comply with the following notification requirements: a. Notification of non-compliance: The Discharger shall notify U.S. EPA Region 9, the Central Coast Regional Board, and the Regional Board located in the region where the biosolids are used or disposed, of any non-compliance within 24 hours if the non-compliance may seriously endanger health or the environment. For other instances of non-compliance, the Discharger shall notify U.S. EPA Region 9 and the affected Regional Boards of the non-compliance in writing within five working days of becoming aware of the non-compliance. The Discharger shall require their biosolids management contractors to notify U.S. EPA Region 9 and the affected Regional Boards of any non-compliance within the same timeframes. See Attachment D for Regional Board contact information. b. If biosolids are shipped to another State or to Indian Lands, the Discharger must send 60 days prior notice of the shipment to the permitting authorities in the CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-12 receiving State or Indian Land (the U.S. EPA Regional Office for that area and the State/Indian authorities). c. For land application: Prior to reuse of any biosolids from this facility to a new or previously unreported site, the Discharger shall notify U.S. EPA and Regional Board. The notification shall include a description and topographic map of the proposed site(s), names and addresses of the applier, and site owner and a listing of any state or local permits which must be obtained. The plan shall include a description of the crops or vegetation to be grown, proposed loading rates and determination of agronomic rates. If any biosolids within a given monitoring period do not meet 40 C.F.R. § 503.13 metals concentration limits, the Discharger (or its contractor) must pre-notify U.S. EPA, and determine the cumulative metals loading at that site to date, as required in 40 C.F.R. § 503.12. d. The Discharger shall notify the applier of all the applier's requirements under 40 C.F.R. part 503, including the requirement that the applier certify that the management practices, site restrictions, and any applicable vector attraction reduction requirements have been met. The Discharger shall require the applier to certify at the end of 38 months following application of Class B biosolids that the harvesting restrictions in effect for up to 38 months have been met. e. For surface disposal: Prior to disposal to a new or previously unreported site, the Discharger shall notify U.S. EPA and the Regional Board. The notice shall include description and topographic map of the proposed site, depth to groundwater, whether the site is lined or unlined, site operator, site owner, and any state or local permits. The notice shall describe procedures for ensuring public access and grazing restrictions for three years following site closure. The notice shall include a groundwater monitoring plan or description of why groundwater monitoring is not required. 3. Biosolids Reporting The Discharger shall submit an annual biosolids report to the U.S. EPA Region 9 Biosolids Coordinator and Regional Board by February 19th of each year for the period covering the previous calendar year. The report shall include: a. The amount of biosolids generated during the reporting period, in dry metric tons, and the amount accumulated from previous years; b. Results of all pollutant and pathogen monitoring required in Item 12 above and the Monitoring and Reporting Program of this Order. Results must be reported on a 100% dry weight basis for comparison with 40 C.F.R. part 503 limits; c. Descriptions of pathogen reduction methods and vector attraction reduction methods, including supporting time and temperature data, and certifications, as required in 40 C.F.R. §§ 503.17 and 503.27; d. Names, mailing addresses, and street addresses of persons who received biosolids for storage, further treatment, disposal in a municipal waste landfill, or for other use or disposal methods not covered above, and volumes delivered to each. e. For land application sites, the following information must be submitted by the Discharger, unless the Discharger requires its biosolids management contractors to report this information directly to the U.S. EPA Region 9 Biosolids Coordinator: CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-13 i. Locations of land application sites (with field names and numbers) used that calendar year, size of each field applied to, applier, and site owner. ii. Volumes applied to each filed (in wet tons and dry metric tons), nitrogen applied, calculated plant available nitrogen; iii. Crop planted, dates of planting and harvesting; iv. For any biosolids exceeding 40 C.F.R. § 503.13 Table 3 metals concentrations: the locations of sites where applied and cumulative metals loading at that site to date; v. Certifications of management practices in 40 C.F.R. § 503.14; and vi. Certifications of site restrictions in 40 C.F.R. § 503(b)(5). f. For surface disposal sites: i. Locations of sites, site operator, site owner, size of parcel on which disposed; ii. Results of any required groundwater monitoring; iii. Certifications of management practices in 40 C.F.R. § 503.24; and iv. For closed sites, date of site closure and certifications of management practices for the three years following site closure. g. For all biosolids used or disposed at the Permittee's facilities, the site and management practice information and certification required in 40 C.F.R. §§ 503.17 and 503.27; and h. For all biosolids temporarily stored, the information required in 40 C.F.R. § 503.20 required to demonstrate temporary storage. Reports shall be submitted to: Regional Biosolids Coordinator USEPA (WTR-7) 75 Hawthorne Street San Francisco, CA 94105-3901 Executive Officer Central Coast Regional Water Quality Control Board 895 Aerovista Place, Suite 101 San Luis Obispo, CA 93455-5411 i. All the requirements of 40 C.F.R. part 503 and 23 CCR 15 are enforceable by the U.S. EPA and this Regional Board whether or not the requirements are stated in an NPDES permit or any other permit issued to the Discharger. B. Pretreatment Monitoring By February 1st of each year, the Discharger shall submit an annual report to the Central Coast Regional Board, State Board, and USEPA describing the Discharger's pretreatment activities over the previous calendar year. In the event that the Discharger is not in compliance with any conditions or requirements of this permit affected by the pretreatment program, including any noncompliance with pretreatment audit or compliance inspection requirements, then the Discharger shall also include the reasons for noncompliance and state CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-14 how and when the Discharger shall comply with such conditions and requirements. This report shall contain, but not be limited to, the following information: 1. A summary of analytical results from representative, flow-proportioned, 24-hour composite samples of the plant's influent and effluent for those pollutants USEPA has identified under Section 307(a) of the CWA which are known or suspected to be discharged by industrial users. The Discharger is not required to sample and analyze for asbestos until USEPA promulgates an applicable analytical technique under 40 C.F.R. part 136. 2. A discussion of upset, interference, or pass-through incidents, if any, at the POTW which the Discharger knows or suspects were caused by industrial users of the POTW system. The discussion shall include the reasons why the incidents occurred, corrective actions taken and, if known, the name and address of the industrial user(s) responsible. Discussions shall also include a review of applicable pollutant limitations to determine whether any additional limitations or changes to existing requirements may be necessary to prevent pass-through, interference, or noncompliance with sludge disposal requirements. 3. The cumulative number of industrial users that the Discharger has notified regarding Baseline Monitoring Reports, and the cumulative number of industrial user responses. 4. An updated list of the Discharger's industrial users, including their names and addresses, or a list of deletions and additions keyed to a previously submitted list. The Discharger shall provide a brief explanation for each deletion. The list shall identify the industrial users subject to Federal Categorical Standards by specifying which set(s) of standards are applicable. The list shall indicate which categorical industries, or specific pollutants from each industry, are subject to local limitations that are more stringent than the Federal Categorical Standards. The Discharger shall also list the non-categorical industrial users that are subject only to local discharge limitations. The Discharger shall characterize the compliance status of each industrial user by employing the following descriptions: a. In compliance with Baseline Monitoring Report requirements (where applicable); b. Consistently achieving compliance; c. Inconsistently achieving compliance; d. Significantly violated applicable pretreatment requirements as defined by 40 C.F.R. § 403.8(f)(2)(vii); e. On a schedule to achieve compliance (include the date final compliance is required); f. Not achieving compliance and not on a compliance schedule; or g. The Discharger does not know the industrial user’s compliance status. 5. A quarterly report describing the compliance status of any industrial user characterized by descriptions in Items 4(c) through (g) above shall be submitted to the Central Coast Water Board, State Board, and USEPA. The report shall identify the specific compliance status of each applicable industrial user. This quarterly reporting requirement shall commence upon issuance of this Order and Permit. Quarterly reports shall be submitted May 1, August 1, November 1, and February 1. Quarterly reports shall briefly describe POTW compliance with audit/pretreatment compliance inspection requirements. If none of the aforementioned conditions exist, at a minimum, a letter indicating that all industries CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-15 are in compliance and no violations or changes to the pretreatment program have occurred during the quarter must be submitted. 6. A summary of inspection and sampling activities conducted by the Discharger during the past year to gather information and data regarding industrial users. The summary shall include: a. Names and addresses of the industrial users subject to surveillance by the Discharger and an explanation of whether they were inspected, sampled, or both, and the frequency of these activities at each user; and b. Conclusions or results from the inspection or sampling of each industrial user. 7. A summary of compliance and enforcement activities during the past year. The summary shall include names and addresses of the industrial users affected by the following actions: a. Warning letters or notices of violation regarding the industrial users' apparent noncompliance with Federal Categorical Standards or local discharge limitations. For each industrial user, identify whether the apparent violation concerned the Federal Categorical Standards or local discharge limitations; b. Administrative Orders regarding the industrial users' noncompliance with Federal Categorical Standards or local discharge limitations. For each industrial user, identify whether the violation concerned the Federal Categorical Standards or local discharge limitations; c. Civil actions regarding the industrial users' noncompliance with Federal Categorical Standards or local discharge limitations. For each industrial user, identify whether the violation concerned the Federal Categorical Standards or local discharge limitations; d. Criminal actions regarding the industrial user's noncompliance with Federal Categorical Standards or local discharge limitations. For each industrial user, identify whether the violation concerned Federal Categorical Standards or local discharge limitations; e. Assessment of monetary penalties. For each industrial user, identify the amount of the penalties; f. Restriction of flow to the POTW; or g. Disconnection from discharge to the POTW . 8. Description of any significant changes in operating the pretreatment program which differ from the information in the Discharger's Approved POTW Pretreatment Program, including but not limited to changes concerning: the program's administrative structure; local industrial discharge limitations; monitoring program or monitoring frequencies; legal authority or enforcement policy; funding mechanisms; resource requirements; or staffing levels. 9. A summary of the annual pretreatment budget, including the costs of pretreatment program functions and equipment purchases. 10. A summary of public participation activities to involve and inform the public. 11. Reports shall be signed by a principal executive officer, ranking elected official, or other duly authorized employee if such employee is responsible for overall operation of the CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-16 POTW. Signed copies of these reports shall be submitted to the USEPA and the State Board at the following addresses: State Water Resources Control Board Regulation Unit P.O. Box 100 Sacramento, CA 95812-0100 US EPA, Region 9 Clean Water Act Compliance Office 75 Hawthorne Street (WTR-7) San Francisco, CA 94105-3901 For reporting to the Central Coast Water Board, reports shall be uploaded using the State Water Board’s California Integrated Water Quality System (CIWQS) Program website (http://www.waterboards.ca.gov/ciwqs/index.html). X. REPORTING REQUIREMENTS A. General Monitoring and Reporting Requirements The Discharger shall comply with all Standard Provisions (Attachment D) related to monitoring, reporting, and recordkeeping. B. Self-Monitoring Reports (SMRs) 1. The Discharger shall electronically submit SMRs using the CIWQS Program website. The CIWQS website will provide additional information for SMR submittal in the event there will be a planned service interruption for electronic submittal. 2. The Discharger shall report in the SMR the results for all monitoring specified in this MRP under sections III through IX. The Discharger shall submit monthly and annual SMRs including the results of all required monitoring using U.S. EPA-approved test methods or other test methods specified in this Order. SMRs are to include all new monitoring results obtained since the last SMR was submitted. If the Discharger monitors any pollutant more frequently than required by this Order, the results of this monitoring shall be included in the calculations and reporting of the data submitted in the SMR. 3. Monitoring periods and reporting for all required monitoring shall be completed according to the following schedule: CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-17 Table E-6. Monitoring Periods and Reporting Schedule SMR Name Permit Section for Monitoring & Sampling Data Included in Report SMR Submittal Frequencies SMR Due Date NPDES Monitoring Report- Monthly MRP Sections III (Influent), IV (Effluent) and VIII (Receiving Water) Monthly First day of second calendar month following period of sampling (first report due February 1st 2015) NPDES Monitoring Report- Quarterly MRP Section IV (Effluent) and VIII (Receiving Water) Quarterly February 1, May 1, August 1, and November 1st (first report due Feb 1st 2015) NPDES Monitoring Report- Annual MRP Section IV (Effluent), V (Toxicity) and VIII (Receiving Water) Annually February 1st, (first report due Feb 1st 2015 following October 2014 sampling) Summary Report[1] Attachment D, Standard Provision VIII.D.8 and Salt and Nutrient Management Plan Order Section VI.C.3.a Annually February 15th Facilities Evaluation Order Section VI.C.2.b Special Provisions Once per permit March 1, 2017 Effluent pH Evaluation Order Section VI.C.2.c Special Provisions Once per permit February 1, 2016 Pretreatment- Quarterly Order Section IX.B (pretreatment) Quarterly February 1, May 1, August 1, and November 1st (first report due Feb 1st 2015) Pretreatment- Annual Order Section IX.B (pretreatment) Annually February 1st Biosolids (Sludge) Technical Report MRP Section IX.A (Biosolids) Annually February 19th [1] Based on Discharger’s request, the standard February 1st deadline for this Summary Report has been revised to February 15th to accommodate work on year-end sampling and pretreatment reporting. 4. Reporting Protocols. The Discharger shall report with each sample result the applicable Reporting Level (RL) and the current Method Detection Limit (MDL), as determined by the procedure in 40 C.F.R. part 136. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-18 The Discharger shall report the results of analytical determinations for the presence of chemical constituents in a sample using the following reporting protocols: a. Sample results greater than or equal to the RL shall be reported as measured by the laboratory (i.e., the measured chemical concentration in the sample). b. Sample results less than the RL, but greater than or equal to the laboratory’s MDL, shall be reported as “Detected, but Not Quantified,” or DNQ. The estimated chemical concentration of the sample shall also be reported. For the purposes of data collection, the laboratory shall write the estimated chemical concentration next to DNQ. The laboratory may, if such information is available, include numerical estimates of the data quality for the reported result. Numerical estimates of data quality may be percent accuracy (± a percentage of the reported value), numerical ranges (low to high), or any other means considered appropriate by the laboratory. c. Sample results less than the laboratory’s MDL shall be reported as “Not Detected,” or ND. d. Dischargers are to instruct laboratories to establish calibration standards so that the ML value (or its equivalent if there is differential treatment of samples relative to calibration standards) is the lowest calibration standard. At no time is the Discharger to use analytical data derived from extrapolation beyond the lowest point of the calibration curve. 5. The Discharger shall submit SMRs in accordance with the following requirements: a. The Discharger shall arrange all reported data in a tabular format. The data shall be summarized to clearly illustrate whether the facility is operating in compliance with interim and/or final effluent limitations. The Discharger is not required to duplicate the submittal of data that is entered in a tabular format within CIWQS. When electronic submittal of data is required and CIWQS does not provide for entry into a tabular format within the system, the Discharger shall electronically submit the data in a tabular format as an attachment. b. Discharger shall include electronic pdfs of all lab data sheets and chain of custodies for analytical data as attachments to the SMRs. Additionally, any calculations used to provide calculated values (e.g., removal efficiencies, coliform medians, average monthly values, average weekly values, intake credits, etc.) shall be attached such that the data and/or assumptions used can be validated. c. In the SMR, the Discharger shall clearly identify violations of the WDRs and discuss corrective actions taken or planned and the proposed time schedule for corrective actions. Identified violations must include a description of the requirement that was violated and a description of the violation. C. Discharge Monitoring Reports (DMRs) 1. At any time during the term of this permit, the State or Central Coast Water Board may notify the Discharger to electronically submit DMRs. Until such notification is given specifically for the submittal of DMRs, the Discharger shall submit DMRs in accordance with the requirements described below. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT E – MRP E-19 2. DMRs must be signed and certified as required by the standard provisions (Attachment D). The Discharger shall submit the original DMR and one copy of the DMR to the address listed below: 3. All discharge monitoring results must be reported on the official U.S. EPA pre-printed DMR forms (EPA Form 3320-1) or on self-generated forms that follow the exact same format of EPA Form 3320-1. D. Other Reports 1. Unless otherwise noted, with the next SMR, the Discharger shall report the results of any special monitoring, TREs, or other data or information that results from the Special Provisions, section V. C, of the Order. STANDARD MAIL FEDEX/UPS/ OTHER PRIVATE CARRIERS State Water Resources Control Board Division of Water Quality c/o DMR Processing Center PO Box 100 Sacramento, CA 95812-1000 State Water Resources Control Board Division of Water Quality c/o DMR Processing Center 1001 I Street, 15th Floor Sacramento, CA 95814 CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-1 F. ATTACHMENT F – FACT SHE ET Contents I. Permit Information ...................................................................................................................... F-3 II. Facility Description ..................................................................................................................... F-4 A. Description of Wastewater and Biosolids Treatment and Controls ...................................... F-4 B. Discharge Points and Receiving Waters ............................................................................. F-4 C. Summary of Existing Requirements and Self-Monitoring Report (SMR) Data ..................... F-5 D. Compliance Summary ......................................................................................................... F-7 E. Planned Changes ............................................................................................................... F-7 III. Applicable Plans, Policies, and Regulations ............................................................................... F-7 A. Legal Authorities ................................................................................................................. F-7 B. California Environmental Quality Act (CEQA) ...................................................................... F-7 C. State and Federal Laws, Regulations, Policies, and Plans .................................................. F-8 D. Impaired Water Bodies on CWA 303(d) List ........................................................................ F-9 E. Other Plans, Policies and Regulations ................................................................................ F-9 IV. Rationale For Effluent Limitations and Discharge Specifications .............................................. F-10 A. Discharge Prohibitions ...................................................................................................... F-10 B. Technology-Based Effluent Limitations ............................................................................. F-11 1. Scope and Authority ..................................................................................................... F-11 2. Applicable Technology-Based Effluent Limitations ........................................................ F-11 C. Water Quality-Based Effluent Limitations (WQBELs) ........................................................ F-13 1. Scope and Authority ..................................................................................................... F-13 2. Applicable Beneficial Uses and Water Quality Criteria and Objectives .......................... F-13 3. Determining the Need for WQBELs .............................................................................. F-14 4. WQBEL Calculations .................................................................................................... F-19 5. Whole Effluent Toxicity (WET) ...................................................................................... F-20 6. Basin Plan .................................................................................................................... F-22 D. Final Effluent Limitation Considerations ............................................................................ F-24 1. Anti-Backsliding Requirements ..................................................................................... F-24 2. Antidegradation Policies ............................................................................................... F-24 3. Stringency of Requirements for Individual Pollutants .................................................... F-25 4. Summary of Final Effluent Limitations – Discharge Point 001 ....................................... F-25 E. Interim Effluent Limitations ................................................................................................ F-27 F. Land Discharge Specifications – Not Applicable ............................................................... F-27 G. Recycling Specifications ................................................................................................... F-27 V. Rationale for Receiving Water Limitations ................................................................................ F-27 A. Surface Water ................................................................................................................... F-27 B. Groundwater ..................................................................................................................... F-27 VI. Rationale For Monitoring and Reporting Requirements ............................................................ F-27 VII. Rationale for Provisions ........................................................................................................... F-29 A. Standard Provisions .......................................................................................................... F-29 B. Special Provisions............................................................................................................. F-29 1. Reopener Provisions .................................................................................................... F-29 2. Special Studies and Additional Monitoring Requirements ............................................. F-29 3. Best Management Practices and Pollution Prevention .................................................. F-30 4. Construction, Operation, and Maintenance Specifications ............................................ F-30 5. Special Provisions for Municipal Facilities (POTWs Only) ............................................. F-30 CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-2 6. Other Special Provisions .............................................................................................. F-31 7. Compliance Schedules – Not Applicable ...................................................................... F-31 VIII. Public Participation ................................................................................................................... F-31 A. Notification of Interested Parties ....................................................................................... F-31 B. Written Comments ............................................................................................................ F-32 C. Public Hearing .................................................................................................................. F-34 D. Reconsideration of Waste Discharge Requirements ......................................................... F-34 E. Information and Copying ................................................................................................... F-34 F. Register of Interested Persons .......................................................................................... F-35 G. Additional Information ....................................................................................................... F-35 Tables Table F-1. Facility Information ......................................................................................................... F-3 Table F-2. Historic Effluent Limitations and Monitoring Data ............................................................ F-5 Table F-3. Compliance Summary .................................................................................................... F-7 Table F-4. Basin Plan Beneficial Uses ............................................................................................. F-8 Table F-5. Technology-Based Effluent Limitations ......................................................................... F-13 Table F-6. Summary of RPA Results ............................................................................................. F-15 Table F-9. Calculation of Human Health WQBELs ......................................................................... F-20 Table F-10. Summary of Final Effluent Limitations ........................................................................... F-26 CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-3 ATTACHMENT F – FACT SHEET As described in section I of this Order, the Central Coast Water Board incorporates this Fact Sheet as findings of the Central Coast Water Board supporting the issuance of this Order. This Fact Sheet includes the legal requirements and technical rationale that serve as the basis for the requirements of this Order. This Order has been prepared under a standardized format to accommodate a broad range of discharge requirements for dischargers in California. Only those sections or subsections of this Order that are specifically identified as “not applicable” have been determined not to apply to this Discharger. Sections or subsections of this Order not specifically identified as “not applicable” are fully applicable to this Discharger. I. PERMIT INFORMATION The following table summarizes administrative information related to the facility. Table F-1. Facility Information WDID 3 400107001 Discharger City of San Luis Obispo Name of Facility Water Resource Recovery Facility Facility Address 35 Prado Road San Luis Obispo, CA 93401 David Hix Facility Contact, Title and Phone David Hix, Deputy Director, Utilities, Wastewater, (805) 781-7039 Authorized Person to Sign and Submit Reports David Hix, Deputy Director, Utilities, Wastewater, (805) 781-7039 Mailing Address 879 Morro Street, San Luis Obispo, CA 93401 Billing Address SAME Type of Facility POTW Major or Minor Facility Major Threat to Water Quality 2 Complexity A Pretreatment Program Y Recycling Requirements Master Permit for Reclamation Order No. R3-2003-0081 Facility Permitted Flow 5.1 million gallons per day (MGD) Facility Design Flow 5.1 million gallons per day (MGD) Watershed Estero Bay Hydrologic Unit Receiving Water San Luis Obispo Creek Receiving Water Type Inland surface water A. The City of San Luis Obispo (hereinafter Discharger) is the owner and operator of the City of San Luis Obispo Water Resource Recovery Facility (hereinafter Facility), a wastewater treatment facility. For the purposes of this Order, references to the “discharger” or “permittee” in applicable federal and state laws, regulations, plans, or policy are held to be equivalent to references to the Discharger herein. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-4 B. The Facility discharges wastewater to San Luis Obispo Creek, a water of the United States. The Discharger was previously regulated by Order No. R3-2002-0043, National Pollutant Discharge Elimination System (NPDES) Permit No. CA0049224, adopted on March 31, 2002, and modified on March 25, 2005, which has been administratively extended. Attachment B provides a map of the area around the Facility. Attachment C provides a flow schematic of the Facility. Prior to making any change in the point of discharge, place of use, or purpose of use of treated wastewater that results in a decrease of flow in any portion of a watercourse, the Discharger must file a petition with the State Water Board, Division of Water Rights, and receive approval for such a change. The State Water Board retains the jurisdictional authority to enforce such requirements under Water Code section 1211. C. The Discharger filed a report of waste discharge and submitted an application for reissuance of its WDRs and NPDES permit on November 29, 2006. II. FACILITY DESCRIPTION The Discharger owns and operates a wastewater collection, treatment, and disposal system for the City of San Luis Obispo, California Polytechnic State University, and the San Luis Obispo Airport, including a population of approximately 40,000 individuals. The WRF design daily average flow capacity is 5.1 million gallons per day (MGD). A. Description of Wastewater and Biosolids Treatment and Controls The Discharger owns and operates a publicly owned treatment works. The treatment system consists of mechanical screening, grit removal, primary settling, biofiltration, secondary settling, nitrification, final settling, cooling using evaporative cooling towers, dual media filtration, and chlorination/dechlorination. Solids are thickened in a dissolved air flotation thickener and stabilized in anaerobic digesters. During the drier parts of the year the sludge is placed in drying beds, dried and stockpiled to await disposal. A belt press is used for the remainder of the year. Biosolids are hauled off- site by a contractor for composting. Finished compost is sold to agricultural, horticultural, and/or landscape operations. California Polytechnic State University and the San Luis Obispo County Airport retain ownership and direct responsibility for wastewater collection and transport systems up to the point of discharge into the wastewater treatment plant and/or interceptors owned and operated by the City of San Luis Obispo. It is incumbent upon these local sewering entities to protect the environment to the greatest degree possible and ensure their local collection systems, as well as the receiving sewerage system, are protected and utilized properly. This responsibility includes preventing overflows and may include restricting or prohibiting the volume, type, or concentration of wastes that might be added to the system. B. Discharge Points and Receiving Waters The Facility is located in Section 10, T31S, R12E, MDB&M, as shown in Attachment B to this Order. Treated municipal wastewater is discharged at Discharge Point 001 to San Luis Obispo Creek, a water of the United States, at a latitude of 35° 14ʹ 10ʺ N and longitude 120° 40ʹ 45ʺ W. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-5 C. Summary of Existing Requirements and Self-Monitoring Report (SMR) Data Effluent limitations contained in the existing Order for discharges from Discharge Point 001 (Monitoring Location EFF-001) and representative monitoring data from the term of the previous Order (i.e., January 2008 through December 2012) are as follows: Table F-2. Historic Effluent Limitations and Monitoring Data Parameter Units Effluent Limitations Monitoring Data (January 2008- December 2012 Monthly Average Weekly Average Daily Maximum Instantaneous Maximum Highest Monthly Average Highest Weekly Average Highest Daily Discharge BOD5 mg/L 10 30 50 --- 13.6 13.7 NA lb/day [1] [2] [3] --- 374 804 NA % removal Not less than 85% removal rate 93.1[4] NA NA TSS mg/L 10 30 75 --- 19 24.9 NA lb/day [2] [3] [5] --- 673 2099 NA % removal Not less than 85% removal rate 95.6[6] NA NA Oil and Grease mg/L 5 --- 10 --- 6 NA 16 lb/day [7] --- [8] --- 405 NA 1372 Dissolved Oxygen mg/L --- --- --- 4.0 NA NA 0.3[9] pH s.u. Between 6.5 and 8.3 at all times 6.6 to 7.8 Fecal Coliform MPN/10 0 mL --- 2.2 --- --- --- 22 --- Total Coliform MPN/10 0 mL --- 23 --- 240 --- 7.9 130 Settleable Solids mL/L 0.1 --- --- --- NA NA < 0.1 Chlorodibro momethane[10] µg/L 0.4 --- 0.8 --- NA NA 13.8 Dichlorobro momethane[10] µg/L 0.6 --- 1.1 --- NA NA 30.8 Selenium µg/L 4.1 --- 8.2 --- 4.1 NA 4.1 Bromoform µg/L 4.3 --- 8.6 --- 1.9 NA 1.9 Cyanide µg/L 4.3 --- 8.6 --- 4.0 NA 4.0 Aluminum µg/L --- --- --- 1,000 NA NA 40 Barium µg/L --- --- --- 1,000 NA NA 36.2 Fluoride µg/L --- --- --- 2,000 NA NA 900 cis-1,2- Dichloroeth ylene µg/L --- --- --- 6 NA NA NA Methyl-tert- butyl ether µg/L --- --- --- 13 NA NA < 1 Styrene µg/L --- --- --- 100 NA NA < 0.5 Trichloroflu oromethan e µg/L --- --- --- 150 NA NA < 1 1,1,2-µg/L --- --- --- 1,200 NA NA < 0.5 CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-6 Parameter Units Effluent Limitations Monitoring Data (January 2008- December 2012 Monthly Average Weekly Average Daily Maximum Instantaneous Maximum Highest Monthly Average Highest Weekly Average Highest Daily Discharge Trichloro- 1,2,2- Trifluoroeth ane Xylenes µg/L --- --- --- 1,750 NA NA 0.5 Alachlor µg/L --- --- --- 2 NA NA < 0.2 Atrazine µg/L --- --- --- 3 NA NA < 0.5 Bentazon µg/L --- --- --- 18 NA NA < 2 Carbofuran µg/L --- --- --- 18 NA NA < 5 2,4-D µg/L --- --- --- 70 NA NA < 2 Dalapon µg/L --- --- --- 200 NA NA < 10 Dibromochl oropropane µg/L --- --- --- 0.2 NA NA NA Di (2- ethylhexyl) adipate µg/L --- --- --- 400 NA NA < 5 Di (2- ethylhexyl) phthalate µg/L --- --- --- 4 NA NA NA Dinoseb µg/L --- --- --- 7 NA NA < 1 Diquat µg/L --- --- --- 20 NA NA < 2 Endothall µg/L --- --- --- 100 NA NA < 40 Ethylene Dibromide µg/L --- --- --- 0.05 NA NA NA Glyphosate µg/L --- --- --- 700 NA NA < 20 Methoxychl or µg/L --- --- --- 40 NA NA < 0.1 Molinate µg/L --- --- --- 20 NA NA < 2 Oxamyl µg/L --- --- --- 200 NA NA < 5 Picloram µg/L --- --- --- 500 NA NA < 1 Simazine µg/L --- --- --- 4 NA NA < 1 Thiobencar b µg/L --- --- --- 70 NA NA < 1 2, 4, 5-TP (Silvex) µg/L --- --- --- 50 NA NA < 1 Footnotes to Table F-4: Source: San Luis Obispo Water Reclamation Facility Modified Order No. R3-2002-0043. Effluent data from January 2008 to December 2012 retrieved from CIWQS and ICIS. [1] Determined by multiplying 10 mg/L times the measured flow rate discharged to San Luis Obispo Creek. [2] Determined by multiplying 30 mg/L times the measured flow rate discharged to San Luis Obispo Creek. [3] Determined by multiplying 50 mg/L times the measured flow rate discharged to San Luis Obispo Creek. [4] This value represents the lowest reported value of the minimum percent removal of BOD. [5] Determined by multiplying 75 mg/L times the measured flow rate discharged to San Luis Obispo Creek. [6] This value represents the lowest reported value of the minimum percent removal of TSS. [7] Determined by multiplying 5 mg/L times the average monthly measured flow rate discharged to San Luis Obispo Creek. [8] Determined by multiplying 10 mg/L times the monthly average daily maximum measured flow rate discharged to San Luis Obispo Creek. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-7 [9] This value represents the lowest reported value of the minimum dissolved oxygen reported concentrations. [10] Final effluent limitations contained in Time Schedule Order R3-2010-0013. mg/L = milligrams per liter µg/L = micrograms per liter lb/day = pounds per day ND = non-detect NA = not available D. Compliance Summary A review of the available effluent monitoring data, submitted in the Discharger’s self- monitoring reports for the period from January 2008 through December 2012, indicate that the Discharger had effluent limitation violations for BOD, TSS, oil and grease, and fecal coliform. The values reported in exceedance of effluent limitations are summarized in the table below. Table F-3. Compliance Summary Monitoring Period Violation Type Pollutant Reported Value Permit Limitation Units March 2008 7-sample median Fecal Coliform 22 2.2 MPN/100 ml July 2008 Monthly Average BOD 13.6 10 mg/L December 2008 Monthly Average TSS 19 10 mg/L November 2009 Monthly Average Oil & Grease 6 5 mg/L January 2010 Daily Maximum Oil & Grease 16 10 mg/L December 2010 Monthly Average TSS 10.3 10 mg/L E. Planned Changes The Discharger will be upgrading the facility to address both nitrogen and trihalomethanes in order to meet the final effluent limitations in this permit. Nitrogen removal will address the new limitations incorporated as part of the implementation of the San Luis Obispo Creek Nutrient Total Maximum Daily Load (see discussion in Attachment F Section IV.C.3). Changes to the disinfection process will prevent the formation of trihalomethanes in the effluent. The City is in the process of studying and designing the upgrades. The City has adopted a rate structure in anticipation of facility upgrades. City staff will be working with the Central Coast Water Board during the duration of this permit term to implement those upgrades. III. APPLICABLE PLANS, POLICIES, AND REGULATIONS The requirements contained in this Order are based on the requirements and authorities described in this section. A. Legal Authorities This Order serves as WDRs pursuant to article 4, chapter 4, division 7 of the California Water Code (commencing with section 13260). This Order is also issued pursuant to section 402 of the federal Clean Water Act (CWA) and implementing regulations adopted by the U.S. EPA and chapter 5.5, division 7 of the Water Code (commencing with section 13370). It shall serve as an NPDES permit for point source discharges from this facility to surface waters. B. California Environmental Quality Act (CEQA) Under Water Code section 13389, this action to adopt an NPDES permit is exempt from the provisions of Chapter 3 of CEQA, (commencing with section 21100) of Division 13 of the Public Resources Code. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-8 C. State and Federal Laws, Regulations, Policies, and Plans 1. Water Quality Control Plan. The Central Coast Water Board has adopted the Water Quality Control Plan for the Central Coastal Basin (hereinafter Basin Plan), which designates beneficial uses, establishes water quality objectives, and contains implementation programs and policies to achieve those objectives for receiving waters within the Region. In addition, the Basin Plan implements State Water Board Resolution 88-63, which established state policy that all waters, with certain exceptions, should be considered suitable or potentially suitable for municipal or domestic supply. The Facility discharges to San Luis Obispo Creek. Beneficial uses applicable to San Luis Obispo Creek (below W. Marsh Street) are as follows: Table F-4. Basin Plan Beneficial Uses Discharge Point Receiving Water Name Beneficial Use(s) 001 San Luis Obispo Creek (below W. Marsh Street) Existing: Municipal and domestic (MUN); agricultural supply (AGR); ground water recharge (GWR); water contact recreation (REC1); non-contact water recreation (REC2); wildlife habitat (WILD); cold fresh water habitat (COLD); warm fresh water habitat (WARM); migration of aquatic organisms (MIGR); fish spawning, reproduction, and/or early development (SPWN); freshwater replenishment (FRESH); commercial and sport fishing (COMM). Intermittent: None. Potential: None. Groundwater throughout the Central Coast Region is suitable for agricultural water supply, municipal and domestic water supply, and industrial use. Requirements of this Order implement the Basin Plan. 2. Thermal Plan. The State Water Board adopted the Water Quality Control Plan for Control of Temperature in the Coastal and Interstate Waters and Enclosed Bays and Estuaries of California (Thermal Plan) on January 7, 1971, and amended this plan on September 18, 1975. This plan contains temperature objectives for inland surface waters. 3. National Toxics Rule (NTR) and California Toxics Rule (CTR). U.S. EPA adopted the NTR on December 22, 1992, and later amended it on May 4, 1995 and November 9, 1999. About forty criteria in the NTR applied in California. On May 18, 2000, U.S. EPA adopted the CTR. The CTR promulgated new toxics criteria for California and, in addition, incorporated the previously adopted NTR criteria that were applicable in the state. The CTR was amended on February 13, 2001. These rules contain federal water quality criteria for priority pollutants. 4. State Implementation Policy. On March 2, 2000, the State Water Board adopted the Policy for Implementation of Toxics Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California (State Implementation Policy or SIP). The SIP became effective on April 28, 2000, with respect to the priority pollutant criteria promulgated for California by the U.S. EPA through the NTR and to the priority pollutant objectives established by the Central Coast Water Board in the Basin Plan. The SIP became CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-9 effective on May 18, 2000, with respect to the priority pollutant criteria promulgated by the U.S. EPA through the CTR. The State Water Board adopted amendments to the SIP on February 24, 2005, that became effective on July 13, 2005. The SIP establishes implementation provisions for priority pollutant criteria and objectives and provisions for chronic toxicity control. Requirements of this Order implement the SIP. 5. Antidegradation Policy. Federal regulation 40 C.F.R. section 131.12 requires that the state water quality standards include an antidegradation policy consistent with the federal policy. The State Water Board established California’s antidegradation policy in State Water Board Resolution 68-16. Resolution 68-16 is deemed to incorporate the federal antidegradation policy where the federal policy applies under federal law. Resolution 68-16 requires that existing water quality be maintained unless degradation is justified based on specific findings. The Central Coast Water Board’s Basin Plan implements, and incorporates by reference, both the State and federal antidegradation policies. The permitted discharge must be consistent with the antidegradation provision of 40 C.F.R. section 131.12 and State Water Board Resolution 68-16. 6. Anti-Backsliding Requirements. Sections 402(o) and 303(d)(4) of the CWA and federal regulations at 40 C.F.R. section 122.44(l) restrict backsliding in NPDES permits. These anti-backsliding provisions require that effluent limitations in a reissued permit must be as stringent as those in the previous permit, with some exceptions in which limitations may be relaxed. 7. Endangered Species Act Requirements. This Order does not authorize any act that results in the taking of a threatened or endangered species or any act that is now prohibited, or becomes prohibited in the future, under either the California Endangered Species Act (Fish and Game Code, §§ 2050 to 2097) or the Federal Endangered Species Act (16 U.S.C.A. §§ 1531 to 1544). This Order requires compliance with effluent limits, receiving water limits, and other requirements to protect the beneficial uses of waters of the state. The Discharger is responsible for meeting all requirements of the applicable Endangered Species Act. D. Impaired Water Bodies on CWA 303(d) List CWA section 303(d) requires states to identify specific water bodies where water quality standards are not expected to be met after implementation of technology-based effluent limitations on point sources. For all 303(d) listed water bodies and pollutants, the Regional Water Boards must develop and implement Total Maximum Daily Loads (TMDLs) that will specify Waste Load Allocations (WLAs) for point sources and Load Allocations (LAs) for non- point sources. The U.S. EPA approved the State’s 2010 303(d) list of impaired water bodies on November 12, 2010. The 2010 303(d) list identifies San Luis Obispo Creek, below West Osos Street is listed for chloride, chlorpyrifos, nitrate, nutrients, pathogens, and sodium. A TMDL for nitrate (reported analytically as nitrate-nitrogen) has been developed for the San Luis Obispo Creek, below West Marsh Street. Effluent limitations for nitrate-nitrogen are implemented in this Permit based on the Central Coast Water Board Resolution R3-2005- 0106 (TMDL for nitrate-nitrogen). E. Other Plans, Policies and Regulations 1. Storm Water Management. For the control of storm water discharged from the site of the wastewater treatment facilities, the Order requires the Discharger to seek authorization to discharge under and meet the requirements of the State Water Resource Control Board’s Water Quality Order No. 97-03-DWQ, NPDES General Permit No. CAS000001, CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-10 Waste Discharge Requirements for Discharges of Storm Water Associated with Industrial Activities Excluding Construction Activities, if applicable. 2. Statewide General Waste Discharge Requirements for Sanitary Sewer Systems (State Water Board Order No. 2006-0003-DWQ). The General Permit, adopted on May 2, 2006, is applicable to all “federal and state agencies, municipalities, counties, districts, and other public entities that own or operate sanitary sewer systems greater than one mile in length that collect and/or convey untreated or partially treated wastewater to a publicly owned treatment facility in the State of California.” The purpose of the General Permit is to promote the proper and efficient management, operation, and maintenance of sanitary sewer systems and to minimize the occurrences and impacts of sanitary sewer overflows. The Discharger has obtained coverage under the General Permit. 3. Recycled Water Policy. The State Water Board’s Recycled Water Policy, which was adopted via Resolution 2009-0011, calls for the development of regional groundwater basin/sub-basin salt/nutrient management plans. Pursuant to the letter from statewide water and wastewater entities dated December 19, 2008, and attached to Resolution 2009-0011, the local water and wastewater entities, together with local salt/nutrient contributing stakeholders, will fund locally driven and controlled, collaborative processes open to all stakeholders that will prepare salt and nutrient management plans for each basin/sub-basin in California, including compliance with CEQA and participation by Central Coast Water Board staff. The policy was added to establish participation in development of a regional groundwater basin/sub-basin salt/nutrient management plan. IV. RATIONALE FOR EFFLUENT LIMITATIONS AND DISCHARGE SPECIFICATIONS The CWA requires point source dischargers to control the amount of conventional, non- conventional, and toxic pollutants that are discharged into the waters of the United States. The control of pollutants discharged is established through effluent limitations and other requirements in NPDES permits. There are two principal bases for effluent limitations in the Code of Federal Regulations: 40 C.F.R. §122.44(a) requires that permits include applicable technology-based limitations and standards; and 40 C.F.R. §122.44(d) requires that permits include water quality- based effluent limitations to attain and maintain applicable numeric and narrative water quality criteria to protect the beneficial uses of the receiving water. When numeric water quality objectives have not been established, but a discharge has the reasonable potential to cause or contribute to an excursion above a narrative criterion, WQBELs may be established using one or more of three methods described at 40 C.F.R. §122.44 (d) - 1) WQBELs may be established using a calculated water quality criterion derived from a proposed State criterion or an explicit State policy or regulation interpreting its narrative criterion; 2) WQBELs may be established on a case-by-case basis using U.S. EPA criteria guidance published under CWA Section 304 (a); or 3) WQBELs may be established using an indicator parameter for the pollutant of concern. Several specific factors affecting the development of limitations and requirements in this Order are discussed below. A. Discharge Prohibitions 1. Discharge Prohibition III.A (No discharge at a location except as described by this Order): The Order authorizes a single, specific point of discharge to surface waters, and the limitations and conditions established by the Order are based on specific information provided by the Discharger and gained by the Central Coast Water Board through site visits, monitoring reports, and other information. Discharges to surface waters at CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-11 locations not contemplated by this Order or discharges of a character not contemplated by this Order are therefore viewed as inconsistent with CWA § 402’s prohibition against discharges of pollutants except in compliance with the Act’s permit requirements, effluent limitations, and other enumerated provisions. This prohibition has been retained from the previous Order. 2. Discharge Prohibition III.B (No discharge of wastewaters to San Luis Obispo Creek containing bentazon, molinate, or thiobencarb): This prohibition is the same as in the previous permit and is based on the requirements of the Basin Plan. B. Technology-Based Effluent Limitations 1. Scope and Authority Section 301(b) of the CWA and implementing U.S. EPA permit regulations at 40 C.F.R. § 122.44 require that permits include conditions meeting applicable technology-based requirements at a minimum, and any more stringent effluent limitations necessary to meet applicable water quality standards. Where the USEPA has not yet developed technology based standards for a particular industry or a particular pollutant, CWA Section 402 (a) (1) and USEPA regulations at 40 C.F.R. § 125.3 authorize the use of best professional judgment (BPJ) to derive technology-based effluent limitations on a case-by-case basis. When BPJ is used, the permit writer must consider specific factors outlined at 40 C.F.R. § 125.3. Regulations promulgated in 40 C.F.R. § 125.3(a)(1) require technology-based effluent limitations for municipal Dischargers to be placed in NPDES permits based on Secondary Treatment Standards or Equivalent to Secondary Treatment Standards. The Federal Water Pollution Control Act Amendments of 1972 (PL 92-500) established the minimum performance requirements for POTWs [defined in section 304(d)(1)]. Section 301(b)(1)(B) of that Act requires that such treatment works must, as a minimum, meet effluent limitations based on secondary treatment as defined by the U.S. EPA Administrator. Based on this statutory requirement, U.S. EPA developed secondary treatment regulations, which are specified in 40 C.F.R. part 133. These technology-based regulations apply to all municipal wastewater treatment plants and identify the minimum level of effluent quality attainable by secondary treatment in terms of biochemical oxygen demand (BOD5), total suspended solids (TSS), and pH. The discharge authorized by this Order must meet minimum federal technology-based requirements based on Secondary Treatment Standards at 40 C.F.R. part 133. 2. Applicable Technology-Based Effluent Limitations Title 40 C.F.R. § 122.45(f)(1) requires effluent limitations be expressed in terms of mass, with some exceptions, and 40 C.F.R. § 122.45(f)(2) allows pollutants that are limited in terms of mass to additionally be limited in terms of other units of measurement. This Order includes effluent limitations expressed in terms of mass and concentration. In addition, pursuant to the exceptions to mass limitations provided in 40 C.F.R. § 122.45(f)(1), some effluent limitations are not expressed in terms of mass, such as pH and temperature, and when the applicable standards are expressed in terms of concentration and mass limitations are not necessary to protect the beneficial uses of the receiving waters. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-12 a. BOD and TSS. Federal regulations, 40 C.F.R. part 133, establish the minimum weekly and monthly average level of effluent quality attainable by secondary treatment for BOD5 and TSS. Section 301(b) of the CWA and section 122.44(d) require that permits include limitations more stringent than applicable federal technology-based requirements where necessary to achieve applicable water quality standards. This Order contains requirements, expressed as a technology equivalence requirements, more stringent than secondary treatment requirements that are necessary to meet applicable water quality standards. The Central Coast Water Board has determined that tertiary treatment is necessary to protect the beneficial uses of the receiving stream, thus the final effluent limitations for BOD5 and TSS are based on the technical capability of the tertiary process. The secondary and tertiary treatment standards for BOD5 and TSS are indicators of the effectiveness of the treatment processes. The principal design parameter for wastewater treatment plants is the daily BOD5 and TSS loading rates and the corresponding removal rate of the system. In applying 40 C.F.R. part 133 for weekly and monthly average BOD5 and TSS limitations, the application of tertiary treatment processes results in the ability to achieve lower levels for BOD5 and TSS than the secondary standards currently prescribed; the 30-day average BOD5 and TSS limitations are 10 mg/L, the 7-day average BOD5 and TSS limitations are 30 mg/L. These effluent limitations are based on the capability of a tertiary system. In addition to the average weekly and average monthly effluent limitations, daily maximum effluent limitation of 50 mg/L and 75 mg/L for BOD5 and TSS, respectively, are included in the Order to ensure that the treatment works are not organically overloaded and operate in accordance with design capabilities. In addition, 40 C.F.R. § 133.102, in describing the minimum level of effluent quality attainable by secondary treatment, states that the 30-day average percent removal shall not be less than 85 percent. If 85 percent removal of BOD5 and TSS must be achieved by a secondary treatment plant, it must also be achieved by a tertiary (i.e., treatment beyond secondary level) treatment plant. This Order contains a limitation requiring an average of 85 percent removal of BOD5 and TSS over each calendar month. These effluent limitations are carried over from Order No. R3-2002-0043. b. pH. Federal Regulations, 40 C.F.R. part 133, establishes technology-based effluent limitations for pH. The secondary treatment standards require the pH of the effluent to be no lower than 6.0 and no greater than 9.0 standard units. This techonology-based effluent limitation is not as stringent as the WQBELs for pH as discussed in section IV.C of this Fact sheet; therefore, this Order establishes the more stringent WQBELs for pH. c. Flow. According to the Report of Waste Discharge, the Facility is designed to provide a tertiary level of treatment for up to a design flow of 5.1 MGD. Order No. R3-2002-0043 permitted a daily flow of 5.2 MGD. This Order has established a maximum flow based on the design capacity of the Facility, thus, this Order contains an average dry weather daily discharge flow effluent limit of 5.1 MGD. Further, in accordance with 40 C.F.R. § 122.45(b), mass-based effluent limitations are based on the facility design flow of 5.1 MGD. The following table summarizes technology-based effluent limitations established by this Order. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-13 Table F-5. Technology-Based Effluent Limitations [1] In addition to concentration-based limitations and mass-based limitations for BOD5 and TSS, the Discharger is required to meet an 85 percent removal discharge specification. [2] Mass -based effluent limitations are established using the following formula: Mass (lbs/day) = flow rate (MGD) x 8.34 x effluent limitation (mg/L) where: Mass = mass limitation for a pollutant (lbs/day) Effluent limitation = concentration limit for a pollutant (mg/L) Flow rate = discharge flow rate (5.1 MGD) C. Water Quality-Based Effluent Limitations (WQBELs) 1. Scope and Authority NPDES regulations at 40 C.F.R. 122.44 (d) require that permits include limitations more stringent than applicable federal technology-based requirements where necessary to achieve applicable water quality standards, including numeric and narrative objectives within a standard. The process for determining “reasonable potential” and calculating WQBELs, when necessary, is intended to protect the designated uses of receiving waters as specified in the Basin Plan, and achieve applicable WQOs and criteria that are contained in the Basin Plan and in other applicable State and federal rules, plans, and policies, including applicable water quality criteria from the CTR and the NTR. Where reasonable potential has been established for a pollutant, but there is no num eric criterion or objective for the pollutant, WQBELs must be established in accordance with the requirements of 40 C.F.R. 122.44(d)(1)(vi), using (1) USEPA criteria guidance under CWA section 304(a), supplemented where necessary by other relevant informat ion; (2) an indicator parameter for the pollutant of concern; or (3) a calculated numeric water quality criterion, such as a proposed State criterion or policy interpreting the State’s narrative criterion, supplemented with other relevant information. 2. Applicable Beneficial Uses and Water Quality Criteria and Objectives Beneficial uses described by the Basin Plan for San Luis Obispo Creek are presented in section III.C.1 of this Fact Sheet. Water quality criteria applicable to this receiving water are established by the CTR, the NTR, and by the Basin Plan. Reasonable potential for pollutants with applicable water quality criteria was evaluated for Discharge Point No. 001. Parameter Units Effluent Limitations Average Monthly Average Weekly Maximum Daily Instantaneous Minimum Instantaneous Maximum Flow MGD -- -- 5.1 -- -- Biochemical Oxygen Demand (BOD5) (5-day @ 20 Deg. C) [1] mg/L 10 30 50 -- -- lbs/day [2] 425 1,275 2,125 -- -- Total Suspended Solids [1] mg/L 10 30 75 -- -- lbs/day [2] 425 1,275 3,188 -- -- pH standard units -- -- -- 6.0 9.0 CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-14 3. Determining the Need for WQBELs NPDES regulations at 40 C.F.R. §122.44(d) require effluent limitations to control all pollutants which are or may be discharged at a level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State water quality standard. The SIP, statewide policy that became effective on May 22, 2000, establishes procedures to implement water quality criteria from the NTR and CTR and for priority, toxic pollutant objectives established in the Basin Plan. The implementation procedures of the SIP include methods to determine reasonable potential (for pollutants to cause or contribute to excursions above State water quality standards) and to establish numeric effluent limitations, if necessary, for those pollutants which show reasonable potential. The SIP Section 1.3 requires the Regional Water Board to use all available valid, relevant, and representative receiving water and effluent data and information to conduct a reasonable potential analysis. The Central Coast Water Board analyzed the Discharger’s data for priority pollutants and the nature of the discharge to determine if the discharge has Reasonable Potential. The RPA is based on effluent data retrieved from CIWQS and ICIS, as well as effluent data received from the Discharger for the period of January 2008 to October 2012. Some freshwater water quality criteria for metals are hardness dependent; i.e., as hardness decreases, the toxicity of certain metals increases and the applicable water quality criteria become correspondingly more stringent. The Discharger has not specifically collected hardness data for the receiving water. However, the Central Coast Water Board’s Central Coast Ambient Monitoring Program has a nearby monitoring stations on San Luis Obispo Creek. The median hardness values from those stations are 400 and 330 mg/L as CaCO3, respectively upgradient and downgradient from the discharge location. The Water Board used 330 mg/L as CaCO3 as a conservative estimate of the receiving water hardness to determine hardness-based criteria. To conduct the reasonable potential analysis, the Central Coast Water Board identified the maximum observed effluent (MEC) from effluent data provided by the Discharger and compared these data to the most stringent applicable water quality criterion (C) for each pollutant from the NTR, CTR, and the Basin Plan. The Discharger did not collect background data (B) from the receiving water. Section 1.3 of the SIP establishes three triggers for a finding of reasonable potential. Trigger 1. If the MEC is greater than C, there is reasonable potential, and an effluent limitation is required. Trigger 2. If B is greater than C, and the pollutant is detected in effluent (MEC > ND), there is reasonable potential, and an effluent limitation is required. In this case, the Discharger did not collect background (B) data, so reasonable potential cannot be found by Trigger 2. Trigger 3. After reviewing other available and relevant information, a permit writer may decide that a WQBEL is required. Such additional information may include, but is not limited to: the facility type, the discharge type, solids loading analyses, lack of dilution, history of compliance problems, potential toxic impact of the discharge, fish tissue residue data, water quality and beneficial uses of the receiving water, CWA section 303(d) listing for the pollutant, and the presence of endangered or threatened species or their critical habitat. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-15 The following table summarizes the RPA for each priority pollutant, toxic pollutant, or Title 22 pollutant that was measured in effluent collected for the period January 2008 to December 2012. Table F-6. Summary of RPA Results CTR# Priority Pollutant MEC or Minimum DL (1)(2) (µg/L) Governing WQO/WQC (µg/L) Maximum Background or Minimum (1)(2) DL (µg/L) RPA Results (3) 1 Antimony <1 6 --- No 2 Arsenic <2 10 --- No 3 Beryllium <0.2 4 --- No 4 Cadmium <0.2 5.0 --- No 5a Chromium (III) <1 550 --- No 5b Chromium (VI) <10 11 --- No 6 Copper 19 25.9 --- No 7 Lead 5 14.5 --- No 8 Mercury <0.02 0.05 --- No 9 Nickel 10 100 --- No 10 Selenium 4.1 5 --- No 11 Silver <1 31.6 --- No 12 Thallium <0.2 1.7 --- No 13 Zinc 50 200 --- No 14 Cyanide 4.0 5.2 --- No 15 Asbestos (Fibers/L) <0.3 7,000,000 --- No 16 2,3,7,8-TCDD <6.8x10-7 1.3x10-8 --- No 17 Acrolein <0.05 320 --- No 18 Acrylonitrile <0.05 0.059 --- No 19 Benzene <0.05 1 --- No 20 Bromoform 1.9 4.3 --- No 21 Carbon Tetrachloride <0.05 0.25 --- No 22 Chlorobenzene <0.05 70 --- No 23 Chlorodibromomethane 20 0.401 --- Yes 24 Chloroethane <0.05 No Criteria --- No 25 2-Chloroethylvinyl ether <0.05 No Criteria --- No 26 Chloroform 85.9 No Criteria --- No 27 Dichlorobromomethane 17.6 0.56 --- Yes 28 1,1-Dichloroethane <0.05 5 --- No 29 1,2-Dichloroethane <0.05 0.38 --- No 30 1,1-Dichloroethylene <0.05 0.057 --- No 31 1,2-Dichloropropane <0.05 0.52 --- No 32 1,3-Dichloropropylene <0.05 0.5 --- No 33 Ethylbenzene <0.05 300 --- No 34 Methyl Bromide <0.05 48 --- No 35 Methyl Chloride 0.9 No Criteria --- Ud 36 Methylene Chloride <0.05 4.7 --- No 37 1,1,2,2-Tetrachloroethane <0.05 0.17 --- No 38 Tetrachloroethylene <0.05 0.8 --- No 39 Toluene 1.0 150 --- No 40 1,2-Trans-Dichloroethylene <0.05 10 --- No 41 1,1,1-Trichloroethane <0.05 200 --- No 42 1,1,2-Trichloroethane <0.05 0.6 --- No 43 Trichloroethylene <0.05 2.7 --- No CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-16 CTR# Priority Pollutant MEC or Minimum DL (1)(2) (µg/L) Governing WQO/WQC (µg/L) Maximum Background or Minimum (1)(2) DL (µg/L) RPA Results (3) 44 Vinyl Chloride <0.05 0.5 --- No 45 2-Chlorophenol <0.05 120 --- No 46 2,4-Dichlorophenol <0.05 93 --- No 47 2,4-Dimethylphenol <0.05 540 --- No 48 2-Methyl- 4,6-Dinitrophenol <0.05 13.4 --- No 49 2,4-Dinitrophenol <0.05 70 --- No 50 2-Nitrophenol <0.05 No Criteria --- Ud 51 4-Nitrophenol <0.05 No Criteria --- Ud 52 3-Methyl 4-Chlorophenol <0.05 No Criteria --- Ud 53 Pentachlorophenol 1.2 0.28 --- Yes 54 Phenol <0.05 21,000 --- No 55 2,4,6-Trichlorophenol <0.05 2.1 --- No 56 Acenaphthene <0.05 1,200 --- No 57 Acenaphthylene <0.05 No Criteria --- Ud 58 Anthracene <0.05 9,600 --- No 59 Benzidine <0.05 0.00012 --- No 60 Benzo(a)Anthracene <0.05 0.0044 --- No 61 Benzo(a)Pyrene <0.05 0.0044 --- No 62 Benzo(b)Fluoranthene <0.05 0.0044 --- No 63 Benzo(ghi)Perylene <0.05 No Criteria --- Ud 64 Benzo(k)Fluoranthene <0.05 0.0044 --- No 65 Bis(2-Chloroethoxy)Methane <0.05 No Criteria --- Ud 66 Bis(2-Chloroethyl)Ether <0.05 0.031 --- No 67 Bis(2-Chloroisopropyl)Ether <0.05 1400 --- No 68 Bis(2-Ethylhexyl)Phthalate <0.05 1.8 --- No 69 4-Bromophenyl Phenyl Ether <0.05 No Criteria --- Ud 70 Butylbenzyl Phthalate <0.05 3000 --- No 71 2-Chloronaphthalene <0.05 1700 --- No 72 4-Chlorophenyl Phenyl Ether <0.05 No Criteria --- Ud 73 Chrysene <0.05 0.0044 --- No 74 Dibenzo(a,h)Anthracene <0.05 0.0044 --- No 75 1,2-Dichlorobenzene <0.05 600 --- No 76 1,3-Dichlorobenzene <0.05 400 --- No 77 1,4-Dichlorobenzene <0.05 5 --- No 78 3,3 Dichlorobenzidine <0.05 0.04 --- No 79 Diethyl Phthalate <0.05 23,000 --- No 80 Dimethyl Phthalate <0.05 313,000 --- No 81 Di-n-Butyl Phthalate <0.05 2,700 --- No 82 2,4-Dinitrotoluene <0.05 0.11 --- No 83 2,6-Dinitrotoluene <0.05 No Criteria --- Ud 84 Di-n-Octyl Phthalate <0.05 No Criteria --- Ud 85 1,2-Diphenylhydrazine <0.05 0.04 --- No 86 Fluoranthene <0.05 300 --- No 87 Fluorene <0.05 1,300 --- No 88 Hexachlorobenzene <0.05 0.00075 --- No 89 Hexachlorobutadiene <0.05 0.44 --- No 90 Hexachlorocyclopentadiene <0.05 50 --- No 91 Hexachloroethane <0.05 1.9 --- No 92 Indeno(1,2,3-cd)Pyrene <0.05 0.0044 --- No CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-17 CTR# Priority Pollutant MEC or Minimum DL (1)(2) (µg/L) Governing WQO/WQC (µg/L) Maximum Background or Minimum (1)(2) DL (µg/L) RPA Results (3) 93 Isophorone <0.05 8.4 --- No 94 Naphthalene <0.05 No Criteria --- Ud 95 Nitrobenzene <0.05 17 --- No 96 N-Nitrosodimethylamine 12 0.00069 --- Yes 97 N-Nitrosodi-n-Propylamine <0.05 0.005 --- No 98 N-Nitrosodiphenylamine <0.05 5 --- No 99 Phenanthrene <0.05 No Criteria --- Ud 100 Pyrene <0.05 960 --- No 101 1,2,4-Trichlorobenzene <0.05 5 --- No 102 Aldrin <0.05 0.00013 --- No 103 alpha-BHC <0.05 0.0039 --- No 104 beta-BHC <0.05 0.014 --- No 105 gamma-BHC <0.05 0.019 --- No 106 delta-BHC <0.05 No Criteria --- Ud 107 Chlordane <0.05 0.00057 --- No 108 4,4'-DDT <0.05 0.00059 --- No 109 4,4'-DDE <0.05 0.00059 --- No 110 4,4'-DDD <0.05 0.00083 --- No 111 Dieldrin <0.05 0.00014 --- No 112 alpha-Endosulfan <0.05 0.056 --- No 113 beta-Endolsulfan <0.05 0.056 --- No 114 Endosulfan Sulfate <0.05 110 --- No 115 Endrin <0.05 0.036 --- No 116 Endrin Aldehyde <0.05 0.76 --- No 117 Heptachlor <0.05 0.00021 --- No 118 Heptachlor Epoxide <0.05 0.0001 --- No 119- 125 PCBs sum <0.05 0.00017 --- No 126 Toxaphene <0.05 0.0002 --- No Drinking Water Quality Objectives Aluminum 40 1,000 --- No Barium 36.2 1,000 --- No Fluoride 900 1,000 --- No Nitrate (as NO3) (mg/L) (4) 260 45 --- Yes Nitrate+Nitrite (sum as N) (mg/L) 58.7 10 --- Yes Nitrite (as N) (mg/L) <0.1 1 --- No Methyl-tert-butyl-ether <1 13 --- No Styrene <0.5 100 --- No Alachlor <0.2 2 --- No Atrazine <0.5 1 --- No Bentazon <2 18 --- No Carbofuran <5 18 --- No 2,4-D <2 70 --- No Dalapon <10 200 --- No Dibromochloropropane --- 0.2 --- No Di (2-ethylhexyl) adipate <5 400 --- No Dinoseb <1 7 --- No Diquat <2 20 --- No CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-18 CTR# Priority Pollutant MEC or Minimum DL (1)(2) (µg/L) Governing WQO/WQC (µg/L) Maximum Background or Minimum (1)(2) DL (µg/L) RPA Results (3) Endothall <40 100 --- No Ethylene Dibromide --- 0.05 --- Ud Glyphosate <20 700 --- No Methoxychlor <0.1 30 --- No Molinate <2 20 --- No Oxamyl <5 50 --- No Picloram <1 500 --- No Simazine <1 4 --- No Thiobencarb <1 70 --- No 2, 4, 5-TP (Silvex) <1 50 --- No Trichlorofluoromethane <1 150 --- No 1,1,2-Trichloro-1,2,2- Trifluoroethane <0.5 1,200 --- No Xylenes 0.5 1,750 --- No Tributyltin --- No Criteria --- Ud Total PAHs --- No Criteria --- Ud Strontium-90 (pCi/L) --- 8 --- Ud Tritium (pCi/L) --- 20,000 --- Ud Ra-226/228 (pCi/L) --- 5 --- Ud Gross Alpha (pCi/L) --- 15 --- Ud Gross Beta (pCi/L) --- No Criteria --- Ud U (pCi/L) --- 20 --- Ud Board 3 Basin Plan WQOs for Agricultural Water Use Manganese 22.6 200 --- No Cobalt 0.5 50 --- No Iron 110 5000 --- No Lithium 17 2500 --- No Molybdenum --- 10 --- Ud Vanadium <1 100 --- No Boron 300 750 --- No Footnotes for Table F-5: (1) The MEC or maximum background concentration is the actual detected concentration. Where detection values were available and the pollutant was not detected, the detection value was provided with a “<” before it. Where the pollutant was non-detect and a detection value was not available, “ND” was entered. (2) Cells marked with “---“ indicate that no effluent data or background data are available for that constituent. (3) RPA Results = Yes, if MEC => WQO/WQC, or if B > WQO/WQC and constituent is detected; = No, if MEC and B are < WQO/WQC or all effluent data are undetected; = Undetermined (Ud), if no criteria have been promulgated or no effluent data available; (4) Converted from nitrate (as N). Reasonable potential has been determined for chlorodibromomethane, dichlorobromomethane, pentachlorophenol, N-nitrosdimethylamine, nitrate, and nitrate+nitrite. WQBELs have been established for chlorodibromomethane, dichlorobromomethane, and N-nitrosdimethylamine based on the procedures identified within Section 1.4 of the SIP, as discussed in section IV.C.4 below. Pentachlorophenol did not ultimately have WQBELs established due to data quality uncertainties. The Discharger provided comment on initial RPA results and noted that they erroneously reported the single detection of pentachlorophenol in October 2012 as CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-19 1.2 µg/L. The Discharger should have reported the results as detected, not quantified (DNQ). According to Section 2.4 of the SIP, when the analytical result is above the method detection limit but below the minimum level, the result shall be reported as DNQ and the estimated concentration reported. If pentachlorophenol had been reported as DNQ in this instance, the RPA would have yielded a “no reasonable potential” conclusion and an effluent limit would not be established. However, increased monitoring for pentachlorophenol has been added to the proposed Order to address the data uncertainty presented by the DNQ result. If future monitoring data indicate a reasonable potential to exceed the water quality objective for pentachlorophenol, an effluent limitation may be established. The Central Coast Water Board developed a WQBEL for nitrate-nitrogen, which has an available wasteload allocation under a Total Maximum Daily Loads (TMDL) in Resolution No. R3-2005-0106 on September 9, 2005. The effluent limitation for this pollutant was established regardless of whether there is reasonable potential for the pollutants to be present in the discharge at levels that would cause or contribute to a violation of water quality standards. The Central Coast Water Board developed a W QBEL for this pollutant pursuant to 40 C.F.R. § 122.44(d)(1)(vii), which does not require or contemplate a reasonable potential analysis. Similarly, the SIP at Section 1.3 recognizes that reasonable potential analysis is not appropriate if a TMDL has been developed. This Order contains a WQBEL for nitrate-nitrogen, established based on the available wasteload allocation of 10 mg/L-N for the Facility contained in Resolution No. R3-2005- 0106. As required by 40 C.F.R. § 122.44(d)(1)(vii), the Central Coast Water Board shall ensure there is a WQBEL for nitrate-nitrogen in the WDRs that is consistent with the assumptions and requirements of the available wasteload allocation. Based on the water quality monitoring done at the time of the TMDL adoption, which set the wasteload allocation at the level necessary to attain water quality standards, the Central Coast Water Board has determined that the WQBEL is consistent with the assumptions of the TMDL. Similarly, compliance with the effluent limitation will satisfy the requirements of the TMDL. A separate WQBEL has not been established for nitrate+nitrite. The Discharger has provided a consistent data set indicating nitrite is not detected in its effluent (and this is consistent with municipal wastewater secondary treatment facilities in general), and therefore establishing a WQBEL for nitrate+nitrite would be duplicative of the nitrate effluent limit discussed above. The Central Coast Water Board has determined the TMDL-based effluent limit is sufficiently protective of the water quality objectives for nitrate+nitrite. 4. WQBEL Calculations Final WQBELs for chlorodibromomethane, dichlorobromomethane, and N- nitrosdimethylamine have been determined using the methods described in Section 1.4 of the SIP. Step 1: For each water quality criterion/objective, an effluent concentration allowance (ECA) is calculated from the following equation to account for dilution and background levels of each pollutant. ECA = C + D (C - B), where C = the applicable water quality criterion (adjusted for receiving water hardness and expressed as total recoverable metal, if necessary) CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-20 D = the dilution credit (here D = 0, as the Central Coast Water Board has no information with which to justify credit for dilution) B = the background concentration Step 2: For each ECA based on an aquatic life criterion, the long-term average discharge condition (LTA) is determined by multiplying the ECA times a factor (multiplier), which adjusts the ECA to account for effluent variability. The multiplier varies depending on the coefficient of variation (CV) of the data set and whether it is an acute or chronic criterion/objective. Table 1 of the SIP provides pre-calculated values for the multipliers based on the value of the CV. When the data set contains less than 10 sample results, or 80 percent or more of the data are reported as non- detect (ND), the CV is set equal to 0.6. Derivation of the multipliers is presented in Section 1.4 of the SIP. Step 3: WQBELs, including an average monthly effluent limitation (AMEL) and a maximum daily effluent limitation (MDEL) are calculated using the most limiting (the lowest) LTA. The LTA is multiplied times a factor that accounts for averaging periods and exceedance frequencies of the effluent limitations, and for the AMEL, the effluent monitoring frequency. Here, the sampling frequency is set equal to 4 (n = 4). The 99th percentile occurrence probability was used to determine the MDEL multiplier and a 95th percentile occurrence probability was used to determine the AMEL multiplier. Table 2 of the SIP presents the MDEL and AMEL multipliers as a function of the CV. When the data set contains less than 10 sample results, or when 80 percent or more of the data set is reported as non-detect (ND), the CV is set equal to 0.6. Otherwise, the CV is calculated as the standard deviation divided by the mean. Step 4: When the most stringent water quality criterion is a human health criterion (i.e., chlorodibromomethane, dichlorobromomethane, and N-nitrosdimethylamine), the AMEL is set equal to the ECA, and the MDEL is calculated by multiplying the ECA times the ratio of the MDEL multiplier to the AMEL multiplier. Final WQBELs for chlorodibromomethane, dichlorobromomethane, and N-nitrosdimethylamine are determined as follows. Table F-9. Calculation of Human Health WQBELs Pollutant ECA MDEL/AMEL Multiplier MDEL (µg/L) AMEL (µg/L) Chlorodibromomethane 0.401 4.96/1.96 = 2.53 1.0 0.40 Dichlorobromomethane 0.56 2.43/1.39 = 1.74 1.0 0.56 N-nitrosdimethylamine 0.00069 3.11/1.55 = 2.01 0.0014 0.00069 5. Whole Effluent Toxicity (WET) WET limitations protect receiving water quality from the aggregated toxic effect of a mixture of pollutants in effluent. WET tests measure the degree of response of exposed aquatic test organisms to an effluent. The WET approach allows for protection of the narrative “no toxics in toxic amounts” criterion while implementing numeric criteria for toxicity. There are two types of WET tests - acute and chronic. An acute toxicity test is conducted over a short time period and measures mortality. A chronic toxicity test is conducted over a longer period of time and may measure mortality, reproduction, and growth. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-21 The Basin Plan requires that all waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. Survival of aquatic organisms in surface waters subjected to a waste discharge or other controllable water quality conditions shall not be less than that for the same water body in areas unaffected by the waste discharge or for another control water. The previous Order included narrative effluent limitations for toxicity to ensure compliance with the Basin Plan narrative objective. The effluent limitation has been retained from the previous Order. Numeric chronic WET effluent limitations have not been included in this Order. The SIP contains implementation gaps regarding the appropriate form and implementation of chronic toxicity limits. This has resulted in the petitioning of a NPDES permit in the Los Angeles Region 1 that contained numeric chronic toxicity effluent limitations. To address the petition, the State Water Board adopted WQO 2003-012 directing its staff to revise the toxicity control provisions in the SIP. The State Water Board states the following in WQO 2003-012, “In reviewing this petition and receiving comments from numerous interested persons on the propriety of including numeric effluent limitations for chronic toxicity in NPDES permits for publicly-owned treatment works that discharge to inland waters, we have determined that this issue should be considered in a regulatory setting, in order to allow for full public discussion and deliberation. We intend to modify the SIP to specifically address the issue. We anticipate that review will occur within the next year. We therefore decline to make a determination here regarding the propriety of the final numeric effluent limitations for chronic toxicity contained in these permits.” The process to revise the SIP is currently underway. Proposed changes include clarifying the appropriate form of effluent toxicity limits in NPDES permits and general expansion and standardization of toxicity control implementation related to the NPDES permitting process. Since the toxicity control provisions in the SIP are currently under revision, it is inappropriate to carry over numeric effluent limitations for chronic toxicity. Therefore, this Order establishes a narrative toxicity effluent limitation and a numeric toxicity triggers consistent with the previous chronic toxicity effluent limitation which will require that the Discharger meet best management practices for compliance with the Basin Plan’s narrative toxicity objective, as allowed under 40 C.F.R. § 122.44(k). To ensure compliance with the Basin Plan’s narrative toxicity objective, the Discharger is required to conduct acute and chronic WET testing, as specified in the Monitoring and Reporting Program (Attachment E, section V). Furthermore, the Special Provision contained at VI.C.2.a of this Order requires the Discharger to investigate the causes of, and identify and implement corrective actions to reduce or eliminate effluent toxicity. If the discharge demonstrates toxicity, the Discharger is required to initiate a Toxicity Reduction Evaluation (TRE) in accordance with an approved TRE workplan. The numeric chronic toxicity monitoring trigger is not an effluent limitation; it is the toxicity threshold at which the Discharger is required to perform accelerated chronic toxicity monitoring, as well as, the threshold to initiate a TRE if effluent toxicity has been demonstrated. 1 In the Matter of the Review of Own Motion of Waste Discharge Requirements Orders R4-2002-0121 [NPDES No. CA0054011] and R4-2002-0123 [NPDES No. CA0055119] and Time Schedule Orders R4- 2002- 0122 and R4-2002-0124 for Los Coyotes and Long Beach Wastewater Reclamation Plants Issued by the California Regional Water Quality Control Board, Los Angeles Region SWRCB/OCC FILES A-1496 and 1496(a). CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-22 6. Basin Plan a. Coliform. The beneficial uses of the receiving surface water include municipal and domestic supply and water contact recreation. The California Department of Public Health (DPH) has developed reclamation criteria, CCR, Division 4, Chapter 3 (Title 22), for the reuse of wastewater. Title 22 requires that for spray irrigation of food crops, parks, playgrounds, schoolyards, and other areas of similar public access, wastewater be adequately disinfected, oxidized, coagulated, clarified, and filtered, and that the effluent total coliform levels not exceed 2.2 MPN/100 mL as a 7-day median; 23 MPN/100 mL, not to be exceeded more than once in a 30-day period; and 240 MPN/100 mL, at any time. Title 22 also requires that recycled water used as a source of water supply for non- restricted recreational impoundments be disinfected tertiary recycled water that has been subjected to conventional treatment. A non-restricted recreational impoundment is defined as “…an impoundment of recycled water, in which no limitations are imposed on body-contact water recreational activities.” Title 22 is not directly applicable to surface waters; however, the Central Coast Water Board finds that it is appropriate to apply an equivalent level of treatment to that required by DPH’s reclamation criteria because the receiving water is used for irrigation of agricultural land and for contact recreation purposes. The stringent disinfection criteria of Title 22 are appropriate since the undiluted effluent may be used for the irrigation of food crops and/or for body-contact water recreation. Coliform organisms are intended as an indicator of the effectiveness of the entire treatment train and the effectiveness of removing other pathogens. The previous Order includes effluent limitations for fecal coliform organisms of 2.2 MPN/100 mL as a 7-day median (in contrast to the Title 22 requirement based on the more conservative total coliform organisms). The consideration for this deviation was based on studies at the Facility during rapid changes in influent wastewater strength and flowrate (e.g., when California Polytechnic State University (Cal Poly) begins sessions or when power supply is interrupted). Those studies showed that, during these events, the Facility can temporarily experience an increased growth of non-pathogenic Klebsiella species of coliform bacterium within the cooling towers. That growth would result in total coliform detections with low-to-no fecal coliform component. In other words, the Facility still maintained the desired effectiveness at removing pathogenic coliform species. According to 2013 monitoring data, these events occurred two times; once in June during a power outage and once in September when Cal Poly began sessions. Fecal coliforms in both instances were below a 2.2 MPN/100 mL 7-sample median. These infrequent, non-pathogenic total coliform exceedances of a 2.2 MPN/100 mL median do not represent a failure of the disinfection system. Based on these studies, the existing effluent limitations have been retained and are protective of the beneficial uses for San Luis Obispo Creek. These effluent limits are generally consistent with other inland surface water discharge permits within the region. b. Dissolved Oxygen. In order to protect the beneficial uses of San Luis Obispo Creek, Order No. R3-2002-0043 established an effluent limitation for dissolved oxygen, prohibiting the discharge from containing a dissolved oxygen concentration of less than 4.0 mg/L or so low that it adversely affects beneficial uses. Due to federal and State anti-backsliding regulations, dissolved oxygen remains a pollutant CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-23 of concern for this discharge and the effluent limitation from the previous Order is carried over. c. Nitrate-Nitrogen. San Luis Obispo Creek is included on the 303(d) List as impaired for nutrients. Central Coast Water Board Resolution R3-2005-0106 establishes TMDLs for nitrate-nitrogen for discharges to San Luis Obispo Creek. The TMDL specifies a wasteload allocation for the City of San Luis Obispo Water Reclamation Facility effluent of 9,740 lbs NO3 (as N)/month. This wasteload allocation will be accomplished by establishing a nitrate-nitrogen effluent monthly average limit of 10 mg/L. Further, the implementation section of the TMDL specifies that the Central Coast Water Board will incorporate an effluent limit for nitrate-nitrogen in the City of San Luis Obispo’s NPDES permit for the Water Reclamation Facility, consistent with the allocations described in the wasteload allocations section at the first permit renewal following TMDL approval by the Central Coast Water Board. Thus, this Order implements the wasteload allocation as specified in Central Coast Water Board Resolution No. R3-2005-0106. Based on 40 C.F.R. § 122.44 (d.1.vii.B.) effluent limitations developed to protect a narrative water quality criterion, a numeric water quality criterion, or both, are consistent with the assumptions and requirements of any available wasteload allocation for the discharge prepared by the State and approved by EPA pursuant to 40 C.F.R. § 130.7. pH. Federal regulations, 40 CFR 133, establish technology-based effluent limitations for pH. The secondary treatment standards require the pH of the effluent to be no lower than 6.0 and no greater than 9.0 standard units. However, the Basin Plan establishes a WQO for pH of between 6.5 to 8.3 standard units for the protection of receiving waters with the beneficial use of Municipal and Domestic Supply (MUN), Agricultural Supply (AGR), and Water Recreation (REC1 and REC2). The Basin Plan establishes a WQO for pH between 7.0 to 8.5 standard units for the beneficial use of Freshwater Habitat (COLD and WARM) and Fish Spawning (SPWN). The previous Order established an effluent limitation of 6.5 to 8.3. However, since San Luis Obispo Creek has MUN, AGR, REC1, REC2, COLD, WARM, and SPWN beneficial uses, a pH effluent limitation of 7.0 to 8.3 may be appropriate in order to protect all beneficial uses. The Discharger shall complete an Effluent pH Evaluation by February 1, 2016, to assess opportunities for effluent pH adjustments consistent with more stringent Basin Plan water quality objectives for receiving water (i.e., 7.0-8.3 standard units), impact on receiving water and environment, cost to pH adjust, and expected frequency and duration that effluent pH would drop below 7.0 s.u. under current operations. Central Coast Water Board staff will review the data to consider whether a more stringent pH effluent limit would indeed be more protective of water quality objectives or if existing pH effluent limits are adequately protective of receiving water quality objectives. d. Oil and Grease. The Basin Plan establishes a narrative effluent limitation for oil and grease, which states, “Waters shall not contain oils, greases, waxes, or other similar materials in concentrations that result in a visible film or coating on the surface of the water or on objects in the water, that cause nuisance, or that otherwise adversely affect beneficial uses.” The previous Order contained an AMEL and MDEL of 5.0 mg/L and 10 mg/L, and corresponding mass-based effluent limitations, respectively. These CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-24 effluent limitations are typical of similar facilities that discharge secondary treated wastewater and are necessary to protect the narrative water quality objective. This Order retains the concentration-based effluent limitations from the previous Order. Mass-based limitations have been removed from the proposed Order. This change does not represent backsliding as the Order contains a flow limitation, which when combined with a concentration-based effluent limitation, provides equivalent protection for this water quality objective. e. Settleable Solids. The Basin Plan establishes a narrative effluent limitation for settleable solids, which states, “Waters shall not contain settleable material in concentrations that result in deposition of material that causes nuisance or adversely affects beneficial uses.” The previous Order contained an average monthly effluent limitation (AMEL) of 0.1 mL/L. This effluent limitation is typical of similar facilities that discharge secondary treated wastewater and is necessary to protect the narrative water quality objective. Therefore, this Order retains the effluent limitation for settleable solids from the previous Order. D. Final Effluent Limitation Considerations 1. Anti-Backsliding Requirements Sections 402(o) and 303(d)(4) of the CWA and federal regulations at 40 C.F.R. section 122.44(l) prohibit backsliding in NPDES permits. These anti-backsliding provisions require effluent limitations in a reissued permit to be as stringent as those in the previous permit, with some exceptions where limitations may be relaxed. The effluent limitations in this Order are at least as stringent as the effluent limitations in the previous Order, with the exception of effluent limitations for selenium, cyanide, bromoform, aluminum, barium, fluoride, cis-1,2-Dichloroethylene, methyl-tertiary-butyl-ether, styrene, trichlorofluoromethane, 1,1,2-Trichloro-1,2,2-Trifluoroethane, xylenes, alachlor, atrazine, bentazon, carbofuran, 2,4-D, dalapon, dibromochloropropane, di(2-ethylhexyl)adipate, di(2-ethylhexyl)phthalate, dinoseb, diquat, endothall, ethylene dibromide, glyphosate, methoxychlor, molinate, oxamyl, picloram, simazine, thiobencarb, and 2,4,5-TP (Silvex). The existing Order (R3-2002-0043) final effluent limitations for selenium, cyanide, bromoform, aluminum, barium, fluoride, cis-1,2-Dichloroethylene, methyl-tertiary-butyl- ether, styrene, trichlorofluoromethane, 1,1,2-Trichloro-1,2,2-Trifluoroethane, xylenes, alachlor, atrazine, bentazon, carbofuran, 2,4-D, dalapon, dibromochloropropane, di(2- ethylhexyl)adipate, di(2-ethylhexyl)phthalate, dinoseb, diquat, endothall, ethylene dibromide, glyphosate, methoxychlor, molinate, oxamyl, picloram, simazine, thiobencarb, and 2,4,5-TP (Silvex). Effluent limitations for selenium, cyanide, bromoform, aluminum, barium, fluoride, cis-1,2-Dichloroethylene, methyl-tertiary-butyl-ether, styrene, trichlorofluoromethane, 1,1,2-Trichloro-1,2,2-Trifluoroethane, xylenes, alachlor, atrazine, bentazon, carbofuran, 2,4-D, dalapon, dibromochloropropane, di(2-ethylhexyl)adipate, di(2-ethylhexyl)phthalate, dinoseb, diquat, endothall, ethylene dibromide, glyphosate, methoxychlor, molinate, oxamyl, picloram, simazine, thiobencarb, and 2,4,5-TP (Silvex) are discontinued in this Order and chlorodibromomethane and dichlorobromomethane effluent limitations are revised in this Order based on the consideration of new information (i.e., current discharge monitoring data and reasonable potential analysis). This relaxation of effluent limitations is consistent with the anti-backsliding requirements of the CWA and federal regulations. 2. Antidegradation Policies CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-25 Provisions of the Order are consistent with applicable anti-degradation policy expressed by NPDES regulations at 40 C.F.R. § 131.12 and by State Water Board Resolution 68- 16. This Order does not authorize increases in discharge rates or pollutant loadings, and its limitations and conditions otherwise assure maintenance of the existing quality of receiving waters. 3. Stringency of Requirements for Individual Pollutants This Order contains both technology-based and water quality-based effluent limitations for individual pollutants. The technology-based effluent limitations consist of restrictions on flow, BOD, and TSS. Restrictions on flow, BOD, and TSS are discussed in section VI.B of the Fact Sheet. This Order’s technology-based pollutant restrictions implement the minimum, applicable federal technology-based requirements. In addition, this Order contains effluent limitations more stringent than the minimum, federal technology-based requirements that are necessary to meet water quality standards. These limitations are not more stringent than required by the CWA. Water quality-based effluent limitations have been derived to implement water quality objectives that protect beneficial uses. Both the beneficial uses and the water quality objectives have been approved pursuant to federal law and are the applicable federal water quality standards. To the extent that toxic pollutant water quality-based effluent limitations were derived from the CTR, the CTR is the applicable standard pursuant to 40 C.F.R. § 131.38. The procedures for calculating the individual water quality-based effluent limitations for priority pollutants are based on the CTR implemented by the SIP, which was approved by U.S. EPA on May 18, 2000. All beneficial uses and water quality objectives contained in the Basin Plan were approved under state law and submitted to and approved by U.S. EPA prior to May 30, 2000. Any water quality objectives and beneficial uses submitted to U.S. EPA prior to May 30, 2000, but not approved by U.S. EPA before that date, are nonetheless “applicable water quality standards for purposes of the CWA” pursuant to 40 C.F.R. § 131.21(c)(1). Collectively, this Order’s restrictions on individual pollutants are no more stringent than required to implement the requirements of the CWA. 4. Summary of Final Effluent Limitations – Discharge Point 001 Final effluent limitations were determined by comparing the technology-based effluent limitations (including the effluent limitations established in Order No. R3-2002-0043) and the WQBELs and applying the most stringent limitations for each individual parameter. Effluent limitations for BOD5 and TSS are technology based and are carried over from Order No. R3-2002-0043. Effluent limitations for chlorodibromomethane, dichlorobromomethane, N-Nitrosodimethylamine, dissolved oxygen, coliform, nitrate- nitrogen, total residual chlorine, settleable solids, oil and grease, and pH are based on applicable water quality criteria. Effluent limitations for selenium, cyanide, bromoform, aluminum, barium, fluoride, cis-1,2-Dichloroethylene, methyl-tertiary-butyl-ether, styrene, trichlorofluoromethane, 1,1,2-Trichloro-1,2,2-Trifluoroethane, xylenes, alachlor, atrazine, bentazon, carbofuran, 2,4-D, dalapon, dibromochloropropane, di(2-ethylhexyl)adipate, di(2-ethylhexyl)phthalate, dinoseb, diquat, endothall, ethylene dibromide, glyphosate, methoxychlor, molinate, oxamyl, picloram, simazine, thiobencarb, and 2,4,5-TP (Silvex) are discontinued in this Order because the discharge did not demonstrate reasonable potential to cause or contribute to an exceedance of a water quality standard. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-26 The effluent limitation established for flow is based on the design flow capacity of the Facility. Mass-based effluent limitations, as required, were calculated based upon the permitted design daily discharge flow of 5.1 MGD. a. The Discharger shall maintain compliance with the following effluent limitations at Discharge Point 001, with compliance measured at Monitoring Location EFF-001 as described in the attached Monitoring and Reporting Program (MRP) (Attachment E). Table F-10. Summary of Final Effluent Limitations Parameter Units Effluent Limitations Basis[1] Average Monthly Average Weekly Maximum Daily Instantaneous Minimum Instantaneous Maximum CONVENTIONALS Biochemical Oxygen Demand (BOD5) (5-day @ 20 Deg. C) [2] mg/L 10 30 50 -- -- C.F.R. lbs/day [3] 425 1,275 2,125 -- -- Oil and Grease mg/L 5 -- 10 -- -- PO pH s.u. -- -- -- 6.5 8.3 BP Total Suspended Solids [2] mg/L 10 30 75 -- -- C.F.R. lbs/day [3] 425 1,275 2,125 -- -- Chlorodibromomethane µg/L 0.40 -- 1.0 -- -- CTR Dichlorobromomethane µg/L 0.56 -- 1.0 -- -- CTR N- Nitrosodimethylamine µg/L 0.00069 -- 0.0014 -- -- CTR Dissolved Oxygen mg/L -- -- -- 4.0 [4] -- PO Flow MGD -- -- 5.1 -- -- DC Nitrate (as N) mg/L 10 -- -- -- -- TMDL Settleable Solids mL/L 0.1 -- -- -- -- PO Coliform MPN/100 mL [5] DPH Total Residual Chlorine µg/L [6] BP [1] C.F.R. – Based on federal regulations contained in 40 C.F.R. part 133. BP – Based on water quality objectives contained in the Basin Plan. CTR – Based on water quality criteria contained in the California Toxics Rule, and applied as specified in the SIP. DC – Based on the design capacity of the facility. PO – Based on the previous order (Order No. R3-2002-0043, modified 2005). TMDL – Based on applicable TMDL. DPH – Based on California Department of Public Health reclamation criteria for the reuse of wastewater. [2] In addition to concentration-based limitations and mass-based limitations for BOD5 and TSS, the Discharger is required to meet an 85 percent removal discharge specification. [3] Mass -based effluent limitations are established using the following formula: Mass (lbs/day) = flow rate (MGD) x 8.34 x effluent limitation (mg/L) where: Mass = mass limitation for a pollutant (lbs/day) Effluent limitation = concentration limit for a pollutant (mg/L) Flow rate = discharge flow rate (5.1 MGD) [4] The discharge shall not have a dissolved oxygen concentration less than 4.0 mg/L or so low that it adversely affects beneficial uses. [5] The median number of fecal coliform organisms in the effluent shall not exceed 2.2 MPN/100 mL as determined by the results of bacteriological analyses for the last 7-days on which samples were taken. No more than one sample shall exceed 23 MPN/100 mL total coliform in any 30-day period. The maximum number of total coliform organisms in any sample shall not exceed 240 MPN/100 mL. [6] Compliance determinations for total chlorine residual shall be based on 99% compliance. To determine 99% compliance with effluent limitations for total chlorine residual, the following conditions shall be satisfied: 1) The total time during which the total chlorine residual values are above 0.01 mg/L (instantaneous maximum value) shall not exceed 7 hours and 26 minutes in any calendar month. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-27 2) No individual excursion from 0.01 mg/L shall exceed 30 minutes; and 3) No individual excursion shall exceed 2 mg/L. If grab sampling is used instead of continuous analysis: 1) The total number of excursions above 0.1 mg/L shall be no more than one individual excursion in any calendar month. 2) No individual excursion from 0.1 mg/L shall exceed 30 minutes, and must include results of no fewer than 2 grab samples. 3) No individual excursion shall exceed 2.0 mg/L. b. Toxicity. The discharge shall not contain substances in concentrations which are toxic to, or which produce detrimental physiological responses in human, plant, or animal (particularly fish or aquatic) life. E. Interim Effluent Limitations – Not Applicable F. Land Discharge Specifications – Not Applicable G. Recycling Specifications The Discharger currently produces and distributes tertiary treated recycled water within the City of San Luis Obispo. Recycled water is regulated under the City’s existing Master Reclamation Permit Order No. R3-2003-081, and therefore no additional specifications are applicable under this permit. V. RATIONALE FOR RECEIVING WATER LIMITATIONS A. Surface Water Receiving water quality is a result of many factors, some unrelated to the discharge. This Order considers these factors and is designed to minimize the influence of the discharge on the receiving water. Specific WQOs established by the Basin Plan to meet this goal for all inland surface waters are included as Receiving Water Limitations in section V.A of the Order. All receiving water limitations are retained from the previous Order. Dissolved oxygen limitation has been revised to be 7 mg/L year-round. The previous permit has seasonal dissolved oxygen limits of 5 and 7 mg/L. This was inconsistent with the Basin Plan water quality objectives, as the beneficial uses for San Luis Obispo Creek were not seasonally specified. The revision to 7 mg/L is consistent with the Basin Plan water quality objectives for spawning and cold water habitat. The revision is more restrictive than the previous seasonal limitation. The un-ionized ammonia limitation has been corrected as un-averaged limitation. The previous permit incorrectly associated a footnote indicating a running annual average limitation for unionized ammonia from Table 3.7 in the Basin Plan. However, that footnote only applies to total dissolved solids, boron, sulfate, sodium, and chloride. The revision is more restrictive than the previous limitation. B. Groundwater Groundwater limitations included in section V.B of the Order include general objectives as established in Chapter 3, Section II.A.4 of the Basin Plan and specific numeric WQOs for groundwater within the San Luis Obispo Creek sub area of the Estero Bay groundwater unit as established in Table 3-8 of the Basin Plan. VI. RATIONALE FOR MONITORING AND REPORTING REQUIREMENTS NPDES regulations at 40 C.F.R. § 122.48 require that all NPDES permits specify requirements for recording and reporting monitoring results. Water Code sections 13267 and 13383 also authorize the Central Coast Water Board to require technical and monitoring reports. Rationale for CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-28 the monitoring and reporting requirements contained in the Monitoring and Reporting Program (MRP), which is presented as Attachment E of this Order, is presented below. A. Influent Monitoring Influent monitoring is required to collect data on the characteristics of the wastewater and to assess compliance with effluent limitations (BOD5 and TSS percent reduction requirements). Monthly monitoring for BOD5 and TSS have been carried over from Order No. R3-2002-0043. Continuous flow monitoring has been established to monitor flow rates in relation to the design capacity of the Facility. B. Effluent Monitoring Effluent monitoring is required to determine compliance with effluent limitations contained in this Order and to determine contributions, if any, by the Discharger to receiving water exceedances above water quality objectives. In addition, annual effluent monitoring for priority toxic pollutants, Basin Plan pollutants, and Title 22 pollutants has been established to evaluate reasonable potential of the Discharger’s effluent to exceed water quality objectives/criteria during the next permit renewal process. Effluent monitoring requirements (i.e., sample type and frequency) have been carried over from Order No. R3-2002-0043, for the most part. Monitoring for selenium, cyanide, and bromoform has been reduced from monthly to annual, included with the annual monitoring requirement for all other priority pollutants. Monitoring for pentachlorophenol, and n-nitrosodimethylamine has been increased from annually to quarterly to resolve data quality uncertainties and determine compliance with the n-nitrosodimethylamine effluent limitation established in this Order. Monitoring for molybdenum has been established in this Order because it is a Basin Plan pollutant of concern and was not included in Order No. R3-2002-0043. An annual effluent monitoring requirement has been added to the Monitoring and Reporting Program (Attachment E). C. Whole Effluent Toxicity Testing Requirements Section 4 of the SIP requires a chronic toxicity effluent limitation in permits for all discharges that will cause, have reasonable potential to cause, or contribute to chronic toxicity in receiving waters. The SIP further requires that to determine compliance with the chronic aquatic life toxicity objective, the Central Coast Water Board shall require the use of short- term chronic toxicity tests. In addition, the Basin Plan establishes a narrative water quality objective for toxicity. Thus, to determine reasonable potential for toxicity and monitor compliance with water quality objectives for toxicity, annual monitoring of whole effluent toxicity (WET) (chronic and acute) has been carried over from Order No. R3-2002-0043. D. Receiving Water Monitoring 1. Surface Water The Basin Plan establishes water quality objectives for surface waters located within the Central Coast Region for the protection of beneficial uses. Receiving water monitoring is carried over from Monitoring and Reporting Program R3-2002-0043 to monitor compliance with the receiving water limitations contained in this Order. 2. Groundwater Consistent with the previous permit, groundwater monitoring requirements have not been included. E. Other Monitoring Requirements 1. Solids/Biosolids Monitoring CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-29 Biosolids monitoring is required to ensure compliance with the biosolids disposal requirements. Biosolids disposal requirements are imposed pursuant to 40 C.F.R. part 503 to protect public health and prevent groundwater degradation. Biosolids monitoring shall be reported in the annual report in accordance with 40 C.F.R. part 503. Biosolids monitoring requirements have been retained from the previous Order. 2. Pretreatment Monitoring Pretreatment monitoring shall be reported in the Annual Report in accordance with requirements of 40 C.F.R. § 403.8. Pretreatment monitoring requirements have been retained from the previous Order. 3. Salt and Nutrient Management Plan Reporting Salt and Nutrient Management Plan reporting requirements have been established in this Order to help identify and reduce salt and nutrient loading in the effluent. This salt/nutrient management report shall be included as part of the Annual Report. VII. RATIONALE FOR PROVISIONS A. Standard Provisions Standard Provisions, which apply to all NPDES permits in accordance with 40 C.F.R. §122.41, and additional conditions applicable to specified categories of permits in accordance with 40 C.F.R. §122.42, are provided in Attachment D. The discharger must comply with all standard provisions and with those additional conditions that are applicable under section 122.42. Sections 122.41(a)(1) and (b) through (n) of 40 C.F.R. establish conditions that apply to all state-issued NPDES permits. These conditions must be incorporated into the permits either expressly or by reference. If incorporated by reference, a specific citation to the regulations must be included in the Order. Section 123.25(a)(12) of 40 C.F.R. allows the state to omit or modify conditions to impose more stringent requirements. In accordance with 40 C.F.R. §123.25, this Order omits federal conditions that address enforcement authority specified in 40 C.F.R. §§122.41(j)(5) and (k)(2) because the enforcement authority under the Water Code is more stringent. In lieu of these conditions, this Order incorporates by reference Water Code section 13387(e). B. Special Provisions 1. Reopener Provisions The Order may be modified in accordance with the requirements set forth at 40 C.F.R. parts 122 and 124, to include appropriate conditions or limits based on newly available information, or to implement any, new State water quality objectives that are approved by the USEPA. As effluent is further characterized through additional monitoring, and if a need for additional effluent limitations becomes apparent after additional effluent characterization, the Order will be reopened to incorporate such limitations. 2. Special Studies and Additional Monitoring Requirements a. Toxicity Reduction Requirements The Order retains the requirement to perform a TRE, if the acute toxicity limitation is exceeded or if chronic toxicity is detected in the effluent above 1 TUc. When toxicity monitoring measures acute or chronic toxicity in the effluent above the limitations established by the Order, the Discharger is required to resample and retest. When all monitoring results are available, the Executive Officer can determine CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-30 whether to initiate enforcement action, whether to require the Discharger to implement TRE requirements, or whether other measures are warranted. b. Facilities Evaluation The report of waste discharge submitted states that the City’s average dry weather flow is approximately 4.5 MGD and that the facility has a design capacity of 5.1 MGD. The current average dry weather flow therefore represents 88% of the design capacity. Based on that data, it appears that the monthly average daily flow will or may reach design capacity during the term of this permit. Pursuant to Central Coast Standard Provisions, the Discharger shall evaluate the need for future expansion of the Facility to accommodate future growth within the City of San Luis Obispo. The evaluation shall quantify future flows to the plant from indirect dischargers, California State Polytechnic University and San Luis Obispo County Airport, and future annexations to the City of San Luis Obispo. This evaluation shall be completed with the planned Facility upgrades to be completed during the term of this permit and submitted to the Central Coast Water Board with the Engineering Report for the Facility upgrades. 3. Best Management Practices and Pollution Prevention a. Salt and Nutrient Management Program Section G of the previous Order (R3-2002-0043) required the Discharger to conduct a Salt Management Study to control levels of TDS, chloride, sodium, sulfate, and boron (collectively referred to as salts) in discharges from the Facility and attain applicable WQOs for salts in the San Luis Obispo Creek Sub-Basin of the Estero Bay Drainage Basin. The Discharger shall develop and implement a Nutrient Management Program as part of the Salt and Nutrient Management Program, as discussed in section VI.C.3.a of this Order, based on the Recycled Water Policy discussed in section III.E.3 of this Fact Sheet. 4. Construction, Operation, and Maintenance Specifications 5. Special Provisions for Municipal Facilities (POTWs Only) a. Biosolids Management The use and disposal of biosolids is regulated under federal and State laws and regulations, including permitting requirements and technical standards included in 40 C.F.R. part 503. The Discharger is required to comply with the standards and time schedules contained in 40 C.F.R. part 503. Title 27, CCR, Division 2, Subdivision 1, Section 20005 establishes approved methods for the disposal of collected screenings, residual sludge, biosolids, and other solids removed from liquid wastes. Requirements to ensure the Discharger disposes of solids in compliance with State and federal regulations have been included in this Order. These requirements have been retained from the previous Order. b. Pretreatment Requirements The federal CWA, Section 307(b), and federal regulations, 40 C.F.R. part 403, require publicly owned treatment works to develop and implement an acceptable industrial pretreatment program. A pretreatment program is required to prevent the introduction of pollutants, which will interfere with treatment plant operations or CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-31 sludge disposal, and prevent pass through of pollutants that exceed water quality objectives, standards or permit limitations. Pretreatment requirements are imposed pursuant to 40 C.F.R. part 403. 6. Other Special Provisions a. Discharges of Storm Water. Discharges of storm water from POTWs with a design capacity greater than 1.0 MGD are eligible for coverage under General State Water Board Order 97-03-DWQ, NPDES General Permit No. CAS000001, Waste Discharge Requirements for Dischargers of Storm Water Associated with Industrial Activities Excluding Construction Activities. The design capacity of the Facility is greater than 1.0 MGD. Therefore, the Discharger shall seek coverage under General Permit No. CAS000001 for all storm water discharges. This is retained from the previous Order. b. Statewide General Waste Discharge Requirements for Sanitary Sewer Systems (State Water Board Order 2006-0003-DWQ). The Order requires coverage by and compliance with applicable provisions of General Waste Discharge Requirements for Sanitary Sewer Systems (State Water Board Order 2006- 0003-DWQ). This General Permit, adopted on May 2, 2006, is applicable to all “federal and state agencies, municipalities, counties, districts, and other public entities that own or operate sanitary sewer systems greater than one mile in length that collect and/or convey untreated or partially treated wastewater to a publicly owned treatment facility in the State of California.” The purpose of the General Permit is to promote the proper and efficient management, operation, and maintenance of sanitary sewer systems and to minimize the occurrences and impacts of sanitary sewer overflows. Furthermore, the General Order contains requirements for operation and maintenance of collection systems and for reporting and mitigating sanitary sewer overflows. Inasmuch that the Discharger’s collection system is part of the system that is subject to this Order, certain standard provisions are applicable as specified in Provisions, section VI.C.5. For instance, the 24-hour reporting requirements in this Order are not included in the General Order. The Discharger must comply with both the General Order and this Order. The Discharger and public agencies that are discharging wastewater into the facility were required to obtain enrollment for regulation under the General Order by December 1, 2006. This provision is retained from the previous Order. 7. Compliance Schedules – Not Applicable VIII. PUBLIC PARTICIPATION The Central Coast Water Board is considering the issuance of WDRs that will serve as an NPDES permit for the City of San Luis Obispo Water Resource Recovery Facility. As a step in the adoption process, Central Coast Water Board staff has developed tentative WDRs and is encouraging public participation in the WDRs adoption process. A. Notification of Interested Parties The Central Coast Water Board notified the Discharger and interested agencies and persons of its intent to prescribe WDRs for the discharge and provided an opportunity to submit written comments and recommendations. Notification was provided through written publication in the Tribune newspaper and posting on the Central Coast Water Board’s website. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-32 The public had access to the agenda and any changes in dates and locations through the Central Coast Water Board’s website at http://www.waterboards.ca.gov/centralcoast/ B. Written Comments Interested persons were invited to submit written comments concerning tentative WDRs as provided through the notification process. Comments were due either in person or by mail to the Executive Officer at the Central Coast Water Board at the address on the cover page or via electronic mail to centralcoast@waterboards.ca.gov. To be fully responded to by staff and considered by the Central Coast Water Board, the written comments were due at the Central Coast Water Board office by 5:00 p.m. on July 25, 2014. On July 24, 2014, the Discharger submitted written comments stating they were in agreement with the requirements of the proposed Order, but had a few remaining comments as described below: 1. N-Nitrosodimethylamine (NDMA)- The Discharger disputed the need for an effluent limit for NDMA. The effluent limit for NDMA is the result of detection in one of six samples in the RPA (see pages F-14 through F-20 for the rationale for NDMA effluent limit), at a relatively high concentration for municipal effluent. The Discharger quoted the SIP statement as follows: “The RWQCB shall have discretion to consider if any data are inappropriate or insufficient for use in implementing this Policy. Instances where such consideration is warranted include,…evidence that a sample…is not representative of the effluent or ambient receiving water quality…” The Discharger concluded that the detection of NDMA was not representative of the City’s effluent, and requested that an NDMA effluent limitation not be established. Staff response: The full text of the statement in the SIP the Discharger referred to includes “instances where such consideration is warranted include, but are not limited to, the following: evidence that a sample has been erroneously reported or is not representative of effluent or ambient receiving water quality, questionable quality control/quality assurance practices; and varying seasonal conditions.” The discretion at question here is the determination whether the sample is representative of the effluent. In this case, there is no compelling reason to consider the sample unrepresentative of the effluent. The laboratory data quality objectives for the detection were met, the sample was collected properly, and no other reason can be found to invalidate the detection. The relatively high concentration is not reason in and of itself to conclude the sample is unrepresentative. In fact, the SIP and RPA are written with methodologies to address these situations. Staff recommends establishing the proposed NDMA effluent limitation and the proposed increased NDMA sampling frequency, consistent with the SIP and RPA methodologies. 2. Mass Effluent Limitations – The Discharger stated, “during wet weather, due to higher flows, the concentration based limits in Table 4 would be met but the mass limitations may be exceeded and beneficial uses will not be impacted.” The Discharger has requested language be included that states effluent mass limitations will not apply in those instances. The Discharger cites specific language from City of Davis’s permit (Central Valley Region). Staff response: According to 40 CFR 122.45, design flow rate and mass-based limitations are fundamental in establishing effluent limitations: CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-33 (b) Production-based limitations. (1) In the case of POTWs, permit effluent limitations, standards, or prohibitions shall be calculated based on design flow. (f) Mass limitations. (1) All pollutants limited in permits shall have limitations, standards or prohibitions expressed in terms of mass except: (i) For pH, temperature, radiation, or other pollutants which cannot appropriately be expressed by mass; (ii) When applicable standards and limitations are expressed in terms of other units of measurement; or (iii) If in establishing permit limitations on a case-by-case basis under § 125.3, limitations expressed in terms of mass are infeasible because the mass of the pollutant discharged cannot be related to a measure of operation (for example, discharges of TSS from certain mining operations), and permit conditions ensure that dilution will not be used as a substitute for treatment. (2) Pollutants limited in terms of mass additionally may be limited in terms of other units of measurement, and the permit shall require the permittee to comply with both limitations. Effluent flow multiplied by pollutant concentration will equal mass-based discharge as described in the footnotes of Table F-5. Unlinking the concentration from the flow, as proposed by the Discharger’s comments, would be inappropriate and not consistent with 40 CFR 122.45(f)(2). Mass-based limitations are still to be enforced, even during times of high flow due to wet weather. On a practical basis, the wet weather flows are expected to decrease concentrations for pollutants entering the treatment works. The cited permit language is consistent with 40 CFR 122.45, and staff does not recommend including it in this proposed Order. 3. Chronic Toxicity Test Species – The Discharger has concerns that Selenastrum species required in the 3-month toxicity screening test may yield false positives. The Discharger requests (1) the toxicity testing procedure be limited to fathead minnows and water fleas, (2) the City’s concerns for false positives be added to Section VI.C of the Fact Sheet, and (3) the potential for false positives be considered when selecting the most sensitive species upon which to base testing following the screening period. Staff Response: The three test species required in this permit are consistent with and derived from U.S. EPA approved methods for chronic toxicity testing found in Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms, 2002. The methods included in that publication are referenced in Table 1A, 40 CFR Part 136 regulations and, therefore, constitute approved methods for chronic toxicity tests. The use of any test specifies or test conditions other than those described in the methods shall be subject to application and approval of alternat ive test procedures under 40 CFR 136.4 and 40 CFR 136.5. The Discharger’s request is for a procedure not consistent with the methodology approved under 40 CFR 136; therefore, staff does not recommend any changes to the required test species. If the results of the screening result in suspected false positives according to the Discharger, Water Board CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-34 staff will consult with U.S. EPA regarding the reliability of the results in consideration of the data validation requirements in the approved methodology. 4. Annual Self-Monitoring Report Date – The Discharger has requested the reporting deadline in Section VIII.D.8 of Attachment D (page D-13) and Section VI.C.3.a.iv (page 11) be changed to February 15. Staff Response: Annual self-monitoring summary reports are typically due by February 1st, according to Standard Provisions adopted by the Central Coast Water Board in January 2013. The proposed Order grants the Discharger an exception to this date and extends the deadline to February 15th. This exception is noted on page E-17 (footnote to Table E- 6) of the proposed Order, and a correction has been made, as requested, to page 11 to be consistent. Staff does not recommend changing the language or dates in the adopted Standard Provisions (page D-13), as that language was specifically adopted by the Central Coast Water Board. The language on page E-17 and page 11 clearly indicates February 15th is a revision to the standard February 1st deadline and adequately addresses the Discharger’s concerns. C. Public Hearing The Central Coast Water Board held a public hearing on the tentative WDRs during its regular Board meeting on the following date and time and at the following location: Date: September 25-26, 2014 Time: 8:30 a.m. Location: Central Coast Water Board Offices 895 Aerovista Drive, Suite 101 San Luis Obispo Interested persons were invited to attend. At the public hearing, the Central Coast Water Board invited interested parties to provide testimony pertinent to the discharge, WDRs, and permit. For accuracy of the record, important testimony is requested in writing. D. Reconsideration of Waste Discharge Requirements Any aggrieved person may petition the State Water Board to review the decision of the Central Coast Water Board regarding the final WDRs. The petition must be received by the State Water Board at the following address within 30 calendar days of the Central Coast Water Board’s action: State Water Resources Control Board Office of Chief Counsel P.O. Box 100, 1001 I Street Sacramento, CA 95812-0100 For instructions on how to file a petition for review, see http://www.waterboards.ca.gov/public_notices/petitions/water_quality/wqpetition_instr.shtml E. Information and Copying The Report of Waste Discharge, other supporting documents, and comments received are on file and may be inspected at the address above at any time between 8:00 a.m. and 5:00 p.m., Monday through Friday. Copying of documents may be arranged through the Central Coast Water Board by calling (805) 549-3147. CITY OF SAN LUIS OBISPO ORDER NO. R3-2014-0033 WATER RESOURCE RECOVERY FACILITY NPDES NO. CA0049224 ATTACHMENT F – FACT SHEET F-35 F. Register of Interested Persons Any person interested in being placed on the mailing list for information regarding the WDRs and NPDES permit should contact the Central Coast Water Board, reference this facility, and provide a name, address, and phone number. G. Additional Information Requests for additional information or questions regarding this Order should be directed to Katie DiSimone at (805) 542-4638 or katie.disimone@waterboards.ca.gov or Sheila Soderberg at (905) 549-3592 or sheila.soderberg@waterboards.ca.gov. STATE OF CALIFORNIA CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD CENTRAL COAST REGION 895 Aerovista Place, Suite 100 San Luis Obispo, CA 93401 TIME SCHEDULE ORDER NO. R3-2014-0036 REQUIRING THE CITY OF SAN LUIS OBISPO WATER RESOURCE RECOVERY FACILITY TO COMPLY WITH REQUIREMENTS PRESCRIBED IN ORDER NO. R3-2014-0033 The California Regional Water Quality Control Board, Central Coast Region (Central Coast Water Board) finds: 1. The City of San Luis Obispo (hereafter Discharger) owns and operates wastewater collection, treatment, and disposal facilities to provide sewerage service to the City of San Luis Obispo, California Polytechnic State University, and the San Luis Obispo County Airport. 2. Treatment facilities include wet-weather flow equalization, screening, grinding, aerated grit removal, primary settling, biofiltration, secondary settling, nitrification using activated sludge, final settling, cooling using evaporative cooling towers, dual media filtration, and chlorination/dechlorination. Solids are thickened in a dissolved air floatation thickener, stabilized in anaerobic digesters, and dewatered either by belt presses or drying beds. Stabilized solids are applied to nonfood agricultural crops. The treatment plant’s design capacity (average dry weather daily discharge) is 5.1 million gallons per day (mgd). 3. The Central Coast Water Board adopted waste discharge requirements regulating the discharge of tertiary-treated effluent from the San Luis Obispo Water Resource Recovery Facility (WRF) to San Luis Obispo Creek. These requirements were issued in Order No. R3-2014-0033, adopted by the Central Coast Water Board on September 25, 2014. Order No. R3-2014-0033 serves as a National Pollutant Discharge Elimination System (NPDES) permit (NPDES No. CA00449224). Effluent is also supplied to various locations within San Luis Obispo for irrigation. Master Reclamation Requirements Order No. R3-2003-0081 regulates the production and use of recycled water. 4. Order No. R3-2014-0033 prescribes final effluent limitations for trihalomethanes (THMs) and nitrate, as shown in Table 1 below. Order No. R3-2014-0036 -2- October 8, 2014 Table 1 – Final Effluent Limitations Pollutant Units Average Monthly Maximum Daily Chlorodibromomethane µg/L 0.40 1.0 Dichlorodibromomethane µg/L 0.56 1.0 Nitrate (as Nitrogen) mg/L 10 - 5. The Policy for Implementation of Toxics Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California (SIP) allows for compliance schedules and interim limitations based on an existing discharger’s request and demonstration that it is infeasible for the discharger to achieve immediate compliance with a California Toxics Rule (CTR) criterion or with an effluent limitation based on a CTR criterion. Numeric interim limitations for the pollutant must be based on current treatment facility performance or on existing permit limitations, whichever is more stringent. 6. Since 2005 and in anticipation of the adoption of final effluent limitations for THMs, the Discharger has been subject to interim THM effluent limitations and compliance activities. Interim limitations and compliance activities, as prescribed in Time Schedule Order (TSO) No. R3-2010-0013, are summarized below. Table 2 – Interim Limitations Pollutant Units Instantaneous Maximum Chlorodibromomethane µg/L 42 Dichlorobromomethane µg/L 36 Table 3 – Compliance Schedule Proposed Action Estimated Time to Complete1 Regulatory Strategies Identify next steps for regulatory strategy in coordination with Regional Water Board, and develop information to support agreed upon course of action, as necessary. 8 months Consideration and adoption of agreed upon regulatory strategy by Regional Water Board, if applicable. 6 months Consideration and adoption of regulatory strategies by State Water Board. 6 months Consideration and adoption of regulatory strategies by the Office Administrative Law and/or U.S. Environmental Protection Agency, if applicable. 9 months WRF Improvements Design WRF Improvements 30 months Request for Bids 36 months Complete Construction 57 months Order No. R3-2014-0036 -3- October 8, 2014 Proposed Action Estimated Time to Complete1 Start-up and Evaluation 60 months Full Compliance 60 months Other Actions Develop Pollution Prevention Plan 6 months Implement Pollution Prevention Plan 12 months Submit Annual Progress Reports Annually starting 12 months 1 From effective date of TSO No. R3-2010-0013, i.e., March 30, 2010 7. Since 2010, the Discharger completed a public outreach and study into alternative regulatory strategies to address THMs and nitrate water quality objectives based on the designation of San Luis Obispo Creek as a potential source of municipal drinking water (MUN). After numerous public meetings and discussions with regulatory agencies, the Discharger concluded in late 2012 that it will no longer pursue alternative regulatory strategies and instead will complete plant upgrades to meet the MUN-based criteria. 8. The Discharger’s delay in complying with the previous TSO No. R3-2010-0013 deadlines for WRF improvements has been due to unexpected delays in the resolution of regulatory strategies to address MUN-based water quality objectives. Without first resolving the regulatory strategy, the Discharger could not substantially begin WRF improvement designs. The Discharger has been submitting update reports and coordinating with Water Board staff regarding these delays. 9. The Discharger has made diligent progress towards alternative disinfection strategies to address THMs. The Discharger completed a pilot test for ozone and is investigating another pilot study that would investigate the use of peracetic acid disinfection. The results of the pilot studies will support the Discharger’s upgrade strategy and design. 10. Order No. R3-2014-0033 implements the Central Coast Water Board’s WRF’s effluent limitation as required in Resolution No. R3-2005-0106 San Luis Obispo Creek Total Maximum Daily Load (TMDL) and Implementation Plan for Nitrate-Nitrogen adopted on September 9, 2005. Prior to the adoption of Order No. R3-2014-0033, the Discharger has not been subject to final or interim effluent limitations for nitrate. 11. The Discharger submitted nitrate sampling data from 2008 to 2012 that indicate an average monthly nitrate (as nitrogen) discharge of 29.0 mg/L with a standard deviation of 6.8 mg/L. Based on the sampling data (average monthly sampling data plus two standard deviations), the current facility’s treatment performance is an average monthly nitrate (as nitrogen) concentration of 42.6 mg/L. 12. The Discharger requested that the Water Board extend the existing compliance schedule under the previous time schedule order for chlorodibromomethane and dichlorobromomethane pursuant to Water Code section 13385 (j)(3)(C)(ii)(II) and to adopt a new compliance schedule for nitrate pursuant to Water Code section 13385 (j)(3)(C)(i) to protect it from mandatory penalties for violations of discharge limits in Order No. R3-2014-0033 until the WRF upgrade is complete. Order No. R3-2014-0036 -4- October 8, 2014 NEED FOR ORDER AND LEGAL BASIS 13. California Water Code Section 13300 authorizes the Central Coast Water Board to establish a time schedule of specific actions a discharger shall take in order to correct or prevent a violation of requirements. 14. The Central Coast Water Board has delegated to its Executive Officer all powers and duties authorized by California Water Code (CWC) section 13223. This power included the authority to issue a time schedule order pursuant to CWC section 13300. 15. The Discharger cannot immediately achieve compliance with the chlorodibromomethane, dichlorobromomethane, and nitrate effluent limitations in Order No. R3-2014-0033. As a result, a discharge of waste from the current facility is taking place which threatens to violate requirements prescribed by the Central Coast Water Board. Therefore, this Order requires the Discharger to undertake actions to comply with final effluent limitations. 16. Violations of the final effluent limits for chlorodibromomethane, dichlorobromomethane, and nitrate are not subject to CWC section 13385 subdivisions (h) and (l) as long as the Discharger complies with all of the requirements of this time schedule order. 17. This time schedule order requires the Discharger to comply with a compliance schedule, which will allow the Discharger to achieve full compliance with chlorodibromomethane, dichlorobromomethane, and nitrate effluent limitations in Order No. R3-2014-0033. 18. This enforcement action is taken for the protection of the environment and as such is exempt from the provisions of the California Environmental Quality Act (Public Resources Code Section 21000, et seq.) in accordance with Section 15321, Chapter 3, Title 14, California Code of Regulations. IT IS HEREBY ORDERED that, pursuant to Section 13300 of the California Water Code, San Luis Obispo Water Resource Recovery Facility shall: 1. Comply with the following interim chlorodibromomethane, dichlorobromomethane, and nitrate effluent limitations commencing on the effective date of TSO No. R3- 2014-0036: Table 4 –Interim Limits Constituent Units Average Monthly Maximum Daily Chlorodibromomethane µg/L - 42 Dichlorobromomethane µg/L - 36 Nitrate (as Nitrogen) mg/L 42.6 - Order No. R3-2014-0036 -5- October 8, 2014 2. Comply with the following compliance schedule commencing on the effective date of Order No. R3-2010-0013: Table 5 –Compliance Schedule Action Time to Complete WRF Improvements 100% Design WRF Improvements May 1, 2017 Request for Bids advertised June 1, 2017 Construction complete August 31, 2019 Start-up and begin commissioning September 1, 2019 Full Compliance with effluent limitations November 30, 2019 Other Actions Update Pollution Prevention Plan June 1, 2015 Submit Annual Progress Reports Annually on February 1 3. Achieve full compliance with the chlorodibromomethane, dichlorobromomethane, and nitrate effluent limitations in Order No. R3-2014-0033 by November 30, 2019. 4. Submit annual progress reports on efforts towards final effluent compliance. Progress reports shall be submitted by February 1st of each year. Progress reports shall include information on the previous reporting year. The first progress report under this TSO shall be submitted to the Central Coast Water Board by February 1, 2015, and shall cover all activities related to the plant upgrades since the Discharger’s last update report. 5. If the Discharger fails to comply with any provisions of this TSO, the Executive Officer may issue a complaint for administrative civil liability pursuant to California Water Code section 13323. The Central Coast Water Board may also refer the case to the Attorney General for injunctive and civil monetary remedies, pursuant to California Water Code sections 13331 and 13385. 6. The Discharger shall comply with all provisions of Order No. R3-2014-0033 that are not in conflict with this Order. Any person aggrieved by this action of the Central Coast Water Board may petition the State Water Board to review the action in accordance with Water Code section 13320 and California Code of Regulations, title 23, sections 2050 and following. The State Water Board must receive the petition by 5:00 p.m., 30 days after the date of the order, except that if the thirtieth day following the date of the order falls on a Saturday, Sunday, or state holiday, the petition must be received by 5:00 p.m. on the next business day. Copies of the law and regulations applicable to filing petitions may be found on the internet at http://www.waterboards.ca.gov/public_notices/petitions/water_quality or will be provided upon request. This Order supersedes TSO No. R3-2010-0013, except for enforcement purposes, and in order to meet the provisions contained in division 7 of the Water Code (commencing with Order No. R3-2014-0036 -6- October 8, 2014 section 13000) and regulations adopted thereunder, and the provisions of the CWA and regulations and guidelines adopted thereunder, the Discharger shall comply with the requirements in this Order. This action in no way prevents the Central Coast Water Board from taking enforcement action for past violations of the previous Order. This Order is effective December 1, 2014. The Executive Officer may modify the time schedule in this Order to permit a specified task or tasks to be completed at later dates if the Discharger demonstrates and the Executive Officer determines that the delay was beyond the reasonable control of the Discharger to avoid. ORDERED BY ___ Kenneth A. Harris Jr., Executive Officer Date KTD P:\NPDES\Facilities\San Luis Obispo\San Luis Obispo\TSO R3-2014-0036\R3-2014-0036 FINAL.doc Place ID: 255380 WRRF Project TM No. 8 – Regulatory Compliance Appendix B City Comments on Draft Tentative NPDES Permit WRRF Project TM No. 8 – Regulatory Compliance Page intentionally blank. WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e B - 1 De t a i l e d Co m m e n t # Do c u m e n t R e f e r e n c e : (D o c . # , S e c t i o n # , P a g e # ) Is s u e Co m m e n t s / d i s c u s s i o n 1. IV . A . 1 . a p . 4 Co p p e r a n d Le a d e f f l u e n t li m i t s Th e p r o p o s e d c o p p e r a n d l e a d e f f l u e n t l i m i t s a r e b a se d o n a h a r d n e s s o f 1 0 0 m g / L w h e r e 1 0 0 m g / L i s u s e d as a de f a u l t v a l u e b e c a u s e a s s t a t e d o n p a g e F - 1 6 o f t h e F a c t S h e e t “ T h e D i s c h a r g e r h a s n o t c o l l e c t e d h a r d n ess data fo r t h e r e c e i v i n g w a t e r . R e g i o n a l W a t e r B o a r d s t a f f u s e d a h a r d n e s s v a l u e o f 1 0 0 m g / L a s a c o n s e r v a t i v e estimate of t h e r e c e i v i n g w a t e r h a r d n e s s t o d e t e r m i n e h a r d n e ss - b a s e d c r i t e r i a . ” H o w e v e r , r e c e i v i n g w a t e r d a t a were co l l e c t e d b y t h e R e g i o n a l W a t e r B o a r d u p s t r e a m a n d do w n s t r e a m o f t h e W R F ’ s d i s c h a r g e . F o r d a t a a v a i l a b le si n c e 2 0 0 8 ( i . e . , t h e t i m e f r a m e t h a t c o r r e s p o n d s t o t h e R O W D d a t a s e t ) , h a r d n e s s v a l u e s f o r S a n L u i s O bispo Cr e e k c o l l e c t e d b y t h e R e g i o n a l W a t e r B o a r d a t L o s Os o s V a l l e y R o a d r a n g e f r o m 2 8 0 m g / L t o 3 8 0 m g / L e x cept fo r a n o u t l i e r h a r d n e s s v a l u e o f 2 2 m g / L f o r a s a m p le c o l l e c t e d o n J a n u a r y 2 1 , 2 0 0 9 w h i c h d o e s n o t a p p ear to be re p r e s e n t a t i v e o f t h e c r e e k ’ s w a t e r q u a l i t y d u r i n g dr y w e a t h e r c o n d i t i o n s . H a r d n e s s m e a s u r e m e n t s t a k e n by the Re g i o n a l W a t e r B o a r d o n J a n u a r y 2 1 , 2 0 0 9 u p s t r e a m ( at M i s s i o n P l a z a ) a n d d o w n s t r e a m ( S a n L u i s B a y D r i v e ) of Lo s O s o s V a l l e y R o a d m e a s u r e d 3 7 0 m g / L a n d 3 5 0 m g / L , r e s p e c t i v e l y . T h i s f u r t h e r s u p p o r t s t h e c o n c e r n t hat the 22 m g / L v a l u e i s n o t r e p r e s e n t a t i v e o f a c t u a l c r e e k c o n d i t i o n s . T h e r e f o r e , t h e C i t y r e q u e s t s t h a t t h e next lowest va l u e m e a s u r e d a t L o s O s o s V a l l e y R o a d o f 2 8 0 m g / L be u s e d t o e v a l u a t e t h e h a r d n e s s b a s e d m e t a l s c r i t e ria. At a h a r d n e s s o f 2 8 0 m g / L t h e a p p l i c a b l e c h r o n i c c r i t e ri o n f o r c o p p e r f o r a s s e s s i n g R e a s o n a b l e P o t e n t i a l would be 22 . 5 g / L . C o m p a r i n g t h i s c r i t e r i o n t o a M E C o f 1 9 g/ L w o u l d n o t t r i g g e r R P o r t h e n e e d f o r a n e f f l u e nt limit. For le a d , t h e a p p l i c a b l e c r i t e r i a w o u l d b e 1 1 . 8 a n d t h e M E C i s 5 . T h e r e f o r e , a n e f f l u e n t l i m i t f o r l e a d w o uld also not be ne c e s s a r y . N o t e t h a t t h e u s e o f 1 0 0 m g / L h a r d n e s s i s o f a c o n c e r n , a s s h o w n b e l o w , b e c a u s e t h e C i t y w i ll not co n s i s t e n t l y c o m p l y w i t h t h e p r o p o s e d e f f l u e n t l i m i ts f o r c o p p e r a n d l e a d . P l e a s e s e e a t t a c h e d T e c h n i c al Me m o r a n d u m e n t i t l e d “ E v a l u a t i o n o f R e c e i v i n g W a t e r Ha r d n e s s t o D e t e r m i n e H a r d n e s s - B a s e d C r i t e r i a ” f o r ad d i t i o n a l i n f o r m a t i o n . WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e B - 2 De t a i l e d Co m m e n t # Do c u m e n t R e f e r e n c e : (D o c . # , S e c t i o n # , P a g e # ) Is s u e Co m m e n t s / d i s c u s s i o n 2. IV . A . 1 . a , p . 4 Ma s s -ba s e d ef f l u e n t l i m i t s Ta b l e 4 o f t h e d r a f t O r d e r c o n t a i n s c o n c e n t r a t i o n a nd m a s s b a s e d e f f l u e n t l i m i t s f o r a l l c o n s t i t u e n t s . Water quality ba s e d e f f l u e n t l i m i t s a r e e s t a b l i s h e d b a s e d o n c o n c en t r a t i o n b a s e d c r i t e r i a h a v e b e e n e s t a b l i s h e d t o e nsure pr o t e c t i o n o f b e n e f i c i a l u s e s . M a s s b a s e d l i m i t s p r ov i d e n o a d d i t i o n a l a s s u r a n c e t h a t b e n e f i c i a l u s e s are being pr o t e c t e d a n d c o u l d r e s u l t i n t h e d i s c h a r g e e f f e c t i ve l y v i o l a t i n g t w o e f f l u e n t l i m i t s b a s e d o n o n e a c t ual exceedance. Th e r e f o r e , t h e C i t y r e q u e s t s t h a t m a s s l i m i t s b e e l im i n a t e d f o r a l l c o n s t i t u e n t s i n T a b l e 4 e x c e p t f o r BOD and TSS wh i c h a r e t e c h n o l o g y b a s e d e f f l u e n t l i m i t s . 3. IV . A . 1 . a , p . 4 Oi l a n d g r e a s e ef f l u e n t l i m i t Th e F a c t S h e e t s t a t e s i n I V . C . 6 . e t h a t t h i s e f f l u e n t l i m i t i s r e t a i n e d f r o m t h e p r e v i o u s O r d e r a n d i m p lements the na r r a t i v e b a s i n p l a n o b j e c t i v e t h a t ‘ W a t e r s s h a l l n ot c o n t a i n o i l s , g r e a s e s , w a x e s , o r o t h e r s i m i l a r m aterials that re s u l t i n a v i s i b l e f i l m o r c o a t i n g o n t h e s u r f a c e of t h e w a t e r o r o n o b j e c t s i n t h e w a t e r … ’ . T h e r e h a ve been no such oc c u r r e n c e s i n t h e v i c i n i t y o f t h e d i s c h a r g e a n d n o o t h e r c o n c e r n s a s s o c i a t e d w i t h o i l a n d g r e a s e a n d the Re c e i v i n g W a t e r L i m i t a t i o n i n S e c t i o n V . A . 6 . e n s u r e s p r o t e c t i o n o f b e n e f i c i a l u s e s . T h e r e f o r e , t h e C i t y believes that th e r e i s n o r e a s o n a b l e p o t e n t i a l f o r t h e d i s c h a r g e to c a u s e o r c o n t r i b u t e t o a n e x c e e d a n c e o f t h i s o b j ective. The Ci t y r e q u e s t s t h a t t h i s e f f l u e n t l i m i t b e e l i m i n a t e d f r o m T a b l e 4 . WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e B - 3 De t a i l e d Co m m e n t # Do c u m e n t R e f e r e n c e : (D o c . # , S e c t i o n # , P a g e # ) Is s u e Co m m e n t s / d i s c u s s i o n 4. IV . A . 1 .a , p . 4 ND M A e f f l u e n t li m i t Ba s e d o n a r e v i e w o f t h e f u l l d a t a s e t a n d w h a t i s kn o w n a b o u t u n c e r t a i n t i e s a s s o c i a t e d w i t h N D M A a n a l ytical me t h o d s , t h e d a t a m a y b e i n s u f f i c i e n t a s d e s c r i b e d in S e c t i o n 1 . 2 o f t h e S I P . S p e c i f i c a l l y , s e c t i o n 1 . 2 provides that: Wh e n i m p l e m e n t i n g t h e p r o v i s i o n s o f t h i s P o l i c y , t h e C C R W Q C B s h a l l u s e a l l a v a i l a b l e , v a l i d , r e l e v a n t , re p r e s e n t a t i v e d a t a a n d i n f o r m a t i o n , a s d e t e r m i n e d by t h e C C R W Q C B . T h e C C R W Q C B s h a l l h a v e d i s c r e t i o n t o co n s i d e r i f a n y d a t a a r e i n a p p r o p r i a t e o r i n s u f f i c i en t f o r u s e i n i m p l e m e n t i n g t h i s P o l i c y . I n s t a n c e s where such co n s i d e r a t i o n i s w a r r a n t e d i n c l u d e , b u t a r e n o t l i m it e d t o , t h e f o l l o w i n g : e v i d e n c e t h a t a s a m p l e h a s been er r o n e o u s l y r e p o r t e d o r i s n o t r e p r e s e n t a t i v e o f t h e e f f l u e n t o r a m b i e n t r e c e i v i n g w a t e r q u a l i t y ; q u e s tionable quality co n t r o l / q u a l i t y a s s u r a n c e p r a c t i c e s ; a n d v a r y i n g s e as o n a l c o n d i t i o n s . 1 A s s h o w n b e l o w , 4 o f 5 s a m p l e s a r e n o t d e t e c t e d a t 0 . 1 4 g / L w i t h o n e d e t e c t e d v a l u e t h a t i s a p p r o x i m ately 2 or d e r s o f m a g n i t u d e g r e a t e r t h a t t h e d e t e c t i o n l i m i t a t 1 2 g / L . E P A m e t h o d 6 2 5 w a s u s e d t o a n a l y z e f o r NDMA. ND M A i s r a r e l y d e t e c t e d i n P O T W e f f l u e n t a n d w h e n i t i s , c o n c e n t r a t i o n s a r e t y p i c a l l y o n t h e o r d e r o f 0.02-0.03 g/ L f o r o n e P O T W ( S R C S D ) . A r e v i e w o f N D M A i n w a s t ew a t e r o b s e r v e d a m e d i a n c o n c e n t r a t i o n o f 0 . 0 4 6 g / L an d m a x i m u m c o n c e n t r a t i o n o f 0 . 3 8 g / L s e c o n d a r y e f fl u e n t f o r 6 P O T W s ( 5 i n C a l i f o r n i a a n d 1 i n A r i z o n a).2 Ty p i c a l l y h i g h e r l e v e l s o f N D M A ( > 0 . 0 1 g / L ) a r e a s so c i a t e d w i t h d i s i n f e c t i o n u s i n g c h l o r a m i n e s o r h i g her am m o n i a e f f l u e n t c o n c e n t r a t i o n ( > 2 0 m g / L ) a n d c h o r i ne d i s i n f e c t i o n . T h e r e f o r e , t h e 1 2 g / L d e t e c t e d v a lue is hi g h l y s u s p e c t . A s s u c h , t h e C i t y r e q u e s t s t h a t a d d it i o n a l m o n i t o r i n g b e r e q u i r e d ( i . e . , 1 / m o n t h a s s h own in the pr o p o s e d M R P ) a n d n o e f f l u e n t l i m i t b e a p p l i e d a t t hi s t i m e . 1 S I P a t p . 5 . 2 S e d l a k , e t . a l . , S o u r c e s a n d F a t e o f N i t r o s o d i m e t h y la m i n e a n d I t s P r e c u r s o r s i n M u n i c i p a l W a s t e w a t e r T re a t m e n t P l a n t s . W a t e r E n v i r o n m e n t R e s e a r c h , V o l . 7 7, No . 1 . J a n u a r y / F e b r u a r y 2 0 0 5 . WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e B - 4 De t a i l e d Co m m e n t # Do c u m e n t R e f e r e n c e : (D o c . # , S e c t i o n # , P a g e # ) Is s u e Co m m e n t s / d i s c u s s i o n Th e r e f o r e , t h e C i t y r e q u e s t s t h a t a d d i t i o n a l m o n i t o ri n g b e r e q u i r e d ( i . e . , 1 / m o n t h a s s h o w n i n t h e p r o posed MRP) an d n o e f f l u e n t l i m i t . 5. IV . A . 1 . a , p . 4 Pe n t a c h l o r o - ph e n o l l i m i t Pe n t a c h l o r o p h e n o l w a s d e t e c t e d o n c e i n t h e e f f l u e n t a t 1 . 2 g/ L . T h e a n a l y t i c a l m e t h o d u s e d w a s E P A m e t h o d 62 5 w h i c h i s a G C / M S m e t h o d . T h e m i n i m u m l e v e l l i s t ed i n A p p e n d i x 4 o f t h e S I P f o r P e n t a c h l o r o p h e n o l a nalyzed us i n g G C / M S i s 5 g / L . S e c t i o n 2 . 4 o f t h e S I P d e s c r ib e s t h e s e l e c t i o n o f R e p o r t i n g L e v e l s b a s e d o n t h e Minimum Le v e l s i n t h e S I P . F o l l o w i n g t h e p r o c e d u r e s i n S e c t io n 2 . 4 , t h e d e t e c t e d v a l u e o f 1 . 2 g / L w o u l d b e c o nsidered a de t e c t e d n o t q u a n t i f i e d v a l u e ( D N Q ) b e c a u s e i t i s b el o w t h e M L o f 5 g / L . T h e r e f o r e , t h e d a t a i s c o n s i dered in s u f f i c i e n t f o r d e t e r m i n i n g r e a s o n a b l e p o t e n t i a l a s d e s c r i b e d i n S e c t i o n 1 . 2 o f t h e S I P . T h e r e f o r e , t he City re q u e s t s t h a t n o e f f l u e n t l i m i t f o r p e n t a c h l o r o p h e n ol b e i n c l u d e d i n t h e p e r m i t . WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e B - 5 De t a i l e d Co m m e n t # Do c u m e n t R e f e r e n c e : (D o c . # , S e c t i o n # , P a g e # ) Is s u e Co m m e n t s / d i s c u s s i o n 6. IV . A . 1 . a , p . 4 IV . A . 1 . d , p . 5 Ma x D a i l y f l o w li m i t Ta b l e 4 o f t h e d r a f t p e r m i t c o n t a i n s a m a x i m u m d a i l y f l o w l i m i t o f 5 . 1 M G D . T h e c u r r e n t p e r m i t c o n t a i n s the fo l l o w i n g f l o w l i m i t ( p a g e 9 ) “ E f f l u e n t d a i l y d r y w ea t h e r f l o w s h a l l n o t e x c e e d a m o n t h l y a v e r a g e o f 5 .2 MGD.” 5.1 MG D i s t h e a v e r a g e d e s i g n f l o w a n d t h e F a c t S h e e t s ta t e s i n S e c t i o n I V . B . 2 . c ( p . F - 1 2 ) t h a t t h e l i m i t is an average da i l y d i s c h a r g e f l o w . I n a d d i t i o n , I V . A . 1 . d o n p . 5 o f t h e d r a f t p e r m i t c o n t a i n s t h e f l o w l i m i t . T h e r e fore, the City re q u e s t s t h a t F l o w b e d e l e t e d f r o m T a b l e 4 a n d t h a t I V . A . 1 . d b e r e v i s e d t o r e a d t h a t t h e a v e r a g e d r y w eather daily di s c h a r g e s h a l l n o t e x c e e d 5 . 1 M G D . In a d d i t i o n , t o c l a r i f y h o w t h i s e f f l u e n t l i m i t i s to b e e v a l u a t e d , t h e C i t y r e q u e s t s t h a t t h e f o l l o w i ng be added to Se c t i o n V I I . C o m p l i a n c e D e t e r m i n a t i o n : Av e r a g e D r y W e a t h e r F l o w E f f l u e n t L i m i t a t i o n s ( S e c t io n I V . A . 1 . d ) . The average dry weather di s c h a r g e f l o w r e p r e s e n t s t h e d a i l y a v e r a g e f l o w w h en g r o u n d w a t e r i s a t o r n e a r n o r m a l a n d r u n o f f i s n ot oc c u r r i n g . C o m p l i a n c e w i t h t h e a v e r a g e d r y w e a t h e r fl o w e f f l u e n t l i m i t a t i o n s w i l l b e d e t e r m i n e d a n n u a l ly ba s e d o n t h e a v e r a g e d a i l y f l o w o v e r t h r e e c o n s e c u t iv e d r y w e a t h e r m o n t h s ( e . g . , J u l y , A u g u s t , a n d Se p t e m b e r ) . WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e B - 6 De t a i l e d Co m m e n t # Do c u m e n t R e f e r e n c e : (D o c . # , S e c t i o n # , P a g e # ) Is s u e Co m m e n t s / d i s c u s s i o n Th i s l a n g u a g e i s c o m m o n l y u s e d i n C e n t r a l V a l l e y p e rm i t s . S o m e r e c e n t l y a d o p t e d p e r m i t s w i t h t h i s l a n g uage in th e C o m p l i a n c e D e t e r m i n a t i o n s e c t i o n i n c l u d e C i t y o f R e d B l u f f ( R 5 - 2 0 1 3 - 0 0 4 4 ) a n d C i t y o f R e d d i n g ( R 5 - 2013- 00 4 3 7. IV . A . 1 . a , p . 4 pH e f f l u e n t l i m i t Ta b l e 4 o f t h e d r a f t p e r m i t c o n t a i n s a p H e f f l u e n t li m i t o f 7 -8. 3 . H o w e v e r , t h e f o o t n o t e t o T a b l e 4 states the range as 6 . 5 – 8 . 3 . I n a d d i t i o n , t h e F a c t S h e e t r e f e r s t o d i f f e r e n t p H r a n g e s i n d i f f e r e n t p l a c e s : • Ta b l e F - 5 o n p . F - 1 3 r e f e r s t o T e c h n o l o g y B a s e E f f l ue n t L i m i t s ( 6 . 0 – 9 ) • Ta b l e F - 1 0 s t a t e s t h e e f f l u e n t l i m i t f o r p H a s 6 . 5 – 8 . 3 • Se c t i o n F . I V . C . 6 s t a t e s t h a t l i m i t i s s e t a t 7 . 0 - 8 . 3 t o p r o t e c t a l l b e n e f i c i a l u s e s . Th e p H l i m i t o f 7 . 0 a p p e a r s t o b e b a s e d o n t h e B a s i n P l a n o b j e c t i v e s f o r t h e C O L D , W A R M a n d S P W N w h i c h have be e n i n t h e B a s i n P l a n s i n c e b e f o r e t h e a d o p t i o n o f t h e c u r r e n t p e r m i t . T h e c u r r e n t p e r m i t c o n t a i n s a n effluent limit of 6 . 5 - 8 . 3 . A s s h o w n b e l o w , t h e C i t y w i l l h a v e d i f f ic u l t y c o m p l y i n g w i t h a m i n i m u m p H l i m i t o f 7 . 0 . H o wever, as also sh o w n b e l o w , t h e r e c e i v i n g w a t e r p H i s v e r y r a r e l y ou t s i d e t h e B a s i n P l a n o b j e c t i v e . T h e C i t y r e q u e s t s that the pH li m i t o f 7 . 0 b e a p p l i e d a s a r e c e i v i n g w a t e r l i m i t to e n s u r e t h a t t h e C i t y d o e s n o t c a u s e o r c o n t r i b u t e to an ex c e e d a n c e i n t h e r e c e i v i n g w a t e r . I f a n e f f l u e n t l im i t i s a l s o n e c e s s a r y , i t s h o u l d b e 6 . 5 t o b e c o n s istent with the te c h n o l o g y b a s e d e f f l u e n t l i m i t i n t h e c u r r e n t p e r m it . T h i s i s c o n s i s t e n t w i t h h o w p H l i m i t s h a v e b e e n applied in ot h e r C e n t r a l C o a s t P e r m i t s w i t h t h e s a m e b e n e f i c i a l u s e s ( e . g . , C i t y o f L o m p o c ( R 3 - 2 0 1 1 - 0 2 1 1 ) , C i t y o f El Paso de R o b l e s ( R 3 - 2 0 1 1 - 0 0 2 ) ) WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e B - 7 De t a i l e d Co m m e n t # Do c u m e n t R e f e r e n c e : (D o c . # , S e c t i o n # , P a g e # ) Is s u e Co m m e n t s / d i s c u s s i o n WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e B - 8 De t a i l e d Co m m e n t # Do c u m e n t R e f e r e n c e : (D o c . # , S e c t i o n # , P a g e # ) Is s u e Co m m e n t s / d i s c u s s i o n 8. IV . A . 1 . a ., p . 4 Ni t r a t e + n i t r i t e ef f l u e n t l i m i t Ta b l e 4 i n c l u d e s e f f l u e n t l i m i t s f o r n i t r a t e a n d f o r n i t r a t e + n i t r i t e . H o w e v e r , s i n c e 2 0 0 8 , n i t r i t e h as not been de t e c t e d i n t h e e f f l u e n t a b o v e a d e t e c t i o n l i m i t o f 0 . 1 m g / l . C o m p a r i n g t h i s t o t h e M C L f o r n i t r i t e o f 1 mg/L indicates th a t t h e r e i s n o r e a s o n a b l e p o t e n t i a l f o r n i t r i t e t o c a u s e o r c o n t r i b u t e t o a n e x c e e d a n c e o f a w a t e r q uality objective. In a d d i t i o n , b e c a u s e n i t r i t e i s n e v e r d e t e c t e d , e f f lu e n t l i m i t s f o r n i t r a t e a n d f o r n i t r a t e + n i t r i t e are both essentially ev a l u a t i n g t h e s a m e t h i n g . T h e r e f o r e , t h e C i t y r e q u es t s t h a t t h e e f f l u e n t l i m i t f o r n i t r a t e + n i t r i t e be removed from Ta b l e 4 . 9. IV . A . 1 . c , p . 5 Fe c a l c o l i f o r m li m i t Th e C i t y s u p p o r t s t h e u s e o f f e c a l c o l i f o r m a s t h e ap p r o p r i a t e p a t h o g e n i n d i c a t o r . WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e B - 9 De t a i l e d Co m m e n t # Do c u m e n t R e f e r e n c e : (D o c . # , S e c t i o n # , P a g e # ) Is s u e Co m m e n t s / d i s c u s s i o n 10 . IV . A . 2 . , p . 5 In t e r i m e f f l u e n t li m i t a t i o n s f o r ni t r a t e a n d TH M s Th e s e i n t e r i m l i m i t s a n d c o m p l i a n c e s c h e d u l e s s h o u l d b e m a i n t a i n e d i n a s e p a r a t e T i m e S c h e d u l e O r d e r a nd not be i n c l u d e d a s p a r t o f t h e p e r m i t . T h e C i t y s u p p o r t s t h e c o n t i n u a t i o n o f t h e T H M t i m e s c h e d u l e t h r o u g h the current ex p i r a t i o n d a t e o f M a r c h 3 1 , 2 0 1 5 . A t t h a t t i m e , t h e C i t y m a y d e t e r m i n e i t n e c e s s a r y t o r e q u e s t a n a d d itional time sc h e d u l e o r d e r , d e p e n d i n g o n t h e s t a t u s o f f a c i l i t y u p g r a d e s . W a t e r C o d e s e c t i o n 1 3 3 8 5 ( j ) ( 3 ) ( C ) ( i i ) ( I I ) provides for an a d d i t i o n a l f i v e y e a r s o f p r o t e c t i o n f r o m M M P s u p on t h e R e g i o n a l B o a r d ’ s f i n d i n g o f c e r t a i n f a c t o r s . The pr o v i s i o n s t a t e s a s f o l l o w s : " F o l l o w i n g a p u b l i c h e ar i n g , a n d u p o n a s h o w i n g t h a t t h e d i s c h a r g e r i s m a king diligent pr o g r e s s t o w a r d b r i n g i n g t h e w a s t e d i s c h a r g e i n t o c om p l i a n c e w i t h t h e e f f l u e n t l i m i t a t i o n , t h e r e g i o n a l board may ex t e n d t h e t i m e s c h e d u l e f o r a n a d d i t i o n a l p e r i o d n ot e x c e e d i n g f i v e y e a r s i n l e n g t h , i f t h e d i s c h a r g e r demonstrates th a t t h e a d d i t i o n a l t i m e i s n e c e s s a r y t o c o m p l y w i t h t h e e f f l u e n t l i m i t a t i o n . " Wi t h r e s p e c t t o n i t r a t e , t h e C i t y r e q u e s t s t h a t a t im e s c h e d u l e o r d e r b e a d o p t e d a l o n g w i t h t h e p e r m i t that protects th e C i t y f r o m M M P s f o r f i v e y e a r s . I n t h e t i m e s c h e du l e o r d e r f o r n i t r a t e , t h e C i t y p r o p o s e s a n i n t e r i m nitrate limit ba s e d o n t h e M E C o f 5 8 . 7 m g / L . As n o t e d a b o v e , t h e r e i s n o r e a s o n a b l e p o t e n t i a l f o r n i t r i t e a n d , t h e r e f o r e , n o n e e d f o r a n e f f l u e n t l imit or a co m p l i a n c e s c h e d u l e f o r n i t r a t e p l u s n i t r i t e . 11 . IV . A . 1 . b , p . 5 VI . C . 2 . a , p . 1 0 To x i c i t y l i m i t Th e Ci t y s u p p o r t s t h e n a r r a t i v e t o x i c i t y l i m i t a t i o n f o u nd i n S e c t i o n I V . A . 1 . b . o f t h e d r a f t p e r m i t . U n t i l the Statewide to x i c i t y p o l i c y i s a d o p t e d , t h i s i s a n a p p r o p r i a t e ef f l u e n t l i m i t . Se c t i o n V I . C . 2 . a ( T o x i c i t y R e d u c t i o n R e q u i r e m e n t s ) re f e r s t o e f f l u e n t l i m i t s t h a t a r e n o t f o u n d i n S e c tion IV.a.1. and th e C i t y r e q u e s t s t h a t t h e s e r e f e r e n c e s b e d e l e t e d . 12 . V. A , p . 6 Re c e i v i n g Wa t e r Li m i t a t i o n s a n d Co m p l i a n c e De t e r m i n a t i o n Re c e i v i n g w a t e r q u a l i t y i s a f f e c t e d b y a n u m b e r o f fa c t o r s u p a n d d o w n s t r e a m o f t h e W R F ’ s discharge. The Re c e i v i n g W a t e r L i m i t a t i o n s a n d t h e C o m p l i a n c e D e t e rm i n a t i o n s e c t i o n s o f t h e P e r m i t s h o u l d a c k n o w l e d g e that ex c e e d a n c e s o f t h e s e l i m i t s m a y b e c a u s e d b y f a c t o r s t h a t a r e n o t a s s o c i a t e d w i t h t h e W R F ’ s d i s c h a r g e (i.e., na t u r a l s o u r c e s , o t h e r p e r m i t t e d d i s c h a r g e s , a g r i c u lt u r e , e t c . ) . T h e C i t y r e q u e s t s t h e f o l l o w i n g r e v i s ions: V. A , p . 6 R e c e i v i n g W a t e r L i m i t a t i o n s Th e d i s c h a r g e s h a l l n o t c a u s e a v i o l a t i o n o f t h e f o ll o w i n g r e c e i v i n g w a t e r l i m i t a t i o n s i n S a n L u i s O b i spo Creek. If re c e i v i n g w a t e r s u p s t r e a m o f t h e W R F d i s c h a r g e p o i n t e x c e e d t h e b a s i n p l a n w a t e r q u a l i t y o b j e c t i v e s , t he WRF wi l l n o t b e i n v i o l a t i o n o f t h e r e c e i v i n g w a t e r l i m it a t i o n s i f t h e W R F e f f l u e n t d a t a d o e s n o t i n d i c a t e an exceedance. WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e B - 1 0 De t a i l e d Co m m e n t # Do c u m e n t R e f e r e n c e : (D o c . # , S e c t i o n # , P a g e # ) Is s u e Co m m e n t s / d i s c u s s i o n Th e R e g i o n a l W a t e r B o a r d m ay r e q u i r e t h e D i s c h a r g e r t o i n v e s t i g a t e t h e c a u s e of e x c e e d a n c e s i n t h e r e c e i v i n g wa t e r i f d a t a i n d i c a t e e x c e e d a n c e s o f t h e R e c e i v i n g W a t e r L i m i t a t i o n s i n t h e e f f l u e n t b e f o r e d e t e r m i n i ng whether th e D i s c h a r g e r c a u s e d a n y w a t e r c o n d i t i o n t h a t e x c e ed s t h e f o l l o w i n g r e c e i v i n g w a t e r l i m i t a t i o n s . 13 . V. A . 1 2 , p . 7 Di s s o l v e d ox y g e n re c e i v i n g w a t e r li m i t Th e d r a f t p e r m i t c o n t a i n s a y e a r r o u n d r e c e i v i n g w a te r d i s s o l v e d o x y g e n l i m i t p r o h i b i t i n g D O t o f a l l b elow 7 mg/L. Th e p r e v i o u s p e r m i t c o n t a i n e d s e a s o n a l l i m i t s f o r d is s o l v e d o x y g e n ( i . e . , n o l o w e r t h a n 5 m g / L M a y – S ept, no lo w e r t h a n 7 m g / L O c t – A p r i l ) . T h e B a s i n P l a n l i s t s D i s s o l v e d O x y g e n a p p l i c a b l e t o b e n e f i c i a l u s e s a s follows: • Ge n e r a l l y – n o t b e l o w 5 m g / L a t a n y t i m e ( B a s i n P l a n, p . I I I - 4 ) • AG R – n o t b e l o w 2 m g / L • SP W N , C O L D – n o t b e l o w 7 m g / L Th e C i t y r e q u e s t s t h a t t h e s e a s o n a l D O l i m i t s b e c a rr i e d o v e r f r o m t h e c u r r e n t p e r m i t . 14 . V. A . 1 5 , p . 7 Un -io n i z e d am m o n i a re c e i v i n g w a t e r li m i t Th e d r a f t p e r m i t c o n t a i n s a l i m i t o f 0 . 0 2 5 m g / L ( a s N ) i n t h e r e c e i v i n g w a t e r an d d o e s n o t s p e c i f y a n a v e r a g i n g pe r i o d . T h e c u r r e n t p e r m i t c o n t a i n s t h e s a m e n u m e r i c u n - i o n i z e d a m m o n i a l i m i t ( 0 . 0 2 5 m g / L a s N ) b u t s p ecifies an an n u a l r u n n i n g m e a n a v e r a g i n g p e r i o d w i t h t h e f o l l o wi n g f o o t n o t e ( p a g e 1 0 ) “ C o m p l i a n c e s h a l l b e m e a s u r ed by co m p a r i s o n t o a n a n n u a l r u n n i n g m e a n o f t h e p a s t f o ur q u a r t e r l y s a m p l i n g e v e n t s . ” T h e r e f o r e , t h e C i t y requests th a t V . A . 1 5 b e r e v i s e d t o r e a d a s f o l l o w s : “ T h e d i s ch a r g e o f w a s t e s s h a l l n o t c a u s e c o n c e n t r a t i o n s o f un-ionized am m o n i a ( N H 3 ) t o e x c e e d a n a n n u a l r u n n i n g m e a n o f 0 .0 2 5 m g / L ( a s N ) i n t h e r e c e i v i n g w a t e r . 15 . VI . C . 5 . a . i i , p . 1 4 Bi o s o l i d s di s p o s a l Th e C i t y d i s p o s e s o f b i o s o l i d s t o t h e E n g e l a n d G r a y, I n c . R e g i o n a l C o m p o s t F a c i l i t y . T h i s h a s b e e n t h e City’s pr a c t i c e s i n c e 2 0 0 1 a n d p r i o r t o a d o p t i o n o f t h e c u rr e n t p e r m i t . T h e r e f o r e , i t i s r e q u e s t e d t h a t V I . C . a.ii be revised to re a d : “S l u d g e a n d w a s t e w a t e r s o l i d s m u s t b e d i s p o s e d o f , ma n a g e d o r r e u s e d i n a m u n i c i p a l s o l i d w a s t e la n d f i l l , r e u s e d b y t h r o u g h l a n d a p p l i c a t i o n , a s a Cl a s s A c o m p o s t , o r d i s p o s e d o f i n a s l u d g e - o n l y l a ndfill in ac c o r d a n c e w i t h 4 0 C . F . R . p a r t s 2 5 8 a n d 5 0 3 a n d T i t le 2 3 , C h a p t e r 1 5 o f t h e C C R … ” 16 . VI . C . 5 . a . i x , p . 1 4 Bi o s o l i d s an n u a l r e p o r t Th e a n n u a l r e p o r t d a t e s h o u l d b e c o n s i s t e n t w i t h t h is p e r m i t s M & RP a n d t h e f e d e r a l r e g u l a t i o n s . T h e C i t y s u g g e s t s th e l a s t s e n t e n c e o f t h i s p a r a g r a p h r e a d s ; T h e a n n u al r e p o r t s h a l l b e s u b m i t t e d b y F e b r u a r y 1 9 o f e a c h year for the pe r i o d c o v e r i n g t h e p r e v i o u s c a l e n d a r y e a r . 17 . VI . C . 6 . b , p . 1 5 Co l l e c t i o n sy s t e m p e r m i t cr o s s - re f e r e n c e Th i s s e c t i o n n o t e s t h a t t h e C i t y h a s o b t a i n e d c o v e r ag e u n d e r S t a t e B o a r d O r d e r 2 0 0 6 -0003. The additional la n g u a g e i n t h i s s e c t i o n s t a t i n g t h a t t h e C i t y i s a ls o s u b j e c t t o r e q u i r e m e n t s a s s o c i a t e d w i t h t h e o p e ration and ma i n t e n a n c e o f i t s c o l l e c t i o n s y s t e m u n d e r t h i s O r d er ( R 3 - 2 0 1 3 - 0 0 3 3 ) i s d u p l i c a t i v e o f t h e S t a t e B o a r d Order re q u i r e m e n t s a n d , t h e r e f o r e , u n n e c e s s a r y . WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e B - 1 1 De t a i l e d Co m m e n t # Do c u m e n t R e f e r e n c e : (D o c . # , S e c t i o n # , P a g e # ) Is s u e Co m m e n t s / d i s c u s s i o n In o r d e r t o a v o i d b e i n g s u b j e c t t o t h e s a m e r e q u i r e me n t s i n m o r e t h a n o n e p e r m i t , t h e C i t y r e q u e s t s t h at the se c o n d p a r a g r a p h o f t h i s s e c t i o n t h a t s t a r t s , “ R e g a rd l e s s o f t h e c o v e r a g e o b t a i n e d u n d e r O r d e r 2 0 0 6 - 0 0 03….”, be de l e t e d . 18 . At t a c h m e n t E , I I , p . E -3 Re c e i v i n g wa t e r mo n i t o r i n g lo c a t i o n s Re c e i v i n g w a t e r m o n i t o r i n g l o c a t i o n s , R S W -00 1 , R S W -00 2 , a n d R S W -00 6 a r e n o l o n g e r i n u s e and have not been us e d f o r o v e r 1 0 y e a r s . T h e y a r e l i s t e d i n T a b l e E - 1 a n d i n t h e h e a d i n g a n d t e x t i n S e c t i o n V I I I . A . 1 o f the Mo n i t o r i n g a n d R e p o r t i n g P r o g r a m . H o w e v e r , a c c o r d i n g t o T a b l e E - 5 , n o m o n i t o r i n g i s r e q u i r e d a t a n y o f these st a t i o n s . T h e C i t y r e q u e s t s t h a t t h e s e s t a t i o n s b e de l e t e d f r o m T a b l e E - 1 a n d d e l e t e d f r o m S e c t i o n V I I I.A.1. 19 . At t a c h m e n t E , V . B . 1 . c Ch r o n i c To x i c i t y T e s t Sp e c i e s Se c t i o n V . B . 1 . c o f t h e M o n i t o r i n g a n d R e p o r t i n g P r o gr a m ( M R P ) r e q u i r e s t h e C i t y t o c o n d u c t a 3 -month screening te s t t o i d e n t i f y t h e m o s t s e n s i t i v e s p e c i e s f r o m f a th e a d m i n n o w , w a t e r f l e a a n d a l g a ( i . e . , Selenastrum ca p r i c o r n u t u m ). B a s e d o n r e c e n t e x p e r i e n c e o f o t h e r d i s c h a r g e r s , t h e C i t y b e l i e v e s t h a t Selanastrum is not a su i t a b l e t e s t s p e c i e s . Ot h e r D i s c h a r g e r s h a v e f o u n d t h a t t o x i c i t y r e s u l t s us i n g S e l a n a s t r u m m a y , i n f a c t , r e p r e s e n t f a l s e p o s itive tests. Be c a u s e o f t h e s e o b s e r v a t i o n s , P a c i f i c E c o R i s k h a s be e n w o r k i n g w i t h v a r i o u s d i s c h a r g e r s r e l a t e d t o t h e oc c u r r e n c e o f f a l s e p o s i t i v e c h r o n i c t o x i c i t y t e s t s u s i n g Se l e n a s t r u m , a n d h a s f o u n d t h a t E P A - a p p r o v e d v a r i a t i o n s in t h e f o l l o w i n g c o m p o n e n t s o f t h e t e s t m e t h o d f o r Se l e n a s t r u m h a v e b e e n o b s e r v e d t o a f f e c t t h e r e s u l t s o f t h e to x i c i t y b i o a s s a y ( C l a r k , 2 0 1 1 ) 3: 1. Va r i a t i o n i n c e l l c o u n t s o b s e r v e d a m o n g v a r i o u s a c c ep t a b l e c e l l c o u n t i n g m e t h o d s ; 2. Ad h e s i o n o f c e l l s t o s i d e o f b i o a s s a y v e s s e l r e s u l t in g i n u n d e r c o u n t i n g o f c e l l s ; 3. Ad h e s i o n o f c e l l s t o b o t t o m o f b i o a s s a y v e s s e l ( a p ro c e s s c a l l e d “ p l a t i n g ” ) r e s u l t i n g i n u n d e r c o u n t i n g of ce l l s ; 4. Al g a s h o w s d e c r e a s e d g r o w t h i n t h e p r e s e n c e s o f h i g h s a l t c o n c e n t r a t i o n s ; 5. In c r e a s e d s t i m u l a t o r y e f f e c t o n c o n t r o l d u e t o u s e of c o n t r o l w a t e r c o n t a i n i n g n u t r i e n t s a n d m i n e r a l s at co n c e n t r a t i o n s a l l o w e d b y t h e U S E P A t e s t m e t h o d ; a n d 6. Cl u m p i n g o f c e l l s c a u s e d b y p o l y m e r s o r o t h e r c o m p o un d s p r e s e n t i n w a s t e w a t e r e f f l u e n t t h a t c a u s e c e l l ag g r e g a t i o n a n d r e s u l t i n u n d e r c o u n t i n g o f c e l l s . Th e C i t y c o n d u c t e d t h i s s c r e e n i n g w i t h f a t h e a d m i n n ow , w a t e r f l e a a n d a l g a f o r t h e c u r r e n t p e r m i t a n d identified th e f a t h e a d m i n n o w a s t h e a p p r o p r i a t e s p e c i e s . T h e Ci t y r e q u e s t s t h a t t h e 3 - m o n t h s c r e e n i n g t e s t r e q u i rement be de l e t e d o r t h a t a n o t h e r s p e c i e s b e i d e n t i f i e d i n p l ac e o f Se l a n a s t r u m . 3 C l a r k , S . L . ( 2 0 1 1 ) . P e r s o n a l c o m m u n i c a t i o n w i t h V ic e P r e s i d e n t / S p e c i a l P r o j e c t s D i r e c t o r a t P a c i f i c Ec o R i s k , F a i r f i e l d , C A . P h o n e c o n v e r s a t i o n r e g a r d i n g is s u e s t h a t c a n c a u s e f a l s e p o s i t i v e r e s u l t s i n c h r on i c t o x i c i t y t e s t s u s i n g Se l e n a s t r u m . J u n e 2 8 . WR R F P r o j e c t TM N o . 8 – R e g u l a t o r y C o m p l i a n c e Pa g e B - 1 2 De t a i l e d Co m m e n t # Do c u m e n t R e f e r e n c e : (D o c . # , S e c t i o n # , P a g e # ) Is s u e Co m m e n t s / d i s c u s s i o n 20 . At t a c hm e n t E , I X . A . 3 , p . E - 12 Bi o s o l i d s re p o r t i n g Th e C i t y d o e s n o t d i s p o s e o f i t s b i o s o l i d s t h r o u g h la n d a p p l i c a t i o n . T h e r e f o r e , t h e b i o s o l i d s a r e n o t subject to these re p o r t i n g r e q u i r e m e n t s a n d t h e C i t y r e q u e s t s t h a t t hi s s e c t i o n b e d e l e t e d . 21 . At t a c h m e n t E , X. B . 5 . c , p E - 18 An n u a l S e l f - Mo n i t o r i n g It h a s b e e n d i f f i c u l t t o a c q u i r e a l l t h e d a t a a n d c om p l e t e t h e a n n u a l s e l f -mo n i t o r i n g r e p o r t 3 1 d a y s a f t e r t h e e n d o f De c e m b e r . C u r r e n t l y t h e C i t y s u b m i t s i t s a n n u a l r e p or t 4 5 d a y s a f t e r D e c e m b e r 3 1 , t o a l l o w a d e q u a t e t i me to co l l e c t a n d v e r i f y t h e d a t a a n d c o m p l e t e t h e r e p o r t . T h e C i t y r e q u e s t t h a t t h e A n n u a l S e l f - M o n i t o r i n g Report be due on F e b r u a r y 1 5 f o l l o w i n g e a c h c a l e n d a r y e a r . WRRF Project TM No. 8 – Regulatory Compliance Appendix C Tables from Larry Walker and Associates on Potential Future Nutrient Limits WRRF Project TM No. 8 – Regulatory Compliance Page intentionally blank. TM D L Na m e R e s o l u t i o n Nu m b e r Ad o p t i o n Da t e Ef f e c t i v e Da t e F i n a l Co m p l i a n c e Da t e Wa t e r b o d i e s Ad d r e s s e d I m p a i r m e n t s Ad d r e s s e d B e n e f i c a l Us e s T M D L Ta r g e t s an d Av e r a g i n g Pe r i o d L o a d Al l o c a t i o n s W L A s R e s p o n s i b l e Parties Ar r o y o Pa r e d o n Ni t r a t e TM D L R 3 ‐20 1 3 ‐00 5 0 1 2 / 5 / 2 0 1 3 2 / 1 3 / 2 0 1 4 1 0 / 1 / 2 0 1 6 A r r o y o Pa r e d o n (a l l tr i b u t a r i e s ) N i t r a t e M U N 1 0 mg / L Ni t r a t e as N R e c e i v i n g Wa t e r : 1 0 mg / L Ni t r a t e as NNone"Owners/operators of irrigated agricultural lands in the Arroyo Paredon Watershed" Be l l Cr e e k Ni t r a t e TM D L R 3 ‐20 1 3 ‐00 1 2 5 / 3 0 / 2 0 1 3 5 / 3 0 / 2 0 1 3 1 0 / 1 / 2 0 1 6 B e l l Cr e e k N i t r a t e M U N 1 0 mg / L Ni t r a t e as N R e c e i v i n g Wa t e r : 1 0 mg / L Ni t r a t e as NNone"Owners and operators of agricultural lans using nitrate are assigned load allocations equal to the TMDL and numeric targets" Re c e v i n g Wa t e r : 1. 5 mg / L ro l l i n g me d i a n ni t r a t e ‐N Max Monthly Effluent: 10 mg/L Nitrate‐N California Men's Colony (CMC) Wastewater Treatment Plant Re c e v i n g Wa t e r : ro l l i n g me d i a n or t h o p h o s p h a t e ‐P co n c e t n r a t i o n sh a l l no t ex c e e n 0. 4 mg / L ‐P Median Effluent: 0.4 mg/L Orthophosphorus‐PCalifornia Men's Colony (CMC) Wastewater Treatment Plant Me d i a n st r e a m sh a d i n g sh a l l no t fa l l be l o w 70 % al o n g Ch o r r o Cr e e k Me d i a n mi n i m u m st r e a m sh a d i n g 70 % L a n d Owners along Chorrow Creek Ef f l u e n t Li m i t : 50 mg / L So d i u m di s c h a r g e d to Ch o r r o Cr e e k an d it s tr i b u t a r i e s . Receiving Water: 50 mg/L SodiumCalifornia Men's Colony (CMC) Wastewater Treatment Plant Ef f l u e n t Li m i t : 50 0 mg / L TD S di s c h a r g e d to Ch o r r o Cr e e k an d it s tr i b u t a r i e s Receiving Water: 500 mg/L TDSCalifornia Men's Colony (CMC) Wastewater Treatment Plant Ef f l u e n t Li m i t : Di s c h a r g e r s sh a l l no t ca u s e re c e i v i n g wa t e r te m p e r a t u r e to in c r e a s e by mo r e th a n 5° F Effluent Limit: Dischargers shall not cause receiving water temperature to increase by more than 5°FCalifornia Men's Colony (CMC) Wastewater Treatment Plant Gl e n n An n i e Ca n y o n Te c o l o t i t o Cr e e k Ca r n e r o s Cr e e k WLAs:City of Arroyo Grande, County of San Luis Obispo LAs:"Owners and operators of agricultural lans using nitrate are assigned load allocations equal to the TMDL and numeric targets" Lo s Os o s Cr e e k , Wa r d e n Cr e e k , an d Wa r d e n La k e We t l a n d Nu t r i e n t TM D L R3 ‐20 0 4 ‐01 6 5 1 2 / 3 / 2 0 0 4 3 / 1 / 2 0 0 5 3 / 1 / 2 0 1 5 W a r d e n Cr e e k N i t r a t e M U N R e c e i v i n g Wa t e r : 1 0 mg / L Ni t r a t e as N R e c e i v i n g Wa t e r : 1 0 mg / L Ni t r a t e as NNone"Owners and operators of agricultural lans using nitrate are assigned load allocations equal to the TMDL and numeric targets" Pa j a r o Ri v e r 5 mg/L nitrate‐N (30day mean); 10 mg/L nitrate ‐N Daily maxSouth County Regional Wastewater Authority Ll a g a s Cr e e k Re c e i v i n g Wa t e r : 1 0 mg / L Ni t r a t e as NCropland and Rangeland Re c e i v i n g Wa t e r : 1 0 mg / L Ni t r a t e as NCropland and Rangeland Lo w e r Sa l i n a s Ri v e r Wa t e r s h e d Nu t r i e n t TM D L R3 ‐20 1 3 ‐00 0 8 2 / 4 / 2 0 1 3 Ni t r a t e as N (D r y Se a s o n ) : 1. 4 mg / L N i t r a t e as N (Dry Season): 1.4 mg/LWLAs: Ni t r a t e as N (W e t Se a s o n ) : 8. 0 mg / L N i t r a t e as N (Wet Season): 8.0 mg/LCity of Salinas Or t h o p h o s p h a t e as P (D r y Se a s o n ) : 0.07 mg/LOrthophosphate as P (Dry Season): 0.07 mg/LCounty of Monterey Or t h o p h o s p h a t e as P (W e t Se a s o n ) : 0.03 mg/LOrthophosphate as P (Wet Season): 0.3 mg/LLAs: NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L N H 3 as N (All Year): 0.025 mg/LOwners/ operators of irrigated agricultural lands and land used for/containing domestic animals/livestock Ni t r a t e as N (A l l Ye a r ) : 10 mg / L LAs: NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L Owners/ operators of irrigated agricultural lands and land used for/containing domestic animals/livestock Ni t r a t e as N (D r y Se a s o n ) : 6. 4 mg / L N i t r a t e as N (Dry Season): 6.4 mg/LWLAs: Ni t r a t e as N (W e t Se a s o n ) : 8. 0 mg / L N i t r a t e as N (Wet Season): 8.0 mg/LCity of Salinas Or t h o p h o s p h a t e as P (D r y Se a s o n ) : 0.13mg/LOrthophosphate as P (Dry Season): 0.13mg/LCounty of Monterey Or t h o p h o s p h a t e as P (W e t Se a s o n ) : 0.3 mg/LOrthophosphate as P (Wet Season): 0.3 mg/LLAs: NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L N H 3 as N (All Year): 0.025 mg/LOwners/ operators of irrigated agricultural lands and land used for/containing domestic animals/livestock Ni t r a t e as N (D r y Se a s o n ) : 2. 0 mg / L N i t r a t e as N (Dry Season): 2.0 mg/LWLAs: Ni t r a t e as N (W e t Se a s o n ) : 8. 0 mg / L N i t r a t e as N (Wet Season): 8.0 mg/LCity of Salinas Or t h o p h o s p h a t e as P (D r y Se a s o n ) : 0.07 mg/LOrthophosphate as P (Dry Season): 0.07 mg/LCounty of Monterey Or t h o p h o s p h a t e as P (W e t Se a s o n ) : 0.3 mg/LOrthophosphate as P (Wet Season): 0.3 mg/LLAs: NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L N H 3 as N (All Year): 0.025 mg/LOwners/ operators of irrigated agricultural lands and land used for/containing domestic animals/livestock Re c e i v i n g Wa t e r : 0. 0 2 5 mg / L NH 3 as N N i t r a t e as N (D r y Se a s o n ) : 2. 0 mg / L N i t r a t e as N (Dry Season): 2.0 mg/LWLAs: Ni t r a t e as N (W e t Se a s o n ) : 8. 0 mg / L N i t r a t e as N (Wet Season): 8.0 mg/LCity of Salinas Or t h o p h o s p h a t e as P (D r y Se a s o n ) : 0.07 mg/LOrthophosphate as P (Dry Season): 0.07 mg/LCounty of Monterey Or t h o p h o s p h a t e as P (W e t Se a s o n ) : 0.3 mg/LOrthophosphate as P (Wet Season): 0.3 mg/LLAs: NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L N H 3 as N (All Year): 0.025 mg/LOwners/ operators of irrigated agricultural lands and land used for/containing domestic animals/livestock Ni t r a t e as N (D r y Se a s o n ) : 6. 4 mg / L L A s : Ni t r a t e as N (W e t Se a s o n ) : 8. 0 mg / L O w n e r s / operators of irrigated agricultural lands and land used for/containing domestic animals/livestock Or t h o p h o s p h a t e as P (D r y Se a s o n ) : 0.13 mg/L Or t h o p h o s p h a t e as P (W e t Se a s o n ) : 0.3 mg/L NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L Pe n d i n g EP A ap p r o v a l In t e r i m Al l o c a t i o n s 12 ye a r s af t e r Ef f e c t i v e Da t e , Fi n a l Al l o c a t i o n s 20 ye a r s af t e r Ef f e c t i v e Da t e Ni t r a t e an d Bi o s t i m u l a t o r y Su b s t a n c e s Na t i v i d a d Cr e e k , Al i s a l Cr e e k M U N , GW R , AG R Me r r i t Di t c h , Al i s a l Sl o u g h , Es p i n o s a Sl o u g h , Te m b l a d e r o Sl o u g h , Bl a n c o Dr i a n RE C 1 , RE C 2 , None MU N , AG R , GW R R e c e i v i n g Wa t e r : 10 m g / L Ni t r a t e ‐N Sa l i n a s Ri v e r , Up s t r e a m of Sp r e c k e l s , CA RE C 1 , RE C 2 , None Sa n t a Ri t a Cr e e k , Re c l a m a t i o n Ca n a l R E C 1 , RE C 2 , Ga b i l a n Cr e e k M U N , GW R , AG R Ni t r a t e M U N R e c e i v i n g Wa t e r : 1 0 mg / L Ni t r a t e as N Sa l i n a s Ri v e r , Do w n s t r e a m of Sp r e c k e l s , CA Ni t r a t e M U N , AG R , GW R R e c e i v i n g Wa t e r : 1 0 mg / L Ni t r a t e as N R e c e i v i n g Wa t e r : 1 0 mg / L Ni t r a t e as NReceiving Water:10 mg/L Nitrate as N Pa j a r o Ri v e r Ni t r a t e TM D L s R 3 ‐20 0 5 ‐01 3 1 1 2 / 2 / 2 0 0 5 1 0 / 1 3 / 2 0 0 6 1 0 / 3 / 2 0 2 6 Re c e i v i n g Wa t e r : 1 0 mg / L Ni t r a t e as N R e c e i v i n g Wa t e r : 1 0 mg / L Ni t r a t e as NNone"Owners and operators of agricultural lands using nitrate are assigned load allocations equal to the TMDL and numeric targets" Lo s Be r r o s Cr e e k Ni t r a t e TM D L R 3 ‐20 1 2 ‐00 1 8 5 / 3 / 2 0 1 2 6 / 1 1 / 2 0 1 2 2 0 2 5 L o s Be r r o r s Cr e e k (a l l tr i b u t a r i e s ) Bi o s t i m u l a t o r y Su b s t a n c e s M U N , CO L D , Na r r a t i v e Bi o s t i m u l a t o r y Su b s t a n c e Ob j e c t i v e Di s s o l v e d Ox y g e n Gl e n An n i e Ca n y o n , Te c o l o t i t o Cr e e k , an d Ca r n e r o s Cr e e k Ni t r a t e TM D L R3 ‐20 1 4 ‐20 1 1 3 / 7 / 2 0 1 4 P e n d i n g EP A ap p r o v a l N i t r a t e M U N Ch o r r o Cr e e k Nu t r i e n t s an d Di s s o l v e d Ox y g e n TM D L R3 ‐20 0 6 ‐04 4 7 / 7 / 2 0 0 6 7 / 1 9 / 2 0 0 7 2 0 1 6 C h o r r o Cr e e k TM D L Na m e R e s o l u t i o n Nu m b e r Ad o p t i o n Da t e Ef f e c t i v e Da t e F i n a l Co m p l i a n c e Da t e Wa t e r b o d i e s Ad d r e s s e d I m p a i r m e n t s Ad d r e s s e d B e n e f i c a l Us e s T M D L Ta r g e t s an d Av e r a g i n g Pe r i o d L o a d Al l o c a t i o n s W L A s R e s p o n s i b l e Parties Lo w e r Sa l i n a s Ri v e r Wa t e r s h e d Nu t r i e n t TM D L R3 ‐20 1 3 ‐00 0 8 2 / 4 / 2 0 1 3 Ni t r a t e as N (D r y Se a s o n ) : 3. 1 mg / L L A s : Ni t r a t e as N (W e t Se a s o n ) : 8. 0 mg / L O w n e r s / operators of irrigated agricultural lands and land used for/containing domestic animals/livestock Or t h o p h o s p h a t e as P (D r y Se a s o n ) : 0.07 mg/L Or t h o p h o s p h a t e as P (W e t Se a s o n ) : 0.3 mg/L NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L Or t h o p h o s p h a t e as P (D r y Se a s o n ) : 0.13 mg/LLAs: Or t h o p h o s p h a t e as P (W e t Se a s o n ) : 0.3 mg/LOwners/ operators of irrigated agricultural lands and land used for/containing domestic animals/livestock To t a l Ni t r o g e n as N (D r y Se a s o n ) : 1. 7 mg/L To t a l Ni t r o g e n as N (W e t Se a s o n ) : 8. 0 mg/L NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L Ni t r a t e as N (A l l Ye a r ) : 10 mg / L LAs: NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L Owners/ operators of irrigated agricultural lands and land used for/containing domestic animals/livestock Sa n Lo r e n z o Ri v e r Ni t r a t e TM D L R 3 ‐20 0 0 ‐00 3 9 / 1 5 / 2 0 0 0 1 / 1 4 / 2 0 0 3 2 0 2 0 S a n Lo r e n z o Ri v e r at Fe l t o n , Ca r b o n e r a Cr e e k at th e co n f l u e n c e of Br a n c i f o r t e Cr e e k , Sh i n g l e Mi l l Cr e e k at th e co n f l u e n c e of th e Sa n Lo r e n z o Ri v e r Ni t r a t e M U N , Ta s t e an d Od o r 1 . 5 mg / L Ni r a t e as Ni t r a t e 1 . 5 mg / L Ni r a t e as Ni t r a t e N o n e S e p t i c System Owners, Boulder Creek County Club, Owners of irrigated agricultura land and land used for livestock and stables.Monthly mean Nitrate‐N effluent shall not exceed 10 mg/L‐NCity of San Lusi Obispo Water Reclamation Facility Stormwater discharge shall not cause an increase in reciving water nitrate‐N greater than current increase resulting from dischargeCity and County of San Luis Obispo, Cal Poly State University SLO Re c e i v i n g Wa t e r : 1 0 mg / L Ni t r a t e as NCropland in Prefumo Creek watershed Ni t r a t e as N (A l l Ye a r ) : 10 mg / L N i t r a t e as N (All Year): 10 mg/LLAs: Owners/ operators of irrigated agricultural lands and land used for/containing domestic animals/livestock NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L NH3 as N (All Year): 0.025 mg/LWLAs:City of Santa Maria MS4s, City of Guadalupe MS4s Ni t r a t e as N (D r y Se a s o n ) : 4. 3 mg / L N i t r a t e as N (Dry Season): 4.3 mg/LLAs: Owners/ operators of irrigated agricultural lands and land used for/containing domestic animals/livestock Ni t r a t e as N (W e t Se a s o n ) : 8. 0 mg / L N i t r a t e as N (Wet Season): 8.0 mg/LWLAs: City of Guadalupe MS4s Or t h o p h o s p h a t e as P (D r y Se a s o n ) : 0.19 mg/LOrthophosphate as P (Dry Season): 0.19 mg/L Or t h o p h o s p h a t e as P (W e t Se a s o n ) : 0.3 mg/LOrthophosphate as P (Wet Season): 0.3 mg/L NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L NH3 as N (All Year): 0.025 mg/L Ni t r a t e as N (D r y Se a s o n ) : 4. 3 mg / L N o n e Ni t r a t e as N (W e t Se a s o n ) : 8. 0 mg / L N o n e Or t h o p h o s p h a t e as P (D r y Se a s o n ) : 0.19 mg/LNone Or t h o p h o s p h a t e as P (W e t Se a s o n ) : 0.3 mg/LNone NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L N o n e Ni t r a t e as N (A l l Ye a r ) : 10 mg / L N i t r a t e as N (All Year): 10 mg/LLAs: Owners/ operators of irrigated agricultural lands and land used for/containing domestic animals/livestock NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L NH3 as N (All Year): 0.025 mg/LWLAs: County of San Luis Obispo MS4s Ni t r a t e as N (D r y Se a s o n ) : 4. 3 mg / L N i t r a t e as N (Dry Season): 4.3 mg/LLAs: Owners/ operators of irrigated agricultural lands and land used for/containing domestic animals/livestock Ni t r a t e as N (W e t Se a s o n ) : 8. 0 mg / L N i t r a t e as N (Wet Season): 8.0 mg/L Or t h o p h o s p h a t e as P (D r y Se a s o n ) : 0.19 mg/LOrthophosphate as P (Dry Season): 0.19 mg/L Or t h o p h o s p h a t e as P (W e t Se a s o n ) : 0.3 mg/LOrthophosphate as P (Wet Season): 0.3 mg/LWLAs: County of Santa Barbara MS4s NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L NH3 as N (All Year): 0.025 mg/L Ni t r a t e as N (A l l Ye a r ) : 5. 7 mg / L N i t r a t e as N (A l l Ye a r ) : 5. 7 mg / L N o n e Or t h o p h o s p h a t e as P (A l l Ye a r ) : 0. 0 8 mg/LNone Or t h o p h o s p h a t e as P (A l l Ye a r ) : 0. 0 8 mg / L NH 3 as N (A l l Ye a r ) : 0. 0 2 5 mg / L N o n e Pe n d i n g EP A ap p r o v a l Ni t r a t e an d Bi o s t i m u l a t o r y Su b s t a n c e s In t e r i m Al l o c a t i o n s 12 ye a r s af t e r Ef f e c t i v e Da t e , Fi n a l Al l o c a t i o n s 20 ye a r s af t e r Ef f e c t i v e Da t e LAs: Owners/ operators of irrigated agricultural lands and land used for/containing domestic animals/livestock Or t h o p h o s p h a t e as P (W e t Se a s o n ) : 0. 3 mg / L Ni p o m o Cr e e k Or c u t t Cr e e k Os o Fl a c o Cr e e k , Li t t l e Os o Fl a c o Cr e e k LAs: Owners/ operators of irrigated agricultural lands and land used for/containing domestic animals/livestock Ni t r a t e , Bi o s t i u m l a t o r y Su b s t a n c e s MU N , N a r r a t i v e Bi o s t i m u l a t o r y Su b s t a n c e Ob j e c t i v e Ni t r a t e as N (D r y Se a s o n ) : 4. 3 mg / L Sa n t a Ma r i a Ri v e r (D o w n s t r e a m of Hi g h w a y 1) Ni t r a t e as N (W e t Se a s o n ) : 8. 0 mg / L Sa n t a Ma r i a Ri v e r Es t u a r y , Br a d l e y Ca n y o n Cr e e k , Gr e e n e Va l l e y Cr e e k Or t h o p h o s p h a t e as P (D r y Se a s o n ) : 0. 1 9 mg / L Sa n Lu i s Ob i s p o Cr e e k N i t r a t e , Bi o s t i u m l a t o r y Su b s t a n c e s MU N R e c e i v i n g Wa t e r : 1 0 mg / L Ni t r a t e as N Sa n t a Ma r i a Wa t e r s h e d TM D L ‐ Nu t r i e n t s R3 ‐20 1 2 ‐00 1 3 2 / 4 / 2 0 1 4 P e n d i n g OA L ap p r o v a l In t e r i m Al l o c a t i o n s 12 ye a r s af t e r Ef f e c t i v e Da t e , Fi n a l Al l o c a t i o n s 20 ye a r s af t e r Ef f e c t i v e Da t e Sa n t a Ma r i a Ri v e r (U p s t r e a m of Hi g h w a y 1) , Bl o s s e r Ch a n n e l , Br a d l e y Ch a n n e l , Ma i n St r e e t Ca n a l , No r t h Ma i n St r e e t Ch a n n e l GW R , RE C 1 , RE C 2 None Ch u a l a r Cr e e k , Qu a i l Cr e e k , Es p e r a n z a Cr e e k RE C 1 , RE C 2 , None Sa n Lu i s Ob i s p o Cr e e k Nu t r i e n t TM D L R3 ‐20 0 5 ‐01 0 6 1 / 1 0 / 2 0 0 7 8 / 4 / 2 0 0 6 2 0 1 2 Ol d Sa l i n a s Ri v e r None Mo r o Co j o Sl o u g h TM D L Na m e Re s o l u t i o n Nu m b e r Ad o p t i o n Da t e Ef f e c t i v e Da t e Fi n a l Co m p l i a n c e Da t e Im p a i r m e n t s Ad d r e s s e d W a t e r b o d i e s Ad d r e s s e d B e n e f i c a l Us e s TM D L Ta r g e t s an d Av e r a g i n g Pe r i o d W L A s R e s p o n s i b l e Parties Re c e v i n g Wa t e r : 1. 5 mg / L ro l l i n g me d i a n ni t r a t e ‐N Ma x Mo n t h l y Ef f l u e n t : 10 mg/L Nitrate‐N Re c e v i n g Wa t e r : 0. 4 mg / L ro l l i n g me d i a n or t h o p h o s p h a t e ‐P Me d i a n Ef f l u e n t : 0. 4 mg / L Orthophosphorus‐P Ni t r a t e as N (D r y Se a s o n ) : 1.4 mg/L Ni t r a t e as N (W e t Se a s o n ) : 8.0 mg/L Or t h o p h o s p h a t e as P (D r y Season): 0.07 mg/L Or t h o p h o s p h a t e as P (W e t Season): 0.3 mg/L Ni t r a t e as N (D r y Se a s o n ) : 6.4 mg/L Ni t r a t e as N (W e t Se a s o n ) : 8.0 mg/L Or t h o p h o s p h a t e as P (D r y Season): 0.13mg/L Or t h o p h o s p h a t e as P (W e t Season): 0.3 mg/L Ni t r a t e as N (D r y Se a s o n ) : 2.0 mg/L Ni t r a t e as N (W e t Se a s o n ) : 8.0 mg/L Or t h o p h o s p h a t e as P (D r y Season): 0.07 mg/L Or t h o p h o s p h a t e as P (W e t Season): 0.3 mg/L Ni t r a t e as N (D r y Se a s o n ) : 4.3 mg/L Ni t r a t e as N (W e t Se a s o n ) : 8.0 mg/L Or t h o p h o s p h a t e as P (D r y Season): 0.19 mg/L Or t h o p h o s p h a t e as P (W e t Season): 0.3 mg/LCity of Salinas, County of MontereyCalifornia Men's Colony (CMC) Wastewater Treatment Plant Sa n t a Ma r i a Wa t e r s h e d TM D L ‐ Nu t r i e n t s R3 ‐20 1 2 ‐00 1 3 2 / 4 / 2 0 1 4 Pe n d i n g OA L ap p r o v a l In t e r i m Al l o c a t i o n s 12 ye a r s af t e r Ef f e c t i v e Da t e , Fi n a l Al l o c a t i o n s 20 ye a r s af t e r Ef f e c t i v e Da t e City of Guadalupe MS4s and County of Santa Barbara MS4s Bi o s t i m u l a t o r y Su b s t a n c e s MU N , CO L D , Na r r a t i v e Bi o s t i m u l a t o r y Su b s t a n c e Ob j e c t i v e Ch o r r o Cr e e k Nu t r i e n t s an d Di s s o l v e d Ox y g e n TM D L R3 ‐20 0 6 ‐04 4 7 / 7 / 2 0 0 6 7 / 1 9 / 2 0 0 7 2 0 1 6 C h o r r o Cr e e k Lo w e r Sa l i n a s Ri v e r Wa t e r s h e d Nu t r i e n t TM D L R3 ‐20 1 3 ‐00 0 8 2 / 4 / 2 0 1 3 Pe n d i n g EP A ap p r o v a l In t e r i m Al l o c a t i o n s 12 ye a r s af t e r Ef f e c t i v e Da t e , Fi n a l Al l o c a t i o n s 20 ye a r s af t e r Ef f e c t i v e Da t e Ni t r a t e an d Bi o s t i m u l a t o r y Su b s t a n c e s MU N , AG R , GW R Ni t r a t e an d Bi o s t i m u l a t o r y Su b s t a n c e s MU N , Na r r a t i v e Bi o s t i m u l a t o r y Su b s t a n c e Ob j e c t i v e Ni t r a t e as N: 4. 3 mg / L (D r y Se a s o n ) an d 8. 0 mg / L (W e t Se a s o n ) Sa n t a Ma r i a Ri v e r (D o w n s t r e a m of Hi g h w a y 1) an d Or c u t t Cr e e k Or t h o p h o s p h a t e as P: 0. 1 9 mg / L (D r y Se a s o n ) an d 0. 3 mg / L (W e t Se a s o n ) Sa l i n a s Ri v e r , Do w n s t r e a m of Sp r e c k e l s , CA Sa n t a Ri t a Cr e e k , Re c l a m a t i o n Ca n a l Re c e i v i n g Wa t e r : 10 mg / L Ni t r a t e ‐N RE C 1 , RE C 2 , Ga b i l a n Cr e e k , Na t i v i d a d Cr e e k , A MU N , GW R , AG R Appendix H TM No. 9 - Capacity Consideration Date: 12/7/2014 Prepared by: Michael Falk, PhD, PE, Mallika Ramanathan, PE Reviewed by: Holly Kennedy, PE Project: WRRF Project SUBJECT: TM NO. 9 –TREATMENT PLANT CAPACITY ASSESSMENT The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long-term strategy for resource management. The purpose of this technical memorandum is to evaluate and determine the capacity for the WRRF Project. The results will be used to identify which unit processes will require upgrades or expansion. Contents Introduction .............................................................................................................................. 3 Background .............................................................................................................................. 4 Approach .................................................................................................................................................. 7 Flow Equalization ..................................................................................................................... 8 Diurnal Flow Equalization ....................................................................................................................... 10 Wet Weather Flow Equalization ............................................................................................................. 11 Flow Equalization Findings ..................................................................................................................... 12 Process Assessment ..............................................................................................................13 Liquid Treatment ..................................................................................................................................... 13 Influent Pumping Station .................................................................................................................... 13 Screens .............................................................................................................................................. 13 Grit Removal ....................................................................................................................................... 14 Influent Flow Meters ........................................................................................................................... 14 Primary Clarification ........................................................................................................................... 14 Biotower Pumping Station .................................................................................................................. 14 Biotowers and Secondary Clarifiers ................................................................................................... 15 Aeration Basins .................................................................................................................................. 15 Final Clarifiers ..................................................................................................................................... 16 Return Activated Sludge ..................................................................................................................... 16 Waste Activated Sludge ..................................................................................................................... 16 Filtration Pumping Station .................................................................................................................. 17 Cooling Towers ................................................................................................................................... 17 Filtration .............................................................................................................................................. 18 Disinfection ......................................................................................................................................... 19 Recycled Water Production ................................................................................................................ 19 WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 2 of 25 Solids Treatment ..................................................................................................................................... 19 Dissolved Air Flotation Thickener ....................................................................................................... 19 Anaerobic Digesters ........................................................................................................................... 19 Dewatering ......................................................................................................................................... 20 Supernatant Lagoon ........................................................................................................................... 20 Plant Capacity Assessment .................................................................................................................... 21 Conclusions ............................................................................................................................23 References ..............................................................................................................................25 List of Tables Table 1. WRRF Energy Efficiency Project Infrastructure Upgrades and Process Improvements (WSC, 2014) ......................................................................................................................................... 3 Table 2. Overview of NPDES Permit Discharge Limitations (Order R3-2014-0033) .................................... 6 Table 3. Summary of Influent Flow and Load Projections (HDR, 2014) ....................................................... 6 Table 4. Liquid Stream Treatment Unit Capacity Criteria ............................................................................. 7 Table 5. Solids Stream Treatment Unit Capacity Criteria ............................................................................. 8 Table 6. Flow Peaking Factors Used in this Capacity Assessment 1 ........................................................... 8 Table 7. Summary of WRRF Capacity Assessment ................................................................................... 24 List of Figures Figure 1. SLO WRRF Existing Process Schematic (includes WRRF Energy Efficiency Project) ................ 5 Figure 2. Envision Sample Screen Capture Depicting Existing WRRF Unit Processes ............................... 9 Figure 3. Hydrographs for Diurnal Flow Equalization Analysis (April 7, 2014 – ADWFCP contribution) ........................................................................................................................................ 10 Figure 4. Influent Hydrograph for 10-Year, 24-Hour Design Storm at Buildout .......................................... 11 Figure 5. Number of Cooling Towers On-Line Distribution (2010-Present) ................................................ 17 Figure 6. Number of Cooling Towers On-Line over Time ........................................................................... 18 Figure 7. Liquid Stream Plant Capacity per Unit Process ........................................................................... 22 Figure 8 Solids Stream Plant Capacity per Unit Process ........................................................................... 23 List of Attachments Attachment A – Process Flow Diagrams (Wet Weather Flow Routing) Attachment B – Influent Hydrograph Simulation TM Attachment C – Flow Equalization Analysis WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 3 of 25 Introduction This technical memorandum (TM) evaluates the plant-wide treatment capacity for the City of San Luis Obispo’s (City) Water Resource Recovery Facility (WRRF). The purpose of this evaluation is to rate the capacity of existing facilities so that improvements, expansions and upgrades at the WRRF can be identified to meet National Pollutant Discharge Elimination System (NPDES) permit limitations, and to accommodate build-out flows and loads as well as recycled water demands. The assessment considers hydraulic and process loading to determine the unit capacities. The improvements listed in Table 1 are underway as part of the WRRF Energy Efficiency Project and were included in this evaluation and considered to be operational. Table 1. WRRF Energy Efficiency Project Infrastructure Upgrades and Process Improvements (WSC, 2014) Identifier Improvement Location Process Existing Infrastructure Impacted WRRF 1 Install cogeneration system that generates electricity and heat onsite from digester gas Unit II: Solids Digestion Existing micro‐turbine system will be removed; New digester heating system interconnection will be installed WRRF 2 Upgrade headworks, including headworks equipment replacement, grit separation equipment replacement, and seasonal shut down of one grit chamber Unit II: Solids Primary Treatment Removal and replacement of bar screens, and screenings washing and dewatering equipment; New grit separation equipment and check valves downstream of grit pumps; Existing grit pumps will remain WRRF 3 * Add timers to primary sludge pump station to satisfy desired sludge depth in primary clarifiers Unit III: Aerobic Primary Treatment and Solids Thickening Primary sludge pumps will run on timers WRRF 4 Install screw press to achieve higher solids concentration Unit II: Solids Solids Dewatering Existing belt press will remain operable WRRF 5 Install RAS pump VFDs to allow speed of RAS pumps to vary with influent flow to WRRF Unit III: Aerobic Secondary Treatment Replacement of existing RAS pump motors; Installation of VFDs and corresponding instrumentation and controls; Installation of magnetic flow meter on pump discharge line from Final Clarifier #5 WRRF 6 Upgrade filter towers, including replacement of control system, filter media and underdrain Unit IV: Disinfection Tertiary Treatment Filter control system will be removed and replaced; Filter media will be replaced with monomedia increasing filter capacity; Underdrain will be replaced; VFDs will be added to backwash pumps WRRF 7 Modify aeration tank air pressure controls to adjust discharge header pressure setpoint based on real time valve position Unit III: Aerobic Secondary Treatment Existing valve controllers and/or PLC interface will be modified to integrate to blower master control panel PLC; Programming will be modified to enable the most open valve and pressure reset sequence WRRF 8 Install LED outdoor lighting Site-wide Electrical Exterior light fixtures throughout plant will be upgraded to LED lights WRRF 9 Upgrade SCADA systems, including replacement of existing RTUs with Allen‐ Bradley PLCs Site-wide O&M Allen‐Bradley PLCs will be installed throughout plant; Some DPCs will be consolidated; PLCs will interface with SCADA via new fiber optic network (separate project); Existing Data Concentrator will be dismantled (no longer be required) * Project WRRF 3 is currently under review and may not be implemented WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 4 of 25 Background The WRRF treats municipal wastewater flow from the City, California Polytechnic State University (Cal Poly), and the San Luis Obispo County Airport. The WRRF has a permitted average dry weather flow (ADWF) capacity of 5.1 million gallons per day (mgd). Currently, the WRRF treats an ADWF with Cal Poly (ADWFCP) flows of approximately 3.5 mgd which occurs during the summer months while Cal Poly is not in session. Due to infiltration and inflow (I/I) in the collection system, influent peak hour flows to the WRRF have been recorded up to 22 mgd. The buildout ADWFCP is projected to be 5.4 mgd (HDR, 2014) and the peak hour flow to the WRRF is projected to be approximately 33.5 mgd ((V&A 2012; WSC, 2014). A general process schematic of the existing treatment plant is shown in Figure 1 and detailed schematics of existing wet weather flow diversions are presented in Attachment A. Treated effluent is discharged to the San Luis Obispo Creek and can also be distributed to recycled water customers. The plant consists of the following processes: Liquid Stream Wet weather and diurnal flow equalization Influent pump station Screening, grinders, and aerated grit removal Primary clarification Biotower Trickling Filters (biotower) with clarification (secondary clarifiers) Air activated sludge and final clarifiers Evaporative cooling towers Filtration Disinfection including chlorination and dechlorination Recycled water storage and pumping Solids Stream Dissolved air flotation thickener (DAFT) Anaerobic digesters Digested solids storage Belt filter press and screw press (sludge dewatering) Drying beds Supernatant lagoon Sidestreams at the WRRF include DAFT subnatant, filter backwash, dewatering filtrate, drying bed supernatant. As indicated in Figure 1, the DAFT subnatant is returned upstream of the aeration basins. The dewatering filtrate and drying bed supernatant are equalized in the Supernatant Lagoon and returned with filter backwash downstream of the headworks. WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 5 of 25 Figure 1. SLO WRRF Existing Process Schematic (includes WRRF Energy Efficiency Project) Headworks (WRRF Energy Efficiency Project) Aeration Basin Mono Media Filter (WRRF Energy Efficiency Project)CCT SLO Creek Emergency Storage 3W Water System Recycled Water PCL SCLBiotower FCL Cooling Tower DAFT AD AD AD Storage Vortex Classifier Drying Bed Supernatant Storage Lagoon Disposal Ferrous Chloride Polymer Raw Influent Sodium HypochloriteMagnesium Hydroxide Filter Backwash Liquid Streams Sludge Streams Return Streams Chemical Streams Primary ClarificationPCL Secondary ClarificationSCL Final ClarificationFCL Chlorine Contact TankCCT Dissolved Air Floatation ThickenerDAFT Anaerobic DigestionAD Belt Filter PressBFP DAFT Supernatant Lagoon Return Sodium Bisulfite Screw Press (WRRF Energy Efficiency Project) RAS (WRRF Energy Efficiency Project) WAS (WRRF Energy Efficiency Project) Flows >32 mgd to Flow EQ Flows >22 mgd to Flow EQ Biotower Bypass Advanced Treatment Bypass (Flows >5.1 mgd)Flows Currently >16 mgd to Flow EQ WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 6 of 25 The WRRF’s renewed permit was adopted in September 2014. Discharge requirements to San Luis Creek for selected pollutants are summarized in Table 2. In order to meet the BOD, TSS, ammonia, nitrate, and coliform limits, all flows require secondary, tertiary, and disinfection treatment. As a result, blending during peak flow events as currently done at WRRF will not be feasible. Table 2. Overview of NPDES Permit Discharge Limitations (Order R3-2014-0033) Parameter Unit ADWF Average Annual Average Monthly Average Weekly Maximum Daily Instant Min. Instant Max. Rated Capacity mgd 5.1 -- -- -- -- -- -- Biological Oxygen Demand, 5-day (BOD) mg/L -- -- 10 30 50 -- -- lb/d 425 1,275 2,125 Total Suspended Solids (TSS ) mg/L -- -- 10 30 75 -- -- lb/d 425 1,275 3,190 Un-ionized Ammonia mg N/L -- -- -- -- 0.025 (a) -- -- Final Nitrate mg N/L -- -- 10 -- -- -- -- Coliform (b) MPN/100 mL -- -- 23 2.2 -- -- 240 pH (c) s.u. -- -- -- -- -- 6.5 8.3 Final Chlorodibromomethane(d) µg/L -- -- 0.40 -- 1.0 -- -- Final Dichlorobromomethane(d) µg/L -- -- 0.56 -- 1.0 -- -- N-Nitrosodimethylamine (NDMA) µg/L -- -- 0.00069 -- 0.0014 -- -- (a) In-stream criteria (i.e., non-discharge limit) (b) The median number of fecal coliforms shall not exceed 2.2 MPN/100 mL for the last 7-days samples were taken. No more than one sample shall exceed 23 MPN/100 mL total coliform in any 30-day period. The maximum number of total coliforms in any sample shall not exceed 240 MPN/100 mL. (c) Receiving water pH must not fall below 7.0 or exceed 8.3, or to change by more than 0.5 units (d) Compliance by November 30, 2019 per Time Schedule Order number R3-2014-0036 dated September 25, 2014. A summary of the projected flows and loads developed in TM1: Wastewater Characterization (HDR, 2014) is shown in Table 3. The more conservative biological oxygen demand (BOD [High]) values have been used for the development of the Facility Plan. Table 3. Summary of Influent Flow and Load Projections (HDR, 2014) Parameter Units ADWFCP Average Annual (AA) Maximum Month (MM) Maximum Week (MW) Maximum Day (MD) Peak Hour (PH) Flow mgd 5.4 6.1 8.4 11.4 17.3 33.5 TSS lb/day 16,200 17,000 24,200 32,600 44,100 - BOD (Low) (a) lb/day 13,100 13,800 19,600 26,400 35,700 - BOD (High) (b) lb/day 17,700 18,600 26,300 35,600 48,100 - Ammonia lb N/day 2,000 2,100 2,900 4,600 9,100 - TKN lb N/day 3,000 3,200 4,300 6,900 13,600 - TSS mg/L 360 340 350 340 300 - BOD (Low) (a) mg/L 290 270 280 275 250 - BOD (High) (b) mg/L 390 370 375 370 330 - Ammonia mg N/L 45 42 41 36 29 - TKN mg N/L 67 63 64 54 94 - (a) BOD:TSS ratio assumed at 0.81 (b) BOD:TSS ratio assumed at 1.09 (c) Peak hour flow results based on collection system monitoring (V&A 2012) and Influent Hydrograph Simulation Technical Memorandum (WSC, 2014). WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 7 of 25 Approach HDR’s ENVision steady state mass balance program, customized for the WRRF, was used to evaluate the process loading and process performance. A screen capture of the ENVision steady state mass balance built for the WRRF is presented in Figure 2. The calibrated model was then used to rate the capacity of each major unit process. The calculated capacity was compared against buildout conditions as a means to identify the limiting unit processes. The model accounts for the facilities that are under construction and/or are being completed as part of the WRRF Energy Efficiency Project. Additionally, diurnal and wet weather flow equalization was reviewed to evaluate the capacity of the existing flow equalization basin. Influent hydrographs as well as downstream treatment capacities were reviewed to perform a flow balance and evaluate the equalization basin capacity. For this analysis, the firm and total capacity is presented for major unit processes. The updated individual treatment unit process capacities are based on criteria from a combination of prior reports prepared for the WRRF and HDR’s professional opinion. A listing of the liquid and solids stream criteria are provided in Table 4 and Table 5, respectively. Table 4. Liquid Stream Treatment Unit Capacity Criteria Unit Process Units Capacity Criteria Averaging Period Source Pumping Stations mgd Firm pumping capacity or ability to bypass/divert PH HDR Criteria Screens mgd Firm treatment capacity or ability to bypass/divert PH HDR Criteria Grit Removal min 3 PH Water Environment Federation Manual of Practice 8 Primary Clarifiers – Detention Time hr 2.0 AA HDR Criteria Primary Clarifiers – Surface Overflow Rate gpd/sf 1,250 MM HDR Criteria Primary Clarifiers – Peak Surface Overflow Rate gpd/sf 2,500 PH HDR Criteria Biotower Trickling Filters lb/1,000 cf/d 150 MM Water Environment Federation Manual of Practice 8 Aeration Basins – MLSS mg/L 3,500 MM HDR Criteria Aeration Basins – Oxygen Uptake Rate (OUR) mg/L/hr 70 MM HDR Criteria Secondary/Final Clarifiers gpd/sf 1,200 MD HDR Criteria Secondary/Final Clarifiers lb/d/sf 30 MM HDR Criteria RAS % 100 MM HDR Criteria Filtration – Average Loading Rate gpm/sf 5 AA For periods of water reclamation; 1 unit out of service Filtration – Peak Loading Rate gpm/sf 8 PH For wet weather events; 1 unit out of service Chlorination – Detention Time min 20 PH HDR Criteria WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 8 of 25 Table 5. Solids Stream Treatment Unit Capacity Criteria Unit Process Units Capacity Criteria Averaging Period Source Dissolved Air Flotation Thickener gpd/sf 2,950 MM WEF MOP 8 Dissolved Air Flotation Thickener lb/d/sf 48 MM WEF MOP 8 Anaerobic Digester days 15 MM USEPA 503 Regulations for Class B Biosolids Screw Press hr/week 168 MM Screw Press gpm 66 MM WRRF Specifications Screw Press lb/hr 500 MM WRRF Specifications For processes governed by average annual (AA), maximum month (MM), maximum week (MW ), or maximum day (MD) averaging periods, the calculated capacity values are translated to ADWF values. For example, the aeration system is governed by MD so the MD flow is translated to ADWF using flow peaking factors. This translation is performed in order to provide an “apples to apples” comparison. For those governed hydraulically by peak flows (i.e., peak hour (PH)), such rated capacity values are listed as peak flow capacity. For example, pumping station capacity is listed as the peak pumping capacity. A listing of the flow peaking factors used in the capacity assessment is provided in Table 6. Table 6. Flow Peaking Factors Used in this Capacity Assessment 1 Averaging Period Value 1 ADWFCP:AA Ratio 0.89 AA:AA Ratio 1.00 MM:AA Ratio 1.38 MW:AA Ratio 1.89 MD:AA Ratio 2.86 PH:AA Ratio 5.49 1- Values from the TM1: Wastewater Characterization Technical Memorandum (HDR, 2014) It is assumed that as much flow will be equalized and attenuated as possible at the WRRF in the future. The following section (Flow Equalization) details the analysis performed for wet weather and diurnal dry weather equalization. Flow Equalization The WRRF currently has a 4 million gallon (MG) flow equalization basin located on the northeastern portion of the site. The basin is typically used for diurnal equalization to provide constant organic loading to the secondary system during dry weather conditions. During wet weather events, peak flows bypass secondary treatment and are blended with nitrified effluent prior to disinfection and discharge to San Luis Creek. Because blending is currently used at the WRRF, flow equalization of peak wet weather flows is not typically employed. WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 9 of 25 Figure 2. Envision Sample Screen Capture Depicting Existing WRRF Unit Processes WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 10 of 28 Based on the discharge limitations in the WRRF’s renewed permit (Table 2), it will be difficult to employ blending during wet weather events and comply with the discharge limitations. For this reason, flow equalization was reviewed at the WRRF for peak wet weather events. Diurnal equalization is a practice that the WRRF Staff would like to continue and therefore is also considered for future plant operation. For diurnal dry weather equalization, it is assumed that primary effluent is diverted to equalization under normal operating conditions. During wet weather events, primary effluent and/or screened and degritted influent would be diverted to equalization. Diversion of influent flows upstream of screening and grit removal would only be performed under emergency conditions. Diurnal Flow Equalization Diurnal equalization was reviewed using influent hydrographs from April 2014. The month of April was selected because it is typically a dry month and includes contributions from Cal Poly and presents a worst case scenario. The hydrographs for existing conditions were reviewed, and the flows were increased to reflect future, design (buildout) conditions. Figure 3 provides the ADWFCP hydrograph that was used to determine diurnal equalization needs. Figure 3. Hydrographs for Diurnal Flow Equalization Analysis (April 7, 2014 – ADWFCP contribution) Influent flows greater than the average daily flow would be diverted to equalization; when influent flows are less than the average daily flow, flows would be routed from equalization to the aeration basins. Based on the buildout hydrograph in Figure 3, the volume for diurnal flow equalization was estimated to be 0.9 million gallons (MG). Attachment C provides the calculations that were performed for estimating the size of the equalization basin. 0.0 2.0 4.0 6.0 8.0 10.0 12.0 0:00 6:00 12:00 18:00 0:00 Fl o w ( m g d ) Time 'April 7, 2014'Buildout Condition ADWFCP at buildout = 5.4 mgd ADWFCP (existing) = 3.5 mgd WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 11 of 25 The existing secondary clarifier has adequate volume for diurnal equalization at buildout conditions. It is recommended that the secondary clarifier be considered for diurnal equalization for ease of operation and maintenance. Additionally, the secondary clarifier could be covered to provide odor control. Wet Weather Flow Equalization Peak wet weather influent hydrographs of two historic rain events were reviewed (January 1 through January 3, 2011 and March 19 through 20, 2011) to review equalization needs under existing conditions. For future conditions, the City’s collection system hydraulic model was used to develop influent hydrographs that include I/I in addition to future baseline flows. Model hydrographs were developed for the January and March 2011 historic rain events as well as for the design storm event, which has been defined as the 10-year, 24-hour storm. Attachment B provides a detailed analysis of the development of the collection system model and influent hydrographs. Figure 4 provides the influent hydrograph for the design storm event that was used to evaluate wet weather flow equalization. It is recommended that the City obtain additional flow data to confirm assumptions in the hydraulic model and refine the model, as appropriate. Figure 4. Influent Hydrograph for 10-Year, 24-Hour Design Storm at Buildout The capacity of flow equalization is dependent on influent flows as well as downstream treatment capacity. Under existing conditions, the aeration basins and final clarifiers limit the secondary treatment capacity to 5.1 mgd. Thus, equalized flows would be returned to the secondary system when influent flows are less than 5.1 mgd. Under such a scenario, the volume for flow equalization at the design storm condition would be approximately 13.5 MG. This equalization volume is approximately 3.5 times greater than the current equalization pond and would be difficult to site at the WRRF. Therefore, increasing the secondary and downstream treatment capacity to accommodate higher flows and loads was reviewed. It was determined that the secondary 0 5 10 15 20 25 30 35 40 0 20 40 60 80 100 120 Fl o w ( M G D ) Time (hours) Wet Weather Hydrograph 10-Yr, 24-Hr Storm WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 12 of 25 treatment facilities (aeration basins, final clarifiers, RAS/WAS pumping) could be sized to treat flows up to 17 mgd. To further reduce downstream tertiary treatment facilities (filtration, cooling and disinfection), secondary effluent could be equalized in the existing 1 MG basins (located east of the chlorine contact basins). A third equalization basin could be constructed to provide a total storage volume of 1.5 MG, which would allow the filtration, cooling and disinfection facilities to be sized for 16 mgd. Flow Equalization Findings Approximately 0.9 MG of diurnal equalization is needed to accommodate buildout ADWFCP. The existing secondary clarifier has a volume of approximately 0.9 MG and could be used to provide diurnal equalization during dry weather conditions. Flow split structures and the recirculation pump station structure will need to be modified to enable the clarifier to be reused for equalization and to provide the proper flow diversions/splits for diurnal and well wet weather flow equalization. It is recommended that conversion of the secondary clarifier for diurnal equalization be considered for the following reasons: Location: The secondary clarifier is adjacent to the aeration basins and hydraulically can be used for equalization upstream of secondary treatment. Odor Control: The tank can be covered and ventilated to provide odor control. Size: The secondary clarifier is the appropriate size for dry weather diurnal equalization at buildout conditions. Aesthetics: The secondary clarifier is located away from the future plant entrance and public facilities. Based on the wet weather flow equalization analysis, it is recommended that the existing 4 MG flow equalization pond be retained for equalization during wet weather events. Using the pond during peak wet weather events will allow the secondary treatment system (aeration basins and secondary clarifiers) to be sized to accommodate peak hour flows up to 17 mgd. Although the pond is located near the future plant entrance, its use will be minimized which will improve aesthetics and minimize odors. Based on this analysis and discussions with WRRF Staff, the following improvements and modifications are recommended with respect to the flow equalization pond: Provide cells within the equalization basin to facilitate use and washdown; Provide water cannons/washdown capabilities for the flow equalization cells; Review the need for lining the floor and sidewalls of the equalization basin; Modify equalization return pumps to provide adequate and redundant return capacity; Provide reliable automation for the equalization return pumps to minimize the need for manual operation. In addition to the equalization pond, it is recommended that the secondary effluent flow equalization basins (located to the east of the chlorine contact basins) be expanded to provide a total volume of 1.5 MG. The tertiary treatment facilities (filtration, cooling and disinfection) can then be sized to treat peak hour flows up to 16 mgd. WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 13 of 25 The noted equalization improvements are based on the influent hydrograph that was developed using available data. It is recommended that the City perform the following steps to refine and improve the accuracy of the influent hydrographs: Refine the collection system hydraulic model to develop RTK factors for each sub-basin. Install datalogger and/or provide SCADA connection to the influent flow meters to improve accuracy of instantaneous and hourly influent flow readings. Modify influent flow meters such that readings greater than 22 mgd can be recorded. Conduct collection system flow monitoring during the wet weather season to refine the collection system model. As additional data is collected and the collection system model is refined, it is recommended that the sizing of the equalization basin and downstream treatment processes be reviewed and adjusted accordingly. Process Assessment The sub-sections below discuss individual unit processes at the WRRF and their capacity. Liquid Treatment The liquid treatment train consists of the influent pumping station, screening, grit removal, primary clarification, biotowers, secondary clarifiers, activated sludge (aeration basins), final clarifiers, RAS and WAS pumping stations, filtration pumping station, filtration, cooling towers, and disinfection. A summary of the criteria used to determine capacities of unit processes was provided in Table 4. For unit processes with multiple capacity criteria, the limiting criterion is used. As previously described, processes governed by AA, MM, MW, or MD averaging periods translate the calculated capacity values to ADWF values using the factors in Table 6. Processes governed by hydraulics are listed as PH capacities. Influent Pumping Station The Influent Pumping Station consists of four pumps that convey screened wastewater to the aerated grit chambers. Two of the pumps are horizontal, dry pit centrifugal pumps (5 mgd capacity each) and two pumps are vertical turbine, solids handling pumps (22 mgd capacity each). The firm pumping capacity with the largest unit of service (3 duty/1 standby) is 32 mgd (i.e., 5 mgd + 5 mgd + 22 mgd = 32 mgd). The total capacity (all pumps in operation) corresponds to 54 mgd. The rated firm capacity of the influent pump station is close to the buildout PH (32.0 mgd versus 33.5 mgd). Pump testing could be performed to evaluate the ability of the existing pumps to pump slightly higher flows. If the existing pumps cannot accommodate the additional flow, it is recommended that the capacity of the pumps be slightly increased when they are replaced. Because 33.5 mgd is projected to occur in the future, expansion of the pump station can be phased. Additionally, in emergency conditions, the WRRF has the ability to divert influent flows to the equalization basin. Screens As part of the WRRF Energy Efficiency Project, the existing mechanical bar screens are being replaced with two new screens (0.25-inch spacing) that have a rated peak flow capacity of 16 WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 14 of 25 mgd/screen. Under emergency conditions, the mechanical bar screens can be bypassed and a manual bar screen is provided in the bypass channel. The governing flow criterion for the mechanical bar screens is PH. Thus, the firm capacity (1 duty/1 standby) of the mechanical bar screens corresponds to a capacity of 16.0 mgd and the total capacity of the screens corresponds to a peak capacity of 32.0 mgd. Because the WRRF has the ability to bypass the mechanical screens under emergency conditions, it can be assumed that both mechanical screens are operational during peak wet weather events. As the hydraulic profile of the WRRF is further developed, the screens will be reviewed to determine if additional capacity can be recognized to provide adequate capacity for buildout conditions. It is not recommended that additional mechanical screen capacity be provided at this time. Grit Removal The capacity of the aerated grit chambers is dictated by the hydraulic residence time (HRT) at PH flows. A 3-minute HRT at PH conditions (WEF MOP8, 2009) is standard design practice. The aerated grit tanks at the WRRF have a HRT of approximately 5.2 minutes at the projected PH conditions with both units in service (2 units; each 34 ft long by 17 ft wide by 12 ft side water depth). Using the 3-min PH capacity criterion results in a 58.6 mgd PH total capacity. Influent Flow Meters Two parshall flumes are located downstream of the grit chambers and are used to measure influent flow. The two flumes can not measure flows greater than 22 mgd. Thus, the flumes total rated capacity is 22 mgd. During significant peak wet weather events, influent flows to the WRRF can be higher than 22 mgd. To provide more accurate influent flow measurements during peak events, it is recommended that modifications to the influent flow meters are made to increase measurements up to 35 mgd. Primary Clarification Primary clarifiers do not have a “rated process capacity” in the traditional sense because they are not the final treatment process. A primary clarifier can be overloaded without compromising the ability of the plant to meet permit, provided that downstream processes can treat the increased load due to poorer primary removal efficiencies. The removal efficiency or targeted capacity of the primary clarifiers is therefore a process decision which balances the cost of additional primary clarification with increased cost of secondary treatment. The primary clarifier capacity at the WRRF considers the AA HRT, MM surface overflow rate (OFR), and PH OFR as presented in Table 4. The AA HRT criterion limits the ADWF capacity to 4.7 mgd, which is less than the projected ADWF (5.4 mgd). The value assumes one clarifier is out of service for routine maintenance. Stress testing could be performed to confirm performance with more aggressive OFRs. Alternatively, because general maintenance activities can be planned in advance to coincide with low flow periods, the WRRF has some flexibility and could accommodate reduced performance in the primary clarifiers. Biotower Pumping Station Primary effluent is routed to the Biotower Pumping Station and flows greater than 16 mgd are currently diverted to the flow equalization basin. For flow conditions less than 16 mgd, the primary effluent flow split structure works in tandem with the secondary effluent flow split structure to WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 15 of 25 produce a steady supply of feed water for the biotower. There are two biotower pumping stations, one for Biotowers 1 and 2 (de-commissioned) and Biotower 3 (on-line). The Biotower Pumping Station for Biotowers 1 and 2 is no longer active so it is not considered in the evaluation. The Biotower 3 Pumping Station is active and it has 2 pumps (8.6 mgd/pump). These two pumps feed/recirculate water to Biofilter 3. The firm pumping capacity for Biotower 3 is 8.6 mgd (1 duty / 1 standby pump) and the total pumping capacity is 17.2 mgd (2 duty / 0 standby). The PH flow to the biotower (secondary treatment) was used as the criterion for the capacity evaluation of the pump station. Biotowers and Secondary Clarifiers There are three biotowers (1, 2, and 3). Biotowers 1 and 2 have been de-commissioned and Biotower 3 is active and on-line. Thus, Biotowers 1 and 2 were not considered in this evaluation. Biotower 3 is on-line and active. The capacity of Biotower 3 is evaluated in this section; however, the decision has been made to decommission the biotower as part of the WRRF upgrades. The organic loading rate (150 lb/1,000 cf/d under MM conditions) is limiting Biotower 3 treatment capacity. Under this capacity criterion, Biotower 3 has a capacity of 6.7 mgd ADWF. The OFR and solids loading rate to the Secondary Clarifier was also considered for establishing this capacity rating. It might be possible to push a higher load through the biotower and secondary clarifier, but this would compromise performance and/or result in media collapsing. The aeration basin capacity is dependent on biotower performance. As a result, loading the biotowers as much as possible without compromising performance is ideal to gain as much capacity, in the interim, as possible out of the downstream aeration basins. Aeration Basins The WRRF has two aeration basins (each 20 ft wide X 184 ft long X 20.5 ft deep; 0.41 MG each). Each aeration basin is equipped with a fine-bubble diffuser aeration system. There are 2 multi-stage blowers (250 hp each) and 1 Turblex blower (variable vane), and these blowers are being replaced with two, 150-hp high speed turbo blowers. It is important to note that the aeration basins and aeration system capacity is based on current operating conditions which assumes i) Biotower 3 and Secondary Clarifier is upstream of the aeration basins and ii) the WRRF has the ability to bypass the aeration basins during wet weather events. Once Biotower 3 and the Secondary Clarifier are decommissioned under the WRRF upgrades, the existing aeration basin capacity would be lower due to additional flows and loads to the aeration basins. Two criteria were evaluated to determine the aeration basins capacity: 1) oxygen uptake rate (OUR) and mixed liquor suspended solids (MLSS). OUR is calculated based on the oxygen demand (lb oxygen/day) and the aeration basin volume as follows: 𝑂𝑈𝑅 (𝑙𝑖 𝐿−�𝑟)= 𝑂𝑥𝑥𝑖𝑑𝑙 𝐷𝑑𝑙𝑎𝑙𝑑 (𝑙𝑎 𝑂𝑥𝑥𝑖𝑑𝑙 𝑑) 𝐴𝑑𝑟𝑎𝑟�ℎ𝑙𝑙 𝐴𝑎𝑟�ℎ𝑙 𝑈𝑙𝑙𝑟𝑙𝑑 (𝐿𝐺) 𝑋 1 8.34 𝑋 1 24 WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 16 of 25 The capacity criteria is calculated to an OUR equal to 70 mg/L/hr (MM averaging period). This results in an aeration system capacity of 5.1 mgd ADWF under current operating conditions. The other parameter evaluated to determine aeration basin capacity is the mixed liquor suspended solids concentration (MLSS). The criterion used for the analysis was 3,500 mg/L during MM conditions at an 8.0-day aerobic solids residence time (SRT). Based on the MLSS criterion, the aeration basin capacity was determined to be 5.1 mgd, as ADWF. Regardless of whether OUR or MLSS is used to determine aeration basin capacity, the current treatment configuration has a capacity of 5.1 mgd ADWF, with Biotower 3 in operation, coupled with the ability to bypass flows around the aeration basins during storm events. To comply with permit limitations, the aeration basins will be upgraded to treat PH flows up to 17 mgd. The required aeration basin expansion volume for the WRRF Project is addressed in the Treatment Alternatives TM. Final Clarifiers The WRRF has two final clarifiers each with an 80 ft diameter and 16 ft side water depth. Two criteria were used to evaluate the final clarifier capacity: 1) solids loading rate (30 lb/sf/day under MM conditions) and 2) hydraulic loading rate (1,200 gpd/sf under MD conditions). The solids loading rate (30 lb/sf/d under MM conditions) is the limiting capacity criteria. At a 3,500 mg/L MLSS, the final clarifiers have a process capacity of 5.0 mgd as ADWF. This value is based on the ability to bypass wet weather flows above about 5.1 mgd. Under the renewed NPDES permit, the final clarifiers will need to treat all the equalized peak flows up to 17 mgd and thus, require expansion. Return Activated Sludge Each final clarifier has two dedicated return activated sludge (RAS) pumps (2.5 mgd per pump). As part of the WRRF Energy Efficiency Project, VFDs will be installed on each RAS pump to enable RAS flow-pacing. The installed VFDs will not change the existing pumping capacity. The firm RAS pumping capacity is 5.0 mgd (2 duty/2 standby) or total capacity of 10.0 mgd (4 duty / 0 standby). The capacity criteria for RAS pumping is to provide 100 percent flow for MM activated sludge feed flow, as well as having a sufficient number of pumps dedicated per final clarifier. The total RAS pumping capacity (10 mgd) translates to a unit process rated capacity of 6.4 mgd as ADWF. Although this is sufficient total capacity, there is a shortage of dedicated RAS pumps for the new final clarifiers required as part of the WRRF Project. As a result, at least two dedicated RAS pumps per final clarifier will be required as part of the WRRF Project. Waste Activated Sludge The waste activated sludge (WAS) pumps have the ability to either draw suction from the RAS pipe returning to the beginning of the aeration tanks, or draw suction from the mixed liquor channel at the end of the aeration tanks. Wasting is typically performed from the mixed liquor channel and pumped to the DAFT for thickening. Each WAS pump has a rated capacity of 100 gpm. The firm capacity of the WAS pumps is 0.14 mgd and the total capacity is 0.28 mgd. To correlate this pumping capacity to ADWFs, an aerobic sludge age must be provided which is inversely related to WAS flow. For example, the WAS flow increases at lower aerobic sludge ages. An 8.0-day aerobic sludge age was used to rate the WAS pumps. The WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 17 of 25 firm and total capacity of the WAS pumps in terms of ADWF was determined to be 6.7 mgd and 13.4 mgd as ADWF, respectively. Filtration Pumping Station The filtration pumping station pumps nitrified effluent to the cooling towers and filtration complex by three pumps (2.6 mgd/pump). Two-0.5 MG equalization tanks are located upstream of the pumps to facilitate pumping a constant flow to the cooling tower/filter complex. The firm PH pumping capacity of the Filtration Pump Station is 5.2 mgd (i.e., 2.6 mgd + 2.6 mgd = 5.2 mgd) and the total capacity is 7.8 mgd. Based on these rated capacities, the filtration pump station will need to be expanded as part of the WRRF upgrades. Cooling Towers There are three cooling towers each at 12 ft wide by 21 ft long by 14 ft tall. A sidestream flow of nitrified effluent is currently diverted to the cooling towers from the filter distribution box. The cooling tower effluent is then pumped back to the filter complex. The cooling tower media was replaced this summer with Brentwood Industries Accu-Pac XF-75 Herringbone Film Fill Media. The media has integrated inlet louvers (XF75 IL) and drift eliminators (XF75 ID). The benefits of the new cooling tower media is improved cooling efficiencies coupled with the ability to maintain and clean biological growth/scaling on the media. Each cooling tower has a dedicated pump that is rated at 1,200 gpm. The rated peak hour cooling tower pumping capacity represents the PH flow that can be routed through the cooling towers. The firm PH capacity of the cooling towers is 3.5 mgd (2 duty / 1 standby) and the total PH capacity is 5.2 mgd (3 duty / 0 standby). Based on a review of historic operational data, all three cooling towers are operated throughout the year (Figure 5). A plot of the number of cooling towers on-line over time is provided in Figure 6. The use of all three cooling towers has typically occurred in the fall/shoulder months when wet weather events can occur and creek temperatures are low. In more recent years (2013 and 2014) three cooling towers were operated for extended durations in summer and fall months, that equated to three towers operating close to 50 percent of the year. This additional use in recent years is attributed to concerns over reliably meeting the NPDES permit limits. Figure 5. Number of Cooling Towers On-Line Distribution (2010-Present) 28% 10% 40% 21% 0 1 2 3 WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 18 of 25 Figure 6. Number of Cooling Towers On-Line over Time To provide adequate redundancy and capacity, two new cooling towers are recommended at this time. The operation of the cooling towers should continue to be monitored to determine if improved efficiencies due to media replacement reduce the need to operate three cooling towers in the fall and summer months. During preliminary design, the timing and need for the need the fifth and/or sixth cooling towers should be confirmed. The cooling tower installation may be phased, depending on the performance of the existing towers with the new media. Filtration The filtration complex contains four granular media filters each at 15 ft wide by 16 ft long (240 sf per filter). The filters provide tertiary treatment for recycled water production and to comply with permit limitations for creek discharge. The WRRF is in the process of replacing the filter media with mono media and installing a new underdrain system as part of the WRRF Energy Efficiency Project. The filter loading rate after completion of the WRRF Energy Efficiency Project upgrades is anticipated to be approximately 8 gpm/sf. The firm and total peak filtration capacity with the improvements are 8.3 mgd and 11.1 mgd, respectively. Filtration of all flows (ADWF and peak wet weather) is recommended because UV disinfection will be used downstream of filtration. As part of the WRRF Project, the filter complex will need to be expanded to treat PH flows up to 16 mgd during wet weather events. To minimize new infrastructure, the filter complex could be operated a higher loading rate during wet weather events, if recycled water demands are not present. During dry conditions, when peak flows subside the filters could be operated within the Title 22 requirements for recycled water production. 0 1 2 3 Jan-10 Jul-10 Feb-11 Aug-11 Mar-12 Sep-12 Apr-13 Nov-13 May-14 Dec-14 Nu m b e r o f C o o l i n g T o w e r s O n -Li n e WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 19 of 25 Disinfection There are four chlorine contact tanks (0.16 MG per tank). Two of the chlorine contact tanks are typically used for discharge to the creek and the other two tanks are typically used for producing recycled water. Chlorine is currently used as the disinfectant at WRRF. A 20-minute total contact time for peak hour flows is industry standard design criteria. Assuming a 20-minute total contact time, the chlorine contact basins have a rated peak capacity of approximately 13.9 mgd. However, due to disinfection byproduct and NDMA limitations in the WRRF’s renewed permit, conversion to UV disinfection has been recommended. Recycled Water Production The City is currently updating their recycled water master plan. The capacity of the recycled water treatment, storage and distribution system is dependent on the current and future recycled water demands as well as the timing of those demands (year round versus seasonal). The WRRF currently produces an average recycled water flow of 0.15 mgd, and a maximum day flow of 0.5 mgd. The storage tank at the WRRF is used to meet the diurnal recycled water demands, and reclaimed water is pumped with five pumps (2-40 hp and 3-120 hp) to various end users. The recycled water pump station was constructed with space for two additional 120 hp distribution pumps. Because tertiary filtration and disinfection is necessary for creek discharge, the WRRF will have adequate filtration and disinfection capacity to produce recycled water (at a peak loading rate of 5 gpm/sf) for unrestricted reuse. Once the timing of the deliveries and demands are understood, pump station and storage requirements can be confirmed. Solids Treatment The solids treatment consists of dissolved air flotation thickeners (DAFTs) to thicken primary sludge and WAS, anaerobic digesters, digested solids storage, and mechanical dewatering. A summary of the capacity criteria and the corresponding source was presented in the Approach Section in Table 5. Dissolved Air Flotation Thickener The DAFT unit has a diameter of 35 ft and side water depth of 11 ft. It is used to thicken primary sludge, primary scum, biotower sludge, and WAS. The biotower solids pass through a snail removal classifier prior to being combined with primary sludge and WAS. Two criteria were evaluated to determine the DAFT capacity: 1) hydraulic loading rate (2,950 gpd/sf for MM conditions) and 2) solids loading rate (48 lb/d/sf for MM conditions). Using the hydraulic loading rate criterion, the DAFT has a capacity of 8.0 mgd as ADWF. Using the solids loading rate criterion, the DAFT has an ADWF capacity of 8.3 mgd. The limiting factor is the hydraulic loading criterion and therefore the DAFT was determined to have a rated ADWF capacity of 8.0 mgd. Despite having sufficient total capacity, there is no standby thickening, which presents operations and maintenance challenges. It is recommended that provisions for a standby thickener be considered. Alternative thickening equipment that is more energy efficient (e.g., rotary drum thickener) could be considered for the standby system. Anaerobic Digesters The WRRF has three digesters in series, whereby the first two digesters are used as primary digestion and the third digester is used for storage. The volume of the first two digesters is a WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 20 of 25 combined 0.83 MG, whereas the third digester volume is 0.23 MG. The third digester is the oldest and is not mixed or heated. Digesters 1 and 2 have a gas mixing system. Digesters 1 and 2 have adequate volume to provide a 15 day HRT under MM flow conditions. A 15- day HRT is the recommended capacity criterion and represents the minimum detention time necessary to produce Class B biosolids. The HRT with the first two units in service under MM conditions is 18.4 days. This corresponds to a total ADWF capacity of 6.6 mgd, assuming a 15-day HRT and two digesters in service. There currently is a lack of redundancy with the anaerobic digesters because a 15-day HRT can not be maintained under MM conditions if the largest digester is taken offline for cleaning and maintenance. The firm ADWF capacity of the digesters with the largest unit out of service is 2.4 mgd. It is recommended that Digester 2 be replaced with a new digester of equal capacity of Digester 1. The WRRF has indicated that digester cleaning and general maintenance activities can be scheduled during low flow months. Digester 3 (0.23 MG) is used as storage prior to dewatering. As a result, the digester does not have a “rated process capacity” in the traditional sense because it is not used for treatment. Rather, it is used to provide flexibility in dewatering frequency. Under the current mode of operation, Digester 3 provides 6.2 days of storage under MM flow conditions. Once Digester 2 is replaced with a unit of equal or greater capacity as Digester 1, Digester 3 will not be required for storage as Digesters 1 and 2 will have adequate capacity to feed dewatering. It is recommended that Digester 3 be re-purposed or de-commissioned once Digester 2 is replaced is replaced with a unit of equal or greater capacity as Digester 1. Dewatering The WRRF currently uses a belt filter press for solids dewatering. There is a single unit and the sludge drying beds provide redundancy for the belt filter press. As part of the WRRF Energy Efficiency Project, one screw press will be installed and the existing belt filter press will serve as a redundant unit. The City intends to abandon the sludge drying beds after the screw press is operational. The screw press will have a peak hydraulic loading rate of approximately 65 gpm (500 lb/hr). This corresponds to an ADWF capacity of 5.4 mgd. The belt filter press has adequate capacity to serve as a redundant unit. It is recommended that in the future, the belt filter press be replaced with a second, redundant screw press to provide common equipment for ease of operations and maintenance. Supernatant Lagoon The Supernatant Lagoon is used to hold dewatering filtrate, and to pump it back to the headworks. The lagoon is roughly one-third of an acre and it provides about 1-2 weeks of storage depending on water depth. The lagoon provides adequate storage for buildout conditions. To minimize odors, the lagoon is aerated with a 5-hp surface aerator. The supernatant lagoon provides operational flexibility because it allows the high-strength filtrate to be slowly returned to the front of the plant during low flow and load periods. Because the lagoon has adequate capacity to accommodate buildout flows, it is recommended that use of the lagoon and/or similar equalization basin be continued for equalization of the dewatering return stream. WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 21 of 25 Plant Capacity Assessment A summary of the updated plant capacity for the liquid and solid streams are provided in Figure 7 and Figure 8 respectively. The desired capacity is at or greater than 5.4 mgd ADWF for projected flows and loads, as well as the ability to hydraulically convey upwards of 33.5 mgd PH flows through the plant. The liquid stream has several unit processes with capacities below the desired treatment capacities, including the following: Influent pumping station, Screens, Primary clarifiers, Aeration basins, Final clarifiers, RAS pumping (inadequate redundancy), WAS pump station (inadequate redundancy), Filtration pumping station, Filtration, and Cooling towers and cooling tower pumping. Disinfection facilities were not included in this list because the decision has been made to convert to UV disinfection, which will be sized accordingly. The influent pumping station and screens capacities are slightly below buildout peak flows. It is recommended that pump testing be performed to determine if the influent pump station capacity can be increased in the future. Alternatively, if the pump station capacity can not achieve buildout conditions, it is recommended that as the existing smaller pumps are replaced to consider larger pumps. Additionally, review of the plant hydraulics and headloss across the new screens is being performed as part of the Facility Plan. A review will be performed to determine if the screens can accommodate the slightly higher buildout flows. The capacity of the primary clarifiers is slightly under the design ADWF condition. Stress testing could be performed to confirm performance with more aggressive OFRs. Alternatively, because general maintenance activities can be planned, the WRRF has some flexibility and the secondary treatment facilities can be designed to accommodate a decline in performance under dry weather flows and loads. WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 22 of 25 Figure 7. Liquid Stream Plant Capacity per Unit Process 0 10 20 30 40 50 60 Ra t e d C a p a c i t y p e r U n i t P r o c e s s ( m g d ) Firm ADWF Capacity Firm Peak Flow Capacity Total Peak Flow Capacity Desired ADWF Capacity = 5.4 mgd ADWF Peak Flow Requirements WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 23 of 25 The capacities of the solids treatment facilities (Figure 8) are dependent on the WRRF redundancy requirements. The DAFT and anaerobic digesters have firm capacities below the desired 5.4 mgd ADWF. This is attributed to a lack of redundancy. In both cases, the total capacity is at or exceeds 5.4 mgd ADWF. The existing belt filter press will provide redundancy to the new dewatering screw press. The screw press has a capacity of 5.4 mgd ADWF and can meet buildout flows and loads. Ultimately, the WRRF should consider replacement of the belt filter press with a redundant screw press. This offers the advantages of common equipment common performance for both operations and maintenance. Figure 8 Solids Stream Plant Capacity per Unit Process Conclusions This TM updates the plant-wide treatment capacity for the WRRF. The analysis considered flow equalization, recycled water production, as well as on-going equipment replacement and upgrades under the WRRF Energy Efficiency Project. Replacement and upgrades that are being implemented now were considered to be part of the existing conditions for the purposes of evaluating the plant capacity compared with future needs. Flow equalization was reviewed at the WRRF. Equalization of projected diurnal dry weather flows can be achieved with a 1.0 MG equalization basin. A wet weather hydrograph for the design storm (10 year, 14-hour storm) was developed using a collection system hydraulic model. Based on the model hydrograph, the existing equalization basin could be used to store wet weather flows greater than 22 mgd. Facilities downstream of equalization (i.e., aeration basins, final clarifiers, filtration and 0 2.4 5.4 8.0 6.6 5.4 0 1 2 3 4 5 6 7 8 9 DAFT Anaerobic Digesters New Screw Press Ra t e d C a p a c i t y p e r U n i t P r o c e s s ( m g d ) Firm ADWF Capacity Total ADWF Capacity Desired ADWF Capacity = 5.4 mgd ADWF WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 24 of 25 disinfection) would be sized for 17 and 16 mgd, depending on location within the treatment train. The flow equalization analysis served as a basis for the capacity analysis. Table 7 provides a summary of the findings from the capacity analysis. The City plans to use this updated capacity assessment to assist in decision making for the upcoming WRRF plant expansion/upgrades. Table 7. Summary of WRRF Capacity Assessment Item Rated Capacity (Firm/Total) Recommended Upgrades/Improvements Liquid Unit Processes Influent pumping station 32.0 mgd/54.0 mgd as Peak Flow Confirm if existing pumps can meet 33.5 mgd. Replace pumps, in future, if needed. Screens 16.0 mgd/32.0 mgd as Peak Flow Two screens operational during wet weather flows. Confirm plant hydraulics to determine if screens can accommodate design flows. Aerated Grit 29.3 mgd/58.6 mgd as Peak Flow No improvements/expansions necessary Influent Flow Meters 22 (total) mgd as Peak Flow Replace/modify flow meters to accurately record/measure peak flows. Biotower Pumping Station 8.6 mgd/17.2 mgd as Peak Flow Biotower & Secondary Clarifier 6.7 (total) mgd as ADWF No improvements necessary – biotower and secondary clarifier will be decommissioned after the upgrades are complete. Aeration Basins 5.1 (total) mgd as ADWF Expansion of aeration basins/blowers (PH equal to 17 mgd) is necessary to accommodate buildout flows and loads and to eliminate wet weather blending. Final Clarifiers 5.0 (total) mgd as ADWF Expansion of aeration basins and blowers (PH equal to 17 mgd) is necessary to accommodate buildout flows and loads and eliminate wet weather blending. Filter Pumping Station 5.2 mgd/7.8 mgd as Peak Flow Expansion of filter pump station to accommodate at PH flow of 16 mgd is necessary. Filtration – Recycled Water Production (Dry Season) 5.0 mgd as ADWF ADWF capacity is based on recycled water production Filtration – Peak Flows during Wet Season 8.3 mgd/11.1 mgd as Peak Flow Expansion of filters to accommodate at PH flow of 16 mgd is necessary to meet permit limits. Disinfection (Chlorination/Dechlorination) 13.9 (total) mgd as Peak Flow Chlorine contact basins to be decommissioned. UV disinfection to replace existing system. New UV Disinfection 16.0 (total) mgd as Peak Flow New UV disinfection to treat equalized peak flows Solids Unit Processes Thickening (DAFT) 0 mgd/8.0 mgd as ADWF Redundant thickener recommended. Look at more energy efficient thickeners (e.g., rotary drum thickener) Anaerobic Digesters 2.4 mgd/6.6 mgd as ADWF Redundant digester recommended to provide adequate HRT when a unit is out of service. Dewatering 5.4 mgd/5.4 mgd as ADWF Future replacement of belt filter press with screw press as part of WRRF Energy Efficiency Project. WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 25 of 25 References Brown and Caldwell (2011) Water Reclamation Facility Plan. Prepared for the City of San Luis Obispo Water Resource Recovery Facility, San Luis Obispo, CA. HDR (2014) Regulatory Compliance Technical Memorandum (2014 Facility Plan). Prepared for the City of San Luis Obispo Water Resource Recovery Facility, San Luis Obispo, CA. HDR (2014) Wastewater Characterization Technical Memorandum (2014 Facility Plan). City of San Luis Obispo Water Resource Recovery Facility, San Luis Obispo, CA. USEPA (1994) A Plain English Guide to the EPA Part 503 Biosolids Rule. Office of Wastewater Management, Washington, DC. V&A (2012) Sanitary Sewer Flow Monitoring and Inflow/Infiltration Study. Water Environment Federation (2009) Design of Municipal Wastewater Treatment Plants: Manual of Practice 8. Water Environment Federation, Washington, D.C. WSC (2014) Site Planning Technical Memorandum (2014 Facility Plan). City of San Luis Obispo Water Resource Recovery Facility, San Luis Obispo, CA. WSC (2014) Wastewater Collection System Infrastructure Renewal Strategy. Prepared for the City of San Luis Obispo Water Resource Recovery Facility, San Luis Obispo, CA. WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Attachment A: Process Flow Diagrams (Wet Weather Flow Routing) WR R F P r o j e c t TM N o . 9 – T R E A T M E N T P L A N T C A P A C I T Y A S S E S S M E N T Fi g u r e A - 1 . S L O W R R F E x i s t i n g D e t a i l e d P r i m a r y a n d S e c o n d a r y T r e a t m e n t S c h e m a t i c Li q u i d S t r e a m s Sl u d g e S t r e a m s Li q u i d R e c i r c u l a t i o n / B y p a s s Op t i o n a l L i q u i d R e c i r c u l a t i o n / B y p a s s Re t u r n S t r e a m s Ch e m i c a l S t r e a m s Pr i m a r y C l a r i f i c a t i o n PC L Se c o n d a r y C l a r i f i c a t i o n SC L Eq u a l i z a t i o n B a s i n EQ B Pr i m a r y E f f l u e n t D i v e r s i o n B o x PE D B Se c o n d a r y E f f l u e n t D i v e r s i o n B o x SE D B We t W e l l WW Ni t r i f i e d E f f l u e n t D i v e r s i o n B o x NE F F D B Sc r e e n Ae r a t e d Gr i t EQ B PC L SC L Tr i c k l i n g Fi l t e r Ra w In f l u e n t PE D B WW SE D B St o r m w a t e r ov e r f l o w Se c o n d a r y E f f l u e n t R e c y c l e To A e r a t i o n T a n k s To N E F F D B ( F l o w s > 5 . 1 m g d ) ) Se c o n d a r y S l u d g e Pr i m a r y S l u d g e Ba c k w a s h R e t u r n La g o o n R e t u r n Se c o n d a r y B y p a s s WR R F P r o j e c t TM N o . 9 – T R E A T M E N T P L A N T C A P A C I T Y A S S E S S M E N T Fi g u r e A - 2 . S L O W R R F E x i s t i n g D e t a i l e d A d v a n c e d T r e a t m e n t S c h e m a t i c EQ T Sa n d Fi l t e r (u n d e r S S T ) CC T SL O C r e e k Em e r g e n c y St o r a g e 3W W a t e r Sy s t e m Re c y c l e d Wa t e r Co o l i n g To w e r So d i u m Hy p o c h l o r i t e NE F F D B Fr o m F i n a l C l a r i f i e r s Fr o m S E D B Fi l t e r B y p a s s So d i u m Bi s u l f i t e Liquid Streams Sludge Streams Liquid Recirculation/Bypass Optional Liquid Recirculation/Bypass Return Streams Chemical Streams Primary Clarification PC L Secondary Clarification SC L Equalization Basin EQ B Primary Effluent Diversion Box PE D B Secondary Effluent Diversion Box SE D B Wet Well WW Nitrified Effluent Diversion Box NE F F D B Fi l t e r B a c k w a s h WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 27 of 25 Attachment B: Influent Hydrograph Simulation TM Date: 11/4/2014 To: Carrie Mattingly Phone: (805) 781‐7205 Utilities Director 879 Morro St. San Luis Obispo, CA 93401 CC: Dave Hix; Howard Brewen; Pam Ouellette Prepared by: Jeanine Genchanok, EIT Reviewed by: Jeroen Olthof, PE; Jeffery Szytel, PE; Lianne Williams, PE Project: Water Resource Recovery Facility (WRRF) Project SUBJECT: INFLUENT HYDROGRAPH SIMULATION FOR THE WRRF ‐ FINAL The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long‐term strategy for resource management. In addition, as part of the Wastewater Collection System Infrastructure Renewal Strategy (WCSIRS), Water Systems Consulting, Inc. (WSC) has developed a hydraulic model to evaluate the capacity of the collection system pipelines. This Technical Memorandum (TM) describes WSC’s development and calibration of the sewer system hydraulic model to simulate the influent hydrograph at the WRRF under various conditions. The purpose of this TM is to describe the modeling process and provide the calculated influent hydrograph at the WRRF for the 10‐yr, 24‐hour design storm. This TM is organized in the following sections: Contents Section 1. Model Development and Calibration ........................................................................................... 2 Section 2. Modeled Hydrographs at the WRRF: System‐Wide RTK Values .................................................. 4 Section 3. Modeled Hydrographs at the WRRF: Basin Specific RTKs .......................................................... 10 Section 4. 10‐Year, 24‐Hour Design Storm ................................................................................................. 14 Section 5. Recommendations ..................................................................................................................... 17 Section 6. References .................................................................................................................................. 17 WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 2 of 17 Section 1. Model Development and Calibration The hydraulic model of the City’s collection system was updated in SewerGEMS (Bentley®) to include elevations for manhole inverts that had not been previously surveyed. Missing invert elevations were interpolated between surveyed values or estimated using an assumed minimum slope. Basins were defined in the model, using the flow monitor basins defined in the 2012 V&A Sanitary Sewer Flow Monitoring and Inflow/Infiltration Study. In some cases the basin boundaries were adjusted based on updated collection system information gathered as part of the WCSIRS project. Each basin was assigned an outlet manhole where the basin’s flow was added to the system. Figure 1 provides a sample observed hydrograph for monitoring location A.2 (manhole HO6‐5: 269 Craig Way) corresponding to the inflow for basin A.2. On the graph, rainfall is shown in the blue bars on an inverted scale. The solid black line represents the total observed flow at the meter. The dashed black line is the estimated dry weather flow at the monitoring site, based on measurements taken during periods with no rain. The area between the solid black line and the dashed black line represents the rainfall‐derived infiltration and inflow and is shaded a light green. Figure 1. Sample Rainfall and Flow Data Provided by V&A WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 3 of 17 The hydraulic model was used to simulate the collection system’s response to rainfall events. For the WRRF Project, the team developed sets of response factors using the three‐triangle R‐T‐K method. This method involves creating a synthetic unit hydrograph based on the summation of three triangles. The first RTK triangle corresponds to rapid inflow, the second to moderate infiltration, and the third to slow infiltration. Each triangle is defined by three variables: R is the percentage of rainfall that becomes rainfall derived inflow and infiltration (RDII) T is the time from when the rain falls to the peak of the RDII K is a lag coefficient that describes how long RDII continues to enter the system. The time from the peak RDII until the end of the RDII is equal to K * T An illustration of a synthetic unit hydrograph derived from three triangles is shown in Figure 2. Figure 2. Example Synthetic Unit Hydrograph Using R‐T‐K Triangles The unit hydrograph is used to simulate the response to a unit (one inch) of rainfall. For each of the three triangles, T is the time in hours until the peak of the triangle; the recession limb of the triangle has a duration of K * T; and the area under the triangle is R. With three factors (R, T, and K) for each of three triangles, a total of nine factors define a set of response factors. Through iterative model simulations, WSC developed sets of response factors to calculate a hydrograph of expected flow in response to a rainfall event. Figure 3 illustrates an example of RTK values assigned for a basin within SewerGEMS. 0 0.05 0.1 0.15 0.2 0.25 051015202530 Fl o w in Re s p o n s e to Un i t of Ra i n f a l l Time (Hours) Triangle 1 Triangle 2 Triangle 3 Combined Unit Hydrograph WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 4 of 17 Figure 3. Sample Basin Parameters The four rainfall events from the V&A study were applied to the hydraulic model, and hydrographs were generated for each basin and for the influent hydrograph to the WRRF. WSC also used the model to simulate additional rainfall events in January and March of 2011. Section 2. Modeled Hydrographs at the WRRF: System‐Wide RTK Values Initially WSC focused on developing a system‐wide set of RTK values that could be used to calculate a response hydrograph from all the basin’s. WSC ran an extended simulation for a five‐day period. WSC first simulated dry weather flow to the WRRF. The modeled hydrograph for dry weather flow was compared to observed dry‐weather flow data from April 7‐11, 2014 as shown in Figure 4. WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 5 of 17 Figure 4. Observed and Modeled Dry Weather Flow at the WRRF Figure 5. Observed and Modeled Cumulative Dry Weather Flow at the WRRF There was generally good agreement between the modeled and observed dry weather flows. WSC then ran the model to simulate two rainfall events: the March 19th‐20th, 2011 rainfall event (4.38 inches of rain over 48 hours) and the January 1st‐5th, 2011 rainfall event (2.6 inches of rain over the first 0 1 2 3 4 5 6 7 020406080100120 MG D Time (hours) Modeled Observed 0 2 4 6 8 10 12 14 16 18 20 020406080100120 Cu m u l a t i v e Fl o w (M i l l i o n Ga l l o n s ) Time (hours) Modeled Observed WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 6 of 17 48 hours). The calculated hydrographs at the plant for present conditions were compared to observed flow values that were transcribed from the circle chart data by HDR. Table 1 lists RTK values that were found to best match modeled and observed flows for the March 2011 rainfall event. Table 1. RTK Set 1 R1 0.008 R2 0.008 R3 0.025 T1 1 T2 6 T3 24 K1 1 K2 2 K3 3 The model results using RTK Set 1 appeared to be in reasonable agreement with the observed flows from the March 2011 event and for the first part of the January 2011 event. However, the January 2011 event showed an extended response of elevated flows for several days after the peak rainfall, with no additional rainfall recorded. It is not clear if these results are due to inaccurate flow measurements or if elevated groundwater levels due to the wet winter caused an extended response. WSC developed a second set of RTK values to generate a modeled response that matched the observed response for the January 2011 event. These values are shown in Table 2. Table 2. RTK Set 2 R1 0.01 R2 0.01 R3 0.04 T1 2 T2 6 T3 24 K1 1 K2 2 K3 3 A flow comparison and a cumulative flow analysis for each RTK set are illustrated in the figures below. WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 7 of 17 Figure 6. Observed and Modeled Flow at the WRRF for the March, 2011 Rainfall Event using RTK Set 1 Figure 7. Observed and Modeled Cumulative Flow at the WRRF for the March, 2011 Rainfall Event using RTK Set 1 0 1 2 3 4 50 5 10 15 20 25 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) March 2011 March 2011 Rainfall Modeled Flow at the WRRF Observed Flow at the WRRF 0 5 10 15 20 25 30 35 40 45 020406080100120 Cu m u l a t i v e Fl o w (M i l l i o n Ga l l o n s ) Time (hours) March, 2011 Modeled Observed WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 8 of 17 Figure 8. Observed and Modeled Flow for the January, 2011 Rainfall Event using RTK Set 1 Figure 9. Observed and Modeled Cumulative Flow at the WRRF for the January, 2011 Rainfall Event using RTK Set 1 0 1 2 30 5 10 15 20 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) January, 2011 January 2011 Rainfall Modeled Flow at the WRRF Observed Flow at the WRRF 0 10 20 30 40 50 60 020406080100120 Cu m u l a t i v e Fl o w (M i l l i o n Ga l l o n s ) Time (hours) January, 2011 Observed Modeled WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 9 of 17 Figure 10. Observed and Modeled Flow at the WRRF for January, 2011 Event using RTK Set 2 Figure 11. Observed and Modeled Cumulative Flow at the WRRF for January, 2011 Event using RTK Set 2 0 1 2 30 5 10 15 20 25 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) January, 2011 January 2011 Rainfall Modeled Flow at the WRRF Observed Flow at the WRRF 0 10 20 30 40 50 60 020406080100120 Cu m u l a t i v e Fl o w (M i l l i o n Ga l l o n s ) Time (hours) January, 2011 Observed Modeled WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 10 of 17 Figure 12. Observed and Modeled Flow at the WRRF for March, 2011 Event using RTK Set 2 Figure 13. Observed and Modeled Cumulative Flow at the WRRF for March, 2011 Event using RTK Set 2 Section 3. Modeled Hydrographs at the WRRF: Basin‐Specific RTK Sets After reviewing and discussing the results obtained with the system‐wide RTK sets, WSC developed individual RTK sets for each basin to better simulate the response to varying storm events within each basin. For each basin, WSC developed a set of response factors that best matched the observed response across both of the storm events as presented in the basin‐specific hydrographs prepared by V&A. Basins are illustrated in Figure 14 below. In addition, constant values of groundwater infiltration were added to select basins to model elevated flows not related to a specific storm event. The calculated hydrographs using the basin‐specific RTK values are shown in the following figures. 0 1 2 3 4 50 5 10 15 20 25 30 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) March 2011 March 2011 Rainfall Modeled Flow at the WRRF Observed Flow at the WRRF 0 10 20 30 40 50 60 020406080100120 Cu m u l a t i v e Fl o w (M i l l i o n Ga l l o n s ) Time (hours) March, 2011 Modeled Observed WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 11 of 17 Figure 14. Basin Areas Map WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 12 of 17 Figure 15. Observed and Modeled Flow at the WRRF for January, 2011 Event using Basin‐Specific RTK Sets Figure 16. Observed and Modeled Cumulative Flow at the WRRF for January, 2011 Event using Basin‐ Specific RTK Sets 0 1 2 30 5 10 15 20 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) January, 2011 January 2011 Rainfall Modeled Flow at the WRRF Observed Flow at the WRRF 0 10 20 30 40 50 60 020406080100120 Cu m u l a t i v e Fl o w (M i l l i o n Ga l l o n s ) Time (hours) January, 2011 Observed Modeled WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 13 of 17 Figure 17. Observed and Modeled Flow at the WRRF for March, 2011 Event using Basin‐Specific RTK Sets Figure 18. Observed and Modeled Cumulative Flow at the WRRF for March, 2011 Event using Basin‐ Specific RTK Sets 0 1 2 3 4 50 5 10 15 20 25 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) March, 2011 March 2011 Rainfall Modeled Flow at the WRRF Observed Flow at the WRRF 0 5 10 15 20 25 30 35 40 45 50 020406080100120 Cu m u l a t i v e Fl o w (M i l l i o n Ga l l o n s ) Time (hours) March, 2011 Modeled Observed WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 14 of 17 Section 4. 10‐Year, 24‐Hour Design Storm The calibrated model was used to generate a hydrograph at the WRRF for the 10‐yr, 24‐hr design storm. The design storm precipitation profile was developed by V&A and is shown in Figure 19. Figure 19. 10‐yr, 24‐hr Design Storm Precipitation Profile (V&A) The model was run using current development and build‐out conditions (as defined for the capacity analysis in the WCSIRS project). A summary of peak flows for dry and wet weather for present and future (build‐out) conditions using the three different RTK sets is shown in Table 3 and illustrated in Figures 20‐22. A comparison of the hydrographs calculated using different RTK parameters is illustrated in Figure 23. WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 15 of 17 Table 3. Model Flow Summary Current Peak Dry Weather Flow (MGD) 5.80 Build Out Peak Dry Weather Flow (MGD) 9.15 RTK Set 1 RTK Set 2 Basin‐Specific RTK Sets Current PWWF (MGD) 31.41 36.00 32.18 Build Out PWWF (MGD) 32.11 36.74 33.49 Figure 20. Modeled 10‐Yr, 24‐hr Design Storm using RTK Set 1 Figure 21. Modeled 10‐Yr, 24‐hr Design Storm using RTK Set 2 0 1 2 3 4 50 5 10 15 20 25 30 35 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) 10‐yr, 24‐hr Design Storm Rainfall Modeled Current Conditions Build_Out Conditions Dry Weather Flow (Build Out Conditions) Dry Weather Flow (Current Conditions) 0 1 2 3 4 50 5 10 15 20 25 30 35 40 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) 10‐yr, 24‐hr Design Storm Rainfall Modeled Current Conditions Build_Out Conditions Dry Weather Flow (Build Out Conditions) Dry Weather Flow (Current Conditions) WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 16 of 17 Figure 22. Modeled 10‐Yr, 24‐hr Design Storm using Basin‐Specific RTK Sets Figure 23. Comparison of Build Out Flows 0 1 2 3 4 50 5 10 15 20 25 30 35 40 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) 10‐yr, 24‐hr Design Storm Rainfall Modeled Current Conditions Build_Out Conditions Dry Weather Flow (Build Out Conditions) Dry Weather Flow (Current Conditions) 0 5 10 15 20 25 30 35 40 020406080100120 Fl o w (M G D ) Time (hours) RTK Set 1, Build Out 10‐Yr Storm RTK Set 2‐ Build Out 10‐Yr Storm Basin Specific RTK Set, Build Out 10‐Yr Storm WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 17 of 17 Section 5. Recommendations This TM describes two rounds of analysis to simulate wastewater flow responses at the WRRF. In Round 1, hydrographs were calculated using two different sets of RTK factors to simulate the wastewater flow response to two specific rain events (January, 2011 and March, 2011). In Round 2, hydrographs were calculated using unique RTK parameters for each basin rather than a uniform system‐wide set. In addition, Round 2 included the addition of groundwater infiltration to some basins to reflect higher flows during the wet season that were not related to a specific storm event. It is recommended that the City consider taking the following steps: Perform additional flow monitoring this winter with a goal of capturing flow data for more storm events. Use the model with the basin‐specific RTK sets for future analysis. The basin‐specific RTK sets were developed to match the observed response across multiple storm events. The calculated hydrograph at the WRRF using the basin‐specific RTK sets appears reasonable in light of operator experience and previous studies. Section 6. References 1. V&A. Sanitary Sewer Flow Monitoring and Inflow/Infiltration Study. 2012 WRRF Project TM No. 9 –Treatment Plant Capacity Assessment Page 28 of 25 Attachment C: Flow Equalization Analysis PURPOSE FIND DescriptionVariableUnitComment Required EQ StorageVGallons The required Equilization Storage Volume to handle buildout ADWFCP Average Max Day FlowQavggpmThis is the average flow on a Day of Maximum Water Usage GIVEN DescriptionValueUnitComment Diurnal FlowsInput into table belowgpmHourly Flow Data for a Day of Maximum Water Usage DIAGRAM EQUATIONS Required EQ Storage (V) =Maximum (Total Consumption - Total Avg. Flow Column) - Minimum (Total Consumption - Total Avg. Flow Column) Average of Max Day Flow (Qavg.) =(Sum of Hourly Consumption / 24 hours) 225,097 1.003.7153,267153,267225,097-71,831 2.002.4101,333254,600450,194-195,594 3.002.083,600338,200675,292-337,092 4.001.041,800380,000900,389-520,389 5.001.041,800421,8001,125,486-703,686 6.002.7111,467533,2671,350,583-817,317 7.003.3139,333672,6001,575,681-903,081 8.007.7320,467993,0671,800,778-807,711 9.008.7362,2671,355,3332,025,875-670,542 10.009.3386,3331,741,6672,250,972-509,306 11.008.4348,3332,090,0002,476,069-386,069 12.006.7278,6672,368,6672,701,167-332,500 13.006.0250,8002,619,4672,926,264-306,797 14.006.0250,8002,870,2673,151,361-281,094 15.005.6234,3333,104,6003,376,458-271,858 16.006.8285,0003,389,6003,601,556-211,956 17.005.4222,9333,612,5333,826,653-214,119 18.005.8240,6673,853,2004,051,750-198,550 19.006.0250,8004,104,0004,276,847-172,847 20.006.0250,8004,354,8004,501,944-147,144 21.006.1253,3334,608,1334,727,042-118,908 22.006.7278,6674,886,8004,952,139-65,339 23.006.4264,7335,151,5335,177,236-25,703 24.006.0250,8005,402,3335,402,3330 CALCULATIONSQavg5.4 mgd V904,000 Gallons Total Average Consumption (Gallons) Total Consumption - Total Avg. FlowTime (Hours) Total Diurnal Consumption (gallons) Hourly Consumption (MGD) Hourly Consumption (gallons) The purpose of this spreadsheet is to determine the required storage capacity of an equalization basin to compensate for diurnalflows to a wastewater treatment plant and enable the treatment plant to operate at a steady flow throughout the day. HDR Engineering, Inc. Diurnal Equalization - ADWF, Future_2.xlsxDIURNAL EQ 12/7/2014 Page 1 REFERENCESWater and Wastewater Technology, Second Edition, Hammer, Mark, pages 212-214 ATTACHMENTS CALCULATIONS Qavg 5.4 mgd V904,000 Gallons 0 1 2 3 4 5 6 7 8 9 10 0510152025 Pl a n t I n f l o w ( M G D ) Hours 0 1000000 2000000 3000000 4000000 5000000 6000000 123456789101112131415161718192021222324 Vo l u m e ( g a l l o n s ) Hours Required Equilization Storage = The vertical difference between the minimum volume (low point) and maximum volume (high point) on this curve. -700000 -600000 -500000 -400000 -300000 -200000 -100000 0 100000 200000 300000 400000 123456789101112131415161718192021222324 Vo l u m e ( g a l l o n s ) Hours FILL AND DRAIN OF THE EQUALIZATION VOLUME Fill and drain constructed from the time where the influent flow is greater than the average flow. HDR Engineering, Inc. Diurnal Equalization - ADWF, Future_2.xlsxDIURNAL EQ 12/7/2014 Page 2 PURPOSE FIND DescriptionVariableUnitComment Required StorageVMG GIVEN DescriptionValueUnitComment Divert17mgdInfluent Flowrate at which flow begins to be diverted Feedback12mgdInfluent Flowrate at which equalized flow is fed back to WWTP Hydrograph ValuesInput into table belowmgdHourly Flow Data DIAGRAM EQUATIONS Diversion Flow =Hydrograph flow (MGD) - Divert (MGD) (0 if Divert is greater than the hydrogpraph flow) Feedback Flow =Feedback Flow (MGD) - Hydrograph Flow (MGD) **If sufficient Storage Volume and Hydrograph flow is less than the feedback flow. Storage Volume =Existing Storage Volume (MG) + (Diversion Flow (MGD) / 24 hr) - (Feedback flow (MGD) / 24 hr) Plant Inflow =Hydrograph (MGD) - Diversion Flow (MGD) + Feedback Flow (MGD) CALCULATIONSRequired Storage4.3 MG The purpose of this procedure is to determine the required storage capacity of an equalization basin at a wastewater treatment plant. If a known maximum equalization storage is known, this procedure can be used with a goal seek function to determine the maximum allowable flow rate for diversion to begin at without overflowing the maximum basin size. HDR Engineering, Inc. WW Equalization - Model 10yr24H_buildout_RTK3.xlsxSTORMWATER EQ 12/7/2014 Page 1 Hydrograph (mgd) TOTAL 0.00 2.21 0.0000.0000.0002.207 1.00 2.58 0.0000.0000.0002.577 2.00 4.64 0.0000.0000.0004.644 3.00 4.94 0.0000.0000.0004.937 4.00 6.85 0.0000.0000.0006.852 5.00 8.93 0.0000.0000.0008.933 6.00 10.69 0.0000.0000.00010.692 7.00 10.32 0.0000.0000.00010.320 8.00 10.45 0.0000.0000.00010.448 9.00 9.06 0.0000.0000.0009.057 10.00 9.93 0.0000.0000.0009.931 11.00 9.50 0.0000.0000.0009.500 12.00 8.29 0.0000.0000.0008.292 13.00 8.09 0.0000.0000.0008.091 14.00 7.47 0.0000.0000.0007.471 15.00 8.95 0.0000.0000.0008.951 16.00 8.90 0.0000.0000.0008.905 17.00 9.28 0.0000.0000.0009.281 18.00 7.77 0.0000.0000.0007.766 19.00 8.12 0.0000.0000.0008.124 20.00 7.85 0.0000.0000.0007.852 21.00 5.63 0.0000.0000.0005.625 22.00 4.54 0.0000.0000.0004.541 23.00 3.74 0.0000.0000.0003.743 24.00 4.29 0.0000.0000.0004.288 25.00 3.32 0.0000.0000.0003.324 26.00 3.84 0.0000.0000.0003.839 27.00 8.49 0.0000.0000.0008.490 28.00 11.51 0.0000.0000.00011.506 29.00 13.57 0.0000.0000.00013.567 30.00 14.39 0.0000.0000.00014.393 31.00 15.81 0.0000.0000.00015.813 32.00 16.74 0.0000.0000.00016.739 33.00 16.83 0.0000.0000.00016.835 34.00 15.94 0.0000.0000.00015.943 35.00 14.81 0.0000.0000.00014.810 36.00 11.96 0.0000.0000.00011.963 37.00 14.42 0.0000.0000.00014.423 38.00 16.33 0.0000.0000.00016.326 39.00 17.42 0.4160.0000.01717.000 40.00 17.72 0.7190.0000.04717.000 41.00 20.91 3.9050.0000.21017.000 42.00 24.51 7.5130.0000.52317.000 43.00 31.73 14.7270.0001.13717.000 44.00 33.49 16.4930.0001.82417.000 45.00 30.43 13.4320.0002.38417.000 46.00 25.50 8.4980.0002.73817.000 47.00 23.24 6.2380.0002.99817.000 48.00 20.91 3.9110.0003.16117.000 49.00 19.65 2.6520.0003.27117.000 50.00 18.74 1.7410.0003.34417.000 51.00 18.13 1.1260.0003.39117.000 52.00 18.34 1.3450.0003.44717.000 53.00 21.06 4.0580.0003.61617.000 54.00 21.43 4.4290.0003.80017.000 55.00 21.33 4.3260.0003.98017.000 56.00 20.47 3.4680.0004.12517.000 57.00 19.38 2.3840.0004.22417.000 58.00 17.83 0.8280.0004.25917.000 59.00 17.52 0.5150.0004.28017.000 60.00 16.33 0.0000.0004.28016.332 61.00 16.38 0.0000.0004.28016.375 62.00 15.71 0.0000.0004.28015.709 63.00 16.58 0.0000.0004.28016.583 64.00 16.27 0.0000.0004.28016.272 65.00 17.23 0.2280.0004.29017.000 Storage Volume (MG)Plant Inflow (mgd) Time from Midnight (Hours) Diversion Flow (mgd) Feedback Flow (mgd) HDR Engineering, Inc. WW Equalization - Model 10yr24H_buildout_RTK3.xlsxSTORMWATER EQ 12/7/2014 Page 2 66.00 16.90 0.0000.0004.29016.902 67.00 16.67 0.0000.0004.29016.667 68.00 16.47 0.0000.0004.29016.473 69.00 15.07 0.0000.0004.29015.074 70.00 13.11 0.0000.0004.29013.114 71.00 12.28 0.0000.0004.29012.277 HDR Engineering, Inc. WW Equalization - Model 10yr24H_buildout_RTK3.xlsxSTORMWATER EQ 12/7/2014 Page 3 72.00 12.35 0.0000.0004.29012.351 73.00 11.88 0.0000.1154.28512.000 74.00 10.27 0.0001.7254.21312.000 75.00 12.08 0.0000.0004.21312.076 76.00 13.73 0.0000.0004.21313.726 77.00 16.34 0.0000.0004.21316.337 78.00 17.23 0.2260.0004.22217.000 79.00 18.00 1.0050.0004.26417.000 80.00 17.05 0.0540.0004.26717.000 81.00 16.81 0.0000.0004.26716.806 82.00 15.62 0.0000.0004.26715.620 83.00 15.38 0.0000.0004.26715.375 84.00 13.08 0.0000.0004.26713.081 85.00 12.66 0.0000.0004.26712.658 86.00 13.73 0.0000.0004.26713.732 87.00 14.18 0.0000.0004.26714.178 88.00 14.67 0.0000.0004.26714.674 89.00 14.36 0.0000.0004.26714.363 90.00 14.87 0.0000.0004.26714.866 91.00 14.43 0.0000.0004.26714.429 92.00 13.50 0.0000.0004.26713.503 93.00 11.50 0.0000.4974.24612.000 94.00 11.37 0.0000.6354.21912.000 95.00 10.14 0.0001.8584.14212.000 96.00 9.39 0.0002.6084.03312.000 97.00 8.04 0.0003.9603.86812.000 98.00 8.84 0.0003.1573.73712.000 99.00 7.84 0.0004.1623.56312.000 100.00 9.91 0.0002.0913.47612.000 101.00 13.07 0.0000.0003.47613.068 102.00 14.85 0.0000.0003.47614.853 103.00 14.55 0.0000.0003.47614.555 104.00 13.75 0.0000.0003.47613.747 105.00 13.45 0.0000.0003.47613.453 106.00 12.78 0.0000.0003.47612.782 107.00 12.11 0.0000.0003.47612.108 108.00 12.07 0.0000.0003.47612.065 109.00 10.91 0.0001.0893.43112.000 110.00 11.23 0.0000.7703.39912.000 111.00 11.36 0.0000.6423.37212.000 112.00 11.53 0.0000.4753.35212.000 113.00 11.21 0.0000.7933.31912.000 114.00 11.86 0.0000.1453.31312.000 115.00 10.68 0.0001.3253.25812.000 116.00 10.28 0.0001.7243.18612.000 117.00 7.95 0.0004.0523.01712.000 118.00 6.64 0.0005.3592.79412.000 119.00 7.19 0.0004.8082.59412.000 120.00 7.44 0.0004.5552.40412.000 HDR Engineering, Inc. WW Equalization - Model 10yr24H_buildout_RTK3.xlsxSTORMWATER EQ 12/7/2014 Page 4 SUMMARYRequired Storage4.3 MG REFERENCEDesign of Municipal Wastewater Treatment Plants, WEF Manual of Practice 8, Fourth Edition, ASCE Manuals and Reports on Engineering Practice No. 76, Volume 1, 1998. Wastewater Engineering Treatment and Reuse, Fourth Edition, Metcalf and Eddy, 2003 ATTACHMENTS 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 020406080100120 Pl a n t I n f l o w ( m g d ) Hours Input Hydrographs Series6 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 020406080100120 Vo l u m e , M G Fl o w ( m g d ) Hours Detention Storage Balance Diverted Flow Feedback Flows Plant Inflow Storage Volume HDR Engineering, Inc. WW Equalization - Model 10yr24H_buildout_RTK3.xlsxSTORMWATER EQ 12/7/2014 Page 5 PURPOSE FIND DescriptionVariableUnitComment Required StorageVMG GIVEN DescriptionValueUnitComment Divert16mgdSecondary Effluent Flow Rate at which flows are diverted to EQ Feedback12mgdInfluent Flowrate at which equalized flow is fed back to Filtration Hydrograph ValuesInput into table belowmgdHourly Flow Data DIAGRAM EQUATIONS Diversion Flow =Hydrograph flow (MGD) - Divert (MGD) (0 if Divert is greater than the hydrogpraph flow) Feedback Flow =Feedback Flow (MGD) - Hydrograph Flow (MGD) **If sufficient Storage Volume and Hydrograph flow is less than the feedback flow. Storage Volume =Existing Storage Volume (MG) + (Diversion Flow (MGD) / 24 hr) - (Feedback flow (MGD) / 24 hr) Plant Inflow =Hydrograph (MGD) - Diversion Flow (MGD) + Feedback Flow (MGD) CALCULATIONSRequired Storage1.3 MG The purpose of this procedure is to determine the required storage capacity of an equalization basin at a wastewater treatment plant. If a known maximum equalization storage is known, this procedure can be used with a goal seek function to determine the maximum allowable flow rate for diversion to begin at without overflowing the maximum basin size. HDR Engineering, Inc. WW Equalization - Model 10yr24H_buildout_RTK3_SECEQ.xlsxSTORMWATER EQ 12/7/2014 Page 1 Hydrograph (mgd) TOTAL 0.00 2.21 0.0000.0000.0002.207 1.00 2.58 0.0000.0000.0002.577 2.00 4.64 0.0000.0000.0004.644 3.00 4.94 0.0000.0000.0004.937 4.00 6.85 0.0000.0000.0006.852 5.00 8.93 0.0000.0000.0008.933 6.00 10.69 0.0000.0000.00010.692 7.00 10.32 0.0000.0000.00010.320 8.00 10.45 0.0000.0000.00010.448 9.00 9.06 0.0000.0000.0009.057 10.00 9.93 0.0000.0000.0009.931 11.00 9.50 0.0000.0000.0009.500 12.00 8.29 0.0000.0000.0008.292 13.00 8.09 0.0000.0000.0008.091 14.00 7.47 0.0000.0000.0007.471 15.00 8.95 0.0000.0000.0008.951 16.00 8.90 0.0000.0000.0008.905 17.00 9.28 0.0000.0000.0009.281 18.00 7.77 0.0000.0000.0007.766 19.00 8.12 0.0000.0000.0008.124 20.00 7.85 0.0000.0000.0007.852 21.00 5.63 0.0000.0000.0005.625 22.00 4.54 0.0000.0000.0004.541 23.00 3.74 0.0000.0000.0003.743 24.00 4.29 0.0000.0000.0004.288 25.00 3.32 0.0000.0000.0003.324 26.00 3.84 0.0000.0000.0003.839 27.00 8.49 0.0000.0000.0008.490 28.00 11.51 0.0000.0000.00011.506 29.00 13.57 0.0000.0000.00013.567 30.00 14.39 0.0000.0000.00014.393 31.00 15.81 0.0000.0000.00015.813 32.00 16.74 0.7390.0000.03116.000 33.00 16.83 0.8350.0000.06616.000 34.00 15.94 0.0000.0000.06615.943 35.00 14.81 0.0000.0000.06614.810 36.00 11.96 0.0000.0370.06412.000 37.00 14.42 0.0000.0000.06414.423 38.00 16.33 0.3260.0000.07816.000 39.00 17.00 1.0000.0000.11916.000 40.00 17.00 1.0000.0000.16116.000 41.00 17.00 1.0000.0000.20316.000 42.00 17.00 1.0000.0000.24416.000 43.00 17.00 1.0000.0000.28616.000 44.00 17.00 1.0000.0000.32816.000 45.00 17.00 1.0000.0000.36916.000 46.00 17.00 1.0000.0000.41116.000 47.00 17.00 1.0000.0000.45316.000 48.00 17.00 1.0000.0000.49416.000 49.00 17.00 1.0000.0000.53616.000 50.00 17.00 1.0000.0000.57816.000 51.00 17.00 1.0000.0000.61916.000 52.00 17.00 1.0000.0000.66116.000 53.00 17.00 1.0000.0000.70316.000 54.00 17.00 1.0000.0000.74416.000 55.00 17.00 1.0000.0000.78616.000 56.00 17.00 1.0000.0000.82816.000 57.00 17.00 1.0000.0000.86916.000 58.00 17.00 1.0000.0000.91116.000 59.00 17.00 1.0000.0000.95316.000 60.00 16.33 0.3320.0000.96616.000 61.00 16.38 0.3750.0000.98216.000 62.00 15.71 0.0000.0000.98215.709 63.00 16.58 0.5830.0001.00616.000 64.00 16.27 0.2720.0001.01816.000 65.00 17.00 1.0000.0001.05916.000 Storage Volume (MG)Plant Inflow (mgd) Time from Midnight (Hours) Diversion Flow (mgd) Feedback Flow (mgd) HDR Engineering, Inc. WW Equalization - Model 10yr24H_buildout_RTK3_SECEQ.xlsxSTORMWATER EQ 12/7/2014 Page 2 66.00 16.90 0.9020.0001.09716.000 67.00 16.67 0.6670.0001.12516.000 68.00 16.47 0.4730.0001.14416.000 69.00 15.07 0.0000.0001.14415.074 70.00 13.11 0.0000.0001.14413.114 71.00 12.28 0.0000.0001.14412.277 HDR Engineering, Inc. WW Equalization - Model 10yr24H_buildout_RTK3_SECEQ.xlsxSTORMWATER EQ 12/7/2014 Page 3 72.00 12.35 0.0000.0001.14412.351 73.00 11.88 0.0000.1151.14012.000 74.00 10.27 0.0001.7251.06812.000 75.00 12.08 0.0000.0001.06812.076 76.00 13.73 0.0000.0001.06813.726 77.00 16.34 0.3370.0001.08216.000 78.00 17.23 1.2260.0001.13316.000 79.00 17.50 1.5000.0001.19516.000 80.00 17.05 1.0540.0001.23916.000 81.00 16.81 0.8060.0001.27316.000 82.00 15.62 0.0000.0001.27315.620 83.00 15.38 0.0000.0001.27315.375 84.00 13.08 0.0000.0001.27313.081 85.00 12.66 0.0000.0001.27312.658 86.00 13.73 0.0000.0001.27313.732 87.00 14.18 0.0000.0001.27314.178 88.00 14.67 0.0000.0001.27314.674 89.00 14.36 0.0000.0001.27314.363 90.00 14.87 0.0000.0001.27314.866 91.00 14.43 0.0000.0001.27314.429 92.00 13.50 0.0000.0001.27313.503 93.00 11.50 0.0000.4971.25212.000 94.00 11.37 0.0000.6351.22612.000 95.00 10.14 0.0001.8581.14812.000 96.00 9.39 0.0002.6081.04012.000 97.00 8.04 0.0003.9600.87512.000 98.00 8.84 0.0003.1570.74312.000 99.00 7.84 0.0004.1620.57012.000 100.00 9.91 0.0002.0910.48312.000 101.00 13.07 0.0000.0000.48313.068 102.00 14.85 0.0000.0000.48314.853 103.00 14.55 0.0000.0000.48314.555 104.00 13.75 0.0000.0000.48313.747 105.00 13.45 0.0000.0000.48313.453 106.00 12.78 0.0000.0000.48312.782 107.00 12.11 0.0000.0000.48312.108 108.00 12.07 0.0000.0000.48312.065 109.00 10.91 0.0001.0890.43712.000 110.00 11.23 0.0000.7700.40512.000 111.00 11.36 0.0000.6420.37812.000 112.00 11.53 0.0000.4750.35912.000 113.00 11.21 0.0000.7930.32612.000 114.00 11.86 0.0000.1450.32012.000 115.00 10.68 0.0001.3250.26412.000 116.00 10.28 0.0001.7240.19212.000 117.00 7.95 0.0004.0520.02412.000 118.00 6.64 0.0000.5680.0007.209 119.00 7.19 0.0000.0000.0007.192 120.00 7.44 0.0000.0000.0007.445 HDR Engineering, Inc. WW Equalization - Model 10yr24H_buildout_RTK3_SECEQ.xlsxSTORMWATER EQ 12/7/2014 Page 4 SUMMARYRequired Storage1.27 MG REFERENCEDesign of Municipal Wastewater Treatment Plants, WEF Manual of Practice 8, Fourth Edition, ASCE Manuals and Reports on Engineering Practice No. 76, Volume 1, 1998. Wastewater Engineering Treatment and Reuse, Fourth Edition, Metcalf and Eddy, 2003 ATTACHMENTS 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 020406080100120 Pl a n t I n f l o w ( m g d ) Hours Input Hydrographs Series6 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 020406080100120 Vo l u m e , M G Fl o w ( m g d ) Hours Detention Storage Balance Diverted Flow Feedback Flows Plant Inflow Storage Volume HDR Engineering, Inc. WW Equalization - Model 10yr24H_buildout_RTK3_SECEQ.xlsxSTORMWATER EQ 12/7/2014 Page 5 Appendix I TM No. 9.1 - Influent and Effluent Flow Monitoring Date: 10/27/2014 To: Carrie Mattingly Phone: (805) 781‐7013 City of San Luis Obispo 879 Morro St. San Luis Obispo, CA 93401 CC: Howard Brewen, Dave Hix Prepared by: Jasmine Diaz, EIT Reviewed by: Jeffery Szytel, PE; Lianne Westberg, PE Project: City of San Luis Obispo Water Resource Recovery Facility Project SUBJECT: TM No. 9.1 - INFLUENT & EFFLUENT FLOW MONITORING The City of San Luis Obispo (City) is carrying out a series of upgrades to the Water Resource Recovery Facility (WRRF). During the initial facilities planning of the WRRF Project, the WRRF staff has expressed uncertainty in the accuracy of the influent flow data. The purpose of this technical memorandum (TM) is to document the equipment used to monitor influent flow and effluent flow at the WRRF and to perform a brief analysis of the flow meter data to support the WRRF Project. Background As part of the facilities planning, the Program Management (PM) Team conducted a capacity consideration study and a wastewater characterization study. These studies rely on WRRF influent and effluent flow data. The results of these studies will drive equipment and facility sizing and design, thus reliable flow data is critical. Since the influent flow meters were replaced in 2011 and 2012, the WRRF staff has expressed concern regarding the consistency and reliability of the data produced by the meters. Table 1 provides an inventory of the flow meters currently installed at the WRRF. The influent flow meters are located downstream of the aerated grit basins, prior to the primary clarifiers. The effluent flow meter is located upstream of the chlorine contact channels. The location of each meter in relation to the plant is shown in Figure 10. City of San Luis Obispo Water Resource Recovery Facility Project INFLUENT & EFFLUENT FLOW MONITORING Table 1. Flow Meter Equipment Information In the Operation’s building, the WRRF uses a chart recorder to record instantaneous flow and total daily influent and effluent flow. The chart recorder has a blue and red pen that move according to the information they receive from the influent and effluent flow meters. See Figure 3 for diagram demonstrating the lines of communication to the chart recorder. The recorder also has counters, Item Manufacturer Model Name/No. WRRF Equip Name Date of Install Date of Last Calibration Location Influent Flow Meter Influent Flow Meter and Sensor Pulsar Process Management Pulsar Ultra 3 AG‐FIT‐150 2/16/20127/31/2013 See Figure 8 & Figure 4 Influent Flow Meter and Sensor Pulsar Process Management Pulsar Ultra 3 AG‐FIT‐250 2/16/20127/31/2013 See Figure 8 & Figure 4 Influent Parshall Flume Mannings 04409XX 18” Influent Parshall Flume 1994 Unknown See Figure 8 Influent Parshall Flume Mannings 04409XX 18” Influent Parshall Flume 1994 Unknown See Figure 8 Effluent Flow Meter Effluent Flow Meter Siemens Siemens OCM III Effluent Flow Meter 3/23/20117/31/2013 See Figure 6 Effluent Parshall Flume Warminster Fiberglass Company 18” Parshall Flume 18” Effluent Parshall Flume 1994 Unknown See Figure 7 Figure 1 WRRF Influent and Effluent Flow Chart Recorder City of San Luis Obispo Water Resource Recovery Facility Project INFLUENT & EFFLUENT FLOW MONITORING located in the bottom left and right hand corners of the chart interface, that record flow throughout the day (see Figure 1). It is the responsibility of the Unit III operator to record both numbers at 7:00 am each morning as part of the daily rounds and replace the chart with a blank one. If an operator does not record the chart values at 7:00 am every morning, the values are not as accurate. The numbers are subtracted from the previous day and multiplied by 1,000 to calculate total daily flow. The data is entered into the operational database (Ops32), where it creates an adjusted value that takes into account the flow received from the Unit IV plant drain . The Unit III operator is also responsible for recording the totalized flow displayed directly on both influent flow meters. This is done shortly after the operator goes out into the field to collect information for the daily morning rounds of that unit. The totalized volume is subtracted from the prior day’s reading and the total influent daily flow is calculated and recorded on the daily round sheets. The information cannot be found in the Ops32 database. Section 2 Flow Data Based on the adjusted influent and effluent data retrieved from Ops32, prior to the replacement of the effluent meter in 2011, the influent flow through the plant was recorded as being consistently higher than the effluent flow. Once the effluent flow meter was replaced, the discrepancy between the recorded influent and effluent flow appeared to decrease. After the influent flow meters were replaced in 2012, the recorded effluent flow consistently appeared to be higher than the recorded influent flow received by the plant. See Figure 12 through Figure 14 for graphs demonstrating 2007 through 2014 flow data in relation to time and when the meters were replaced and calibrated. The “Adjusted Daily Influent Flow” accounts for the liquid that is captured by a sump pump from the Unit IV plant drain that flows into Laguna Lift Station, and is pumped from there directly to the beginning of the treatment process. The Unit IV plant drain sump pump is typically used for process flow, an event where the Unit IV plant drain sump is typically used is when the operators need to drain one (or more) chlorine contact channels or an equalization tank. Unit IV plant drain volume is calculated multiplying the run time of the sump pump by the estimated flow rate of the pump. To avoid double counting the flow, it is subtracted from the originally recorded totalized influent flow. The effluent flow readings on the chart recorder do not take into account the water generated for reuse. Prior to entering the chlorine contact channels, the flow is split, and the majority of the flow goes to three (3) out of the four (4) chlorine contact channels, and the rest goes through a vault prior to entering the fourth disinfection channel. The recycled water tank, which stores the effluent from the fourth chlorine contact channel, has a meter that measures the volume of recycled water that has been pumped into the recycled water distribution system. The “Adjusted Effluent Flow” data adds recycled water production to the flow recorded by the effluent flow meter. Section 3 Parshall Flumes Little information about the flumes themselves is documented and the only information that was accessible at the time of writing this TM was physically visible on the flumes themselves and in the 2011 WRF Master Plan. The manufacturer information was shown on the topside lip of both the influent and City of San Luis Obispo Water Resource Recovery Facility Project INFLUENT & EFFLUENT FLOW MONITORING effluent parshall flumes. The effluent parshall flume manufacturer is “Warminster Fiberglass Company” (P.O. Box 188, South Hampton, PA 18966; phone 215‐953‐1260) and has a throat width of 18” (see Figure 15 for manufacturer drawing of flume). Figure 16 demonstrates the flow sizing that is appropriate for the 18” parshall flume (among other sizes) and it shows a maximum flow of 16 MGD. The manufacturer of the influent parshall flume with a throat width of 18” and the manufacturer is believed to be “Manning”. The known dimensions of the influent parshall flumes are the throat width, 18”, and the depth of the mouth of the flume, 36” (see Figure 8 & Figure 9 for images of the influent parshall flume ruler). Short of isolating one of the influent parshall flumes and physically measuring the dimensions, all of the dimensions of the influent parshall flumes could not be obtained. The influent parshall flume documentation that was found was in the 2011 WRF Master Plan developed by Brown and Caldwell. Figure 2 shows a portion of the 2011 WRF Master Plan that contains information regarding the influent parshall flumes. Figure 2. Brown & Caldwell 2011 Master Plan caption concerning the WRRF influent parshall flumes The “TM No. 3” referenced in the Master Plan evaluates the influent parshall flumes and it states that the two flumes have a capacity of 15.9 mgd each, for a combined capacity of 31.8 mgd. However, the approach channel is larger than it should be, which may contribute to the “waves” problem referenced above. For more information, see Appendix A for Technical Memorandum prepared by Brown & Caldwell. Section 4 Flow Meters Each flow meter has a sensor located directly above a parshall flume. Each parshall flume was built and installed as part of the 1994 upgrades. The WRRF staff has mentioned that at times in the past, and confirmed by the installation technician, that the influent flow meter sensors have moved, or tilted, away from their intended positions. They recognize that the sensor movement could also cause the data transmitted to be inaccurate. The staff takes precautions to monitor this phenomenon by periodically inspecting and tightening the clamps that hold the sensor in place. According to influent flow meter service technician, Rick Morris from MCR Technologies, when the influent flow meters are calibrated it is assumed that the influent parshall flume is made to industry parshall flume standards. City of San Luis Obispo Water Resource Recovery Facility Project INFLUENT & EFFLUENT FLOW MONITORING Sheets containing calibration dates and results for each meter are shown in Figure 17, Figure 18, and Figure 19. The links below present the operation manuals for both meters. Influent: http://www.pulsar‐pm.com/Portals/0/docs/manuals/Ultra%203%20Third%20Edition.pdf Effluent: http://www.lesman.com/unleashd/catalog/sensors/Siemens‐Milltronics‐OCM‐III/spl_0749.pdf The communication between the flow meters and the circle chart is shown in Figure 3. “PRICLAR.NO1.FLOW” AND “PRICLAR.NO2.FLOW” are the signal names for each influent meter. Figure 3. Influent Flow Meter Summation Calculator (B&C Drawings from 1994 Upgrade) Losses in flow measurement accuracy occur as the signal is converted from digital to analog to digital, then finally to the analog circle chart. Section 5 Conclusion When the effluent and influent flow meters were replaced in 2011 and 2012, respectively, the data collected by the meters demonstrated significant differences compared to the prior years. This discrepancy should be accounted for when using the flow data for analysis. In addition, there is uncertainty in the influent flow meter readings due to the factors described in this TM and in Brown & City of San Luis Obispo Water Resource Recovery Facility Project INFLUENT & EFFLUENT FLOW MONITORING Caldwell’s TM (Appendix A). The following are recommendations that could aid in improving reliable flow measurements: Install a data logger on both the influent and effluent flow meters until the planned upgrade to the SCADA system is complete. Perform annual calibration on the influent and effluent flow meters. Enter the data from the influent flow meters directly into Ops 32. This data is currently collected every morning directly from the influent flow meters as part of the morning rounds. Having the ability to compare this data to the circle chart data will help determine if there are any communication issues. Confirm the geometry of the influent parshall flumes and use the standard parshall flume calibration curves to translate and validate the flow level. Ensure that the flow meter sensors are in the correct position. In the past, the facility staff has found the influent flow meter sensors at a slight tilt, which could also contribute to the inaccuracies of the data. Investigate options to retrofit parshall flumes and/or improve upstream and downstream conditions to increase accuracy. City of San Luis Obispo Water Resource Recovery Facility Project INFLUENT & EFFLUENT FLOW MONITORING Figure 4. Influent Flow Monitoring Device (FIT‐150) Figure 5. Location of Influent flow monitor in relation to the parshall flumes Figure 6. Effluent flow monitor Figure 7. Effluent flow monitor in relation to the parshall flume City of San Luis Obispo Water Resource Recovery Facility Project INFLUENT & EFFLUENT FLOW MONITORING Figure 8. Influent Flow Meter Ultrasonic Sensor & Flume Ruler Figure 9. Influent Parshall Flume Ruler Fi g u r e 10 . Lo c a t i o n of In f l u e n t an d Ef f l u e n t Fl o w Me t e r s at th e WR R F LE G E N D = In f l u e n t Fl o w Me t e r s = Ef f l u e n t Fl o w Me t e r Ci t y of Sa n Lu i s Ob i s p o Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t IN F L U E N T & EF F L U E N T FL O W MO N I T O R I N G Fi g u r e 11 . Ad j u s t e d da i l y in f l u e n t an d ef f l u e n t fl o w da t a fr o m Ja n u a r y 1, 20 1 0 th r o u g h Se p t e m b e r 30 , 20 1 4 0. 0 0 2. 0 0 4. 0 0 6. 0 0 8. 0 0 10 . 0 0 12 . 0 0 14 . 0 0 16 . 0 0 1/1/2010 1/31/2010 3/2/2010 4/1/2010 5/1/2010 5/31/2010 6/30/2010 7/30/2010 8/29/2010 9/28/2010 10/28/2010 11/27/2010 12/27/2010 1/26/2011 2/25/2011 3/27/2011 4/26/2011 5/26/2011 6/25/2011 7/25/2011 8/24/2011 9/23/2011 10/23/2011 11/22/2011 12/22/2011 1/21/2012 2/20/2012 3/21/2012 4/20/2012 5/20/2012 6/19/2012 7/19/2012 8/18/2012 9/17/2012 10/17/2012 11/16/2012 12/16/2012 1/15/2013 2/14/2013 3/16/2013 4/15/2013 5/15/2013 6/14/2013 7/14/2013 8/13/2013 9/12/2013 10/12/2013 11/11/2013 12/11/2013 1/10/2014 2/9/2014 3/11/2014 4/10/2014 5/10/2014 6/9/2014 7/9/2014 8/8/2014 9/7/2014 Flow (MGD) Fl o w Me t e r Da t a 20 1 0 ‐20 1 4 Ad j u s t e d Da i l y In f l u e n t Fl o w Ad j u s t e d Da i l y Ef f l u e n t Fl o w Effluent Flow Meter Replaced Influent Flow Meters Replaced Meters Calibrated Ci t y of Sa n Lu i s Ob i s p o Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t IN F L U E N T & EF F L U E N T FL O W MO N I T O R I N G Fi g u r e 12 . Ad j u s t e d da i l y in f l u e n t an d ef f l u e n t fl o w 5‐da y mo v i n g av e r a g e fr o m Ja n u a r y 1, 20 1 0 th r o u g h Se p t e m b e r 30, 2014 0. 0 0 2. 0 0 4. 0 0 6. 0 0 8. 0 0 10 . 0 0 12 . 0 0 1/1/2010 1/31/2010 3/2/2010 4/1/2010 5/1/2010 5/31/2010 6/30/2010 7/30/2010 8/29/2010 9/28/2010 10/28/2010 11/27/2010 12/27/2010 1/26/2011 2/25/2011 3/27/2011 4/26/2011 5/26/2011 6/25/2011 7/25/2011 8/24/2011 9/23/2011 10/23/2011 11/22/2011 12/22/2011 1/21/2012 2/20/2012 3/21/2012 4/20/2012 5/20/2012 6/19/2012 7/19/2012 8/18/2012 9/17/2012 10/17/2012 11/16/2012 12/16/2012 1/15/2013 2/14/2013 3/16/2013 4/15/2013 5/15/2013 6/14/2013 7/14/2013 8/13/2013 9/12/2013 10/12/2013 11/11/2013 12/11/2013 1/10/2014 2/9/2014 3/11/2014 4/10/2014 5/10/2014 6/9/2014 7/9/2014 8/8/2014 9/7/2014 Flow (MGD) Fl o w Me t e r Da t a 20 1 0 ‐20 1 4 Ad j u s t e d In f l u e n t (5 ‐da y mo v i n g av e r a g e ) Ad j u s t e d Ef f l u e n t (5 ‐da y mo v i n g av e r a g e ) Effluent Flow Meter Replaced Influent Flow Meters Replaced Meters Calibrated Ci t y of Sa n Lu i s Ob i s p o Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t IN F L U E N T & EF F L U E N T FL O W MO N I T O R I N G Fi g u r e 13 . Pe r c e n t (% ) Di f f e r e n c e be t w e e n Ad j u s t e d Ef f l u e n t Fl o w an d Ad j u s t e d In f l u e n t Fl o w Fi g u r e 14 . Di f f e r e n c e be t w e e n ad j u s t e d in f l u e n t an d ef f l u e n t fl o w da t a re c o r d e d fr o m Oc t o b e r 1, 20 0 7 th r o u g h Se p t e m b e r 30, 2014 ‐0. 6 ‐0. 4 ‐0. 2 0 0. 2 0. 4 0. 6 0. 8 1 10/1/2007 11/30/2007 1/29/2008 3/29/2008 5/28/2008 7/27/2008 9/25/2008 11/24/2008 1/23/2009 3/24/2009 5/23/2009 7/22/2009 9/20/2009 11/19/2009 1/18/2010 3/19/2010 5/18/2010 7/17/2010 9/15/2010 11/14/2010 1/13/2011 3/14/2011 5/13/2011 7/12/2011 9/10/2011 11/9/2011 1/8/2012 3/8/2012 5/7/2012 7/6/2012 9/4/2012 11/3/2012 1/2/2013 3/3/2013 5/2/2013 7/1/2013 8/30/2013 10/29/2013 12/28/2013 2/26/2014 4/27/2014 6/26/2014 8/25/2014 % Di f f e r e n c e in Fl o w 20 0 7 ‐20 1 4 % Di f f e r e n c e ‐4. 0 ‐2. 0 0. 0 2. 0 4. 0 6. 0 Million Gallons Per Day Difference Di f f e r e n c e in Fl o w 20 0 7 ‐20 1 4 Ad j u s t e d : In f l u e n t ‐ Ef f l u e n t Ef f l u e n t Fl o w Me t e r Re p l a c e d Ef f l u e n t Fl o w Me t e r Re p l a c e d In f l u e n t Fl o w Me t e r s Re p l a c e d In f l u e n t Fl o w Me t e r s Re p l a c e d Al l Meters Ca l i b r a t e d Al l Meters Ca l i b r a t e d Ci t y of Sa n Lu i s Ob i s p o Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t IN F L U E N T & EF F L U E N T FL O W MO N I T O R I N G Fi g u r e 15 . Ef f l u e n t Pa r s h a l l Fl u m e Ma n u f a c t u r e r Dr a w i n g (W a r m i n s t e r Fi b e r g l a s s ) Figure 16. Warminister Sizing Guide for Parshall Flumes (sizing is based on throat width) City of San Luis Obispo Water Resource Recovery Facility Project INFLUENT & EFFLUENT FLOW MONITORING Figure 17. Influent Flow Meter (AG‐FIT‐150) Certificate of Calibration City of San Luis Obispo Water Resource Recovery Facility Project INFLUENT & EFFLUENT FLOW MONITORING Figure 18. Influent Flow Meter (AG‐FIT‐250) Certificate of Calibration City of San Luis Obispo Water Resource Recovery Facility Project INFLUENT & EFFLUENT FLOW MONITORING Figure 19. Effluent Flow Meter Certificate of Calibration Fi g u r e 20 . Si t e La y o u t of Pa r s h a l l Fl u m e s re l a t i v e to th e ae r a t e d gr i t ta n k s City of San Luis Obispo Water Reclamation Facility Technical Memorandum 3 – Evaluation of Influent Parshall Flumes Prepared By: Brown and Caldwell Date: March 2004 Introduction Background Brown and Caldwell has been retained by the City of San Luis Obispo to prepare an update to the Master Plan for the City’s Water Reclamation Facility (WRF). The City asked Brown and Caldwell (BC) staff to investigate the performance of the influent Parshall flumes and make recommendations. Information has been supplied by City staff, and BC staff has been able to observe the performance of the influent Parshall flumes. BC staff have analyzed the design and evaluated the flumes’ performance. This technical memorandum summarizes the results of our evaluation. Statement of Problem The influent Parshall flumes have a hydraulic constraint at the downstream end, that causes surging through the flumes at high flow rates. Observations 1. There may be air binding in the outlet pipe leading from the southerly flume to Primary Clarifier 2 (west clarifier) due to adverse piping grades and/or lack of an air break prior to diving down to go under the clarifier to the center well inlet. Air could easily be entrained in the flow exiting the flumes and then carried into the outlet pipes where it would coalesce and form a large bubble where the outlet pipe dives down due to a grade change. 2. There likely are restrictions in both clarifier inlet pipes caused by significant deposition that built up over 12 to 60 years as a result of the normally extremely low flow velocities (0.85 fps in both 30” clarifier inlet pipes at 5.5 mgd AWSF). These deposits would be extremely difficult to remove. 23960--03/29/04 1 Appendix A City of San Luis Obispo Water Reclamation Facility TM 3 – Evaluation of Influent Parshall Flumes 3. Because of the possible air binding and the almost certain flow restrictions due to deposits, it is EXTREMELY unlikely that the clarifier inlet pipes have the capacity required to meet the year 2015 PWWF (32 MGD). In fact, these restrictions would result in significant flows bypassing the primary clarifiers and thereby not receiving primary treatment. 4. Portions of the oldest clarifier inlet pipes, including all pipe under the clarifiers, are A.B. corrugated metal pipe that is not encased in concrete. It is extremely likely that the steel has corroded away leaving only the asphalt bitumastic lining/coating over rust. (This writer has witnessed this phenomenon.) If this old pipe is cleaned to remove internal deposits, by a polyjet or other pigging device, the entire pipe may disintegrate and collapse. 5. Flume inlet conditions are poor, with two abrupt 90° turns and apparently excessively wide approach channels. Flume submittals were located. The flumes are standard and have a throat width “W” of 1’-6”, which allows a maximum flow rate of 15.9 mgd. Therefore, two flumes would have a combined capacity of 31.8 mgd, which approximates the year 2015 PWWF design flow rate of 32 mgd. Since “W” = 1’-6”, the maximum width of the approach channel should be 5’-6”. However, the approach channel is 6’-3” wide and this may be contributing to the reported “waves” problem. 6. Upstream channel agitation air, which is introduced through shear box diffusers in the floor of the grit tanks effluent channel, may be producing waves that are being reflected downstream and through the flumes. 7. The primary clarify pipe inlets just downstream of the flumes do not have the best configuration for a smooth transition from the flume outlets to the pipe inlets. The inlets do not appear to line up with the flumes. The channel floor is flat with abrupt pipe inlets (no flared pipe inlets). Better transitions would reduce headloss at this location. Recommended Modifications 1. Waves Problem: Verify if shear box diffusers are contributing to the “waves” problem. First turn off the middle diffuser between column lines 2 and 3 (see Unit 3 Improvements drawing 2M101) and observe the response. If that has minimal or no effect, then also turn off the first adjacent northerly and southerly shear box diffusers (3 diffusers off line) and observe the response. If this has minimal or no effect, the approach channels may need to be narrowed temporarily (e.g., using wood) to see if that helps. This approach should be tested with and without the above shear box diffusers being in service. The approach channels should not be permanently narrowed (e.g., with concrete) unless the temporary approach produces satisfactory results. 2. Surging: a. Replace all A.B. corrugated primary clarifier inlet pipes, including pipe under the floors of both clarifiers. Clean newer pipes. b. Construct an air break on the Primary Clarifier 2 (west) inlet pipe, likely adjacent to the existing air break on the Primary Clarifier 1 inlet pipe. 23960--03/29/04 2 Appendix A City of San Luis Obispo Water Reclamation Facility TM 3 – Evaluation of Influent Parshall Flumes c. Break out approximately a 42” square section of the floor of each flume channel just downstream of the flume outlet and including the primary clarifier inlet pipe, and reconstruct a flared inlet into each primary clarify inlet pipe. The entrance to the new inlet should line up with the center of the flume outlet. Include straightening vanes in the flared inlets. The goal is to minimize headloss at the inlets; to assure a free discharge from the flumes to the pipe inlets at higher flow rates; and to prevent vortex formation at the pipe inlets, which would aspirate air into the flow. d. Perform maintenance on all clarifier mechanical equipment while the clarifier is out of service to replace the inlet pipe. Replace worn mechanical and structural items, and sandblast and paint equipment. Estimate of Probable Construction Cost The estimate of probable construction cost is based on implementing all recommended modifications, and does not include engineering, construction management, administration or mobilization/demobilization costs, but does include a construction contingency of 30 percent and a construction cost escalation factor to anticipated 2005 dollars. Note that the contingency amount may need to be increased depending on the size and complexity of an individual project. The estimate includes industry standard markups on labor, materials, equipment and subcontractors and for general conditions (less mobilization/demobilization), taxes, bonds, shipping and handling, travel and subsistence, insurance, and startup, training and O&M. Division 1..............................................................$ 7,648 Division 2...............................................................92,869 Division 3...............................................................21,217 Division 5.................................................................3,809 Division 9...............................................................30,874 Division 15.............................................................91,063 Markups...............................................................116,831 Subtotal.............................................................$ 379,486 Contingency.........................................................113,846 Escalation.................................................................8,536 TOTAL............................................................$ 501,868 23960--03/29/04 3 Appendix A City of San Luis Obispo Water Reclamation Facility TM 3 – Evaluation of Influent Parshall Flumes 23960--03/29/04 4 Appendix A City of San Luis Obispo Water Reclamation Facility TM 3 – Evaluation of Influent Parshall Flumes 23960--03/29/04 5 Appendix A City of San Luis Obispo Water Reclamation Facility TM 3 – Evaluation of Influent Parshall Flumes 23960--03/29/04 6 Appendix A City of San Luis Obispo Water Reclamation Facility TM 3 – Evaluation of Influent Parshall Flumes 23960--03/29/04 7 Appendix A City of San Luis Obispo Water Reclamation Facility TM 3 – Evaluation of Influent Parshall Flumes 23960--03/29/04 8 Appendix A City of San Luis Obispo Water Reclamation Facility TM 3 – Evaluation of Influent Parshall Flumes 23960--03/29/04 9 Appendix A City of San Luis Obispo Water Reclamation Facility TM 3 – Evaluation of Influent Parshall Flumes 23960--03/29/04 10 Appendix A Appendix J TM No. 9.2 - Influent Hydrograph Simulation for the WRRF Date: 11/4/2014 To: Carrie Mattingly Phone: (805) 781‐7205 Utilities Director 879 Morro St. San Luis Obispo, CA 93401 CC: Dave Hix; Howard Brewen; Pam Ouellette Prepared by: Jeanine Genchanok, EIT Reviewed by: Jeroen Olthof, PE; Jeffery Szytel, PE; Lianne Williams, PE Project: Water Resource Recovery Facility (WRRF) Project SUBJECT: TM No. 9.2 - INFLUENT HYDROGRAPH SIMULATION FOR THE WRRF ‐ FINAL The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long‐term strategy for resource management. In addition, as part of the Wastewater Collection System Infrastructure Renewal Strategy (WCSIRS), Water Systems Consulting, Inc. (WSC) has developed a hydraulic model to evaluate the capacity of the collection system pipelines. This Technical Memorandum (TM) describes WSC’s development and calibration of the sewer system hydraulic model to simulate the influent hydrograph at the WRRF under various conditions. The purpose of this TM is to describe the modeling process and provide the calculated influent hydrograph at the WRRF for the 10‐yr, 24‐hour design storm. This TM is organized in the following sections: Contents Section 1. Model Development and Calibration ........................................................................................... 2 Section 2. Modeled Hydrographs at the WRRF: System‐Wide RTK Values .................................................. 4 Section 3. Modeled Hydrographs at the WRRF: Basin Specific RTKs .......................................................... 10 Section 4. 10‐Year, 24‐Hour Design Storm ................................................................................................. 14 Section 5. Recommendations ..................................................................................................................... 17 Section 6. References .................................................................................................................................. 17 WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 2 of 17 Section 1. Model Development and Calibration The hydraulic model of the City’s collection system was updated in SewerGEMS (Bentley®) to include elevations for manhole inverts that had not been previously surveyed. Missing invert elevations were interpolated between surveyed values or estimated using an assumed minimum slope. Basins were defined in the model, using the flow monitor basins defined in the 2012 V&A Sanitary Sewer Flow Monitoring and Inflow/Infiltration Study. In some cases the basin boundaries were adjusted based on updated collection system information gathered as part of the WCSIRS project. Each basin was assigned an outlet manhole where the basin’s flow was added to the system. Figure 1 provides a sample observed hydrograph for monitoring location A.2 (manhole HO6‐5: 269 Craig Way) corresponding to the inflow for basin A.2. On the graph, rainfall is shown in the blue bars on an inverted scale. The solid black line represents the total observed flow at the meter. The dashed black line is the estimated dry weather flow at the monitoring site, based on measurements taken during periods with no rain. The area between the solid black line and the dashed black line represents the rainfall‐derived infiltration and inflow and is shaded a light green. Figure 1. Sample Rainfall and Flow Data Provided by V&A WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 3 of 17 The hydraulic model was used to simulate the collection system’s response to rainfall events. For the WRRF Project, the team developed sets of response factors using the three‐triangle R‐T‐K method. This method involves creating a synthetic unit hydrograph based on the summation of three triangles. The first RTK triangle corresponds to rapid inflow, the second to moderate infiltration, and the third to slow infiltration. Each triangle is defined by three variables: R is the percentage of rainfall that becomes rainfall derived inflow and infiltration (RDII) T is the time from when the rain falls to the peak of the RDII K is a lag coefficient that describes how long RDII continues to enter the system. The time from the peak RDII until the end of the RDII is equal to K * T An illustration of a synthetic unit hydrograph derived from three triangles is shown in Figure 2. Figure 2. Example Synthetic Unit Hydrograph Using R‐T‐K Triangles The unit hydrograph is used to simulate the response to a unit (one inch) of rainfall. For each of the three triangles, T is the time in hours until the peak of the triangle; the recession limb of the triangle has a duration of K * T; and the area under the triangle is R. With three factors (R, T, and K) for each of three triangles, a total of nine factors define a set of response factors. Through iterative model simulations, WSC developed sets of response factors to calculate a hydrograph of expected flow in response to a rainfall event. Figure 3 illustrates an example of RTK values assigned for a basin within SewerGEMS. 0 0.05 0.1 0.15 0.2 0.25 051015202530 Fl o w in Re s p o n s e to Un i t of Ra i n f a l l Time (Hours) Triangle 1 Triangle 2 Triangle 3 Combined Unit Hydrograph WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 4 of 17 Figure 3. Sample Basin Parameters The four rainfall events from the V&A study were applied to the hydraulic model, and hydrographs were generated for each basin and for the influent hydrograph to the WRRF. WSC also used the model to simulate additional rainfall events in January and March of 2011. Section 2. Modeled Hydrographs at the WRRF: System‐Wide RTK Values Initially WSC focused on developing a system‐wide set of RTK values that could be used to calculate a response hydrograph from all the basin’s. WSC ran an extended simulation for a five‐day period. WSC first simulated dry weather flow to the WRRF. The modeled hydrograph for dry weather flow was compared to observed dry‐weather flow data from April 7‐11, 2014 as shown in Figure 4. WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 5 of 17 Figure 4. Observed and Modeled Dry Weather Flow at the WRRF Figure 5. Observed and Modeled Cumulative Dry Weather Flow at the WRRF There was generally good agreement between the modeled and observed dry weather flows. WSC then ran the model to simulate two rainfall events: the March 19th‐20th, 2011 rainfall event (4.38 inches of rain over 48 hours) and the January 1st‐5th, 2011 rainfall event (2.6 inches of rain over the first 0 1 2 3 4 5 6 7 020406080100120 MG D Time (hours) Modeled Observed 0 2 4 6 8 10 12 14 16 18 20 0 20 40 60 80 100 120 Cu m u l a t i v e Fl o w (M i l l i o n Ga l l o n s ) Time (hours) Modeled Observed WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 6 of 17 48 hours). The calculated hydrographs at the plant for present conditions were compared to observed flow values that were transcribed from the circle chart data by HDR. Table 1 lists RTK values that were found to best match modeled and observed flows for the March 2011 rainfall event. Table 1. RTK Set 1 R1 0.008 R2 0.008 R3 0.025 T1 1 T2 6 T3 24 K1 1 K2 2 K3 3 The model results using RTK Set 1 appeared to be in reasonable agreement with the observed flows from the March 2011 event and for the first part of the January 2011 event. However, the January 2011 event showed an extended response of elevated flows for several days after the peak rainfall, with no additional rainfall recorded. It is not clear if these results are due to inaccurate flow measurements or if elevated groundwater levels due to the wet winter caused an extended response. WSC developed a second set of RTK values to generate a modeled response that matched the observed response for the January 2011 event. These values are shown in Table 2. Table 2. RTK Set 2 R1 0.01 R2 0.01 R3 0.04 T1 2 T2 6 T3 24 K1 1 K2 2 K3 3 A flow comparison and a cumulative flow analysis for each RTK set are illustrated in the figures below. WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 7 of 17 Figure 6. Observed and Modeled Flow at the WRRF for the March, 2011 Rainfall Event using RTK Set 1 Figure 7. Observed and Modeled Cumulative Flow at the WRRF for the March, 2011 Rainfall Event using RTK Set 1 0 1 2 3 4 50 5 10 15 20 25 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) March 2011 March 2011 Rainfall Modeled Flow at the WRRF Observed Flow at the WRRF 0 5 10 15 20 25 30 35 40 45 020406080100120 Cu m u l a t i v e Fl o w (M i l l i o n Ga l l o n s ) Time (hours) March, 2011 Modeled Observed WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 8 of 17 Figure 8. Observed and Modeled Flow for the January, 2011 Rainfall Event using RTK Set 1 Figure 9. Observed and Modeled Cumulative Flow at the WRRF for the January, 2011 Rainfall Event using RTK Set 1 0 1 2 30 5 10 15 20 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) January, 2011 January 2011 Rainfall Modeled Flow at the WRRF Observed Flow at the WRRF 0 10 20 30 40 50 60 020406080100120 Cu m u l a t i v e Fl o w (M i l l i o n Ga l l o n s ) Time (hours) January, 2011 Observed Modeled WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 9 of 17 Figure 10. Observed and Modeled Flow at the WRRF for January, 2011 Event using RTK Set 2 Figure 11. Observed and Modeled Cumulative Flow at the WRRF for January, 2011 Event using RTK Set 2 0 1 2 30 5 10 15 20 25 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) January, 2011 January 2011 Rainfall Modeled Flow at the WRRF Observed Flow at the WRRF 0 10 20 30 40 50 60 020406080100120 Cu m u l a t i v e Fl o w (M i l l i o n Ga l l o n s ) Time (hours) January, 2011 Observed Modeled WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 10 of 17 Figure 12. Observed and Modeled Flow at the WRRF for March, 2011 Event using RTK Set 2 Figure 13. Observed and Modeled Cumulative Flow at the WRRF for March, 2011 Event using RTK Set 2 Section 3. Modeled Hydrographs at the WRRF: Basin‐Specific RTK Sets After reviewing and discussing the results obtained with the system‐wide RTK sets, WSC developed individual RTK sets for each basin to better simulate the response to varying storm events within each basin. For each basin, WSC developed a set of response factors that best matched the observed response across both of the storm events as presented in the basin‐specific hydrographs prepared by V&A. Basins are illustrated in Figure 14 below. In addition, constant values of groundwater infiltration were added to select basins to model elevated flows not related to a specific storm event. The calculated hydrographs using the basin‐specific RTK values are shown in the following figures. 0 1 2 3 4 50 5 10 15 20 25 30 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) March 2011 March 2011 Rainfall Modeled Flow at the WRRF Observed Flow at the WRRF 0 10 20 30 40 50 60 020406080100120 Cu m u l a t i v e Fl o w (M i l l i o n Ga l l o n s ) Time (hours) March, 2011 Modeled Observed WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 11 of 17 Figure 14. Basin Areas Map WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 12 of 17 Figure 15. Observed and Modeled Flow at the WRRF for January, 2011 Event using Basin‐Specific RTK Sets Figure 16. Observed and Modeled Cumulative Flow at the WRRF for January, 2011 Event using Basin‐ Specific RTK Sets 0 1 2 30 5 10 15 20 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) January, 2011 January 2011 Rainfall Modeled Flow at the WRRF Observed Flow at the WRRF 0 10 20 30 40 50 60 020406080100120 Cu m u l a t i v e Fl o w (M i l l i o n Ga l l o n s ) Time (hours) January, 2011 Observed Modeled WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 13 of 17 Figure 17. Observed and Modeled Flow at the WRRF for March, 2011 Event using Basin‐Specific RTK Sets Figure 18. Observed and Modeled Cumulative Flow at the WRRF for March, 2011 Event using Basin‐ Specific RTK Sets 0 1 2 3 4 50 5 10 15 20 25 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) March, 2011 March 2011 Rainfall Modeled Flow at the WRRF Observed Flow at the WRRF 0 5 10 15 20 25 30 35 40 45 50 020406080100120 Cu m u l a t i v e Fl o w (M i l l i o n Ga l l o n s ) Time (hours) March, 2011 Modeled Observed WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 14 of 17 Section 4. 10‐Year, 24‐Hour Design Storm The calibrated model was used to generate a hydrograph at the WRRF for the 10‐yr, 24‐hr design storm. The design storm precipitation profile was developed by V&A and is shown in Figure 19. Figure 19. 10‐yr, 24‐hr Design Storm Precipitation Profile (V&A) The model was run using current development and build‐out conditions (as defined for the capacity analysis in the WCSIRS project). A summary of peak flows for dry and wet weather for present and future (build‐out) conditions using the three different RTK sets is shown in Table 3 and illustrated in Figures 20‐22. A comparison of the hydrographs calculated using different RTK parameters is illustrated in Figure 23. WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 15 of 17 Table 3. Model Flow Summary Current Peak Dry Weather Flow (MGD) 5.80 Build Out Peak Dry Weather Flow (MGD) 9.15 RTK Set 1 RTK Set 2 Basin‐Specific RTK Sets Current PWWF (MGD) 31.41 36.00 32.18 Build Out PWWF (MGD) 32.11 36.74 33.49 Figure 20. Modeled 10‐Yr, 24‐hr Design Storm using RTK Set 1 Figure 21. Modeled 10‐Yr, 24‐hr Design Storm using RTK Set 2 0 1 2 3 4 50 5 10 15 20 25 30 35 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) 10‐yr, 24‐hr Design Storm Rainfall Modeled Current Conditions Build_Out Conditions Dry Weather Flow (Build Out Conditions) Dry Weather Flow (Current Conditions) 0 1 2 3 4 50 5 10 15 20 25 30 35 40 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) 10‐yr, 24‐hr Design Storm Rainfall Modeled Current Conditions Build_Out Conditions Dry Weather Flow (Build Out Conditions) Dry Weather Flow (Current Conditions) WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 16 of 17 Figure 22. Modeled 10‐Yr, 24‐hr Design Storm using Basin‐Specific RTK Sets Figure 23. Comparison of Build Out Flows 0 1 2 3 4 50 5 10 15 20 25 30 35 40 020406080100120 Ra i n f a l l (i n / h r ) Fl o w (M G D ) Time (hours) 10‐yr, 24‐hr Design Storm Rainfall Modeled Current Conditions Build_Out Conditions Dry Weather Flow (Build Out Conditions) Dry Weather Flow (Current Conditions) 0 5 10 15 20 25 30 35 40 020406080100120 Fl o w (M G D ) Time (hours) RTK Set 1, Build Out 10‐Yr Storm RTK Set 2‐ Build Out 10‐Yr Storm Basin Specific RTK Set, Build Out 10‐Yr Storm WRRF Project Influent Hydrograph Simulation for the WRRF ‐ FINAL Page 17 of 17 Section 5. Recommendations This TM describes two rounds of analysis to simulate wastewater flow responses at the WRRF. In Round 1, hydrographs were calculated using two different sets of RTK factors to simulate the wastewater flow response to two specific rain events (January, 2011 and March, 2011). In Round 2, hydrographs were calculated using unique RTK parameters for each basin rather than a uniform system‐wide set. In addition, Round 2 included the addition of groundwater infiltration to some basins to reflect higher flows during the wet season that were not related to a specific storm event. It is recommended that the City consider taking the following steps: Perform additional flow monitoring this winter with a goal of capturing flow data for more storm events. Use the model with the basin‐specific RTK sets for future analysis. The basin‐specific RTK sets were developed to match the observed response across multiple storm events. The calculated hydrograph at the WRRF using the basin‐specific RTK sets appears reasonable in light of operator experience and previous studies. Section 6. References 1. V&A. Sanitary Sewer Flow Monitoring and Inflow/Infiltration Study. 2012 Appendix K TM No. 9.3 - Wet Weather Flow Equalization Page 1 of 19 Date: 5/19/2015 Prepared by: Matt Chapman, PE Reviewed by: Holly Kennedy, PE; Jeff Szytel, PE Project: WRRF Project SUBJECT: TM NO. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long-term strategy for resource management. The purpose of this technical memorandum (TM) is to describe the analysis of the flow equalization optimization analysis that was conducted and the recommendations to be implemented as part of future WRRF upgrades. Contents Introduction ................................................................................................................................. 2 Influent Characteristics .............................................................................................................. 3 Flow Hydrograph ...................................................................................................................................... 3 Consecutive Storm Events ................................................................................................................... 3 Frequency of Occurrence ......................................................................................................................... 4 Water Quality during Storm Events .......................................................................................................... 5 Approach ..................................................................................................................................... 5 Storage Sizing .......................................................................................................................................... 5 Impacts on Downstream Processes ......................................................................................................... 6 Operations & Maintenance ................................................................................................................... 7 Dormant Equipment.............................................................................................................................. 7 Hydraulics .................................................................................................................................... 8 Flow Equalization Facilities ....................................................................................................... 9 Storage Reservoir Construction ............................................................................................................... 9 Feed/Drain Pumping ............................................................................................................................... 10 Mixing...................................................................................................................................................... 10 Aeration .................................................................................................................................................. 10 Pump Out to Treatment ...................................................................................................................... 10 Odor Control ........................................................................................................................................... 11 Other Considerations ............................................................................................................... 12 Geotechnical ........................................................................................................................................... 12 Earth Materials ................................................................................................................................... 12 Ground Water ..................................................................................................................................... 12 Siting ....................................................................................................................................................... 12 WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 2 of 19 Use for Diurnal Equalization ................................................................................................................... 14 Height Limitations ................................................................................................................................... 14 Alternative Analysis .................................................................................................................. 14 Recommended Equalization Facility ....................................................................................... 18 Introduction The influent flow of domestic wastewater to the San Luis Obispo Water Resource Recovery Facility (WRRF) is highly influenced by rainfall-derived infiltration and inflow (RDII) in the collection system. Flow projections indicate that while future average dry weather flows may be approximately 5.4 million gallons per day (MGD), the peak wet-weather flows associated with a 10-yr storm event could be closer to 32 MGD. This average to peak ratio of 6:1 is significant. With such large swings in flow rate, equalization facilities can be beneficial. The alternative is to provide additional treatment capacity to handle these sporadic wet weather peaks. The associated cost of the equalization (EQ) facilities can potentially be offset by savings in the downstream processes. The purpose of this memorandum is to evaluate wet-weather flow equalization options for the WRRF, present sizing criteria, and recommend an equalization strategy that optimizes the overall cost and environmental benefit of new facilities. The evaluation includes both initial capital investment and long-term impacts on maintenance for both the equalization facility and the downstream treatment facilities. The WRRF currently has a 4 million gallon (MG) EQ pond (see Figure 1) and an associated return flow pumping system. The existing pond requires relining and some earthwork to raise the perimeter berm above the 100-yr flood elevation. Continued use of this facility should be considered a “baseline” alternative. The cost of the repairs and improvements could be credited to other alternatives if they do not involve maintaining the existing pond. Improvement options considered here will be for equalization capacity greater than is currently available. The processes downstream of the equalization facility that may benefit from reduced peak flows include aeration basins, final clarifiers, filter influent pumping, filters, and Figure 1. Existing Flow Equalization Basin at the WRRF WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 3 of 19 disinfection. The impact on these facilities is largely based on the design “averaging period” because facilities that are designed for “Peak Hour” are more likely to benefit from equalized flows. Influent Characteristics Flow Hydrograph For future conditions, the City’s collection system hydraulic model was used to develop influent hydrographs that include inflow and infiltration (I/I) in addition to future baseline flows. Model hydrographs were developed for the January and March 2011 historic rain events as well as for the design storm event, which is defined as the 10-year, 24-hour storm (hydrograph is illustrated in Figure 2).1 This design storm produces 4.16 inches of rain. Consecutive Storm Events Flow equalization sizing is determined almost entirely by the influent flow pattern and the subsequent pump-out rate. If the pump-out period is extended then there is an increased potential that a subsequent storm event could occur before the full equalization volume is again available. A review of the historical rainfall gage data indicates that consecutive large events have occurred in the past, although infrequently. Over the past 54 years (period of record reviewed 1960 – 2014) there have been 7 events that have had rainfall depth greater than 4.16 inches over a 24-hour period, as summarized below. Event Date 24-HR Rainfall Accumulation 2/10/1963 ................................. 4.67 Inches 1/19/1969 ................................. 4.93 Inches 1/20/1969 ................................. 5.60 Inches 1/25/1969 ................................. 5.90 Inches 1/19/1973 ................................. 4.25 Inches 3/2/1974 ................................. 4.26 Inches 2/13/1986 ................................. 4.74 Inches Large storms on consecutive days have occurred once in the 54 years of record, in 1969. While this scenario is too infrequent to drive an investment in substantial facilities to store or treat the flow, consideration should be given to at least hydraulically pass the flow through the plant as a preferable alternative to overflowing within the plant. 1 HDR (2014) Draft Facility Plan – TM 9: Capacity Consideration Study. Prepared for the City of San Luis Obispo. San Luis Obispo, CA. WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 4 of 19 Figure 2. Projected Future Un-Equalized Raw Influent Flow to the WRRF, 10-year Storm Frequency of Occurrence With increasing size of equalization capacity and associated reduction in design capacity of downstream treatment facilities, it is expected that the equalization facility would be utilized more frequently. This is because smaller, more frequently occurring storms will exceed the rated treatment capacity and thus need to be equalized. This greater frequency of equalizing events is an important consideration when deciding, for example, what type and to what extent to provide odor control. In order to do the optimization analysis, peak flows were considered based on various build-out averaging periods: Draft Facility Plan (Maximum Day): flows greater than 17 mgd diverted to the flow equalization basin Maximum 2-Days: flows greater than 15.2 mgd diverted to flow equalization Maximum 3-Days: flows greater than 13.9 mgd diverted to flow equalization Maximum 5-Days: flows greater than 12.1 mgd diverted to flow equalization Maximum Week: flows greater than 11.4 mgd diverted to flow equalization Figure 3 illustrates the equalized influent flows for the three averaging periods considered. The flat region of the curves is representative of the period that the equalization basins are in use, either filling or draining. This in-service period grows in duration for each averaging period. The number included in parentheses in the legend indicates the associated equalization volume as described further in the following section. 0 mgd 5 mgd 10 mgd 15 mgd 20 mgd 25 mgd 30 mgd 35 mgd 40 mgd 024487296120144168192216240 In f l u e n t t o H e a d w o r k s Elapsed Time (Hours) WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 5 of 19 Figure 3. Equalized Influent Flow for Various Averaging Periods, 10-year 24-hr Storm. Water Quality during Storm Events During periods of heavy infiltration, the wastewater strength can potentially be more dilute than during dry weather periods. However, higher velocity in the collection system during these storm events has a tendency to re-suspend and flush sediments that have accumulated during dry weather conditions. The impact on wastewater strength of this flushing effect has not been specifically quantified for the WRRF and so for the purpose of this analysis it was conservatively assumed that the wastewater solids and BOD concentrations do not change during a wet- weather event. Approach Storage Sizing The storage volume calculation is based on the following assumptions: 1. During the pump-out phase of operation, the EQ basin pumping rate will be balanced with the plant influent to maximize the rated throughput of the downstream facilities. This minimizes the time that sewage is stored and returns the facility to a “ready-state” as soon as possible. 2. Total volume calculations include 1.5 FT of freeboard 3. In every alternative it is assumed that the storage facility is constructed to be protected from inundation during the 100-YR flood event. 0 mgd 5 mgd 10 mgd 15 mgd 20 mgd 25 mgd 30 mgd 35 mgd 40 mgd 024487296120144168192216240 In f l u e n t t o P r i m a r y C l a r i f i e r s Elapsed Time (Hours) Influent Hydrograph (No EQ) Max Day (4 MG) Max 2-Day (7 MG) Max 3-Day (9 MG) WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 6 of 19 Impacts on Downstream Processes Table 1 presents the liquid stream treatment processes and their associated design averaging periods. Those facilities designed for Peak Hour (PH) could benefit from flow equalization. Influent Pumping, Screening and Grit Removal will be designed for peak flow as pre-treatment for the equalization facility. Table 1. Liquid Stream Treatment Unit Capacity Criteria(a) Unit Process Units Capacity Criteria Averaging Period Source Pumping Stations mgd Firm pumping capacity or ability to bypass/divert PH HDR Criteria Screens mgd Firm treatment capacity or ability to bypass/divert PH HDR Criteria Grit Removal min 3 PH Water Environment Federation Manual of Practice 8 Primary Clarifiers – Detention Time hr 2.0 AA HDR Criteria Primary Clarifiers – Surface Overflow Rate gpd/sf 1,250 MM HDR Criteria Primary Clarifiers – Peak Surface Overflow Rate gpd/sf 2,500 PH HDR Criteria Aeration Basins – MLSS mg/L 3,500 MM HDR Criteria Aeration Basins – Oxygen Uptake Rate (OUR) mg/L/hr 70 MM HDR Criteria Secondary/Final Clarifiers gpd/sf 1,200 MD HDR Criteria Secondary/Final Clarifiers lb/d/sf 30 MM HDR Criteria RAS % 100 MM HDR Criteria Filtration – Average Loading Rate gpm/sf 5 AA For periods of water reclamation; 1 unit out of service Filtration – Peak Loading Rate gpm/sf 8 PH For wet weather events; 1 unit out of service UV Disinfection mJ/cm2 100 PH National Water Research Institute (NWRI 2012) (a) Appendix H - TM No. 9 –Treatment Plant Capacity Assessment of the Facilities Plan WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 7 of 19 The major liquid stream unit processes that could be affected by flow equalization include: Aeration basins: the volume requirements do not change for the various equalization scenarios Final clarifiers: the diameter potentially reduces as more flows are diverted to flow equalization Filter feed pumping station: the pumping requirements reduce as more flows are diverted to flow equalization Filters: the filter footprint reduces as more flows are diverted to flow equalization Ultraviolet (UV) disinfection: the facilities may be reduced as more flows are diverted to flow equalization It should be noted that proposed effluent cooling facilities are not listed here because they are sized based on peak dry weather flows. This considers the assumption that during peak wet- weather events, the flows coming into the plant are mostly from stormwater I/I and should be of a temperature very close to that in the receiving stream. In addition, the relative contribution of flow from the WRRF to the stream in wet-weather should be less than during normal dry- weather operation. Operations & Maintenance On average, power and chemical costs will not be affected significantly by flow equalization. Although the peaks may be shaved, eventually the same volume will be passed through the plant and thus will be pumped or treated, requiring similar levels of power or chemical. In fact, in-plant pumping increases with more frequent use of the equalization facilities, although not an annually significant amount. As this is not a significant differentiator between alternatives, these costs have been excluded form this analysis. Maintenance costs can benefit from equalization wherever there is an associated reduction in the amount of facilities and equipment. Generally, every new piece of equipment will require associated labor, parts, and other expendables as part of a preventive maintenance (PM) routine. To the extent that facilities can be down-sized to reduce the number of installed units, maintenance costs can be reduced. Dormant Equipment Of particular concern is installed equipment that is strictly used only during peak flow events. Although such pieces of equipment may be rarely used, it still requires preventive maintenance to ensure that it will function correctly during storm events. Maintenance on these units can be difficult to prioritize as they are not a part of the normal daily operation of the plant. Peak flow equalization facilities should attempt to minimize these “dormant” units. The equalization facilities themselves will fall in this “dormant” category. For this reason, an effort should be made to equip the EQ basins with technologies that minimize the “preventive” maintenance routine required. Typical equalization facility components such as odor control, WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 8 of 19 basin aeration, mixing, and return pumping should be easy to startup with only occasional use. For example, in the case of aeration, aspirating air injectors (no moving parts) may be preferable to mechanical blowers. Hydraulics There are two potential points in the process scheme to divert flows from the treatment process to equalization, as shown in Table 2. It is not anticipated that the primary clarifiers will be expanded and thus the current capacity of 22 MGD is limiting and should trigger equalization upstream of primary treatment. Table 2. Diversion Point Alternatives Location Maximum HGL (FT-AMSL) Divert at Flows Above Downstream of the Grit Basins 134.0 22 MGD Downstream of the Primary Clarifiers 129.3 Based on secondary/tertiary capacity The preferred point-of-diversion is after primary treatment. Primary effluent in the EQ Pond is less likely to become septic and will deposit fewer solids in the EQ Pond making it easier to clean after a storm event. However, this option is limited by the available head downstream of the primaries. Currently the available head is only enough to partially fill the existing EQ Pond. The remaining volume must be diverted following the grit basins as there is additional head available to fill the EQ Pond by gravity. The flow schematic in Figure 4 depicts use of the existing 4 MG EQ Pond to equalize at the Max Day averaging period. The return line from the equalization return pumps allows them to be used to maintain mixing during equalization. Headworks (PH=33.5 mgd) Primary Clarifiers (PH=22 mgd) Secondary Treatment (PH=17 MGD) Filtration EQ Pond Figure 4. Flow Schematic for existing 4 MG EQ Pond to equalize at the Max Day flow WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 9 of 19 As indicated in Figure 5, the Max 3-Day scenario would require using both the existing EQ pond and an additional equalization tank. The new tank could be deeper so it could be configured to be the primary storage unit, only spilling into the pond as necessary during larger storm events. Figure 5. Flow Schematic to equalize the Max 3-Day flow It is preferable to set the storage tank elevation such that it can be filled by gravity and then pumped out after the peak flow has passed. The alternate configuration requires a pump station that can keep pace with potentially significant incoming peak flows. This large capacity pump station would sit largely unused for long periods of time and could be vulnerable to mechanical failure during a storm event. Instead, diverting by gravity into the storage tank affords a failsafe operation that provides relief even in a complete mechanical/electrical failure. Therefore, for purposes of this evaluation, storage facilities were assumed to be vertically located low enough to be filled by gravity. Flow Equalization Facilities Storage Reservoir Construction Storage reservoirs can be constructed of concrete, earth (pond), or steel. Steel tanks are not common in wastewater equalization applications because of corrosion concerns and were not considered here. Table 3 summarizes the various types of storage reservoirs that were considered for this analysis, and their respective advantages and disadvantages. Headworks (PH=33.5 mgd) Primary Clarifiers (PH=22 mgd) Secondary Treatment (PH=13.9 MGD) Filtration EQ Pond New EQ Tank WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 10 of 19 Table 3. Various storage reservoirs types of construction. Type of Construction Advantages Disadvantages Pond Pond systems are typically the least costly to construct on a per volume basis. Susceptible to failure from shallow groundwater. Mixing and cleaning can be challenging in very large ponds. Practical limitations on depth and available area. Above grade construction (berms) increase the footprint for the same volume. Difficult to control odors Difficult to clean Liner life-cycle will be generally shorter and require replacement sooner than concrete. Cast-in-Place Reinforced Concrete Tank Flexible footprint. Can be circular, rectangular or customized to site constraints. Can be designed to resist uplift from groundwater Less cost effective at larger volumes Horizontal Wire-Wound Prestressed Concrete Tank (AWWA D110 Standard) Economical to build at very large volumes Can be very deep to reduce footprint Can be designed to resist uplift from groundwater Circular tanks only Feed/Drain Pumping With the exception of the Max-Day alternative, which utilizes existing facilities, each alternative will require a new pumping station to return wastewater to the treatment process after influent flows have abated. Mixing Ideally, the flow equalization basins would be fed exclusively with primary effluent. This reduces the potential for odors, septicity and accumulation of solids. However, the primary clarifiers are limited to 22 mgd capacity so large storms will exceed this. Additionally, there is not enough available hydraulic head downstream of the primary clarifiers to completely fill the equalization basins. This means that in order to use the full EQ volume, some flow must be diverted from upstream of the primaries. The net result is that as much as 40 percent of the stored wastewater will be “unclarified” influent. For the Max 3-Day scenario it would be closer to 50 percent. As such, mixing should be provided to reduce solids deposition. Typical design criteria for such mixing ranges from 0.02 hp to 0.04 hp per 1,000 gallons of stored volume. Aeration Aeration can prevent septicity and reduce the potential for odor generation and can often provide the required mixing at the same time. Aerobic conditions can be maintained with an air supply of 1.25 to 2 CFM per 1,000 gallons of stored volume. WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 11 of 19 Pump Out to Treatment Given that the EQ basins will be filled by gravity, pumping will be required to return the stored wastewater to the treatment process after the storm peak has passed. With additional valves, these return pumps may also be used to promote mixing in the basin during the storage event. This may eliminate the need for additional mixing equipment. Used in conjunction with aspirating style air injectors (see Figure 6), the pump out facility can simultaneously be used to promote aerobic conditions in the basin without the need for additional aeration equipment. Figure 6. Example of an aspirating air injector installed on a recirculation pump discharge to provide basin air (photo courtesy of Mazzei Injector Company, LLC). Odor Control Factors such as the duration of the storage period, amount of raw “unclarified” sewage, degree of mixing/aeration and proximity to neighbors affect the decision to include odor control in the equalization facility. Odor control facilities cover a wide spectrum of complexity and cost. Since this is an intermittently used facility, biological systems are not optimal as they require some time to startup. A simple chemical feed system, such as ferric chloride, might be adequate for smaller volumes and durations. As the EQ facilities get larger, store longer, with more solids to contend with, they may require covers and more complex odor scrubbing facility that includes fans, ducting and chemical contact towers. Odor control assumptions are summarized Table 4 in the Alternatives Evaluation Section. WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 12 of 19 Other Considerations Geotechnical Earth Materials Deep hydraulic structures such as those potentially proposed for the Equalization Basins can produce high soil bearing pressures and thus can be impacted significantly if soil conditions are poor. A review of past geotechnical reports suggests some factors to consider in the alternative analysis. One unique feature is the presence of artificial fill, possibly an abandoned disposal area, ranging in depth up to 14 feet under a large portion of the site along San Luis Obispo Creek. The geotechnical study conducted by for the “San Luis Obispo Wastewater Treatment Plant Expansion” (Stall, Gardner & Dunne, Inc., 1988) identifies the following “significant geotechnical factors” that may affect structure design: 1. The presence of debris-laden fill soils, 2. The presence of soft silty clays at and below the proposed bearing elevations, and 3. The fluctuating groundwater table. Based on this and other reports, for facility planning purposes, the cost of deep foundation systems will not be included as it seems that traditional spread footing type foundation system might be sufficient. However, some additional allowance will be included for removal of artificial fill if the bottom of the structure is less than 14 feet below grade. All of these assumptions should be further evaluated during design with the supporting geotechnical investigations. Ground Water In the 1988 study, groundwater was encountered at approximately 19 feet below grade or elevation 111 FT. However, it seems to fluctuate widely and may have at times been encountered as shallow as 15 feet below grade, or approximately elevation 115 FT. Siting The existing trickling filter is a 200 FT diameter by 4 FT tall structure that is to be abandoned and could be retrofitted to serve as a storage tank. However, its 0.8 MG of volume is not significant enough to provide much benefit to downstream facilities and it does not meet the hydraulic requirement to be filled by gravity during a storm event. However, the structure could be demolished to provide space for a replacement tank on the site (refer to Figure 7). Alternatives 3 & 4 Demolish Existing Biofilter and Install new spiral wound post tensioned concrete tank Alternative 5 Demolish Existing Pond and Install new spiral wound post tensioned concrete tank Alternatives 2 & 4 Demolish Existing Pond and Install new deeper pond with new liner FLOW EQUALIZATION FACILITY ALTERNATIVES WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 14 of 19 Use for Diurnal Equalization Depending on the selected type, size and location of the peak wet-weather flow equalization facilities, it may be appealing to consider the use of the facilities on a daily basis for diurnal equalization. However, this use is generally not compatible with the wet-weather facilities without some improvements. For example, diurnal equalization tanks should be continuously mixed and aerated. They may additionally require a full-time odor control solution and be generally self-cleaning. Compartmented storage also allows for smaller cells within the facility to be used for diurnal variations without having to outfit the entire facility. As this memo addresses only peak wet-weather equalization, these features are not considered in this evaluation. Height Limitations The “Airport Land Use Plan for San Luis Obispo County Regional Airport” identifies the WRRF site as located entirely within Airport Safety Zone S-1b. As such, there may be limits placed on the height of new structures. This could be a concern if storage was to be constructed above ground. However, since a gravity fill configuration is preferred, it is anticipated that the new structures will be constructed at or below other existing hydraulic structures on the site. Alternative Analysis The equalization alternatives and associated assumptions that were considered are summarized in Table 4. The use of EQ storage can potentially affect the operation of downstream facilities. Theoretically, more storage means that the treatment processes will tend to routinely run closer to average conditions and thus should maximize their usage. However, there is a practical point of diminishing return where redundancy requirements prevent further reductions in equipment and the cost of additional storage becomes prohibitive. WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 15 of 19 Table 5 provides a perspective on how the WRRF is expected to normally operate seasonally and during peak wet-weather events. With the exception of the filters, there is no difference between the operating units during normal wet-weather operations and peak rainfall derived events. This means that all the same equipment will normally be in-service already and it is not necessary to bring additional “dormant” equipment, tanks, or process on-line to pass a peak flow event. With the exception of the filters, there is generally no change in operating units during storms. WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 16 of 19 Table 4. Alternative Process Features Recurrence Interval Max-1 Day Max-2 Days Max-3 Days Max-5 Days Max-Week EQ Facility Improvement Description Baseline. Rehabilitate and flood protect existing pond. Deeper Pond. Excavate existing EQ pond to a total depth of 14 FT. Replace Biofilter with New Tank. Install new horizontal wire- wound prestressed concrete tank in place of biofilter and Rehab existing Pond. Replace Biofilter and Deeper Pond. Install concrete tank in place of abandoned biofilter and excavate deeper pond. Replace Pond with New Tank. Install horizontal wire-wound prestressed concrete tank in place of existing EQ Pond. Downstream Treatment Design Capacity 17.0 MGD 15.2 MGD 13.9 MGD 12.1 MGD 11.4 MGD Storage Volume 4.2 MG 7.2 MG 8.7 MG Pond - 4.2 MG Tank – 4.5 MG 13.5 MG Pond – 7.2 MG Tank – 6.3 MG 16.6 MG Dimensions 420’Lx15’Wx7.5’H 420’Lx15’Wx14’H 420’Lx15’Wx7.5’H 200’D x 21’ 420’Lx15’Wx14’H 200’D x 21’ 300’D x 25’ Return Flow Pumping Capacity 7.6 MGD 8.6 MGD 11.7 MGD 9.9 MGD 9.2 MGD Storage Time in 10-Yr Storm Event(a) 2.4 d 3.8 d 4.4 d 5.7 d 6.5 d Return Flow Pumping Rehabilitate existing New pumping station New pumping station New pumping station New pumping station Odor Control None Ferric Chloride Feed Facility Ferric Chloride Feed Facility Odor Scrubbing Odor Scrubbing Aeration Use Return Flow Pumps with Air Injection Use Return Flow Pumps with Air Injection Blowers and Course Bubble Diffusers Blowers and Course Bubble Diffusers Blowers and Course Bubble Diffusers Tank Mixing Recirculation Recirculation Air Mixing Air Mixing Air Mixing Replace Existing Facilities Demolish existing pond liner Demolish existing pond liner and pump station Demolish biofilter, pond liner and pump station Demolish biofilter, pond liner and pump station Demolish biofilter, pond liner and pump station (a) Event Duration represents the period of time the basin would contain wastewater from initial fill to final pump out. WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 17 of 19 Table 5. Comparison of Normally Operating Process Units and Peak Flow Units. Unit Process Dry Season Units in Service Wet Season Units in Service Peak Rain Events Units in Service Note Aerated Grit 1 1-2 2 • Relatively easy to bring on-line with peak flows Primaries 1 2 2 • Number of basins on-line changes with seasons, not with storm events Aeration Basins 2-3 5 5 • Same comment as above Final Clarifiers 2-3 4 4 • Same comment as above Filters 4 (existing mono-media cells) 4 All cells • Relatively easy to bring on-line with peak flows • All units on-line for peak events • Adjust running units to minimize timed-out backwash events UV Channels 1 1-2 2 • Relatively easy to bring on-line with peak flows Figure 8 illustrates the comparative total project cost and associated volume for the equalization alternatives described in Tables 4 and 5. As shown, the base option presented in the Facility Plan, which would provide equalization for flows above the Max Day, is comparatively the lowest cost option. Table 6 provides additional cost information. Figure 8. Capital Cost and Equalization Volume of Flow EQ Alternatives 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 50 55 60 65 70 75 80 85 90 95 100 Fl o w E Q V o l u m e ( M G ) Pr o j e c t C o s t ( $ M i l ) Project Cost Flow EQ Volume WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 18 of 19 Table 6. Comparison of Estimated Project Capital Costs Annual Recurrence Frequency Equalization Facility Description Design Treatment Capacity (MGD) EQ Storage Volume (MG) Return Flow Pump Station Capacity (MGD) EQ Facility Capital Cost Treatment Facility Capital Cost Project Capital Cost(a) Max 1-Day Rehab Existing Pond 17.0 4.2 MG 7.6 MGD $1.6M $64.5M $66.2M Max 2-Day Deeper Pond 15.2 7.2 MG 8.6 MGD $4.7M $62.4M $67.1M Max 3-Day Replace Biofilter w/ Tank and Rehab Pond 13.9 8.6 MG 11.7 MGD $10.2M $59.0M $69.2M Max 5-Day Replace Biofilter w/ Tank and Deeper Pond 12.1 13.5 MG 9.9 MGD $14.6M $56.6M $71.2M Max Week Replace Existing Pond with Tank 11.4 16.6 MG 9.2 MGD $22.3M $54.0M $76.3M (a) For purposes of this analysis, “Project Capital Cost” incorporates the relative cost differences between alternatives for comparison purposes but is not intended to be directly representative of the actual overall project cost. Recommended Equalization Facility The estimated costs provided in Figure 8 and Table 6 do not indicate a distinct cost advantage for any one alternative. The cost difference between the alternatives is largely within the margin of error in the estimates. There is a trend toward higher total cost as the EQ facilities get larger, which is consistent with diminishing return on savings within the treatment facility. Given the lack of a clear cost advantage, it is recommended that the Max-Day facility be constructed. It is largely the same as the existing facilities with some rehabilitation, flood protection and aeration being provided. It is also the simplest to operate and requires the least amount of additional equipment to maintain on an on-going basis. This also results in a more robust treatment process that gives operators the greatest operational flexibility. As a result, the following improvements are recommended: Rehabilitate the existing 4 MG pond and pump out facility including replacement of existing pond liner. Upgrade pump-out facility to a peak capacity of 8 mgd. Grade a berm around perimeter of existing pond to provide protection from inundation during a 100 year storm event. Provide 2 FT of freeboard from projected 100-year storm flood elevation. Provide vehicle access around top of berm. Install perimeter hydrants and water cannons supplied by plant 3W water for flushing out residual solids after use. Install a return line from pump-out station to allow the pumping station to be used for recirculation and mixing when not pumping back to the process. WRRF Project TM No. 9.3 – INFLUENT WET-WEATHER FLOW EQUALIZATION Page 19 of 19 o Consider the installation of an aspirating type induction aerator on the discharge of the return line to help maintain aerobic conditions. Appendix L TM No. 10.1 - Infrastructure Planning, Stormwater Page 1 Date: 5/29/2015 Prepared by: Libby Mesbah, PE and Chris Acosta, EIT Reviewed by: Paymon Fardanesh, PE; Holly Kennedy, PE Project: WRRF Project SUBJECT: TM NO. 10.1 – STORMWATER AND SAN LUIS OBISPO CREEK FLOOD MANAGEMENT The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long-term strategy for resource management. The purpose of this technical memorandum (TM) is to describe the stormwater management and low impact development (LID) recommendations to be implemented as part of future WRRF upgrades. Flood risks and management tactics associated with the San Luis Obispo Creek are also discussed. Contents Introduction .............................................................................................................................. 5 Purpose..................................................................................................................................................... 5 Site Description ......................................................................................................................................... 5 Scope of Work .......................................................................................................................................... 6 Low Impact Development Options .......................................................................................... 6 Hydrologic Summary ............................................................................................................... 7 Watershed Description ............................................................................................................................. 7 Hydrology Design Criteria ......................................................................................................................... 7 Hydrology Analysis Inputs ........................................................................................................................ 8 Precipitation .......................................................................................................................................... 8 Soil Types ............................................................................................................................................. 9 Proposed Land Use ............................................................................................................................ 10 Hydrologic Analysis Results ..................................................................................................11 Individual Watershed Recommendations .............................................................................14 Watershed A ........................................................................................................................................... 14 Watershed B ........................................................................................................................................... 16 Watershed C ........................................................................................................................................... 18 Watershed D ........................................................................................................................................... 20 Watershed E ........................................................................................................................................... 22 Watershed F ........................................................................................................................................... 24 Watershed G ........................................................................................................................................... 25 Watershed H ........................................................................................................................................... 26 WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 2 Other Considerations .............................................................................................................28 Outfall Releases to the Creek during High Creek Flows ........................................................................ 28 Identify Existing Underground Utilities .................................................................................................... 28 Collect Soils Percolation Rate Data ........................................................................................................ 28 Protect Site during Construction ............................................................................................................. 28 Increased Operations and Maintenance ................................................................................................. 28 Irrigation Required During Plant Establishment ..................................................................................... 29 Flood Risk from the San Luis Obispo Creek .........................................................................29 Preliminary Water Surface Elevation Development ............................................................................... 29 Existing Conditions Hydraulic Model .................................................................................................. 29 Proposed Conditions Hydraulic Model ............................................................................................... 29 Flood Protection Alternatives .................................................................................................................. 29 Recommended Improvements ............................................................................................................... 32 References ..............................................................................................................................34 Figures Figure 1. Watershed A ................................................................................................................................ 15 Figure 2. Watershed B ................................................................................................................................ 17 Figure 3. Watershed C ................................................................................................................................ 19 Figure 4. Watershed D ................................................................................................................................ 21 Figure 5. Watershed E ................................................................................................................................ 23 Figure 6. Watershed F ................................................................................................................................ 24 Figure 7. Watershed G ................................................................................................................................ 26 Figure 8. Watershed H ................................................................................................................................ 27 Figure 9. Proposed Flood Protection Improvements for the Primary Clarifiers .......................................... 31 Tables Table 1. 95th Percentile Rainfall Event .......................................................................................................... 8 Table 2. NOAA Atlas 14 Volume 6 Depth-Duration-Frequency .................................................................... 9 Table 3. Watershed Land Use Coverage .................................................................................................... 11 Table 4. 95th Percentile Stormwater Runoff Results ................................................................................... 12 Table 5. 10-Year 24-Hour Stormwater Runoff Results ............................................................................... 13 Table 6. 10-Year 24-Hour Storm Watershed Release Peak Discharges ................................................... 14 Table 7. Comparison of Relative Costs of Alternatives ............................................................................. 32 Table 8. Specific Improvements Recommended for Facilities Found to be Potentially Inundated in a 100-yr Storm Event ...................................................................................................................... 33 List of Photos Photo 1. Watershed A Photographs ........................................................................................................... 15 Photo 2. Watershed B Photographs ........................................................................................................... 17 Photo 3. Watershed C Photographs ........................................................................................................... 19 Photo 4. Watershed E Photographs ........................................................................................................... 23 Photo 5. Watershed F Photographs ............................................................................................................ 25 Photo 6. Watershed G Photographs – No Photographs Available ............................................................. 26 Photo 7. Watershed H Photographs ........................................................................................................... 27 WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 3 List of Appendices Appendix A Proposed WRRF Site Drainage Figure Appendix B Watershed Management Zones Appendix C NOAA Daily Rainfall Percentile versus Depth Graph Appendix D NOAA Atlas 14 Point Precipitation Frequency Estimates Appendix E NRCS Soils Data Appendix F Proposed WRRF Site Plan Figure Appendix G Stormwater and Flood Management Presentation (January 29, 2015) Appendix H San Luis Obispo Creek Flooding Alternatives Workshop Presentation (March 24, 2015) Appendix I Proposed WRRF 100-Year Water Surface Elevation from San Luis Obispo Creek Appendix J Proposed WRRF HEC-RAS Cross Sections Remainder of page intentionally blank WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 4 Page intentionally blank. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 5 Introduction Purpose This TM provides a stormwater management plan for the City of San Luis Obispo’s Water Resource Recovery Facility (WRRF) for consideration during the planning of future treatment upgrades. The stormwater management plan provides recommendations that increase the level of flood protection against rainfall runoff while improving water quality at discharge locations using the design principles of low impact development (LID). Stormwater management recommendations for each of the eight (8) delineated watersheds covering the WRRF are provided. Recommendations include minor upgrades, such as reconfiguring existing vegetated areas to include LID features, to major upgrades, such as incorporating LID/stormwater collection features as part of newly constructed buildings and treatment facilities. The stormwater management recommendations provided do not protect the WRRF when the San Luis Obispo Creek overtops its banks and flows into the facility. Additional flood protection measures must be considered to reduce/remove the risk of San Luis Obispo Creek overtopping its banks. This TM provides 100-year water surface elevations throughout the WRRF so that appropriate flood management alternatives can be developed and analyzed. Flood protection alternatives are presented, including the preferred alternative, as well as recommended next steps. Site Description The WRRF’s developed area is approximately 30 acres in size and is primarily paved with small vegetated/dirt swales distributed throughout. Additional acreage to the southwest of the developed area is vegetated open space and wetlands. Stormwater runoff is collected at different locations throughout the facility and transported via concrete swales, vegetated ditches, and culverts to three (3) existing outfalls to the San Luis Obispo Creek as well as overland release to open areas southwest of the WRRF. Outfalls A and B flow to the Creek through piped storm drain systems which are controlled by manual release gates. Outfall C flows through a recently constructed vegetated bioswale and only flows out to the creek through an overflow basin inlet during large storm events. The WRRF maintains its own Industrial Storm Water Pollution Prevention Plan (SWPPP) satisfying requirements of the local Central Coast Regional Water Quality Control Board (CCRWQCB). The City’s Bus Barn facility is adjacent to the WRRF and collects contained runoff from the bermed bus parking area and drains through an in-ground oil/sediment separator before flowing into a shared storm drain with WRRF stormwater runoff collected and released through Outfall B. See Appendix A for outlet locations and drainage facilities. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 6 Scope of Work Tasks completed and summarized within this technical memorandum include: Performing a hydrologic analysis for the project area considering future upgrades by evaluating drainage area, imperviousness, soils conditions, precipitation and land use conditions to develop stormwater runoff volumes and maximum outfall peak discharges. Developing LID recommendations and stormwater retention facilities that will improve stormwater quality and flood protection throughout the WRRF. Performing a hydraulic analysis for the project area to determine finish floor elevations for proposed structures and other critical infrastructure to remain above the inundation by riverine flooding for a 100-year flood event. Evaluating flood management alternatives and developing recommendations for improvements to address inundation by riverine flooding for a 100-year flood event. Low Impact Development Options LID is defined for this plan as a stormwater and land use management strategy that strives to mimic pre-disturbance hydrologic processes of infiltration, filtration, storage, evaporation, and transpiration by emphasizing conservation, use of on-site natural features, site planning, and distributed stormwater management practices that are integrated into a project design. The term pre-disturbance is being used in this document as managing precipitation as close to where it hits the ground as possible. Proposed LID facilities would be implemented at an individual project level as the design and construction proceed forward for each facility upgrade throughout the WRRF. Since the selection of these facilities is highly site specific, and because there are many to choose from, specific facilities were not selected as part of this plan. The required storage volume needed in each watershed area has instead been computed for use during the future design of each facility. Onsite LID facilities would be selected and designed during the development of each individual facility upgrade. Some examples of the LID facilities0F 1 that could be used include: Infiltration Basins; shallow impoundment designed to collect and infiltrate stormwater. 1 The Low Impact Development Manual for Southern California: Technical Guidance and Site Planning Strategies https://www.casqa.org/resources/lid/socal-lid-manual and the Central Coast Lidi Organization http://centralcoastlidi.org/Central_Coast_LIDI/Home.html provides detailed photographs and examples of LID options. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 7 Bio-retention areas; small-scale, landscaped, shallow areas that slow, treat, retain and infiltrate stormwater runoff, mimicking the natural, pre-development hydrology of a site. Pervious pavements; permeable surface underlain by a storage reservoir consisting of a uniformly graded aggregate bed or pre-manufactured structural stormwater units. Constructed wetlands; shallow, engineered vegetated system designed to provide stormwater detention and pollutant removal. Vegetated Swales; broad, shallow channels designed to convey and either filter or infiltrate stormwater runoff. Capture and Reuse; system collects and stores rainwater for later use, such as landscape irrigation, vehicle washing, etc. Downspout Disconnection; redirection of stormwater from an existing downspout to a vegetated area or collection system. Green roofing; vegetated roof systems that filter, absorb, and retain or detain the rain that falls upon them. Hydrologic Summary Watershed Description Stormwater runoff watersheds were delineated to adequately capture similar flow behavior and flow direction throughout the WRRF. The subbasins were delineated primarily considering highest elevation ridge lines of existing topography. The slope of the overall WRRF is very flat, on the average of 0.004 ft/ft. Proposed development features that affect flow patterns, such as proposed curbs and gutter, re-grading, self containing structures, were also taken into consideration when delineating the watersheds. The resulting eight (8) watersheds areas are shown in Appendix A. Hydrology Design Criteria Stormwater runoff volumes and peak discharges were determined referencing design criteria from the local Central Coast Regional Water Quality Control Board (CCRWQCB) as well as the City and County of San Luis Obispo’s Drainage Design Manual. The stormwater runoff volumes computed will be available to use in future design to size LID/stormwater facilities. To satisfy CCRWQCB water quality requirements and provide a greater level of stormwater runoff protection, LID parameters have been computed as a minimum to contain and infiltrate the 95th percentile rainfall event. It is recommended to set the basin’s overflow inlet elevation at a minimum elevation equal to the 95th rainfall event computed maximum water depth. The Central Coast Regional Water Quality Control Board (CCRWQCB) has adopted the Central Coast Simple Method for sizing LID best management practices (BMPs). Applying the WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 8 methodology from the Central Coast Region’s Post Construction Stormwater Management Requirements for Developing Projects in the Central Coast Region, dated July 12, 2013, determined that the proposed drainage facilities should retain 100-percent of the 95th percentile 24-hour design storm since the WRRF is located in the designated Watershed Management Zone 1 area (see Appendix B). It is recommended that the LID facilities should be ultimately sized to contain the 10-Year 24- Hour event without overtopping. Emergency overflow locations should be sized and set at a slightly lower elevation than the remaining perimeter of the LID basin/swale to control overflow flows greater than the 10-Year 24-Hour event. The outfalls and emergency overflow paths are designated in Appendix A. The peak discharges were also computed at the terminus of each of the eight (8) watersheds and at the designated outfalls to the San Luis Obispo Creek to be used to properly size connector culverts and overflow inlets at the designated outfall locations. Hydrology Analysis Inputs Precipitation The 95th percentile rainfall event was calculated for stormwater quality/sediment mitigation using daily precipitation record data from the nearest precipitation gage, National Oceanic and Atmospheric Administration’s (NOAA) San Luis Obispo Polytech (USC00047851) gage. Daily precipitation depths from 1960 to 2014 were ranked, excluding depths less than 0.1 inch, to determine the 95th percentile rainfall depth. The resulting 95th percentile rainfall depth was computed at 2.05 inches. The depth-duration-frequency relationships for the 95th percentile rainfall event are listed in Table 1. The percentile versus rainfall depth graph generated to determine the 95th percentile rainfall depth is included in Appendix C. Table 1. 95th Percentile Rainfall Event Duration 95th Percentile Rainfall Event (in) 24 hr 2.05 Latitude = 35.3, Longitude = -120.6667 NOAA Atlas 14 Volume 6 provides precipitation frequency estimates for the State of California. The 10-year rainfall event 24-hour design storm was used to size the maximum volume required. The depth-duration-frequency relationships for these events are listed in Table 2; additional NOAA Atlas 14 depth-duration-frequency information is presented in Appendix D. The 10-Year 24-hour storm event will be used to compute the size of emergency outlet pipes and LID facilities. Data from the NOAA website correlated fairly well with the City/County Drainage Design Manual 10-Year 24-Hour storm event; therefore, it was used as the source of data. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 9 Table 2. NOAA Atlas 14 Volume 6 Depth-Duration-Frequency Duration 10-Year Rainfall Event (in) 24 hr 4.16 Latitude = 35.2542, Longitude = -120.6737 Soil Types HDR obtained the hydrologic soil types from Natural Resources Conservation Service (NRCS) website (www.nrcs.usda.gov) for the project area; see Appendix E for details. No soils explorations were conducted as part of this study. NRCS data included a table with hydrologic soil group (HSG) classifications that correspond to each soil type. NRCS hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one (1) of four (4) groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four (4) groups (A, B, C, and D) and three (3) dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. The entire WRRF facility is classified as Group C, soils having slow infiltration rate. Group C soils may provide some challenges for the WRRF proposed LID facilities to drain within the required maximum 48-hour infiltration period especially during back-to-back storms where the native soils will be saturated. A portion of the WRRF was also previously a landfill. Impacts of the landfill to soils conditions are unknown. Soils percolation data will need to be collected prior to any design of LID facilities. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 10 Proposed Land Use Proposed land use data was developed for the project area by conducting a site visit, evaluating existing aerial imagery, and accounting for the future development of the site, which is included as Appendix F. Each watershed was broken up into four (4) different land use categories: self- contained, impervious, pervious, and isolated pervious areas. The watershed land use coverage breakdown is provided in Table 3. Self contained areas are defined as areas that trap fallen precipitation within a designated type of physical boundary. The WRRF contains many large footprint treatment structures which are open to the air (for example the primary and final clarifiers, sludge drying beds, equalization basin). For this management plan, it is assumed that these structures will continue to act as self contained areas which do not discharge collected stormwater to any outfall location. Collected stormwater will be treated by the plant and discharged as part of the treated water. Impervious areas are defined as paved areas or building footprints preventing infiltration into the ground. Pervious areas are defined as open areas that allow infiltration into the ground and that are recommended for LID improvements. Isolated pervious areas are defined as isolated areas that allow infiltration into the ground and that are recommended for LID improvements. These may have limited capacity depending on available area and will not be directly linked to an emergency outfall due to their isolated location. Although the entire designated pervious area may allow for infiltration into the ground, not all designated areas can be used for LID upgrades. Many of these areas are already established and contain mature vegetation with root systems that should not be disturbed. Even though the entire pervious area was used to compute the contributing area requiring LID upgrades, the maximum depth of the LID facility assumes the percentage of available area estimated for LID upgrades. This in turn increased the depths of the LID facilities, but makes the estimated depths more realistic for planning purposes. The estimated percentages and the computed pervious area available for LID upgrades are also listed in Table 3. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 11 Table 3. Watershed Land Use Coverage Watershed ID Total Watershed Area (ac) Self Contained Area (ac) Impervious Area (ac) Isolated Pervious Area (ac) Pervious Area (ac) Percentage of Pervious Area Available for LID Upgrades (%) Pervious Area Available for LID Upgrades (ac) A 3.9 0.3 2.6 0.7 0.3 -- -- B 2.6 0.0 2.0 0.0 0.6 50% 0.3 C 2.4 0.0 1.8 0.2 0.4 80% 0.3 D 4.6 1.5 1.8 0.5 0.7 70% 0.5 E 2.6 0.4 1.8 0.0 0.4 80% 0.3 F 3.6 1.0 2.1 0.1 0.3 90% 0.3 G 2.5 0.0 1.0 0.0 1.2 70% 0.8 H 6.8 2.3 2.4 0.0 2.1 50% 1.0 -- Not applicable for Watershed A since it does not currently require any LID or stormwater collection improvements since utilizing the open area southwest of the WRRF. Hydrologic Analysis Results Hydrologic stormwater runoff volumes and associated depths of LID facilities parameters were computed for each defined watershed area. For computing the 95th percentile stormwater runoff volumes, the contributing drainage area consists of the Impervious Area and Pervious Area. For this size of storm (the 95th percentile is equivalent to little over a 1-year 24-hour storm event), the Isolated Pervious and Self Contained Areas are assumed to contain the fallen rainfall within their designated areas. Due to the limited availability of infiltration rates of the soils, it was assumed that the Impervious Area from the contributing drainage areas would infiltrate an insignificant amount of volume during the event, therefore providing zero storage. It was also assumed that 100-percent of precipitation that fell on the Pervious Area would be conveyed to the LID facilities. The runoff volumes were calculated by taking the 95th percentile precipitation depth, 2.05 inches, and multiplying it by the contributing area. The runoff volume was then distributed in the Pervious Areas available for LID Upgrades, thus providing a maximum water depth. The LID basin overflow inlet would be set to the computed maximum water depth. The assumed contributing areas and estimated LID facility basin depths are included in Table 4. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 12 Table 4. 95th Percentile Stormwater Runoff Results Watershed ID Contributing Area requiring LID Upgrades (ac) Required LID Storage Volume (ac-ft) Maximum Water Depth of LID Basin1 (ft) A 2.9 (IA=2.6 + PA=0.3) 0.5 -- B 2.6 (IA=2.0 + PA=0.6) 0.4 1.4 C 2.2 (IA=1.8 + PA=0.4) 0.4 1.3 D 2.5 (IA=1.8 + PA=0.7) 0.4 0.9 E 2.2 (IA=1.8 + PA=0.4) 0.4 1.2 F 2.4 (IA=2.1 + PA=0.3) 0.4 1.3 G 2.1 (IA=1.0 + PA=1.2) 0.4 0.4 H 4.5 (IA=2.4 + PA=2.1) 0.8 0.7 -- Not applicable for Watershed A since it does not currently require any LID or stormwater collection improvements since utilizing the open area southwest of the WRRF. 1 The percolation rate of the soil has not been taken into consideration when computing the maximum water depth. Once percolation rates are known, depths can be reduced accordingly. Maximum depths are provided for planning purposes only. IA = Impervious Area; PA = Pervious Area For computing the 10-Year 24-Hour event stormwater runoff volumes, the contributing drainage area consists of the Impervious Area, Pervious Area, and 50-percent of the Isolated Pervious Area. The 50-percent assumption was applied since it is anticipated that the Isolated Pervious Area will not be able to self contain the runoff within its designated area. The Self Contained Areas are assumed to contain the runoff within the designated area, and therefore, do not contribute to the stormwater runoff. The runoff volumes were calculated by taking the 10-Year 24-Hour storm precipitation depth, 4.16 inches, and multiplying it by the contributing area. The runoff volume was then distributed in the Pervious Areas available for LID Upgrades, thus providing a maximum water depth. An additional 1.0 foot of freeboard was also included. The assumed contributing areas and estimated LID facility basin depths are included in Table 5. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 13 Table 5. 10-Year 24-Hour Stormwater Runoff Results Watershed ID Contributing Drainage Area requiring LID Upgrades (ac) Required LID Storage Volume (ac-ft) Maximum Water Depth of LID Basin1 (ft) Maximum Water Depth of LID Basin including Freeboard2 (ft) A 3.2 (IA=2.6 + PA=0.3 + IPA=50%*0.7) 1.1 -- -- B 2.6 (IA=2.0 + PA=0.6 + IPA=50%*0.0) 0.9 2.8 3.8 C 2.3 (IA=1.8 + PA=0.4 + IPA=50%*0.2) 0.8 2.7 3.7 D 2.8 (IA=1.8 + PA=0.7 + IPA=50%*0.5) 1.0 1.9 2.9 E 2.2 (IA=1.8 + PA=0.4 + IPA=50%*0.0) 0.8 2.5 3.5 F 2.5 (IA=2.1 + PA=0.3 + IPA=50%*0.1) 0.9 2.8 3.8 G 2.2 (IA=1.0 + PA=1.2 + IPA=50%*0.0) 0.8 1.9 2.9 H 4.5 (IA=2.4 + PA=2.1 + IPA=50%*0.0) 1.5 1.5 2.5 -- Not applicable for Watershed A is it does not currently need any LID or stormwater collection improvements since utilizing the open area southwest of the WRRF 1 The percolation rate of the soil has not been taken into consideration when computing the maximum water depth. Once percolation rates are known, depths can be reduced accordingly. Maximum depths are provided for planning purposes only. 2 Assumes 1.0 foot of freeboard. IA = Impervious Area; PA = Pervious Area; IPA = Isolated Pervious Area To maximize stormwater storage capacity throughout the WRRF, it is recommended to connect LID facilities with culverts. These culverts will be sized to allow the LID facilities to fill up uniformly from collected stormwater assuming that the basin’s invert elevations can be set as fairly equal elevations. Culverts will need to be sized to pass the computed peak discharges provided in Table 6. Sizing the basin’s overflow inlet pipe diameter for the outfalls is also necessary. The 10-Year 24-Hour storm would be sized to drain down to the basin’s overflow inlet within 24 hours when the San Luis Obispo Creek water surface elevation is below the outlet invert elevation. The stormwater collection system will not be able to discharge when the San Luis Obispo Creek water surface elevation is above the top of outlet pipe elevation. Freeboard is provided to provide additional capacity during these events. Peak flows are computed by taking the total volume needed to drain and dividing over a 24-hour duration. Table 6 below also provides the peak discharge required to be passed through the overflow inlet pipe. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 14 Table 6. 10-Year 24-Hour Storm Watershed Release Peak Discharges Watershed System Location of Computed Peak Flow Peak Flows (cfs) Watersheds G and H Peak Flow from G to H 0.20 Peak Flow from H to Outfall D into SLO Creek 0.59 Watersheds E, C, D, and B Peak Flow from C to D 0.21 Peak Flow from E to D 0.19 Peak Flow from D to B 0.68 Peak Flow from B to Outfalls A&B into SLO Creek 0.90 Watershed F Peak flow from F to Outfall C into SLO Creek 0.22 Individual Watershed Recommendations Watershed A Watershed A is located at the southwest end of the WRRF and contains the existing chlorine contact basin which will be removed. It is currently planned that a smaller UV basin facility will be located here in the future. The drainage behavior of Watershed A is primarily overland flow collected and routed via a street gutter system. Watershed A outflows into two (2) concrete sloped outfalls that feed into a deep swale filled with cottonwood trees which then discharge out into vegetated open areas southeast of the WRRF, which are also owned by the City of San Luis Obispo. This area functions fairly well during large rainfall events due to the large storage southwest of the WRRF. There is also a smaller swale on the southwest side located west of the fence line beyond the vehicle access gate near the Laguna lift station. If any development occurs in the vegetated open area southwest of the WRRF, alternative stormwater storage areas and LID facilities upgrades would be required. Existing drainage issues of Watershed A include small isolated areas of poor drainage that result in stagnant water in existing street gutter that are not properly sloped. Minor improvements could include re-grading and installing properly sloped gutters to improve site drainage. Additional recommendations for Watershed A include repairing or armoring the outfalls to prevent damage due to erosion and under cutting of the road. Another alternative could also include routing other watershed runoff to the vegetated open areas via connected vegetated swales. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 15 Figure 1. Watershed A Photo 1. Watershed A Photographs WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 16 Watershed B Watershed B spans from the existing Administrative Building and barbeque/picnic area and ends just before the EQ basin control structure. The drainage behavior of Watershed B is overland flow that is routed via a street gutter system, controlled by two (2) manual gates, then is directly released to the San Luis Obispo Creek through Outfall A and B. Watershed B is being considered to be repurposed as the Interpretive Center. This watershed will have significant exposure to the public and should exhibit multiple LID features such as typical bioretention swales, green roofs, and porous pavement/pavers to showcase the WRRF in a forward-thinking light. Although some of these LID features can be costly to install and maintain in large areas, focusing on smaller areas around the Interpretive Center would be more manageable both economically and for long-term maintenance. Currently, the Bus Barn’s stormwater runoff is combined with the WRRF runoff through the pipe network and released at Outfall B. It is recommended to separate the Bus Barn’s runoff from the WRRF runoff to better monitor water quality coming directly from the WRRF. This would be achieved by the WRRF abandoning the use of Outfall B and dedicating Outfall B solely for use by the Bus Barn’s stormwater runoff. It is recommended that Watershed B stormwater drain through the existing grated inlets but then the pipelines should be retrofitted to release flows into a proposed bioretention swale that would utilize the recreational barbeque/picnic area adjacent to the existing Administration Building and some of the open space southwest of the Administration Building. Speed bumps have also been installed to help direct stormwater flows to dedicated drainage swales. Additional bumps maybe considered to help redirect stormwater flows without major infrastructure changes. Since multiple watersheds ultimately drain through Watershed B (Watersheds C, D and E), it is recommended to construct or retrofit several bioretention swales that will be connected via underground culverts to ultimately provide capacity to contain the 10- year 24-hour event. The existing Outfall A would be retrofitted to act as the emergency overflow release inlet within the proposed bioswale for events greater than the 95th percentile event. These proposed bioswales would take into consideration the existing mature trees and would try not to disturb WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 17 the root system as much as possible. The base of the tree trunks may be flooded for short durations of time during large storm events; however, it is assumed that this would not impact the overall long-term health of the trees. Proposed designs should be reviewed by an arborist for concurrence. Figure 2. Watershed B Photo 2. Watershed B Photographs WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 18 Watershed C Watershed C includes the planned maintenance shop located on the northwestern side of the WRRF adjacent to Highway 101. The drainage behavior of Watershed C is overland flow onto an unpaved open area. It is recommended to incorporate LID features within the design of the maintenance shop that will contain the runoff volumes generated from the watershed. Watershed C will be connected via underground culverts to Watershed D and B to ultimately convey larger events than the 95th percentile storm to the San Luis Obispo Creek. Depending on future plans for Watershed C, the area could potentially be managed as an isolated pervious area. Remainder of page intentionally blank. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 19 Figure 3. Watershed C Photo 3. Watershed C Photographs WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 20 Watershed D Watershed D contains the existing and proposed Final Clarifiers, existing Primary Clarifiers, existing and proposed Aeration Basins, proposed digester, and proposed switchgear building. The drainage behavior of Watershed D is overland flow that is collected and routed via the streets and walkways sloped to drain towards the San Luis Obispo Creek. It is proposed that the Watershed D’s collected stormwater drain into a proposed bioretention swale that would be located adjacent to the existing main entrance to the WRRF. Currently, the location of the proposed bioretention swales have existing vegetated planter that could be retrofitted to become a bioretention swale. Watershed D is upstream of Watershed B and releases flows through Outfall B during storms larger than the 95th percentile event into Watershed B. LID facilities would ultimately sized to provide capacity to contain the 10-year 24-hour event. Remainder of page intentionally blank. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 21 Figure 4. Watershed D Photo 4. Watershed D Photographs WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 22 Watershed E Watershed E is located in the northwest corner of the WRRF and contains the proposed Equalization Basin area (the existing secondary clarifier). The drainage behavior of Watershed E is overland flow that is collected and routed via the streets and walkways sloped to drain towards the San Luis Obispo Creek. It is proposed that Watershed E’s collected stormwater drain into a proposed bioretention swale that would be located adjacent to the proposed Equalization Basin and retrofit a swale along the existing main entrance to the WRRF. Currently, the locations of the proposed bioretention swales have an existing vegetated planter that could be retrofitted to become a bioretention swale. Watershed E would be connected to Watershed C, which eventually releases flows through Outfall B during storms larger than the 95th percentile event. LID facilities would be sized to provide capacity to contain the 10-year 24-hour event. A secondary option would be to connect Watershed E to Watershed G to utilize stormwater flows in the Laboratory, Operations and Welcome Center landscaping and LID facilities. Remainder of page intentionally blank. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 23 Figure 5. Watershed E Photo 4. Watershed E Photographs WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 24 Watershed F Watershed F includes the existing bioretention swale that drains to the San Luis Obispo Creek at Outfall C. The drainage behavior of Watershed F is overland flow that is collected and routed via the streets and walkways to the existing bioretention swale. The existing bioretention swale performs well, but the capacity and percolation rate of the basin is unknown. It is recommended that the bioretention be retrofitted to ensure capacity up to a 10-yr 24-hr storm. Portions of the swale may need to be deepened and/or the perimeter bermed. Figure 6. Watershed F WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 25 Photo 5. Watershed F Photographs Watershed G Watershed G is located at the proposed entrance to the WRRF. As part of the upgrades, Watershed G will be re-graded and repurposed to incorporate a proposed Laboratory, Operations and Welcome Center. The proposed drainage behavior of Watershed G is overland flow that is collected and routed via the streets. This watershed will have significant exposure to the public and should exhibit multiple LID features such as typical bioretention swales, green roofs, and porous pavement/pavers to showcase the W RRF in a forward-thinking light. Although some of these LID features can be costly to install and maintain in large areas, focusing on smaller areas around the Laboratory, Operations and Welcome Center would be more manageable both economically and for long-term maintenance. It is proposed that Watershed G be sloped to drain into a proposed bioretention swale and include pervious concrete/pavers in parking stalls that would be incorporated to the design of the Interpretive Center. A green rooftop could also be considered and incorporated into the design of the Interpretive Center. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 26 Watershed G will be connected via underground culverts to Watershed H to ultimately convey larger events than the 95th percentile storm to the San Luis Obispo Creek via Proposed Outfall D. LID facilities would ultimately sized to provide capacity to contain the 10-year 24-hour event. Figure 7. Watershed G Photo 6. Watershed G Photographs – No Photographs Available Watershed H Watershed H is located at the most easterly part of the WRRF. The drainage behavior of Watershed H is overland flow that is sloped to drain towards the San Luis Obispo Creek. The proposed modifications to this area will include an installation of a Garden/Public Green Space. This watershed will have the substantial exposure to the public and should exhibit multiple LID features such as typical bioretention swales, pervious concrete/pavers along walkways, etc. to showcase the WRRF. It is proposed that Watershed H drain into a proposed bioretention swale that would be incorporated to the design of the Garden/Public Green Space and pervious concrete/pavers in walkways. Several bioretention swale will be connected via underground culverts to convey events larger than the 95th percentile to the San Luis Obispo Creek though a proposed new outfall location, Outfall D. Watershed H would connect directly to Proposed Outfall D. LID facilities would be sized to provide capacity to contain the 10-year 24-hour event. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 27 Figure 8. Watershed H Photo 7. Watershed H Photographs WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 28 Other Considerations Outfall Releases to the Creek during High Creek Flows The outfalls should be protected by flap gates preventing creek water from backing into the bioswale basins. If the interior drainage system cannot drain to the creek, flooding within the WRRF may occur. Existing drainage outfall elevations should be compared against San Luis Obispo Creek water surface elevation profiles to determine if outfalls are set at the proper elevation to allow for maximum discharge during large creek flood events. This analysis should also be conducted to properly set new drainage outfalls elevations as well. Identify Existing Underground Utilities It is important to identify where underground existing utilities are to design LID facilities properly. Designers will need to ensure that bioswales are draining properly and not draining out through pipeline gravel conduits. Collect Soils Percolation Rate Data Percolation testing of existing soil at proposed LID improvements locations is required to compute accurate infiltration rates for design. Protect Site during Construction Construction BMPs are critical to protect bioretention swales from sediment buildup and to allow plants to establish. Increased Operations and Maintenance O&M services will increase to maintain the constructed LID facilities. At a minimum, annual removal of collected sediment and debris is necessary. Collected sediment can reduce the infiltration rate of infiltration/bioswales. Long–term maintenance will require full replacement of materials after an unknown number of years. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 29 Irrigation Required During Plant Establishment Irrigation will be required to establish plants for 1 to 2 years. See the LIDI website for Central Coast’s bioretention plant list. Flood Risk from the San Luis Obispo Creek The San Luis Obispo Creek spills out of its banks during flooding events less than the 100-year event inundating portions of the City including the WRRF. San Luis Obispo Creek overtops its banks near Elks Lane and flows southwest across Prado Road and across the WRRF. The flow eventually spills back into the Creek on the southeast side of the WRRF. These flow patterns has been witnessed by WRRF staff during past flooding events and verified with the latest hydraulic modeling developed for the San Luis Obispo Creek. Preliminary Water Surface Elevation Development The City’s ordinance currently requires structures to be built above the 100-year with an additional one foot of freeboard at a minimum. For any future on-site improvements, the 100- year water surface elevation is required to determine finish floor elevation for potential new structures and/or to establish elevation to place critical infrastructure above the design water surface elevation. The 100-year water surface elevations throughout the WRRF were computed using a hydraulic HEC-RAS model. Existing Conditions Hydraulic Model The Wallace Group developed an updated HEC-RAS model of the San Luis Obispo Creek. It is assumed that this model is the best available information and more accurately maps flooding throughout the WRRF than the currently published FEMA Flood Insurance Rate Map. The HEC-RAS model developed by the Wallace Group modeled blocked obstructions for existing structures throughout the WRRF to account for large structures. Results produced flood depths ranging from 0 to 3 feet across the WRRF during a 100-year flood event. Proposed Conditions Hydraulic Model The Wallace Group model was updated to reflect the proposed site plan layout using the same blocked obstructions method. By comparing existing conditions results against the proposed conditions results, the impact of the proposed layout on water surface elevations was determined. Appendices I and J illustrate the proposed block structures locations that were modeled in HEC-RAS in plan view and cross sectional view. The proposed site plan layout slightly increases the 100-Year water surface elevation (+0.1 FT) at one cross-section compared to the existing Wallace Group model. Water surface elevations ranged from 136.9 FT at the north end of the WRRF to 125.4 FT at the south end. The proposed 100-year water surface elevations are shown in Appendices I and J. Flood Protection Alternatives The City of San Luis Obispo has multiple projects currently proposed that provide flood protection to the City of San Luis Obispo. Alternatives ranged from addressing flooding through upstream and regional improvements to retrofitting and designing new facilities to withstand WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 30 flooding. These potential project alternatives provide different levels of flood protection benefit at the WRRF. Alternatives to address flood protection at the WRRF were presented and discussed during the January 29, 2015 and March 24, 2015 project workshops. Workshop presentations are included in Appendix G and H, respectively. Alternatives were compared side by side evaluating potential project costs, risk of schedule delays and overall advantages and disadvantages of each alternative. One alternative was selected for immediate implementation additional recommended next steps were provided. Two primary level of service objectives were identified to address riverine inundation which included (1) keeping the WRRF operational during and immediately after a flooding event; and (2) meeting local and state permit requirements in regards to treatment and discharge. To achieve the level of service objectives, multiple flood protection alternatives were evaluated, including: 1. Upstream /Regional Improvements: The San Luis Obispo Creek Watershed Waterway Plan identifies several upstream / regional improvement projects that could potentially reduce flooding in the City and the WRRF. The Mid Higuera Flood Control project is going through environmental review; however, it will not decrease flooding impacts at the WRRF. The Cuesta Park Detention project was also considered as a regional solution, but it may not resolve the problem at the WRRF. The City still considers these projects as viable solutions to decrease flooding throughout San Luis Obispo, however, funding is limited and the schedule of completion is unknown. 2. Bypass Channel Improvements: The Elks Lane Capital Improvement Project was also taken directly from the San Luis Obispo Creek Watershed Waterway Management Plan. The proposed project includes constructing a semi-parallel bypass channel to San Luis Obispo Creek to allow breakout flows to be captured and stored in the bypass until it merges together adjacent to the WRRF. This alternative would require the use of a portion of WRRF property to develop a flood terrace. A separate bypass alternative that was proposed as part of this study includes constructing a bypass channel along Highway 101. This channel would extend approximately 6,900 linear feet allowing flow to leave the channel just upstream of the Elks Lane Bridge and tying back into Prefumo Creek or San Luis Obispo Creek near the WRRF outlet. A weir inlet allowing flow to spill into the bypass would need to be designed as well as a protected outlet. 3. Ring Levee and/or Floodwall around the WRRF A ring levee/floodwall around the WRRF was also considered. A minimum length of 1.3 miles would be required with approximately 4 – 6 feet in height. Entrance and exit gates or ramps would need to be designed. A major concern with the construction of a ring levee/floodwall around the WRRF would be the water surface elevation impacts to surrounding neighbors. By blocking off a significant portion of the floodplain with a levee/floodwall, floodwaters would be WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 31 displaced and could potentially increase water surface elevation greater than existing conditions. To mitigate these negative impacts, additional upstream flood improvements would most likely be required making this alternative costly. 4. On-site Improvements On-site improvements were considered and recommendations were provided for new and existing structures. On-site improvements are seen as a viable and immediate solution to providing the WRRF facilities protection without relying on larger flood control projects with unknown completion schedules. For new facilities, critical infrastructure will be built above the 100-year water surface elevation including 2 feet of freeboard at a minimum. For existing facilities, critical infrastructure will be inventoried and evaluated for retrofit above the 100-year water surface elevation or to be flood proofed in its current location. A spreadsheet tool was presented at the March 24, 2015 workshop meeting demonstrating how equipment/infrastructure could be evaluated for flood risk and repair cost. The major categories of facilities requiring additional protection include the large liquid stream process tankage and junction/diversion boxes and the electrical MCC buildings. Figure 9 illustrates a typical improvement to tankage where the exterior concrete walls are extended with additional reinforced concrete caps. The vulnerable electrical MCC buildings should be flood proofed as much as possible to prevent water intrusion through walls or under doors. The primary vulnerability is likely through conduit duct banks entering the buildings from exterior at- grade electrical vaults. These conduits should be inventoried, sealed and tested. Also, anticipating that these measures may not be completely reliable, a sump with a pump or other means of pumping out the protected MCC rooms should be considered to mitigate any remaining leakage into the space. Figure 9. Proposed Flood Protection Improvements for the Primary Clarifiers WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 32 A comparison of relative costs of the alternatives is presented in Table 7. An estimated cost, potential schedule risk, and advantages and disadvantages are listed for each. The schedule risk was determined as yes or not depending if the WRRF staff would have a higher level of control of the proposed project and associated schedule. Table 7. Comparison of Relative Costs of Alternatives Alternative Cost Schedule Risk Advantages/Disadvantages Upstream Improvement Projects $20M+ Yes • Regional solution • May not solve the problem at WRRF Elks Lane Bypass $15M Yes • Doesn’t completely protect the WRRF • Uses WRRF Property for terrace 101 Bypass Channel $12-$15M Yes • Protects the WRRF • Safety Issues • Caltrans coordination needed • Prefumo Creek impacts undetermined • Utility conflicts unquantified Ring Levee/Floodwall $13-$20M+ No • Protects the WRRF • Keeps it dry/accessible internally • Requires additional upstream improvements (not quantified) On-Site Improvements $1.5M No • Protects key WRRF facilities • Minimal impacts on community • Site access during storms may be impacted Recommended Improvements As indicated in Table 7, any of the larger flood protection measures that involve major offsite improvements represent major investments with long planning and design schedules. These larger projects generally involve greater levels of schedule risk because of the unknowns associated with environmental permitting, property acquisitions and other required agency approvals. The least costly, most readily implementable project with the least impact on neighboring properties is the On-Site Improvement option. It is recommended that this option be included in the facility plan for implementation. An initial review of the WRRF facilities was conducted to determine the magnitude of the improvements that would be required to prevent inundation. Table 8 provides a subset of the WRRF facilities that were determined to be potentially vulnerable. This is based on their Top-of- Wall or Finish Floor elevation being within 0.5 FT of the projected flood elevation. Although an improvement might be triggered by this 0.5 FT threshold, it is recommended that improvements should be designed for a 2 FT freeboard. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 33 Table 8. Specific Improvements Recommended for Facilities Found to be Potentially Inundated in a 100-yr Storm Event Facility Name Facility Plan Proposed Status TOC/FF EL 100 YR WSEL ABOVE/ (BELOW) PROPOSED IMPROVEMENT Influent EQ Pond UPGRADE/REHAB 131.7 FT 132.3 FT (0.6)FT Regrade berm around pond before planned relining project Influent EQ Pond Control Structure UPGRADE/REHAB 131.7 FT 133.1 FT (1.4)FT Concrete wall to connect to berm MCC-C (EQ Pond) MAINTAIN 131.7 FT 133.1 FT (1.4)FT 3 FT Perimeter wall, steps, conduit seal, sump pump Bar Screens UPGRADE/REHAB 130.5 FT 131.3 FT (0.8)FT Raise Steel Curb by 18IN. Replaces lower section of handrail Influent Pumping MAINTAIN 130.5 FT 131.3 FT (0.8)FT Raise Concrete Curb MCC-A Bldg (Headworks) MAINTAIN 130.0 FT 130.9 FT (0.9)FT 2 FT Perimeter wall, steps, conduit seal, sump pump Primary Clarifiers MAINTAIN 130.7 FT 131.3 FT (0.5)FT Raise Concrete Curb Primary Effluent Diversion Box MAINTAIN 130.5 FT 131.3 FT (0.8)FT Raise Concrete Curb Aeration Basins (existing) MAINTAIN 130.0 FT 131.3 FT (1.3)FT Raise Concrete Curb Spiral Energy Dissipator MAINTAIN 126.3 FT 126.8 FT (0.5)FT Raise Concrete Curb Cooling Towers EXPAND 125.5 FT 126.8 FT (1.2)FT Flood Wall/Footing & Stair (2) It is further recommended that the City take the following next steps to provide flood protection at the WRRF: 1. Verify the Wallace Group HEC-RAS model has been reviewed, approved, and accepted by the City’s hydraulic engineer. It is currently assumed that this model satisfies FEMA’s technical review standards. 2. Pursue a Conditional Letter of Map Revision (CLOMR) and/or Letter of Map Revision (LOMR) for large changes to FEMA’s Flood Insurance Rate Map. 3. Construct all new infrastructure with adequate freeboard above the 100-year water surface elevation to prevent inundation. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page 34 References Post-Construction Stormwater Management Requirements for Development Projects in the Central Coast Region, dated July 12, 2013 (Resolution No. R3-2013-0032) Section 438 Technical Guidance, Stormwater Management for Federal Facilities under Section 438 of the Energy Independence and Security Act, dated 12/4/09 City of SLO, Utilities Department, Storm Water Pollution Prevention Plan, Water Resource Recovery Facility City of SLO, Waterway Management Plan Volume 1, San Luis Obispo Creek Watershed, dated 3/3/03 NOAA, Precip Daily Precipitation Data and NOAA Atlas 14 Point Precipitation Frequency Estimates, downloaded 12/24/14 NRCS Hydrologic Soils Group Data, San Luis Obispo County, CA, downloaded 11/3/14 WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Appendix A – Proposed WRRF Site Drainage Figure WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page intentionally blank. ! ! ! ! SanLuisObispo Creek Filter FeedEqualizationBasin AerationBasins EqualizationBasin Laboratory, Operations, & Welcome Center EQ Pond Garden/PublicGreen Space SludgeDrying Beds Headworks PC 1 PC 2FC 1FC 2 Entrance FC 4 FC 5Filters FutureUpgrades Garden/PublicGreen Space Interpretive Center ProposedOutfall D ExistingOutfall C ExistingOutfall A ExistingOutfall B £¤101 D A F H G B C E F:\Projects\028_226664_City_of_SLO_WRR F_Upgrades\m ap_docs\m xd\Proposed_WRR F_SiteDrainage.m xd_5/12/2015_emesbah - 0 100 200 30050Feet Main MapExtent 0 50 10025Meters HDR | 2015 City of San Luis Obispo City of San Luis ObispoWater ReclamationRecovery Facility !Outfall LocationCulvert ConnectionEmergency Overflow Path Data Source: HDR, ESRIMap information was compiled from the bestavailable sources. No warranty is made for itsaccuracy or completeness.Projection is California State Plane Zone 5. Figure 1Proposed WRRFSite Drainage A Prad o R d Watershed BoundaryImpervious AreaPervious AreaIsolated Pervious AreaSelf Contained Area WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Appendix B – Watershed Management Zones WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page intentionally blank. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Appendix C – NOAA Daily Rainfall Percentile versus Depth Graph WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page intentionally blank. 0.00 1.00 2.00 3.00 4.00 5.00 6.00 0%5%10%15%20%25%30%35%40%45%50%55%60%65%70%75%80%85%90%95%100% Ra i n f a l l D e p t h ( i n c h e s ) Percentile NOAA San Luis Obipso Polytech Precipitation Gage USC00047851 1/1/1960 - 12/14/2014 WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Appendix D – Atlas 14 Point Precipitation Frequency Estimates WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page intentionally blank. www.nws.noaa.gov HomeSite MapNewsOrganization Search NWS All NOAA Go General Info Homepage Current Projects FAQ Glossary Precipitation Frequency (PF) PF Data Server •PF in GIS Format •PF Maps •Temporal Distr. •Time Series Data •PFDS Perform. PF Documents Probable Maximum Precipitation (PMP) PMP Documents Miscellaneous Publications AEP Storm Analysis Record Precipitation Contact Us Inquiries List-server DATA DESCRIPTION Data type:precipitation depth Units: english Time series type:partial duration SELECT LOCATION 1. Manually: a) Enter location (decimal degrees, use "-" for S and W): latitude: 35.2542 longitude: -120.6737 submit b) Select station (click here for a list of stations used in frequency analysis for CA):select station 2. Use map: a) Select location (move crosshair or double click) b) Click on station icon (show stations on map) LOCATION INFORMATION: Name: San Luis Obispo, California, US* Latitude: 35.2542° Longitude: -120.6737° Elevation: 126 ft* * source: Google Maps PF tabular PF graphical Supplementary information PDS-based precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration Average recurrence interval (years) 1251025501002005001000 5-min 0.145 (0.127-0.168) 0.178 (0.156-0.206) 0.221 (0.192-0.257) 0.256 (0.220-0.300) 0.303 (0.249-0.371) 0.339 (0.271-0.427) 0.375 (0.291-0.488) 0.412 (0.308-0.556) 0.462 (0.328-0.657) 0.500 (0.339-0.743) 10-min 0.208 (0.182-0.241) 0.255 (0.223-0.295) 0.317 (0.276-0.368) 0.367 (0.316-0.430) 0.434 (0.357-0.532) 0.485 (0.389-0.612) 0.538 (0.417-0.700) 0.591 (0.442-0.797) 0.662 (0.470-0.942) 0.716 (0.487-1.07) 15-min 0.252 (0.220-0.291) 0.309 (0.270-0.357) 0.383 (0.333-0.445) 0.443 (0.382-0.520) 0.525 (0.432-0.644) 0.587 (0.470-0.740) 0.650 (0.505-0.846) 0.714 (0.535-0.964) 0.800 (0.568-1.14) 0.866 (0.588-1.29) 30-min 0.350 (0.307-0.405) 0.429 (0.375-0.497) 0.533 (0.464-0.618) 0.616 (0.531-0.723) 0.730 (0.601-0.895) 0.816 (0.654-1.03) 0.904 (0.702-1.18) 0.993 (0.743-1.34) 1.11 (0.790-1.58) 1.20 (0.818-1.79) 60-min 0.494 (0.432-0.571) 0.606 (0.529-0.701) 0.751 (0.654-0.872) 0.869 (0.748-1.02) 1.03 (0.848-1.26) 1.15 (0.922-1.45) 1.28 (0.989-1.66) 1.40 (1.05-1.89) 1.57 (1.11-2.23) 1.70 (1.15-2.53) 2-hr 0.748 (0.654-0.863) 0.925 (0.808-1.07) 1.15 (1.00-1.34) 1.33 (1.15-1.56) 1.57 (1.29-1.93) 1.75 (1.40-2.21) 1.93 (1.50-2.51) 2.11 (1.58-2.85) 2.34 (1.66-3.34) 2.52 (1.71-3.75) 3-hr 0.946 (0.828-1.09) 1.18 (1.03-1.37) 1.48 (1.28-1.71) 1.71 (1.47-2.01) 2.02 (1.66-2.47) 2.25 (1.80-2.83) 2.47 (1.92-3.22) 2.70 (2.02-3.64) 3.00 (2.13-4.27) 3.22 (2.19-4.79) 6-hr 1.28 (1.12-1.48) 1.63 (1.42-1.88) 2.06 (1.79-2.39) 2.40 (2.07-2.82) 2.84 (2.34-3.48) 3.17 (2.54-3.99) 3.49 (2.71-4.54) 3.81 (2.85-5.14) 4.22 (3.00-6.01) 4.53 (3.08-6.74) 12-hr 1.60 (1.40-1.84) 2.08 (1.81-2.40) 2.68 (2.33-3.11) 3.15 (2.71-3.70) 3.77 (3.10-4.62) 4.22 (3.38-5.33) 4.67 (3.63-6.08) 5.12 (3.83-6.91) 5.70 (4.04-8.11) 6.13 (4.16-9.11) 24-hr 1.99 (1.82-2.21) 2.65 (2.42-2.96) 3.49 (3.18-3.91) 4.16 (3.75-4.70) 5.04 (4.38-5.92) 5.70 (4.83-6.86) 6.35 (5.24-7.86) 7.01 (5.60-8.96) 7.87 (6.00-10.5) 8.52 (6.25-11.9) 2-day 2.43 (2.22-2.71) 3.30 (3.02-3.69) 4.43 (4.03-4.96) 5.33 (4.81-6.03) 6.54 (5.68-7.68) 7.45 (6.32-8.97) 8.37 (6.90-10.4) 9.30 (7.42-11.9) 10.5 (8.03-14.1) 11.5 (8.41-16.0) NOAA ATLAS 14 POINT PRECIPITATION FREQUENCY ESTIMATES: CA Map data ©2014 GoogleReport a map error1 km POINT PRECIPITATION FREQUENCY (PF) ESTIMATES WITH 90% CONFIDENCE INTERVALS AND SUPPLEMENTARY INFORMATION NOAA Atlas 14, Volume 6, Version 2 Print Page Page 1of 2PFDS: Contiguous US 12/22/2014http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html?bkmrk=ca 3-day 2.75 (2.51-3.06) 3.76 (3.44-4.20) 5.09 (4.63-5.70) 6.16 (5.56-6.97) 7.61 (6.61-8.94) 8.71 (7.39-10.5) 9.83 (8.10-12.2) 11.0 (8.76-14.0) 12.5 (9.53-16.7) 13.7 (10.0-19.1) 4-day 2.99 (2.73-3.33) 4.10 (3.75-4.58) 5.58 (5.08-6.25) 6.78 (6.11-7.66) 8.40 (7.30-9.88) 9.66 (8.19-11.6) 10.9 (9.01-13.5) 12.2 (9.77-15.6) 14.0 (10.7-18.8) 15.4 (11.3-21.4) 7-day 3.54 (3.24-3.95) 4.86 (4.44-5.43) 6.62 (6.03-7.41) 8.07 (7.28-9.13) 10.1 (8.75-11.8) 11.7 (9.88-14.0) 13.3 (10.9-16.4) 14.9 (11.9-19.1) 17.3 (13.2-23.1) 19.1 (14.0-26.6) 10-day 3.97 (3.63-4.43) 5.43 (4.96-6.06) 7.40 (6.74-8.29) 9.04 (8.15-10.2) 11.3 (9.84-13.3) 13.1 (11.1-15.8) 15.0 (12.4-18.6) 17.0 (13.5-21.7) 19.7 (15.0-26.3) 21.8 (16.0-30.4) 20-day 5.05 (4.62-5.63) 6.90 (6.31-7.71) 9.42 (8.58-10.6) 11.5 (10.4-13.1) 14.5 (12.6-17.1) 16.9 (14.3-20.3) 19.3 (15.9-23.9) 21.9 (17.5-28.0) 25.5 (19.4-34.2) 28.4 (20.8-39.5) 30-day 6.12 (5.60-6.83) 8.34 (7.62-9.31) 11.4 (10.3-12.7) 13.9 (12.5-15.7) 17.5 (15.2-20.5) 20.3 (17.2-24.4) 23.2 (19.1-28.7) 26.3 (21.0-33.6) 30.6 (23.3-41.0) 34.0 (24.9-47.4) 45-day 7.46 (6.83-8.32) 10.1 (9.22-11.3) 13.7 (12.4-15.3) 16.6 (15.0-18.8) 20.8 (18.1-24.5) 24.1 (20.5-29.1) 27.6 (22.7-34.1) 31.2 (24.9-39.8) 36.1 (27.5-48.4) 40.1 (29.4-55.8) 60-day 8.81 (8.06-9.82) 11.8 (10.8-13.2) 15.9 (14.4-17.8) 19.2 (17.3-21.7) 23.9 (20.8-28.1) 27.6 (23.4-33.2) 31.4 (25.9-38.9) 35.4 (28.3-45.3) 40.9 (31.2-54.8) 45.2 (33.1-63.0) 1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Estimates from the table in csv format: precipitation frequency estimates Submit Main Link Categories: Home | OHD US Department of Commerce National Oceanic and Atmospheric Administration National Weather Service Office of Hydrologic Development 1325 East West Highway Silver Spring, MD 20910 Page Author:HDSC webmaster Page last modified: August 27, 2014 Map Disclaimer Disclaimer Credits Glossary Privacy Pol About Career Opportuniti Page 2of 2PFDS: Contiguous US 12/22/2014http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html?bkmrk=ca WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Appendix E – NRCS Soils Data WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page intentionally blank. Hydrologic Soil Group—San Luis Obispo County, California, Coastal Part (City of San Luis Obispo - WRRF Upgrade Project) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/3/2014 Page 1 of 4 39 0 2 9 0 0 39 0 3 1 0 0 39 0 3 3 0 0 39 0 3 5 0 0 39 0 3 7 0 0 39 0 3 9 0 0 39 0 4 1 0 0 39 0 4 3 0 0 39 0 4 5 0 0 39 0 4 7 0 0 39 0 4 9 0 0 39 0 2 9 0 0 39 0 3 1 0 0 39 0 3 3 0 0 39 0 3 5 0 0 39 0 3 7 0 0 39 0 3 9 0 0 39 0 4 1 0 0 39 0 4 3 0 0 39 0 4 5 0 0 39 0 4 7 0 0 39 0 4 9 0 0 711000 711200 711400 711600 711800 712000 712200 712400 711000 711200 711400 711600 711800 712000 712200 712400 35° 15' 54'' N 12 0 ° 4 0 ' 5 4 ' ' W 35° 15' 54'' N 12 0 ° 3 9 ' 5 2 ' ' W 35° 14' 47'' N 12 0 ° 4 0 ' 5 4 ' ' W 35° 14' 47'' N 12 0 ° 3 9 ' 5 2 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84 045090018002700 Feet 0100200400600 Meters Map Scale: 1:10,100 if printed on A portrait (8.5" x 11") sheet. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: San Luis Obispo County, California, Coastal Part Survey Area Data: Version 6, Sep 26, 2014 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: May 8, 2010—May 21, 2010 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Hydrologic Soil Group—San Luis Obispo County, California, Coastal Part (City of San Luis Obispo - WRRF Upgrade Project) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/3/2014 Page 2 of 4 Hydrologic Soil Group Hydrologic Soil Group— Summary by Map Unit — San Luis Obispo County, California, Coastal Part (CA664) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 120 Concepcion loam, 2 to 5 percent slopes D 22.9 9.0% 127 Cropley clay, 0 to 2 percent slopes C 66.9 26.2% 169 Marimel sandy clay loam, occasionally flooded C 2.3 0.9% 183 Obispo-Rock outcrop complex, 15 to 75 percent slopes D 0.0 0.0% 197 Salinas silty clay loam, 0 to 2 percent slopes C 163.2 63.9% Totals for Area of Interest 255.4 100.0% Hydrologic Soil Group—San Luis Obispo County, California, Coastal Part City of San Luis Obispo - WRRF Upgrade Project Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/3/2014 Page 3 of 4 Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Hydrologic Soil Group—San Luis Obispo County, California, Coastal Part City of San Luis Obispo - WRRF Upgrade Project Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 11/3/2014 Page 4 of 4 WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Appendix F – Proposed WRRF Site Plan WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page intentionally blank. WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Appendix G – Stormwater and Flood Management Presentation (January 29, 2015) WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page intentionally blank. Water Resource Recovery Facility Project Engage. Transform. Sustain. January 29, 2015 STORMWATER AND FLOOD MANAGEMENT Scope of Work •Stormwater Management –Perform on-site Hydrologic Evaluation –Consider Low Impact Development Options –Provide Individual Watershed Recommendations •Flood Management –Identify Flood Risks from San Luis Obispo Creek –Determine Proposed 100-Yr Water Surface Elevations –Recommend Next Steps to Manage Creek Flooding Stormwater Management Plan To be used as a basis for planning and design of future WRRF upgrades. Stormwater recommendations do not protect the WRRF from SLO Creek flooding. Additional flood protection is needed. Hydrology Evaluation •Delineate watersheds –Existing topographic data, drainage patterns •Determine proposed land use coverage •Determine precipitation depths –95th Percentile 24-hour event –10-year 24-hour storm event (4.16 in) •Determine soil type coverage Site Plan – used to determine land use coverage Proposed Watersheds and Land Use Coverage Precipitation Depths Event Duration Precipitation Depth 95th Percentile 24-hour 2.05 inches 10-Year 24-hour 4.16 inches LID Option - Bioretention Facility Watershed Recommendations Watershed ID 95th Percentile Storm Required LID Storage Volume (ac-ft) Maximum Water Depth of LID Basin 10-Year 24 - Hour Storm Required LID Storage Volume (ac-ft) Maximum Water Depth of LID Basin Retrofitting Opportunities New Construction Planned A 0.5 -- 1.1 -- X B 0.4 1.4 0.9 2.8 X X C 0.4 1.3 0.8 2.7 X D 0.4 0.9 1.0 1.9 X X E 0.4 1.2 0.8 2.5 X X F 0.4 1.3 0.9 2.8 X G 0.4 0.4 0.8 1.9 X X H 0.8 0.7 1.5 1.5 X X Low Impact Development Options Other Stormwater Considerations •Outfall releases to the Creek during high flows •Identify existing underground utilities •Collect soils percolation rate data •Protect site during construction •Increased operation and maintenance Flood Risk From San Luis Obispo Creek •Existing Conditions HEC-RAS model received from Wallace Group –Results showed much more extensive flooding compared to FEMA •Evaluate proposed site plan layout increases existing water surface elevation •Flood protection is needed for the WRRF Effective FEMA FIRM Wallace Group 100-Year Floodplain Map (2014) Proposed WRRF 100-Year Water Surface Elevation Proposed WRRF 100-Year Water Surface Elevation Flood Protection Alternatives •Setting finished floor elevations above the 100-year WSE •Flood proofing by installing perimeter levee/ floodwalls on site •Constructing a levee/floodwall along the Creek banks •Dredging a bypass channel Recommended Next Steps •Establish objectives to providing flood protection at the WRRF •Verify Wallace Group HEC-RAS model has been reviewed, approved, and accepted by the City’s hydraulic engineer •Identify critical infrastructure that will require mandatory 100-year level of protection •Determine most cost beneficial solution to providing 100-year level of protection •Determine if larger scale flood protection is necessary or warranted •Pursue a CLOMR and/or LOMR for changes to FEMA’s Flood Insurance Rate Map Flood Protection Objectives •How does the WRRF need to function during a 100-year flood? •How would the WRRF be accessed during a 100-year flood? •Is the City interested in removing any other areas of the City out of the San Luis Obispo Creek 100-year floodplain while providing WRRF site protection? •Environmental objectives? No spills? Questions? WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Appendix H – San Luis Obispo Creek Flood Alternatives Workshop Presentation (March 24, 2015) WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page intentionally blank. Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t En g a g e . Tr a n s f o r m . Su s t a i n . March 24, 2015 FL O O D MA N A G E M E N T WORKSHOP Ag e n d a 1. B a c k g r o u n d 2. L e v e l Of Se r v i c e Ob j e c t i v e s 3. F l o o d Ma n a g e m e n t Al t e r n a t i v e s 4. R e c o m m e n d e d Al t e r n a t i v e 5. N e x t St e p s Ef f e c t i v e FE M A FI R M Wa l l a c e Gr o u p 10 0 ‐Ye a r Fl o o d p l a i n Ma p (2 0 1 4 ) 10 0 ‐Ye a r Fl o o d De p t h s (f t ) Mi n i m u m Re q u i r e m e n t s • Fr o m NP D E S Pe r m i t (A t t a c h m e n t D – S t a n d a r d Pr o v i s i o n s ) : – II . B . Ce n t r a l Co a s t St a n d a r d Pr o v i s i o n s –P r o v i s i o n s 2. Al l fa c i l i t i e s us e d fo r tr a n s p o r t or tr e a t m e n t of wa s t e s sh a l l be ad e q u a t e l y protected fr o m in u n d a t i o n an d wa s h o u t as th e re s u l t of a 10 0 ‐ye a r fr e q u e n c y flood. • Fr o m NP D E S Pe r m i t (V I . Pr o v i s i o n s , C. 5 . ) : – “a . Bi o s o l i d s Ma n a g e m e n t vi i . Th e so l i d s an d sl u d g e tr e a t m e n t an d st o r a g e si t e sh a l l ha v e ad e q u a t e fa c i l i t i e s … A d e q u a t e pr o t e c t i o n is de f i n e d as pr o t e c t i o n , at th e mi n i m u m , from a 10 0 ‐ye a r st o r m an d pr o t e c t i o n fr o m th e hi g h e s t po s s i b l e ti d a l st a g e that may oc c u r . ” • Fr o m Re c o m m e n d e d St a n d a r d s fo r Wa s t e w a t e r Fa c i l i t i e s (1 0 St a t e s ) : – “51 . 2 F l o o d Pr o t e c t i o n Th e tr e a t m e n t pl a n t st r u c t u r e s , el e c t r i c a l , an d me c h a n i c a l eq u i p m e n t sh a l l be protected fr o m ph y s i c a l da m a g e by th e on e hu n d r e d (1 0 0 ) ye a r fl o o d .T r e a t m e n t plants should re m a i n fu l l y op e r a t i o n a l an d ac c e s s i b l e du r i n g th e tw e n t y ‐fi v e (2 5 ) ye a r flood.This re q u i r e m e n t ap p l i e s to ne w co n s t r u c t i o n an d to ex i s t i n g fa c i l i t i e s un d e r g o i n g major mo d i f i c a t i o n . F l o o d pl a i n re gu l a t i o n s of st a t e , pr o v i n c e , an d fe d e r a l ag e n c i e s shall be co n s i d e r e d . ” Le v e l of Se r v i c e Ob j e c t i v e s • Ke e p WW R F op e r a t i o n a l • Me e t pe r m i t re q u i r e m e n t s Al t e r n a t i v e s o Up s t r e a m / Re g i o n a l Im p r o v e m e n t s o By p a s s Ch a n n e l (E l k s La n e CI P or al o n g Hw y 101) o Ri n g Le v e e / Fl o o d w a l l ar o u n d WW R F o Sp e c i f i c On s i t e Im p r o v e m e n t s Up s t r e a m / Re g i o n a l Im p r o v e m e n t s Mu l t i p l e su b ‐wa t e r s h e d dr a i n i n g in t o Sa n Lu i s Ob i s p o Cr e e k So u r c e : 20 0 3 SL O Cr e e k Wa t e r s h e d Wa t e r w a y Ma n a g e m e n t Pl a n SL O Cr e e k Wa t e r s h e d Wa t e r w a y Pl a n Pr e f e r r e d Pr o j e c t s Li s t : • Cu e s t a Pa r k De t e n t i o n St o r a g e • El k s La n e By p a s s • Mi d Hi g u e r a F l o o d Co n t r o l • Ch a n n e l / B r i d g e Re p l a c e m e n t s at Lo s Os o s V a l l e y Ro a d El k s La n e By p a s s Ch a n n e l So u r c e : 20 0 3 SL O Cr e e k Wa t e r s h e d Wa t e r w a y Ma n a g e m e n t Pl a n Es t i m a t e d co n s t r u c t i o n cost: $15M By p a s s Ch a n n e l – Al o n g Hw y 10 1 Es t i m a t e d ch a n n e l di m e n s i o n s : • ~6 , 0 0 0 cf s b y p a s s fl o w • 70 ft c h a n n e l to p wi d t h • 2H : 1 V ch a n n e l si d e sl o p e s • 1 ft o f fr e e b o a r d • 5 ft i n fl o w de p t h • Co n c r e t e li n e d • 6, 9 0 0 ft l e n g t h • we i r in l e t • sl o p e pr o t e c t i o n ou t l e t Co n c e r n s : de e p wa t e r , hi g h ve l o c i t i e s , li m i t e d ch a n n e l wi d t h Es t i m a t e d co n s t r u c t i o n co s t : $1 2 ‐$1 5 Mi l l i o n Ri n g Le v e e / F l o o d w a l l ar o u n d WRRF • 1. 3 mi l e s of le v e e / f l o o d w a l l le n g t h • 4‐6 ft t a l l • 3 ft o f fr e e b o a r d • En t r a n c e / E x i t ga t e s ra m p ne e d e d • Ut i l i t y re l o c a t i o n s re q u i r e d • Ac c e p t a b l e le v e e fi l l ma t e r i a l av a i l a b l e • Ge o t e c h n i c a l co n d i t i o n ev a l u a t e d • Re q u i r e s US im p r o v e m e n t s Co n c e r n s : re q u i r e s US im p r o v e m e n t s Es t i m a t e d co n s t r u c t i o n co s t : $1 3 ‐$2 0 + Mi l l i o n Fl o o d Ga t e Ac c e s s Ma n u a l l y In s t a l l St o p Lo g s and I‐Beams Ma n u a l l y Cl o s e d Fl o o d Ga t e s So u r c e : Ty p i c a l Ve h i c u l a r Ga t e fr o m FloodBreak On ‐Si t e Im p r o v e m e n t Op t i o n s • Ne w Fa c i l i t i e s – De s i g n pr o t e c t i o n s fo r 10 0 ‐Yr Fl o o d • Ex i s t i n g & Im p r o v e d Fa c i l i t i e s – Do no t h i n g – Mi n i m u m pr o t e c t i o n to me e t pe r m i t re q u i r e m e n t s – Pr o v i d e ad d i t i o n a l pr o t e c t i o n to re d u c e co s t / t i m e to re c o v e r Al t e r n a t i v e s Ev a l u a t i o n Al t e r n a t i v e Co s t S c h e d u l e Ri s k Ad v a n t a g e s / D i s a d v a n t a g e s Up s t r e a m I m p r o v e m e n t Pr o j e c t s $2 0 M + Y e s ‐ Re g i o n a l so l u t i o n ‐Ma y no t so l v e th e pr o b l e m at WRRF El k s La n e By p a s s $1 5 M Y e s ‐Do e s n ’ t co m p l e t e l y pr o t e c t t h e WRRF ‐Us e s WR R F Pr o p e r t y fo r te r r a c e 10 1 By p a s s Ch a n n e l $ 1 2 ‐$1 5 M Y e s ‐Pr o t e c t s th e WR R F ‐Sa f e t y I s s u e s ‐Ca l T r a n s c o o r d i n a t i o n ne e d e d ‐Pr e f u m a C r e e k im p a c t s un d e t e r m i n e d ‐Ut i l i t y co n f l i c t s un q u a n t i f i e d Ri n g Le v e e / F l o o d w a l l $ 1 3 ‐ $2 0 M + No ‐Pr o t e c t s th e WR R F ‐Ke e p s it dr y / a c c e s s i b l e i n t e r n a l l y ‐Re q u i r e s ad d i t i o n a l up s tr e a m improvements (n o t qu a n t i f i e d ) On ‐Si t e I m p r o v e m e n t s ~ $ 1 M N o ‐Pr o t e c t s ke y WR R F fa c i l i t i e s ‐Mi n i m a l i m p a c t s on co m m u n i t y ‐Si t e A c c e s s du r i n g st o r m s ma y be impacted On ‐Si t e Im p r o v e m e n t s In i t i a l Co s t Br e a k d o w n CO S T SU M M A R Y BY PR I O R I T Y Po w e r L i q u i d S o l i d s A d m i n T O T A L PRIORITY LO W $3 6 , 0 0 0 $ 1 5 6 , 5 0 0 $ 3 9 , 0 0 0 $ 0 $ 2 3 1 , 5 0 0 ME D I U M $3 9 , 0 0 0 $ 2 2 4 , 0 0 0 $ 0 $ 0 $ 2 6 3 , 0 0 0 HI G H $1 3 8 , 0 0 0 $ 7 4 , 0 0 0 $ 0 $ 0 $ 2 1 2 , 0 0 0 TO T A L $2 1 3 , 0 0 0 $ 4 5 4 , 5 0 0 $ 3 9 , 0 0 0 $ 0 $ 7 0 6 , 5 0 0 Ne x t St e p s • Su m m a r i z e wo r k s h o p ou t c o m e s • Up d a t e Fa c i l i t i e s Pl a n • Ad d i t i o n a l Ac t i o n s It e m s : – Ve r i f y Wa l l a c e Gr o u p HE C ‐RA S mo d e l ha s be e n re v i e w e d , ap p r o v e d , an d ac c e p t e d by th e Ci t y ’ s hy d r a u l i c en g i n e e r – Pu r s u e a CL O M R an d / o r LO M R fo r ch a n g e s to FEMA’s Fl o o d In s u r a n c e Ra t e Ma p WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Appendix I – Proposed WRRF 100-Year Water Surface Elevations from San Luis Obispo Creek WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page intentionally blank. ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! SanLuisObispo Creek Q100 = 5,124cfs Q100 = 1 1 , 9 0 5 c f s Q100 = 8,223cfs £¤101 XS 1 3 8 8 1 . 8 0 XS 1 3 6 5 9 . 6 6 XS 1 3 4 3 9 . 9 4 XS 13776.59 XS 13 5 4 1 . 9 9 XS 1 3 2 7 5 . 5 7 XS 1 3 3 8 1 . 5 1 XS 9 8 . 7 2 / 1 0 0 y r W S E = 1 2 5 . 4 XS 4 5 0 . 7 4 / 1 0 0 y r W S E = 1 2 9 . 0 XS 6 6 7 . 0 3 / 1 0 0 y r W S E = 1 3 0 . 6 XS 9 4 7 . 0 8 / 1 0 0 y r W S E = 1 3 2 . 2 XS 1 1 8 5 . 4 6 / 1 0 0 y r W S E = 1 3 3 . 5 XS 1 4 7 4 . 5 2 / 1 0 0 y r W S E = 1 3 4 . 8 XS 1 7 3 4 . 7 8 / 1 0 0 y r W S E = 1 3 5 . 6 X S 1 9 7 6 . 2 / 1 0 0 y r W S E = 1 3 6 . 9 131.8 130.2 131.3 132.2 131.3 130.5 131.8 132.4 130.2 129.1 130.3 129.6 129.5 128.2 136.3 136.5135.4 135.5 133.2 134.5 134.3 134.1 136.8 137.9 137.3 135.6 132.3 132.4 126.4 126.5 126.1 124.4 125.1 124.4 125.4 124.9 F: \ P r o j e c t s \ 0 2 8 _ 2 2 6 6 6 4 _ C i t y _ o f _ S L O _ W R R F _ U p g r a d e s \ m a p _ d o c s \ m x d \ P r o p o s e d _ W R R F _ X S - C o p y . m x d _ 1 / 2 3 / 2 0 1 5 _ J K a t z m a n - 0 100 200 30050 Feet Main MapExtent 0 50 10025Meters HDR | © 2014 City of San Luis Obispo City of San Luis Obispo Water Reclamation Recovery Facility Data Source: HDR, ESRI Map information was compiled from the best available sources. No warranty is made for its accuracy or completeness. Projection is California State Plane Zone 5. Figure 2Proposed WRRF100 Year WaterSurface Elevation Pr a d o R d Project Boundary Project Cross Section Stream Cross Section Weir Control Structure !Elevation Point Modeled Structure above 100 Yr WSE Qtransfer = 1,887cfs Qtransfer = 1,432cfs WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Appendix J – Proposed WRRF HEC-RAS Cross Sections WRRF Project TM No. 10.1 – Stormwater and San Luis Obispo Creek Flood Management Page intentionally blank. Proposed Water Surface Elevation Cross Section 1976.2 100-Year WSE 136.90 ft (NAVD 88) 400 600 800 1000130 132 134 136 138 140 142 144 WG_SLO_Update Plan: WG_SLO_Proposed100 12/23/2014 RS = 1976.2 Station (ft) El e v a t i o n ( f t ) Legend WS Questa100 Ground Ineff Bank Sta .035 100-Year Event WSE NOTE: 1. - Ground elevation reflects existing conditions. 2. - Cross section display is limited to WRRF area only. Proposed Water Surface Elevation Cross Section 1734.78 100-Year WSE 135.56 ft (NAVD 88) 400 600 800 116 118 120 122 124 126 128 130 132 134 136 138 140 142 144 146 148 150 WG_SLO_Update Plan: WG_SLO_Proposed100 12/23/2014 RS = 1734.78 Station (ft) El e v a t i o n ( f t ) Legend WS Questa100 Ground Levee Bank Sta .035 100-Year Event WSE Equalization Pond Laboratory, Operations & Interpretive Center NOTE: 1. - Ground elevation reflects existing conditions. 2. - Building elevation are set above the 100-Year Event WSE 3. - Cross section display is limited to WRRF area only. Proposed Water Surface Elevation Cross Section 1474.52 100-Year WSE 134.84 ft (NAVD 88) 0 200 400 600 800 1000 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 WG_SLO_Update Plan: WG_SLO_Proposed100 12/23/2014 RS = 1474.52 Station (ft) El e v a t i o n ( f t ) Legend WS Questa100 Ground Bank Sta .035 Cal Poly Research Center Odor Control 100-Year Event WSE Control BLDG NOTE: 1. - Ground elevation reflects existing conditions. 2. - Building elevation are set above the 100-Year Event WSE 3. - Cross section display is limited to WRRF area only. MCC’s, MgOH2 Storage, Methanol Storage Odor Control and Grit Removal Equalization Basin Proposed Water Surface Elevation Cross Section 1185.46 100-Year WSE 133.48 ft (NAVD 88) 0 200 400 600 800128 130 132 134 136 138 140 WG_SLO_Update Plan: WG_SLO_Proposed100 12/23/2014 RS = 1185.46 Station (ft) El e v a t i o n ( f t ) Legend WS Questa100 Ground Bank Sta .035 100-Year Event WSE Dewatering Ferrous Chloride Storage Primary Clarifier 1 and 2 Aeration Basin 3-6 NOTE: 1. - Ground elevation reflects existing conditions. 2. - Building elevation are set above the 100-Year Event WSE 3. - Cross section display is limited to WRRF area only. Aeration Basin 1 and 2 Proposed Water Surface Elevation Cross Section 947.08 100-Year WSE 132.16 ft (NAVD 88) 0 200 400 600 126 128 130 132 134 136 138 140 142 144 WG_SLO_Update Plan: WG_SLO_Proposed100 12/23/2014 RS = 947.08 Station (ft) El e v a t i o n ( f t ) Legend WS Questa100 Ground Bank Sta .035 100-Year Event WSE Thickening and Solid Blend Tank NOTE: 1. - Ground elevation reflects existing conditions. 2. - Building elevation are set above the 100-Year Event WSE 3. - Cross section display is limited to WRRF area only. Final Clarifier 4 Final Clarifier 4 Proposed Water Surface Elevation Cross Section 667.03 100-Year WSE 130.64 ft (NAVD 88) 0 100 200 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 WG_SLO_Update Plan: WG_SLO_Proposed100 12/23/2014 RS = 667.03 Station (ft) El e v a t i o n ( f t ) Legend WS Questa100 Ground Bank Sta .035 100-Year Event WSE NOTE: 1. - Ground elevation reflects existing conditions. 2. - Building elevation are set above the 100-Year Event WSE 3. - Cross section display is limited to WRRF area only. Administration Building Filters 1-4 Proposed Water Surface Elevation Cross Section 450.74 100-Year WSE 128.98 ft (NAVD 88) 0 100 200 300 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 WG_SLO_Update Plan: WG_SLO_Proposed100 12/23/2014 RS = 450.74 Station (ft) El e v a t i o n ( f t ) Legend WS Questa100 Ground Bank Sta .035 100-Year Event WSE NOTE: 1. - Ground elevation reflects existing conditions. 2. - Building elevation are set above the 100-Year Event WSE 3. - Cross section display is limited to WRRF area only. Filters Cooling Towers Proposed Water Surface Elevation Cross Section 98.72 100-Year WSE 125.43 ft (NAVD 88) 0 100 200 300 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 WG_SLO_Update Plan: WG_SLO_Proposed100 12/23/2014 RS = 98.72 Station (ft) El e v a t i o n ( f t ) Legend WS Questa100 Ground Bank Sta .035 100-Year Event WSE NOTE: 1. - Ground elevation reflects existing conditions. 2. - Building elevation are set above the 100-Year Event WSE 3. - Cross section display is limited to WRRF area only. UV Disinfection Appendix M TM No. 10.2 - Infrastructure Planning, Electrical and I&C Date: 12/15/2014 Prepared by: Bill Ettlich, PE Reviewed by: Mallika Ramanathan, PE, Holly Kennedy, PE, Lianne Westberg, PE, Jeff Szytel, PE, Jasmine Diaz, EIT Project: WRRF Project SUBJECT: TM NO. 10.2 – ELECTRICAL AND I&C The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long-term strategy for resource management. The purpose of this technical memorandum (TM) is to describe the existing electrical and instrumentation systems, perform an electrical load study and provide recommendations for system upgrades. Contents Introduction .............................................................................................................................. 3 Plant Electrical System ............................................................................................................ 3 Existing Plant Electrical Loads ................................................................................................................. 7 Future Plant Loads ................................................................................................................................... 8 Major Plant Electrical Equipment Condition Assessment ......................................................................... 9 Plant Electrical System Improvement Recommendations ...................................................................... 11 Equipment Preferences .......................................................................................................................... 12 Instrumentation and Controls ................................................................................................15 Current SCADA/PLC System ................................................................................................................. 15 Planned SCADA/PLC Upgrades ............................................................................................................ 15 Inventory of Existing SCADA Equipment ........................................................................................... 15 Utilization of Existing SCADA System ................................................................................................ 16 Energy Efficiency Project SCADA Improvements .............................................................................. 16 Plant Control ........................................................................................................................................... 16 Equipment Preferences .......................................................................................................................... 18 SCADA System Improvements .............................................................................................................. 18 List of Tables Table 1. Existing Electrical Loads ................................................................................................................. 7 Table 2. Projected Electrical Loads .............................................................................................................. 8 Table 3. Electrical Equipment Condition Assessment Summary .................................................................. 9 WRRF Project TM No. 10.2 – Electrical and I&C Page 2 of 20 List of Figures Figure 1. Existing Plant Electrical Facilities .................................................................................................. 4 Figure 2. Existing Main Plant Electrical System............................................................................................ 5 Figure 3. Existing Reclamation Electrical System......................................................................................... 6 Figure 4. Plant Upgrade Electrical System ................................................................................................. 13 Figure 5. Reclamation Upgrade Electrical System ..................................................................................... 14 Figure 6. Typical SCADA Block Diagram .................................................................................................... 19 List of Appendices Appendix A – Electrical Load Calculations WRRF Project TM No. 10.2 – Electrical and I&C Page 3 of 20 Introduction This technical memorandum (TM) evaluates electrical and instrumentation and control (I&C) facilities at the City of San Luis Obispo’s (City) Water Resource Recovery Facility (WRRF). The purpose of this evaluation is to assess the condition and capacity of the electrical and I&C facilities and identify improvements needed at the WRRF. Plant Electrical System The WRRF is served by two PG&E 480 volt, 3 phase, 4 wire electrical services. The main service (Plant Service 1) is rated for 3,000 amperes (amp) and is located in the plant electrical building. This service consists of a 3,000 amp Main Switchgear (MSG) which includes PG&E metering, main 3,000 amp breaker, feeder breaker for the 150 KW digester gas cogeneration unit and feeder breakers for each major plant load center including MCC A1, A2, B1, B2, J1, J2, F1, F2 and H. A natural gas/propane standby generator rated 560 KW (700 KVA) is available to provide standby power to motor control centers (MCC)A1, A2, B1, B2, J1E, J2E and H and panelboards F and G through individual automatic transfer switches (ATS). This generator can only serve a portion of the plant load during power outages and the ATS’s can be used to shed plant load to match the generator capacity. The City is presently purchasing electricity at the main plant service from PG&E and primary rate schedule and owns the service transformer. The other plant service (Plant Service 2) is rated for 1,200 amps, consists of a service switchboard with PG&E meter, future standby generator breaker and feeders for MCC-R (including pumps WRP 101 and 201), pumps WRP 301, 501, 701, two spare 400 ampere feeders and a Square D Accusine active harmonic control unit for control of harmonics for the pump variable frequency drives (VFD’s). This service presently serves the recycled water pumps at the WRRF. This service, the VFD’s and MCC-R are located in an electrical building in the Reuse Area, located in the southwestern area of the site. The MCCs at the WRRF are located as follows: • MCC-A1 and A2 are located in a building near Digester 1, • MCC-B1 and B2 are located in a building near Primary Clarifier 2, • MCC-J1, J2, J1E and J2E are located in a building near Flow Equalization Tank 1, • MCC-F1, F2 and H are located in the main electrical building, • MCC-G1 and G2 are located in the building near the DAF thickener, and • MCC-C is located outdoors at the far NE part of the plant site by the Equalization Pond. MCC-D was located in a building near MCC-A, but has been abandoned and the loads were incorporated into MCC-A. The locations of the various plant electrical load centers and MCC’s are shown in Figure 1. Single line diagrams for the existing main plant service and reclamation plant service are shown in Figures 2 and 3. WRRF Project TM No. 10.2 – Electrical and I&C Page 7 of 20 Currently all load centers are radially fed with single feeders from the main switchboard, MSG. This system has been trouble free over the years it has been in use. Existing Plant Electrical Loads The existing loads on the various plant load centers are shown in Table 1. Both the total connected load (all plant load) and the demand load (maximum load that can occur concurrently) are shown. The loads include the plant improvements underway including installation of 2 high-speed turbo blowers, 150 KW cogeneration unit and abandonment of the Turblex and 2 Lamson blowers. There is capacity available for future plant electrical loads and most load centers are only nominally loaded as shown in Table 1. Table 1. Existing Electrical Loads PANEL PANEL FEEDER CAPACITY EXISTING LOAD, KVA Amperes KVA Connected Demand MCC-A1 400 266 265 230 MCC-C 150 100 20 15 MCC-A2 400 266 187 150 MCC-B1 300 199 42 22 MCC-B2 300 199 55 30 MCC-J1 800 532 600 408 Admin Bldg. 175 116 166 128 MCC-J1E 150 100 79 44 MCC-J2 800 532 477 259 MCC-J2E 50 33 65 34 MCC-F1 1200 798 332 238 MCC-G1 600 399 85 47 MCC-F2 1200 798 274 199 MCC-G2 600 399 63 13 MCC-H 400 266 81 54 SWBD-MSG 3000 2494 2791 1871 SWBD-R 1200 798 487 352 MCC-R 400 266 122 102 MCC – Motor control center SWBD – Switchboard WRRF Project TM No. 10.2 – Electrical and I&C Page 8 of 20 Future Plant Loads The capability of the plant to serve the expected loads for the WRRF expansion are shown in Table 2 in a format similar to Table 1. The expected loads were estimated to include expansion of the aeration basins and blowers, tertiary filters, cooling towers and conversion to ultraviolet (UV) disinfection. Appendix A provides details on loads for the electrical load calculations. Improvements that are underway as part of the SST Project as well as aeration blower replacement were assumed in the existing electrical load calculations. The projected future demand load of 3285 KVA for SWBD – MSG is greater than its capacity of 2494 KVA, but with a conservative diversity factor of 70% applied to this total plant demand load the actual demand is 2300 KVA, well within the switchboard capacity. The diversity factor considers that not all motors and loads are operating at full motor horsepower or at rated load and that not all loads will be operating exactly concurrently. A factor of 70% is considered to be conservative for this facility. The plant electrical system has the capability to serve these expected plant load increases with some reserve for additional future load except for the standby generation system. There are several plant electrical system deficiencies which are covered in another section of this TM. Table 2. Projected Electrical Loads PANEL PANEL FEEDER CAPACITY FUTURE LOAD, KVA Amperes KVA Connected Demand MCC-A1 400 266 405 370 MCC-C 150 100 20 15 MCC-A2 400 266 217 170 MCC-B1 300 199 162 142 MCC-B2 300 199 55 30 MCC-J1 800 532 818 520 Admin Bldg. 300 199 166 128 MCC-J1E 150 100 79 44 MCC-J2 800 532 608 390 MCC-J2E 50 33 65 34 MCC-F1 1200 798 754 649 MCC-G1 175 116 76 36 MCC-F2 1200 798 710 635 MCC-G2 175 116 28 8 MCC-H 400 266 81 54 SWBD-MSG TOTAL 3000 2494 4244 3285 Overall Diversity Factor (70%) for SWBD-MSG SWBD-MSG Total Diversified Load 2300 SWBD-R 1200 798 1032 882 MCC-R 400 266 112 102 WRRF Project TM No. 10.2 – Electrical and I&C Page 9 of 20 Major Plant Electrical Equipment Condition Assessment Each major plant electrical equipment was visually inspected to determine the current condition in order to determine suitability for continued service. A summary of the major electrical equipment condition is shown in Table 3. The following general observations relate to the equipment condition. Table 3. Electrical Equipment Condition Assessment Summary Equipment Condition Short Circuit Bracing, Amperes Suitable For Continued Service SWBD-MSG Good 75,000 Yes MCC-A1 Very Good 42,000 Yes MCC-A2 Very Good 42,000 Yes MCC-B1 Very Good 42,000 Yes MCC-B2 Very Good 42,000 Yes MCC-J1 Very Good 42,000 Yes MCC-J2 Very Good 42,000 Yes MCCJ1E Very Good 42,000 Yes MCC-J2E Very Good 65,000 Yes MCC-F1 Very Good 65,000 Yes MCC-F2 Very Good 42,000 Yes MCC-G1 Very Good 42,000 Yes MCC-G2 Very Good 42,000 Yes MCC-H Very Good 65,000 Yes MCC-C Fair Unknown Yes (1) MCC-D Abandoned Standby Generator Good - Yes (2) SWBD EG Good 50,000 Yes SWBD-R Very Good Unknown Yes MCC-R Very Good Unknown Yes ATS’s (9) Very Good Matches respective MCC Yes Notes: (1) Under present use. Replace if load is to be added. (2) Undersized for current plant needs, see improvement schedule. 1. In general the minor electrical equipment including lighting and power panelboards, dry type transformers, stand alone VFD’s, ATS’s and similar equipment are in good condition and are serviceable for continued use. Equipment appeared to be complete with all protective panels and doors in place. Panelboards contained directories of the circuits. 2. Both main electrical service switchboards are in serviceable condition. Some of the paint on switchboard MSG in the electrical building is faded due to sun exposure at some time (it is now inside a building), but this does not impact its serviceability. 3. All of the MCC’s except MCC-C are Westinghouse Model 2100 which are no longer manufactured, but spare parts are available. These MCC’s are all in excellent condition, are located inside buildings and are suitable for continued service. It will probably WRRF Project TM No. 10.2 – Electrical and I&C Page 10 of 20 become desirable to replace the existing MCC’s to take advantage of newer MCC features such as arc-flash reduction features and “smart” MCC features before the existing MCC’s become unserviceable as the existing MCC’s probably would be serviceable for another 15 years. 4. MCC-C is a very old Autocon unit located in a NEMA 3R outdoor enclosure. This MCC is in fair condition and would not be suitable for service as a major MCC under future conditions. It currently serves only 3 pumps which are not critical to plant operations so continued service with existing conditions will not impact plant reliability. If additional load needs to be added to MCC-C in the future or if the MCC needs to be moved, MCC-C should be upgraded otherwise it can continue to service the existing load. 5. There are nine ATS’s which transfer plant load to the standby generator during a power failure. These transfer switches are located in the various electrical buildings and are in excellent condition. See the discussion in this section of the TM related to standby generation for additional comments. 6. The existing standby generator is a Caterpillar 560 KW propane gas driven unit and is located in the electrical building. It is also capable of operation on natural gas. This unit is only used as a standby generator and is not used for peak shaving as it has no capability for synchronizing onto a hot bus and is not PG&E approved for parallel operation with the PG&E system. The generator is in excellent condition and has about 400 operating hours but is much too small to serve even existing loads. There are feeders from the standby generator switchboard, SWBD EG, to each of the seven standby generator powered MCC’s (MCC A1, A2, B1, B2, J1E, J2E and H) and to Panelboards LP-F and LP-F1 (Electrical building and Telemetry Shop) and LP-G (solids thickening). Switchboard EG is located in the electrical building and is in serviceable condition. 7. The short circuit (fault interrupting) rating of each major equipment is shown in Table 3. All of the major electrical equipment is adequately rated for the maximum fault current except for MCC-C. This is not a critical MCC and the feeder breaker for MCC-C in MCC-A2 can interrupt and clear any potential fault in MCC-C. All of the ATS’s are rated for fault currents in excess of the highest possible fault current. 8. Confirmation that the various adjustable trip plant circuit breakers are properly coordinated so the breaker closest to a fault will trip first is necessary. It is recommended that a coordination study be undertaken as part of the WRRF upgrades to determine correct circuit breaker settings. The breakers should be adjusted to these recommended settings. 9. Current practice and code requirements require arc flash labelling for essentially all electrical equipment for new installations. Generic arc flash labels such as Brady Catalog #101518 should be installed on existing plant electrical equipment. An arc flash study should be conducted on the plant electrical equipment as part of the WRRF upgrades and more detailed arc flash labels installed which show the level of protective clothing required at each electrical panel. WRRF Project TM No. 10.2 – Electrical and I&C Page 11 of 20 Plant Electrical System Improvement Recommendations The proposed upgraded single line diagrams for plant and reclamation electrical systems are shown in Figures 4 and 5. The following plant electrical system improvements are recommended. 1. The plant standby generation system is undersized for the existing plant and is much too small for the planned plant improvements. The standby generator is rated 560 KW (700 KVA) and is too small even when the plant is operating under dry weather conditions. The present system of multiple ATS’s is complicated and does not allow operation of secondary biological treatment or filtration during power outages. The existing ATS’s can not remain in service for load sheading purposes as they and the associated feeders are too small. It is recommended that a standby generator sized adequately for the plant load with a single 3000 amp ATS be installed at the electrical building. This will allow full plant operation during power outages. This system can also be designed to allow the use of the cogeneration system during power outages if the cogenerator is isolated from PG&E by the ATS. This standby generator should be sized for 2000 KW (2500 KVA) so the full plant demand can be served, should be installed outdoors with a weather protection acoustical enclosure and integral base fuel tank. We recommend the installation of a diesel powered generator as it will be much smaller and less expensive compared to a gas powered generator. The existing generator building can be used for other purposes. 2. Serve the UV electrical load from SWBD-R and install a standby generator and ATS at SWBD-R as there is no existing standby generator at this location. This generator should be sized for the full capacity of SWBD-R, 1000 KW, should be installed outdoors with a weather protection acoustical enclosure and integral base fuel tank. The existing standby generator is too small to be moved to serve SWBD R and it would not be cost effective to move it because of the high cost of moving. 3. The WRRF upgrades should include requirements for a short circuit/coordination/arc flash study, arc flash labeling of all existing and new electrical panels and adjustment of all protective device settings. The contract should include testing of all existing protective devices for proper operation. 4. All electrical panels should be labelled with the location of the primary disconnect for each panel. 5. As part of this TM, HDR looked at the continuation of the existing radial feeder system and the possibility of implementing a dual feeder system to each load center. The existing radial feed system has been trouble free over the years. If a radial feeder is lost it is possible to bring in a portable generator to serve that load center until the feeder can be repaired or replaced. The dual feeder system may provide some measure of increased continuity of service of reliability, but at greatly increased cost and complication. Implementation of the dual feeder system would require additional underground duct banks and an expanded switchboard MSG for the added feeders. Based on past plant experience, the cost to convert to a dual feeder system is not justified based on a very slight increase in continuity of service and reliability. WRRF Project TM No. 10.2 – Electrical and I&C Page 12 of 20 6. A loop system for the 12 KV service can be considered in the future if additional 480 volt load centers are needed. 7. It is recommended that power monitors be added to the major load centers such as switchboards and MCC’s for purposes of power and energy management. This can be done as part of the next plant upgrade or when major equipment is replaced. Power monitors have a wide range of capability and are relatively inexpensive to install. They can be tied into existing PLC’s using a data link in order to take advantage of their range of capabilities. 8. All of the MCC’s except MCC-C are Westinghouse Series 2100, are in excellent condition and are suitable for continued service. Existing Autocon MCC-C should be replaced if it is moved or if any additional load is to be added as it is very old and is not of modern construction. While the Westinghouse Series 2100 MCC’s would probably provide satisfactory service for another 15 or 20 years newer MCC’s have advanced features that will probably dictate replacement before the end of their actual service life. These new features include “smart” construction which allows complete monitoring of the MCC drives over a single digital data link which can be connected directly into the PLC network just like the other PLC’s. There are also other advanced features such as IR monitoring and certain arc flash protection features. It is recommended that the existing MCC’s be retired and replaced over a period of time in conjunction with other projects or if major new load is to be added to a MCC. This replacement could commence with the next major plant upgrade project. Replacement of MCC’s while keeping the plant in service is tricky and must be carefully planned. The dual MCC arrangement at most of the locations at the City plant will facilitate this replacement because many critical loads are split between the dual MCC’s at each location. 9. The existing electrical service is adequate for the planned plant upgrade. Any major future expansion of the plant electrical load after this plant upgrade will require a new higher capacity electrical service. Any future service expansion will probably require the installation of additional 480 volt load centers and expansion of the 12 KV primary system either as a loop or with radial feeders to the 480 volt load centers. Equipment Preferences Plant staff has indicated that they would like new electrical equipment to match existing equipment where there is a synergy such as common spare parts. This should be considered in future electrical designs, however we doubt that the City will realize much advantage to this with major electrical equipment because many of the components in equipment like MCC’s are easy to replace with other manufacturers’ components like starters and switches. WRRF Project TM No. 10.2 – Electrical and I&C Page 15 of 20 Instrumentation and Controls Current SCADA/PLC System The current plant SCADA System consists of 7 older Bristol-Babcock (Emerson) 3330 DPC’s and 2 newer Bristol-Babcock “Control Wave” DPC’s configured in hot standby. These DPC’s are currently hard wired to one new central SCADA Dell computer based work station, which is operating on Intellution iFIX64 SCADA software, through a data concentrator. There is also a larger wall mounted monitor. This work station is located in the Operations Building. This is the only iFIX64 SCADA work station in the plant. The old iFIX32 based work station is still in place in the Operations Building because it contains Data View software to be able to communicate with the older Bristol- Babcock 3330 DPC’s. The iFIX32 work station will be abandoned when it is no longer needed for the Bristol-Babcock 3330 DPC’s. The iFIX64 contains alarm autodialer software which will dial the designated operator’s cell phones with a text message of the alarm condition. This alarm software will also dial the designated standby operator when the plant is unattended from 7 pm to 6 am and leave an alarm message. Planned SCADA/PLC Upgrades Inventory of Existing SCADA Equipment The plant currently consists of the following hardware after the current energy efficiency upgrades. 1. Seven Allen Bradley ControlLogix PLC based RTU’s in the plant at the following locations. These are presently Bristol Babcock (Emerson) 3330 DPC’s, but are in the process of being replaced with Allen Bradley ControlLogix PLC’s installed into the existing cabinets. a. Main Electrical Building. b. Filter Tower 1. c. Filter Tower 2. d. MCC-B. e. MCC-G. f. MCC-J. g. MCC-R. 2. Two newer Bristol-Babcock “Control Wave” hot standby DPC’s in the plant at the following locations: a. MCC-A Building, DPC-A. b. MCC-J Building, DPC-B. 3. Fiber optic plant Ethernet network installed throughout the plant.. 4. iFIX64 SCADA software based operator work station on Dell desktop computer with flat screen monitor, located in Operations Building. 5. Wall mounted 32 inch flat screen monitor located adjacent to work station in Operations Building. WRRF Project TM No. 10.2 – Electrical and I&C Page 16 of 20 6. iFIX32 SCADA software based operator work station on Dell desktop computer with monitor located in Operations Building. This work station is used only to access data from the older Bristol-Babcock 3330 DPC’s and will be abandoned when all of those DPC’s are replaced with Allen Bradley ControlLogix PLC’s under the current SST Program. 7. Data concentrator which is used to access data from the older Bristol-Babcock 3330 DPC’s and will be abandoned when those older DPC’s are all replaced. Utilization of Existing SCADA System 1. The City has installed Hach data management software and have historian software as part of the iFIX64 SCADA. The City plans to use I-PADS to access SCADA data when in the plant. 2. The iFIX64 software includes an autodialer which will call designated operators’ cell phones and report designated plant alarms with a text message. When the plant is unattended the on-call operator carries a standby cell phone which will receive alarm text messages from the autodialer. Energy Efficiency Project SCADA Improvements There are a number of SCADA/PLC upgrades being undertaken through the WRRF Energy Efficiency Project. These improvements will be completed by the end of 2015 and include the following: • Installation of fiber optic backbone communication throughout the plant. This work is currently underway by Electrocraft Contractors. • Replacement of the 7 Bristol-Babcock 3330 DPC’s with Allen Bradley ControlLogix PLC’s. The new PLC’s will be installed by TESCO in the existing DPC cabinets for ease of wiring the inputs and outputs (I/O) since the wires already exist in the cabinets. These PLC’s will be connected to the new fiber optic Ethernet data link to SCADA. The 2 newer Bristol-Babcock “Control Wave” hot standby DPC’s will remain in place at this time as they are compatible with iFIX64 and contain sufficient I/O’s. The existing SCADA data concentrator will be removed when the new PLC’s are in place. There are no planned changes in PLC I/O points or control functions under this current project. The City’s control integrator, South Coast Systems, will continue to configure the iFIX64 system for the new PLC hardware. The City has recently implemented use pf I-PADS to access data from the SCADA HMI’s. Plant Control The existing plant control is mostly manual with very little automation. Plant staff would like additional plant functions to be monitored and automated as follows: 1. Equalization. Presently the Equalization Basin control is manual. Operators use the basin to shave off diurnal peaks and would like a more automated system to return these stored flows back to the plant at a controlled flow rate during low flow periods using VFD controlled pumping, meter the flow and monitor the basin level; in other words automate the return from WRRF Project TM No. 10.2 – Electrical and I&C Page 17 of 20 the pond in order to minimize the impact on the plant. It is recommended that the control of the return flow be automated. 2. Provide additional monitoring and automation of the aeration system which is a well proven technology and would fit in well with the new blowers. This automation would include added monitoring, flow meters and control of air blowers and valves. This could include: a. Air valve monitoring and control b. Blower control c. pH, temperature and ammonia monitoring d. RAS, WAS, AB influent and ML flow monitoring 3. Equalization Tank monitoring and control to allow the pumps to run automatically according to tank level. 4. Cooling tower control and monitoring to include control level in towers, monitor influent and effluent water temperature, program the pump operation according to cooling tower level and be able to change set points. 5. Provide better digester performance by automatically controlling digester temperature and monitoring digester temperature, pressure, carbon dioxide, flows, gas production, boiler operation and mixing. 6. Increase use of surveillance cameras (at least 17 locations have been identified). 7. Install motor actuators for a number of large gate valves that are currently difficult to operate or are not accessible. 8. Expand SCADA system to be able to monitor and control various pumps and drives throughout the plant including monitoring run times. 9. Monitor power and energy usage throughout the plant by including power monitors at each MCC. 10. Add flow meters throughout the plant including the potable water used for the recycled water system. 11. Monitor additional levels including chemical tanks, plant drains, supernatant lagoon and influent wet well. 12. Monitor and control plant access at entrance gate and back gate (Gate D). 13. Provide chlorine residual information and tie into the chlorine dosing system for automatic control. This will focus on chlorine addition for recycled water prior to distribution. 14. Expand the alarms brought into SCADA and be able to change alarm set points at SCADA. 15. Be able to historically trend the data brought into SCADA from the various equipment and processes in the plant. In general the plant control should be set up in the following manner: 1. Highest level control; automatic from the PLC. In this automatic control mode the process component under control will automatically be maintained within a preset setpoint or control WRRF Project TM No. 10.2 – Electrical and I&C Page 18 of 20 band which will be maintained by the PLC. Operators may set the control parameters within which the control will operate. These parameters, setpoints and tuning constants can be set by the operator from SCADA or from a local operator interface where available. 2. Manual control from SCADA or operator interface where the operator can manually start and stop drives, manually set analog variables and otherwise assume control. 3. Manual local control from hard switches locally at the drive and/or at motor control centers. This mode is the lowest level control and can be used for testing, maintenance, adjustment or emergency control. 4. All drives will be set up so the drive can be stopped locally in an emergency and can be locked out in the off position at the local disconnect or at the motor control center depending on the arrangement of the drive. Equipment Preferences Plant staff has indicated that they would like new control equipment to match existing equipment where there is a synergy such as compatibility of operation, common spare parts or a steep learning curve for different manufacturers’ equipment. This preference should be observed in the facility upgrades. SCADA System Improvements The following presents recommended improvements to the SCADA system as part of the WRRF upgrades: 1. New major equipment containing PLC’s should be specified with Allen Bradley PLC’s where possible and be set up for connection into the existing PLC Ethernet network so the equipment PLC can be accessed directly from SCADA. Most manufacturers can accommodate this arrangement and can provide Allen Bradley PLC’s for compatibility with the plant PLC’s and with the plant SCADA. 2. Implement separate SCADA and PLC fiber optic Ethernet networks. See the typical SCADA block diagram in Figure 6. 3. Extend SCADA network from Operations Building to all locations where work stations, printers and plant HMI’s are desired. 4. Extend PLC network from operations building to all PLC locations including manufacturer’s equipment that contains a PLC such as, MCC’s, filters, UV and dewatering. 5. Provide local HMI’s for all PLC based process control panels including filters, UV, and dewatering for local process control and monitoring. 6. Provide a plant HMI or work station at all locations where access to plant SCADA data is needed or convenient such as operations building, administration building and filtration. 7. The PLC network should terminate at the historian work station so all PLC data is processed and controlled by the historian and the other plant work stations and HMI’s will receive PLC data through the historian. WR R F P r o j e c t TM N o . 1 0 . 2 – E l e c t r i c a l a n d I & C P a g e 2 0 o f 2 0 Pa g e i n t e n t i o n a l l y b l a n k . WRRF Project TM No. 10.2 – Electrical and I&C Appendix A Electrical Load Calculations WRRF Project TM No. 10.2 – Electrical and I&C Page intentionally blank. WRRF Project TM No. 10.2 – Electrical and I&C Page A-1 Summary of Proposed Project Electrical Loads A. Plant PANEL PANEL FEEDER CAPACITY LOAD, KVA Amperes KVA Connected Demand MCC-A1 400 266 405 370 MCC-C 150 100 20 15 MCC-A2 400 266 217 170 MCC-B1 300 199 162 142 MCC-B2 300 199 55 30 MCC-J1 800 532 818 580 Admin Bldg. 175 116 166 128 MCC-J1E 150 100 79 44 MCC-J2 800 532 608 390 MCC-J2E 50 33 65 34 MCC-F1 1200 798 754 649 MCC-G1 600 399 76 36 MCC-F2 1200 798 710 635 MCC-G2 600 399 28 8 MCC-H 400 266 81 54 TOTALS 4244 3285 Overall Diversity Factor (70%) SWBD MSG 3000 2494 2300 B. Reclamation Panel Panel Feeder Capacity Load, KVA Connected Demand MCC-R 400 266 1112 102 SWB-D R 1200 798 1032 882 Diversity Factor 80% SWBD-R 706 WRRF Project TM No. 10.2 – Electrical and I&C Page A-2 MCC A1, 400 Amp KVA Connected Demand Screen 1, 1.5 HP 1.5 1.5 Screenings Pump 1, 15 HP 15 15 Screenings Compactor, ¾ HP 1 1 Influent Pump 5, 75 HP 75 75 Influent Pump 2, 20 HP 20 20 Grit Pump 1, 20 HP 20 20 Grit Pump 3, 20 HP 20 20 Channel Blower 1, 15 HP .5 15 Grit Tank Sump Pump 1, 2 HP 2 - Supply Fan Grit Tanks, 1-1/2 HP 1.5 1.5 Exhaust Fan Grit Tank 1, ½ HP 0.5 0.5 LPA2, LPA1, 30 KVA 30 20 Welding Outlet, 20 KW 20 - Hot Water Pump 1, 1/3 HP .3 .3 Moyno Sludge Pump, 10 HP 10 10 Digester 2 Compressor, 5 HP 5 5 LP”L”, 37.5 KVA 37.5 20 MCCA AHU, 4.7 KW 5 5 Dewatering Screw Press, 6 HP (New) 5 5 Dewatering Fan 1, 20 HP (New) 20 20 Dewatering Fan 2, 20 HP (New) 20 20 Dewatering Fan 3, 20 HP (New) 20 20 Headworks Fan 1, 20 HP (New) 20 20 Headworks Fan 2, 20 HP (New) 20 20 Headworks Fan 3, 20 HP (New) 20 20 Headworks Fan 4, 20 HP (New) 20 20 Existing KVA 265 230 Amps 319 277 Existing Plus New KVA 405 370 Amps 487 445 WRRF Project TM No. 10.2 – Electrical and I&C Page A-3 MCC A2, 400 Amp KVA Connected Demand Influent Screen 2, 1.5 HP 1.5 1.5 Screenings Pump 2, 15 HP 15 15 Grit Dewater, 2 HP 2 2 Influent Pump 6, 75 HP - - Influent Pump 3, 20 HP 20 20 Grit Pump 2, 20 HP 20 20 Grit Pump 4, 20 HP 20 20 Grit Blower 2, 15 HP 15 15 Grit Tank Sump Pump 1, 2 HP 2 - Flush Water Pump 1, 5 HP 5 5 MCC”C” Feeder 20 15 Welding Outlet, 20 KW 20 - Hot Water Pump 2, 1/3 HP .3 .3 Digester 1 Mixer/Comp, 20 HP 20 20 Potable Water Pump, 5 HP 5 5 Filter EQ Pump 1, 3 HP 3 3 Filter EQ Pump 2, 3 HP 3 3 SST Blower 1, 20 HP (New) 20 20 SST Blower 2, 20 HP (New) 20 - Supernatant Lagoon Power Center, 10 KVA 10 - Dewatering Screw Press, 5 HP 5 5 Existing KVA 187 150 Amps 224 180 Existing Plus New KVA 217 170 Amps 261 205 WRRF Project TM No. 10.2 – Electrical and I&C Page A-4 MCC B1, 300 Amp KVA Connected Demand Primary Sludge Pump 1, 7.5 HP 7.5 7.5 Primary Scum Pump 3, 5 HP 5 5 Sludge Pump 5, 5 HP 5 5 Odor Control Fan, 20 HP (New) 20 20 Odor Control Fan, 20 HP (New) 20 20 Odor Control Fan, 20 HP (New) 20 20 Odor Control Fan, 20 HP (New) 20 20 Odor Control Fan, 20 HP (New) 20 20 Odor Control Fan, 20 HP (New0 20 20 Primary Clarifier 1, ½ HP .5 .5 Welding Outlet, 20 KW 20 - Caustic Soda Feed Pump 2, ½ HP .5 .5 Caustic Soda Mixing Pump, 3 HP 3 3 Existing KVA 42 22 Amps 51 27 Existing Plus New KVA 162 142 Amps 195 191 MCC B2, 300 Amp KVA Connected Demand Primary Sludge Pump 2, 7.5 HP 7.5 7.5 Primary Scum Pump 4, 5 HP 5 5 Sludge Pump 6, 5 HP 5 5 Primary Clarifier 2, ½ HP .5 .5 Secondary Clarifier 3, ¾ HP 0.75 0.75 LP”B”, 15 KVA 15 10 Welding Outlet, 20 KW 20 - Caustic Soda Feed Pump 1, 1/2 HP 0.5 0.5 KVA 55 30 Amps 66 36 WRRF Project TM No. 10.2 – Electrical and I&C Page A-5 MCC J1, 800 Amp KVA Connected Demand Filter Feed Pump 1, 30 HP 30 30 Filter Feed Pump 3, 30 HP 30 30 Filter Feed Pump 5, 30 HP (New) 30 30 Filter Feed Pump 6, 30 HP (New) 30 - Filter Backwash Pump 1, 50 HP 50 50 Filter Backwash Blower 1, 50 HP 50 - Cooling Tower Fan 1, 40 HP 40 40 Cooling Tower Fan 3, 40 HP (New) 40 40 Cooling Tower Fan 5, 40 HP (New) 40 40 Cooling Tower Pump 1, 15 HP 15 15 Cooling Tower Pump 3, 15 HP (New) 15 15 Cooling Tower Pump 5, 15 HP (New) 15 - Cooling Tower Recirc Pump 1, 15 HP (New) 15 15 Cooling Tower Recirc Pump 3, 15 HP (New) 15 15 Cooling Tower Recirc Pump 5, 15 HP (New) 15 15 MCC J Building AHU, 11 KW 11 11 Waste Backwash Pump 1, 5 HP 5 - Tank Drain sump Pump 1, 7.5 HP 7.5 - Filter Distribution Panel 1, 50 KVA 50 30 MCC J Lighting Panel 1, 30 KVA 30 20 Filter Area Power Panel, 15 KVS 15 10 Welding Outlet, 20 KW 20 - Cooling Tower Influent Valve 1, 1 HP 1 0 Cooling Tower Influent Valve 3, HP (New) 1 1 Cooling Tower Influent Valve 5, HP (New) 1 1 MCC-J1E Feeder, 250 Amp 79 44 Administration Building, 250 Amp 166 128 Existing KVA 600 408 Amps 722 491 Existing Plus New KVA 818 580 Amps 984 698 WRRF Project TM No. 10.2 – Electrical and I&C Page A-6 MCC J2, 800 Amp KVA Connected Demand Cooling Tower Pump 2, 15 HP 15 15 Cooling Tower Pump 4, 15 HP 15 15 Cooling Tower Pump 6, 15 HP (New) 15 15 Filter Feed Pump 2, 30 HP 30 30 Filter Feed Pump 7, 30 HP (New) 30 30 Filter Backwash Pump 2, 50 HP 50 - Filter Backwash Blower 2, 50 HP 50 50 Cooling Tower Fan 2, 40 HP 40 40 Cooling Tower Fan 4, 40 HP 40 40 Cooling Tower Fan 6, 40 HP (New) 40 40 Cooling Tower Recirc Pump 2, 15 HP (New) 15 15 Cooling Tower Recirc Pump 4, 15 HP (New) 15 15 Cooling Tower Recirc Pump 6, 15 HP (New) 15 15 Waste Backwash Pump 2, 5 HP 5 5 Tank Drain Sump Pump 2, 7.5 HP 7.5 0 Filter Distribution Panel 2, 50 KVA 50 30 Cooling Tower Influent Valve 2, 1 HP 1 - Cooling Tower Influent Valve 4, 1 HP 1 - Cooling Tower Influent Valve 6, 1 HP (New) 1 1 Welding Outlet, 20 KW 20 - Welding Outlet, 20 KW 20 - MCC-J2E Feeder, 100A 65 34 Existing KVA 477 259 Amps 574 312 Existing Plus New KVA 608 390 Amps 731 469 MCC J1E, 150 Amp KVA Connected Demand NaHSO Mixer, 3 HP 3 3 Effluent Sample Pump 1, ¾ HP 1 1 MCC J, LPJ2, 75 KVA 75 40 KVA 79 44 Amps 95 53 WRRF Project TM No. 10.2 – Electrical and I&C Page A-7 MCC J2E, 50 Amp KVA Connected Demand NaHSO Mixing Pump, 1.5 HP 1.5 1.5 Effluent Sample Pump 2, 1 HP 1 1 Effluent Sample Pump 3, 1 HP 1 1 3W Strainer, 1 HP 1 0 3W Pump 1, 30 HP 30 30 3W Pump 2, 30 HP 30 - KVA 65 34 Amps 78 41 Administration Building, 175 Amp KVA Connected Demand Lab Power Panel, 37.5 KVA 37.5 20 AHU-1, 50 KVA 50 50 AHU-2, 33 KVA 33 33 LP-1, LP-2, 45 KVA 45 25 KVA 166 128 Amps 200 154 WRRF Project TM No. 10.2 – Electrical and I&C Page A-8 MCC F1, 1200 Amp KVA Connected Demand Aeration Blower 1, 150 HP (Neuros) 150 150 RAS Pump 1, 10 HP 10 10 RAS Pump 3, 10 HP 10 10 RAS Pump 5, 10 HP (New) 10 - RAS Pump 6, 10 HP (New) 10 - WAS Pump 1, 5 HP 5 5 Plant Drainage Pump 1, 15 HP 15 - Final Clarifier Scum Pump 1, 3 HP 3 3 Final Clarifier 1, ¾ HP 0.75 0.75 Final Clarifier 3, 1 HP (New) 0.75 0.75 LP “LP1”, “LPF1”, 30 KVA 30 20 Welding Outlet, 20 KW 20 - MCC G1 Feeder 76 36 Reclaimed Water Pump 1, 3 HP 3 3 Internal ML Recycle Pump 1, 10 HP (New) 10 10 Internal ML Recycle Pump 2, 10 HP (New) 10 10 Internal ML Recycle Pump 3, 10 HP (New) 10 10 Aeration Blower 4, 350 HP (New) 350 350 Anoxic Mixer 1, 5 HP (New) 5 5 Anoxic Mixer 2, 5 HP (New) 5 5 Anoxic Mixer 3, 5 HP (New) 5 5 Anoxic Mixer 4, 5 HP (New) 5 5 Anoxic Mixer 5, 5 HP (New) 5 5 Anoxic Mixer 6, 5 HP (New) 5 5 Existing KVA 332 238 Amps 399 286 Existing Plus New KVA 754 649 Amps 907 781 WRRF Project TM No. 10.2 – Electrical and I&C Page A-9 MCC F2, 1200 Amp KVA Connected Demand Aeration Blower 1, 150 HP (Neuros) 150 150 RAS Pump 2, 10 HP 10 - RAS Pump 4, 10 HP 10 - RAS Pump 7, 10 HP (New) 10 10 RAS Pump 8, 10 HP (New) 10 10 WAS Pump 2, 5 HP 5 - Plant Drainage Pump 2, 15 HP 15 15 Final Clarifier Scum Pump 2, 3 HP 3 3 Final Clarifier 2, ¾ HP 0.75 0.75 Final Clarifier 4, 3/4 HP (New) 0.75 0.75 Maintenance Shop Feeder, 30 KVA 30 20 Welding Outlet, 20 KW 20 - MCC G2 Feeder 27.5 7.5 Reclaimed Water Pump 2, 3 HP 3 3 Internal ML Recycle Pump 4, 10 HP (New) 10 10 Internal ML Recycle Pump 5, 10 HP (New) 10 10 Internal ML Recycle Pump 6, 10 HP (New) 10 10 Aeration Blower 5, 350 HP (New) 350 350 Anoxic Mixer 3, 5 HP (New) 5 5 Anoxic Mixer 7, 5 HP (New) 5 5 Anoxic Mixer 8, 5 HP (New) 5 5 Anoxic Mixer 9, 5 HP (New 5 5 Anoxic Mixer 10, 5 HP (New) 5 5 Anoxic Mixer 11, 5 HP (New) 5 5 Anoxic Mixer 12, 5 HP (New) 5 5 Existing KVA 274 199 Amps 330 240 Existing Plus New KVA 710 635 Amps 854 764 WRRF Project TM No. 10.2 – Electrical and I&C Page A-10 MCC G1, 600 Amp KVA Connected Demand Rotating Drum thickener 1, 2 HP (New) 2 2 Rotating Drum Thickener 2, 2 HP (New) 2 2 Floc Tank 1, 1 HP (New) 1 1 Floc Tank 2, 1 HP (New) 1 1 RDT Feed Pump 1, 7.5 HP (New) 7.5 7.5 RDT Feed Pump 2, 7.5 HP (New) 7.5 7.5 RDT Feed Pump 3, 7.5 HP (New) 7.5 - Thickened Sludge Pump 1, 7.5 HP 7.5 - Odor Reduction Unit, 5 HP 5 5 LP “LPG”, 15 KVA 15 10 Welding Outlet, 20 KW 20 - Existing Plus New KVA 76 36 Amps 91 43 MCC G2, 600 Amp KVA Connected Demand Thickened Sludge Pump 2, 7.5 HP 7.5 7.5 Welding Outlet, 20 KW 20 - Existing Plus New KVA 27.5 7.5 Amps 33 9 MCC H, 400 Amp KVA Connected Demand Air Comp 1, 20 HP 20 20 Air Comp 2, 20 HP 20 - Inst. Air Comp 1, 7.5 HP 7.5 7.5 Inst. Air Comp 2, 7.5 HP 7.5 - Electrical Building Attu, 18 KW 18 18 Generator Block Heater, 8 KW 8 8 KVA 81 54 Amps 97 64 MCC-C, 150 Amp KVA Connected Demand Load, 20 KVA 20 15 KVA 20 15 Amps 24 18 WRRF Project TM No. 10.2 – Electrical and I&C Page A-11 MCC R, 600 Amp KVA Connected Demand Lighting, 30 KVA 30 20 WRP 101, 40 HP 40 40 WRP 201, 40 HP 40 40 WRP 801 (Potential Future) WRP 901 (Potential Future) RCN 502, 2 HP 2 2 KVA 112 102 Amps 134 122 SWBD R, 1200 Amp KVA Connected Demand MCC R Feeder 112 102 UV, 500 KW (New) 500 500 WRP 301, 125 HP 125 125 WRP 501, 125 HP 125 125 WRP 701, 125 HP 125 - MCC E Feeder (New) 45 30 Existing KVA 487 352 Amps 586 423 Existing Plus New KVA 1,032 882 Amps 1,241 1,061 New MCC E KVA Connected Demand Return Pump 1, 15 HP (New) 15 15 Return Pump 2, 15 HP (New) 15 15 Return Pump 3, 15 HP (New) 15 - KVA 45 30 Amps 54 36 WRRF Project TM No. 10.2 – Electrical and I&C Page A-12 Page intentionally blank. Appendix N TM No. 10.3 - Infrastructure Planning, Site Access and Security Page 1 of 11 Date: 12/10/2014 Prepared by: Mallika Ramanathan, PE Reviewed by: Holly Kennedy, PE, Lianne Westberg, PE, Jeff Szytel, PE Project: WRRF Project SUBJECT: TM NO. 10.3 – SITE ACCESS AND SECURITY The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long-term strategy for resource management. The purpose of this technical memorandum (TM) is to describe the site access and security that will implemented as part of the WRRF upgrades. Contents Introduction .............................................................................................................................. 2 Perimeter Access ..................................................................................................................... 2 Vehicle Access ......................................................................................................................... 6 Intrusion Detection .................................................................................................................. 6 Building Access ....................................................................................................................... 9 Interior Sensitive Areas ........................................................................................................... 9 Remote Buildings ...................................................................................................................10 Security System Integration ...................................................................................................10 Conclusions ............................................................................................................................11 List of Tables Table 10-1. Perimeter Fence Estimated Costs ............................................................................................. 2 Table 10-2. Intrusion Detection Equipment ................................................................................................... 9 Table 10-3. Building Access Equipment ....................................................................................................... 9 Table 10-4. Interior Sensitive Areas Equipment ......................................................................................... 10 Table 10-5. Security System Integration Components ............................................................................... 10 List of Figures Figure 10-1. Proposed Site Plan ................................................................................................................... 3 Figure 10-2. Omega Style Fence .................................................................................................................. 5 Figure 10-3. Typical Chain Link Fence Detail ............................................................................................... 5 Figure 10-4. Card Reader ............................................................................................................................. 7 Figure 10-5. Pan, Tilt, Zoom Camera ........................................................................................................... 8 WRRF Project TM No. 10.3 – Site Access and Security Page 2 of 11 Introduction This technical memorandum (TM) describes site access and security considerations for the City of San Luis Obispo’s (City) Water Resource Recovery Facility (WRRF). As part of the upgrades, access into the plant will be modified and security improvements are desired. This TM addresses improvements at the plant that address security, perimeter access, vehicle access to the plant and public facilities, as well as building security. Perimeter Access The integrity of a facility perimeter is most commonly maintained by the use of fences to prevent unauthorized access to critical assets contained within. Without this physical barrier, limits of the property cannot be clearly established. Because the WRRF is surrounded by public areas and services (e.g., Bob Jones Trail, Prado Day Center, City Public Works Facilities), security at the plant must be maintained. The WRRF currently has a chain-link fence surrounding the plant and the fencing should be maintained. Because areas and access to the plant will be modified, the chain link fence will need to be extended and modified in select locations. Figure 10-1 provides the updated site plan and includes the perimeter fencing that is recommended. In areas that have high visibility with the public, a more decorative fence such as one made by the Omega Corporation (Figure 10-2) may be desired. This Omega style of fence is manufactured with a climb and cut resistant fabric to provide adequate security, while providing a non-institutional look. For areas that do not have high visibility to the public, an 8-foot chain-link fence with a 12-inch high, vertically-mounted, barbed-wire top rigger is recommended. The fence would be installed with no top rail and provided with a bottom rail. By removing the top rail, climbing over the fence is much more difficult as there is nothing to grab or step onto to transition over the top of the fence. Utilizing a bottom rail provides a means to attach the fence material and prevents the bottom of the fence from being pulled up to crawl under. A 12-inch wide by 4-inch deep concrete maintenance strip is also recommended along the fenceline to inhibit tunneling. Figure 10-3 shows a typical chain-link fence detail. Table 10-1 provides the differences in costs between the two types of perimeter fences. Table 10-1. Perimeter Fence Estimated Costs Manufacturer/Type Estimated Cost Installed (June 2014) Omega Fence $50± / ft. Chain-link fence with barbed wire and footer $27± / ft The condition of the existing chain link fence along the entire perimeter of the WRRF is unknown. For the purposes of this facility plan, it is assumed that new fencing is needed along the northern WRRF border. At this location, Omega style fence was assumed. Along the remaining plant perimeter, it is assumed that the existing chain link fence is in good condition and replacement at select locations was needed. WRRF Project TM No. 10.3 – Site Access and Security Page 4 of 11 Page intentionally blank. WRRF Project TM No. 10.3 – Site Access and Security Page 5 of 11 Figure 10-2. Omega Style Fence Figure 10-3. Typical Chain Link Fence Detail WRRF Project TM No. 10.3 – Site Access and Security Page 6 of 11 Vehicle Access As shown in Figure 10-1, the WRRF is accessible by vehicle from Prado Road. Currently visitors, employees, and delivery trucks enter the plant from one of two roads. The first access road is on the east side of the Prado Day Center; the second access road is to the west of the existing Equalization Pond. In the future, a single access road will be provided from Prado Road. The access road will be located to the west of the Equalization Pond. For security, it is recommended that all vehicle access portals into the WRRF be equipped with motorized gates. Employee vehicles would be able to enter the WRRF using ingress and egress stanchions equipped with proximity card readers, intercom and video camera. The card reader should be a HID Max Prox or equivalent as long as it can interface with the City’s current card access system to provide a read range of approximately 30 inches. This allows the vehicles of different heights to utilize a single reader .Figure 10-4 is an illustration of a typical proximity card reader, intercom and video camera for employee access. WRRF visitor traffic that requires vehicle entry into the plant (e.g., chemical delivery trucks, etc) would enter the WRRF after checking in with administrative staff. Vehicle gates during business hours would be monitored to control visitor and delivery traffic in and out of the facility. Assigned personnel would verify all non-employee business with administrative staff prior to admittance, issue visitor ID passes, control gate operations and monitor facility security systems. Visitors to the WRRF that do not require vehicle access inside the plant would be directed to the visitor parking area by signage. To minimize visitor traffic inside the plant, the visitor parking area would be located outside the plant perimeter fence, near the operations building. Visitors would check in with administrative staff prior to admittance, and then would be issued a visitor ID pass. Intrusion Detection Immediately contiguous to the inside of the fence line, an area free of obstructions called a clear zone should be maintained. At a minimum the clear zone should be approximately 20 feet wide. This clear zone provides an area of surveillance of the entire WRRF perimeter. It is further recommended that pole or parapet mounted pan, tilt, and zoom (PTZ) equipped color video cameras be provided as needed to automatically assess any intrusions of the clear zone. Lighting for the cameras could be incorporated on the mounting brackets so that they pan and tilt with the cameras. This ensures that the required lighting level would be maintained no matter where the camera is directed. During low light level situations, the camera light source could be white light or infrared light or both depending on the security strategy being employed. Infrared illuminators would be recommended for non-obtrusive light and surreptitious surveillance. The recommended illuminators cast sufficient non- visible illumination for camera zones up to 500 feet, which would coincide with the microwave zones. Figure 10-5 shows the type of PTZ camera proposed. In addition to the lighting provided for video requirements, employee and visitor parking areas should be provided with security lighting at levels consistent with those recommended by the Illuminating Engineering Society of North America. Metal halide lighting is preferred to provide full color spectrum light to support color camera operations. WRRF Project TM No. 10.3 – Site Access and Security Page 7 of 11 Figure 10-4. Card Reader WRRF Project TM No. 10.3 – Site Access and Security Page 8 of 11 Figure 10-5. Pan, Tilt, Zoom Camera WRRF Project TM No. 10.3 – Site Access and Security Page 9 of 11 At a minimum, the interior roads and building walls would be lit for security and video surveillance. Landscaping planted around the buildings should be the low-lying type to prevent hiding areas. Trees around the facility perimeter should be limbed up 10 feet from the ground to facilitate surveillance and located away from fence lines and building walls to prevent the trees from becoming an aid to climbing and/or an obstruction to video surveillance fields of view. Table 10-2 summarizes the intrusion detection equipment recommended. Table 10-2. Intrusion Detection Equipment Security Device Manufacturer / Model # Est. Unit Cost Installed Infrared Illuminator Bosch Aegis UFLEO $4,000 / pair Color Video Camera w/ PTZ Pelco Esprit $10,000 Building Access Door position switches should be provided to monitor all entrances to the various buildings. Proximity card readers should be provided on specific doors based on the door’s function and frequency of use. All offices and interior spaces that are designed with windows should be equipped with glass break detection. The intrusion detection and access control alarms should be pushed out to cell, radio or other selected communication devises determined during the design phase. Depending on the system selected, the system may have visual/audio capabilities. Visitor access to the new operations offices should be restricted to the main lobby by physical barriers. The lobby should also be equipped with video surveillance. Doors leading to private space should be controlled by card readers. The intent would be to preclude visitor access to the employee circulation of the facility. After-hours employees should utilize a proximity card reader at a designated entrance to access the facility. Request-to-exit motion sensors would permit egress of the controlled doors without initiating the intrusion detection system. The recommendations for building access equipment are summarized in Table 10-3. Table 10-3. Building Access Equipment Security Device Manufacturer / Model # Est. Unit Cost Installed (June 2014) Door Position Switch Sentrol # 2700 $1,000± Dual Technology Motion Detector (Glass Break) Sentrol # 2T70 / 2T360 $1,000± Card Reader w/ Electronic Lock HID Proxpro $4,500± Request-to-Exit Motion Sensor Sentrol #RTE 1000 $1,000± Interior Sensitive Areas Designated areas within the facility, such as server room, Headworks, SCADA and the chemical storage areas should be compartmentalized to add an extra level of security to limit access to these security sensitive locations. Access control for these sensitive areas should, if feasible be controlled by multiple technology utilizing proximity cards and biometrics. The chemical delivery sites as well as the digester handling areas should also be provided with a closed circuit video camera triggered by a WRRF Project TM No. 10.3 – Site Access and Security Page 10 of 11 motion detector to monitor and record the activity in this area. A duress alarm could be provided for employee safety. The equipment recommendations for interior sensitive areas are summarized in Table 10-4. Table 10-4. Interior Sensitive Areas Equipment Security Device Manufacturer / Model # Est. Unit Cost Installed (June 2014) Proximity Card/ Fingerprint Reader Bioscrypt FLEX Reader $1,100± Duress Alarm Alarm Control Corp #KR44L4 $500± Fixed Color Video Camera Pelco SARIX $1,000± Remote Buildings Currently, there are no planned remote buildings at the WRRF. Should remote facilities become necessary in the future, the remote buildings could be provided with access control readers and an intrusion detection system. The intrusion detection system would include door position switches as well as dual technology (passive infrared/microwave) motion detectors. A limited number of video cameras would be added to these sites in strategic locations for video surveillance to assess any intrusion. Lighting to support the cameras for nighttime operations must also be provided. Security System Integration All security related systems for the WRRF should be integrated into a single security monitoring system. Video surveillance, building perimeter and microwave intrusion sensors, an intercom substation at the employee entrance and access control systems should interface with the current system to provide seamless monitoring and operation of all devices. The cameras that monitor critical assets/areas should be displayed for real time monitoring, The video surveillance system will be interfaced with the card access control/intrusion detection system for automatic camera "call up" at the security monitoring station during an event. All surveillance cameras are to be recorded and available for forensic review including video clips "tagged" with an associated event. Access control workstations would be provided at the new operations building to monitor the security systems locally. Security system integration components are summarized in Table 10-5. Table 10-5. Security System Integration Components Security Device Manufacturer / Model # Est. Unit Cost Installed (June 2014) Network Video Recorder Pelco D5NVR $13,500± 20” Color LED Flat Panel Monitor Philips LED $800± Intercom System Zenitel Alphacom $8,000± Access Control Workstation AMAG Professional Edition $10,000± Access Control Remote Panel AMAG #M2100 $5,000± WRRF Project TM No. 10.3 – Site Access and Security Page 11 of 11 Conclusions The security countermeasures recommended in this memorandum would provide physical and electronic devices to secure the plant site and facilities. Employee security awareness training coupled with well-defined policies and procedures are equally as important. It is therefore recommended that security policies and procedures designed specifically for the operation be developed and implemented. The policies and procedures should be developed by security and operations staff in order to provide guidance to employees on their first day of employment. Every employee would then be provided a copy or computer access to the policies and procedures and be required to follow them, under penalty of disciplinary action, in order to ensure compliance and maintain the integrity of security at the facility. Appendix O TM No. 12 - Process Alternatives Analysis Date: 10/22/2014 Prepared by: Michael Falk, PhD, PE Reviewed by: Mallika Ramanathan, PE Project: WRRF Project SUBJECT: TM NO. 12 – PROCESS ALTERNATIVES ANALYSIS The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long-term strategy for resource management. The purpose of this technical memorandum (TM) is to present the treatment alternative findings for use in the WRRF Project. Potential nitrate removal alternatives are presented and evaluated, and a technology is recommended for further development. Contents Introduction .............................................................................................................................. 3 Background .............................................................................................................................. 3 Technology Screening ............................................................................................................. 5 Treatment Alternatives ............................................................................................................ 8 Alternatives Development ......................................................................................................................... 8 Alternative 1: MLE .................................................................................................................................... 9 Alternative 2: VertiCel® .......................................................................................................................... 12 Alternative 3: High Rate A/B Process ..................................................................................................... 15 Alternative 4: BioMag® ........................................................................................................................... 18 Alternatives Evaluation ........................................................................................................................... 21 Conclusions ............................................................................................................................22 Appendices Appendix A – Workshop Meeting Minutes and Presentation Slides Appendix B – Technology Status Write-Up Appendix C – Mass Balance Results for each Alternative Appendix D – Life-Cycle Analysis Results for each Alternative Appendix E – Non-Economic Criteria Results for each Alternative WRRF Project TM No. 12 – Process Alternatives Analysis Page 2 of 22 List of Tables Table 1. Overview of NPDES Permit Discharge Limitations (Order R3-2014-0033) .................................... 3 Table 2. List of Alternative Technologies for Screening ............................................................................... 5 Table 3. Technology Screening Matrix Results ............................................................................................ 7 Table 4. Flows and Loads Conditions Used for Comparison of the Alternatives .......................................... 8 Table 5: Facility Needs for Alternative 1: MLE .............................................................................................. 9 Table 6. Evaluation of MLE Alternative ....................................................................................................... 12 Table 7. Facility Needs for Alternative 2- VertiCel® ................................................................................... 13 Table 8. Evaluation of VertiCel® ................................................................................................................. 13 Table 9. Facility Needs for Alternative 3 – High Rate A/B Process ............................................................ 16 Table 10. Evaluation of High Rate A/B ....................................................................................................... 16 Table 11. Facility Needs for Alternative 4- BioMag® Process .................................................................... 19 Table 12. Evaluation of BioMag® ............................................................................................................... 19 Table 13. Facility Needs Comparison of Alternatives ................................................................................. 21 Table 14. Non-Economic and Economic Comparison of Alternatives ........................................................ 21 List of Figures Figure 1. SLO WRRF Existing Process Schematic (includes WRRF Energy Efficiency Project) ................ 4 Figure 2. Modified Ludzack-Ettinger Process ............................................................................................... 9 Figure 3. Alternative 1- MLE Site Layout .................................................................................................... 11 Figure 4. VertiCel® Process Flow Schematic ............................................................................................. 12 Figure 5. VLR® Reactor Configuration ....................................................................................................... 12 Figure 6. Alternative 2- VertiCel® Site Layout ............................................................................................ 14 Figure 7. Schematic of A/B Process ........................................................................................................... 15 Figure 8. Alternative 3 – High Rate A/B Process Site Layout ..................................................................... 17 Figure 9. Schematic of BioMag® ................................................................................................................ 18 Figure 10. Alternative 4 - BioMag® Process Site Layout ............................................................................ 20 WRRF Project TM No. 12 – Process Alternatives Analysis Page 3 of 22 Introduction The City of San Luis Obispo’s Water Resource Recovery Facility (WRRF) treats municipal wastewater flow from the City, California Polytechnic State University (Cal Poly), and the San Luis Obispo County Airport. The WRRF has a permitted average dry weather flow (ADWF) capacity of 5.1 million gallons per day (mgd). Currently, the WRRF treats an ADWF of approximately 3.2 mgd. Buildout ADWF and peak hour flows are projected to be 5.4 mgd and 32.8 mgd, respectively (HDR 2014; WSC 2014). In September 2014, the WRRF’s National Pollutant Discharge Elimination System (NPDES) permit (Order R3-2014-0033) was renewed. The renewed permit includes more stringent nitrogen discharge limitations, specifically for ammonia and nitrate. To meet the nutrient limitations, upgrades are needed at the WRRF. This TM presents the screening and evaluation process that was undertaken to identify a secondary treatment technology for inclusion in the Facility Plan. Twelve treatment alternatives were screened and four alternatives were identified for further development. The four alternatives were then developed and evaluated and a preferred alternative was identified. Background A general process schematic of the existing treatment plant is shown in Figure 1. During wet weather events, advanced treatment (aeration basins, tertiary treatment and cooling towers) is bypassed and blended effluent (nitrified effluent and primary/secondary effluent) is disinfected prior to discharge. Treated effluent is discharged to San Luis Obispo Creek and/or distributed to recycled water customers. Discharge requirements to San Luis Creek for selected pollutants are summarized in Table 1. In order to meet the BOD, TSS, ammonia, nitrate, and coliform limits, all flows require secondary, tertiary, and disinfection treatment. As a result, blending during peak flow events as currently done at the WRRF will not be feasible. Table 1. Overview of NPDES Permit Discharge Limitations (Order R3-2014-0033) Parameter Unit ADWF AA Average Monthly Average Weekly Max. Daily Instant. Min. Instant Max. Rated Capacity mgd 5.1 -- -- -- -- -- -- Biological Oxygen Demand, 5-day (BOD) mg/L -- -- 10 30 50 -- -- lb/d -- -- 425 1,275 2,125 -- -- Total Suspended Solids (TSS ) mg/L -- -- 10 30 75 -- -- lb/d -- -- 425 1,275 2,125 -- -- Un-ionized Ammonia mg N/L -- -- -- -- 0.025 (a) -- -- Final Nitrate mg N/L -- -- 10 -- -- -- -- Coliform (b) MPN/100 mL -- -- -- 2.2 & 23 -- 240 pH s.u. -- -- -- -- -- 6.5 8.3 Final Chlorodibromomethane(c) g/L -- -- 0.40 -- 1.0 -- -- Final Dichlorobromomethane(c) g/L -- -- 0.56 -- 1.0 -- -- N-Nitrosodimethylamine (NDMA) g/L -- -- 0.00069 -- 0.0014 -- -- (a) In-stream criteria (i.e., non-discharge limit) (b) The median number of fecal coliforms shall not exceed 2.2 MPN/100 mL for the last 7-days samples were taken. No more than one sample shall exceed 23 MPN/100 mL total coliform in any 30-day period. The maximum number of total coliforms in any sample shall not exceed 240 MPN/100 mL. (c) Compliance by November 30, 2019 per Time Schedule Order number R3-2014-0036 dated September 25, 2014. WR R F P r o j e c t TM N o . 1 2 – P r o c e s s A l t e r n a t i v e s A n a l y s i s Pa ge 4 o f 2 2 Fig u r e 1 . S L O W R R F E x i s t i n g P r o c e s s S c h e m a t i c ( i n c l u d es W R R F E n e r g y E f f i c i e n c y P r o j e c t ) He a d w o r k s (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) Ae r a t i o n Ba s i n Mo n o M e d i a Fi l t e r ( W R R F En e r g y E f f i c i e n c y Pr o j e c t ) CC T SLO Creek Emergency Storage3W Water System Recycled Water PC L SC L Bi o t o w e r FC L Co o l i n g To w e r DA F T AD AD AD St o r a g e Vo r t e x Cl a s s i f i e r Dr y i n g B e d Su p e r n a t a n t St o r a g e La g o o n Di s p o s a l Fe r r o u s Ch l o r i d e Po l y m e r Ra w In f l u e n t So d i u m Hyp o c h l o r i t e Ma g n e s i u m Hy d r o x i d e Fi l t e r B a c k w a s h Li q u i d S t r e a m s Sl u d g e S t r e a m s Re t u r n S t r e a m s Ch e m i c a l S t r e a m s Pr i m a r y C l a r i f i c a t i o n PC L Se c o n d a r y C l a r i f i c a t i o n SC L Fi n a l C l a r i f i c a t i o n FC L Ch l o r i n e C o n t a c t T a n k CC T Di s s o l v e d A i r F l o a t a t i o n T h i c k e n e r DA F T An a e r o b i c D i g e s t i o n AD Be l t F i l t e r P r e s s BF P DA F T S u p e r n a t a n t La g o o n R e t u r n Sodium Bisulfite Sc r e w P r e s s (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) RA S (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) WA S (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) Fl o w s > 3 2 m g d to F l o w E Q Fl o w s > 2 2 m g d to F l o w E Q Bi o t o w e r B y p a s s Ad v a n c e d T r e a t m e n t B y p a s s ( F l o w s > 5 . 1 m g d ) Fl o w s C u r r e n t l y >1 6 m g d t o F l o w E Q WRRF Project TM No. 12 – Process Alternatives Analysis Page 5 of 22 Technology Screening Screening of secondary treatment technologies was conducted with the City at Workshop 1 (July 14, 2014). Twelve technologies, presented in Table 2, were reviewed with the City and evaluated against economic and non-economic criteria (refer to criteria below). Table 2. List of Alternative Technologies for Screening Item Technology 1 Modified Ludzack-Ettinger (MLE) (Conventional with and without contact stabilization) 2 VertiCel® (Oxidation Ditch) 3 High Rate A/B Process 4 Integrated Fixed-Film Activated Sludge (IFAS) 5 BioMag® 6 Nereda® Granular Sludge 7 Biobrimstone® 8 Denitrification Filters 9 Wetlands 10 Membrane Bioreactor (MBR) 11 MBR Parallel Treatment with Bioaugmentation 12 Mainstream Anaerobic Treatment The City participated with assigning scores to each technology (1, 2, or 3) for each criterion. Scores were assigned for each technology relative to Modified Ludzack-Ettinger (MLE) alternative. The MLE alternative was selected as the baseline because it was the recommended alternative in the 2011 Master Plan. After the scoring was complete, the screening criteria were weighted. The scores were multiplied by the criterion weight to provide an overall screening value. Appendix A provides details of the workshop screening and rankings. 1. Meet Permit Limits: Focuses on the ability to meet nitrogen species limits (ammonia and nitrate) plus the other permit limits (DO, BOD, TDS, turbidity, pentachlorophenol). A 3 = reliably meet permit limits, 2 = might meet permit limits (occasional excursion), and 1 = inability to meet permit limits. 2. Technology Status: This labels technologies according to their technology status. A 3 = established technology, 2 = emerging technology, and 1 = embryonic technology. A more detailed write-up on Technology Status is provided in Appendix B. 3. Good Neighbor (odor): Focuses on odors as chemical traffic and safety is addressed in the next criterion. A 3 = less odors than baseline, 2 = odor emissions for baseline (i.e., minimal concerns), and 1 = odor concerns. 4. Minimize Chemicals (safety and TDS concerns): Focuses on the amount of chemicals required for each alternative. The concern is safety for operations/neighbors and increase in TDS levels. A 3 = less chemicals than baseline, 2 = chemicals required for baseline, and 1 = more chemicals required than baseline. WRRF Project TM No. 12 – Process Alternatives Analysis Page 6 of 22 5. Ability to Meet Lower Limits: The alternative has the flexibility to meet lower nitrate and/or phosphorus limits. For example, a denitrifying filter can meet lower nitrate limits by adding more external carbon source and phosphorus by adding a metal salt upstream of the filters. A 3 = ability to reliably meet lower limits without chemicals, 2 = ability to meet lower limits with chemicals, and 1 = inability to meet lower limits. 6. Compatibility with Biosolids Treatment: Ability to integrate with biosolids management, such as the impact on the new screw press dewatering technology. A 3 = compatibility and less biosolids production than the baseline, 2 = compatibility and similar biosolids production as the baseline, and 1 = incompatibility and/or more biosolids production than the baseline. 7. Facilitate Flow Equalization: This criterion considers the impact of peak flows on the overall plant and a technologies ability to handle peak flows. A 3 = more robust than the baseline at handling peak flows, 2 = baseline ability to handle peak flows, and 1 = struggles with peak flows. 8. Ease of Operation: Focuses on operator attention and level of complexity required to operate each alternative. A 3 = relatively simple to operate with minimal operator attention, 2 = operator attention and level of complexity required for the baseline, and 1 = complex technology that would require more operator attention than the baseline. 9. Relative Capital Cost: Relative capital cost compared against the baseline alternative. A 3 = less expensive than the baseline, 2 = comparable cost with the baseline, and 1 = more expensive than the baseline. 10. Relative O&M Cost: Relative O&M cost compared against the baseline alternative. A 3 = less expensive than the baseline, 2 = comparable cost with the baseline, and 1 = more expensive than the baseline. 11. GHG Emissions: Focuses on the GHG emissions associated with energy and chemicals demand for each alternative. A 3 = less GHG emissions than the baseline, 2 = comparable GHG emissions with the baseline, and 1 = more GHG emissions than the baseline. 12. Ease of Implementation: Focuses on the construction sequencing and relative ease of implementing at the WRRF. A 3 = easier to implement than the baseline, 2 = comparable implementation to the baseline, and 1 = more difficult to implement than the baseline. The scoring results from Workshop 1 are provided in Table 3. The top four ranked alternatives (from highest to low ranking) were determined to be: 1. High Rate A/B Process 2. Conventional nitrification/denitrification using the MLE process 3. Conventional nitrification/denitrification using the VertiCel® technology 4. Wetlands WR R F P r o j e c t TM N o . 1 2 – P r o c e s s A l t e r n a t i v e s A n a l y s i s Pa g e 7 o f 2 2 Ta b l e 3 . T e c h n o l o g y S c r e e n i n g M a t r i x R e s u l t s ID Al t e r n a t i v e Meet Permit Limits * Technology Status Good Neighbor (Odor) Minimize Chemicals (Safety and TDS concerns) Ability to Meet Lower Limits Emerging Contaminants Removal Compatibility with UV Compatibility with Biosolids Treatment Facilitate Flow Equalization Ease of Operation Relative Capital Cost Relative O&M Cost GHG Emissions Ease of Implementation Non-Weighted Score Weighted Score 3 H i g h R a t e A / B P r o c e s s 3 2 2 2 2 2 2 3 2 1 3 3 3 2 3 2 1 1 4 1 C o n v e n t i o n a l N D N ( M L E ) 3 3 2 2 2 2 2 2 2 2 2 2 2 2 3 0 1 0 8 2 C o n v e n t i o n a l N D N ( V e r t i c e l ® ) 3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 9 1 0 5 9 W e t l a n d s 1 2 2 3 1 3 1 3 2 3 1 3 3 1 2 9 1 0 3 4 IF A S ( A t t a c h e d G r o w t h M e d i a ; Pa s t a ) 3 3 2 2 2 3 2 2 2 1 1 1 2 2 2 8 1 0 2 6 N e r e d a ® G r a n u l a r S l u d g e 2 2 2 2 2 2 2 3 1 1 1 3 3 2 2 8 1 0 2 5 B i o M a g ® ( M a g n e t i t e ) 3 2 2 2 2 3 2 2 3 1 1 1 1 2 2 7 1 0 1 11 M B R ( s t a n d a l o n e ) 3 3 2 2 2 3 3 2 1 1 1 1 1 2 2 7 9 9 10 MB R ( P a r a l l e l T r e a t m e n t w/ B i o a u g m e n t a t i o n ) 2 3 2 2 1 3 3 2 1 1 2 1 1 2 2 6 9 2 8 D e n i t e F i l t e r s + A c t i v a t e d S l u d g e 3 3 1 1 3 2 2 2 1 1 3 1 1 1 2 5 8 5 12 Ma i n s t r e a m A n a e r o b i c Tr e a t m e n t + A c t S l u d g e 2 1 1 2 1 2 2 3 1 1 1 2 3 1 2 3 8 3 7 B i o b r i m s t o n e ® 1 1 2 1 1 1 2 1 2 1 1 1 1 1 1 7 6 5 13 14 W e i g h t i n g 5 3 5 3 3 3 5 3 5 3 1 5 3 3 * D o e s n o t i n c l u d e d i s i n f e c t i o n r e q u i r e m e n t s WRRF Project TM No. 12 – Process Alternatives Analysis Page 8 of 22 The wetlands alternative was determined to be fatally flawed because of its inability to reliably meet permit limits under worst-case conditions. Integrated fixed-film attached growth (IFAS), Nereda® granular sludge, and BioMag® were considered to be close in scoring and offered similar advantages and disadvantages. It was agreed that only one of the three technologies (IFAS, Nereda®, and BioMag®) would be carried forward as an alternative for further evaluation. BioMag® was selected over IFAS and Nereda® because of its ability to handle large peak flows without compromising process performance. The final four technologies carried forward for further evaluation were as follows: 1. High Rate A/B Process 2. Conventional nitrification/denitrification using the MLE process 3. Conventional nitrification/denitrification using the VertiCel® technology 4. BioMag® Treatment Alternatives Alternatives Development Based on the technology screening performed at Workshop 1, four alternatives were identified to be further developed. The four alternatives were then evaluated with the City at Workshop 2, held on August 25, 2014. The four alternatives were developed by using HDR’s Envision steady state mass balance model. The mass balance output sheets are provided in Appendix C. The mass balance results also were also used to calculate the average annual energy and chemical demands for quantifying annual operations cost. Table 4 provides a summary of the flows and loads that were used as a basis for alternatives development. It should be noted that the MD and PH flows will be further refined once an alternative is selected. Wet weather flow equalization and MD influent flows are being further reviewed to determine the peak flow that will ultimately be routed through the secondary process. Table 4. Flows and Loads Conditions Used for Comparison of the Alternatives Parameter Unit ADWF AA MM MW MD PH Flow mgd 5.4 6.6 9.7 11.9 16.0 32.8 TSS lb/d 15,000 18,000 27,000 33,000 40,000 -- BOD lb/d 17,000 20,000 29,000 36,000 44,000 -- NH3 lb N/d 1,900 2,200 3,200 3,700 4,500 -- TKN lb N/d 2,800 3,400 4,800 5,600 6,800 -- Provision of an external carbon source is one assumption that was included for each alternative. Additional BOD data is needed to confirm if there is adequate carbon in the influent wastewater. The City is in the progress of collecting additional data. Until data is available, it was assumed that an external carbon source would be needed. WRRF Project TM No. 12 – Process Alternatives Analysis Page 9 of 22 Each alternative also includes the cost of expanding the tertiary filters to treat peak hour flows. For the purpose of this alternatives evaluation, granular media filtration, to match existing, was assumed. Appendix A includes details of common assumptions carried through on all four alternatives. Alternative 1: MLE MLE is a well-established, activated sludge technology that is commonly used within the United States for nitrogen removal. A flow schematic of the MLE process is provided as Figure 2. This technology was recommended in the 2011 Master Plan and had the second highest screening score (Table 3). This process is capable of removing nitrogen to moderately low levels and can be easily modified to include enhanced biological phosphorous removal, if needed. During peak flows, MLE can be operated in contact stabilization mode. In contact stabilization mode, primary effluent is introduced into the aerobic zone and bypasses the anoxic zone. The RAS is stored in the anoxic zone and internal mixed liquor is not returned to the anoxic zone. The benefit of contact stabilization mode is that it reduces solids loading to the final clarifiers by holding biomass in the anoxic zone, and it minimizes solids overflow into the final effluent. Figure 2. Modified Ludzack-Ettinger Process The facility needs for the MLE retrofit are listed in Table 5. An aerial site layout of where these additional facilities could be located is provided in Figure 3. Table 5: Facility Needs for Alternative 1: MLE Area/Unit Process Facility Needs Equalization 4 Mgal Primary Clarifiers 10,000 sf (2 in total @ 80 ft diameter each) Secondary Treatment Aeration Basin Volume (total) SRT (Aerobic) Contact Stabilization Mode Aeration Blowers (total) Methanol Addition (Liquid) * Alkalinity Addition (Magnesium Hydroxide) Final Clarifiers 2.5 Mgal 6.5 days At flows > 14.2 mgd 930 hp 200 gpd 140 gpd 20,000 sf (4 in total @ 80’ dia each) Filtration Granular Mono-Media Influent Primary Clarifier Anoxic Final Clarifier Mixed Liquor Return Return Activated Sludge Aerobic Wet Weather/Peak Flow Diversion WRRF Project TM No. 12 – Process Alternatives Analysis Page 10 of 22 Filters Type Surface Area (total) Hydraulic Loading (1 off line) 2,600 sf (11 total units) 5 gpm/sq ft *Methanol facility needs requires additional data analysis Remainder of page intentionally blank. WR R F P r o j e c t TM N o . 1 2 – P r o c e s s A l t e r n a t i v e s A n a l y s i s Pa g e 1 1 o f 2 2 Fig u r e 3 . A l t e r n a t i v e 1 - M L E S i t e L a y o u t WRRF Project TM No. 12 – Process Alternatives Analysis Page 12 of 22 The advantages and disadvantages for the MLE Treatment Alternative are presented in Table 6. Table 6. Evaluation of MLE Alternative Advantages Disadvantages • Established technology (operational history) • Can accommodate peak flows under contact stabilization mode • Flexibility to meet more stringent limits • Not proprietary • Frequent routine equipment maintenance • Large footprint • Number of additional final clarifiers Alternative 2: VertiCel® VertiCel® is a proprietary process by EVOQUA Water Technologies. The VertiCel® process is an activated sludge process employing aerated-anoxic tanks, mixed and aerated with disc aerators as well as coarse bubble diffusers, followed by reactors aerated with fine-bubble diffusers in the second part of the process (Figure 4). Aerated anoxic tanks or Vertical Loop Reactor (VLR®) are divided into two compartments, an upper and lower as shown in Figure 5. Oxygen delivery and mixing are accomplished by disk aerator located in the upper compartment, while the lower compartment contains coarse bubble diffusers. Figure 4. VertiCel® Process Flow Schematic Figure 5. VLR® Reactor Configuration VertiCel® was considered in the 2011 Master Plan as an alternative technology but the MLE alternative was recommended. This alternative has efficient aeration by the use of mechanical aerators and coarse bubble aerators. Higher SRT results in a lower sludge yields. As with MLE, Influent Primary Clarifier Final Clarifier Mixed Liquor Return Return Activated Sludge Wet Weather/Peak Flow Diversion Vertical Loop Reactor WRRF Project TM No. 12 – Process Alternatives Analysis Page 13 of 22 VertiCel® has the flexibility to operate in contact stabilization mode during peak flows. Figure 6 shows how VertiCel® could be incorporated into the existing treatment train. The facility needs for the VertiCel® retrofit to SLO WRRF are listed in Table 7. An aerial site layout of where these additional facilities might go is provided in Figure 6. Table 7. Facility Needs for Alternative 2- VertiCel® Area/Unit Process Facility Needs Equalization 4 Mgal Primary Clarifiers 10,000 sf (2 in total @ 80 ft diameter each) Secondary Treatment Aeration Basin Volume (total) SRT (Aerobic) Contact Stabilization Mode Aeration Blowers (total) Methanol Addition (Liquid) * Alkalinity Addition (Magnesium Hydroxide) Final Clarifiers 3.8 Mgal 10 days At flows > 14.2 mgd 700 hp 200 gpd 140 gpd 20,000 sf (4 in total @ 80’ dia each) Filtration Filters Type Surface Area (total) Hydraulic Loading (1 off line) Granular Mono-Media 2,600 sf (11 total units) 5 gpm/sf *Methanol facility needs requires additional data analysis The advantages and disadvantages for the VertiCel® Treatment Alternative are presented in Table 8. Table 8. Evaluation of VertiCel® Advantages Disadvantages • Can accommodate peak flows under contact stabilization mode • Robust process • Flexibility to meet more stringent limits • Low sludge production due to a long SRT • Less operational history than MLE • Proprietary system • Largest footprint of the alternatives • Lack of flexibility to leverage existing aeration basins • Frequent routine equipment maintenance • Number of additional final clarifiers WR R F P r o j e c t TM N o . 1 2 – P r o c e s s A l t e r n a t i v e s A n a l y s i s Pa g e 1 4 o f 2 2 Fig u r e 6 . A l t e r n a t i v e 2 - V e r t i C e l ® S i t e L a y o u t WRRF Project TM No. 12 – Process Alternatives Analysis Page 15 of 22 Alternative 3: High Rate A/B Process The A/B (Adsorption/Bio-oxidation) process consists of an “A-stage” high rate activated sludge process followed by a “B-stage” MLE process as shown in Figure 7. The A-Stage typically operates at a very short SRT (0.25-0.5 days), a low dissolved oxygen concentration and a high food to microorganism (F:M) ratio. The general objective of an A-stage is to enhance flocculation for organics removal. The BOD load removal in the A-stage is thought to be about twice as much as a primary clarifier. As a result, the BOD load is reduced for the downstream “B-stage” process which results in a reduction of reactor footprint and energy demand. The A-stage has also been shown to act as a barrier against any shock loads and inhibitory industrial inputs to the B-stage. The High Rate A/B Process is an emerging technology in the US; there are about 12 installations in Europe. High Rate A/B process had a highest score in the technologies evaluation mostly due to the low energy demand of the process, compact footprint of the installation and low solids yield. In addition, this process has flexibility to be retrofitted for mainstream deammonification. Mainstream deammonification would further reduce the energy/chemical demand by requiring less oxygen and an alkalinity/external carbon source (if necessary). Figure 7. Schematic of A/B Process A-Stage Clarifier Final Clarifier Mixed Liquor Return Return Activated Sludge Low Rate “B-Stage”; MLE Influent High Rate “A-Stage” Wet Weather/Peak Flow Diversion WRRF Project TM No. 12 – Process Alternatives Analysis Page 16 of 22 The facility needs for the A/B Process retrofit to SLO WRRF are listed in Table 9. An aerial site layout of where these additional facilities might go is provided in Figure 8. Table 9. Facility Needs for Alternative 3 – High Rate A/B Process Area/Unit Process Facility Needs Equalization 4 Mgal A-Stage Aeration Basins/Clarifiers To Flow Equalization 0.3 Mgal (2 in total; use existing primaries) At flows >16.0 mgd Primary Clarifiers 10,000 sf (2 in total @ 80 ft diameter each) B-Stage Aeration Basin Volume (total) SRT (Aerobic) Contact Stabilization Mode Aeration Blowers (total) Methanol Addition (Liquid) * Alkalinity Addition (Magnesium Hydroxide) Final Clarifiers 1.8 Mgal 6.5 days At flows > 14.2 mgd 700 hp 250 gpd 140 gpd 20,000 sf (4 in total @ 80’ dia each) Filtration Filters Type Surface Area (total) Hydraulic Loading (1 off line) Granular Mono-Media 2,600 sf (11 total units) 5 gpm/sf *Methanol facility needs requires additional data analysis The advantages and disadvantages for the High Rate A/B Treatment Alternative are provided as Table 10. Table 10. Evaluation of High Rate A/B Advantages Disadvantages • Flexibility for implementing mainstream Deammonification in the future • Divert more carbon to solids handling (i.e., more biogas production and smaller aeration basin footprint) • Lower aeration requirements • Limited operating experience • Challenge to implement within TSO dates (pilot testing needed) • More difficult to operate • Reliance on instrumentation • External carbon demands may be greater WR R F P r o j e c t TM N o . 1 2 – P r o c e s s A l t e r n a t i v e s A n a l y s i s Pa g e 1 7 o f 2 2 Fig u r e 8 . A l t e r n a t i v e 3 – H i g h R a t e A / B P r o c e s s S i t e La y o u t WRRF Project TM No. 12 – Process Alternatives Analysis Page 18 of 22 Alternative 4: BioMag® Magnetite ballasted settling is an emerging technology that is gaining popularity. Patented by Siemens, the BioMag® system is an enhanced biological wastewater treatment process that uses magnetite, a common inert iron derivative, to increase the specific gravity of biological floc. The addition of magnetite allows for the secondary clarifiers to operate at a higher solids loading rate so that additional tankage can be avoided. The majority of equipment and modifications associated with the technology are for the removal and recovery of the magnetite from the WAS prior to disposal. The magnetite is recovered from the waste stream and returned into the biological process. During this process, some magnetite is lost and additional magnetite will need to be added. A flow schematic of the BioMag® process is shown in Figure 9. BioMag® had the fourth highest score in the technologies screening mainly due to the compact footprint from high MLSS, high clarifier loading rates and dense sludge blanket. Figure 9. Schematic of BioMag® The facility needs for the BioMag® Process retrofit to SLO WRRF are listed in Table 11. An aerial site layout of where these additional facilities might go is provided in Figure 10. WRRF Project TM No. 12 – Process Alternatives Analysis Page 19 of 22 Table 11. Facility Needs for Alternative 4- BioMag® Process Area/Unit Process Design Criteria Equalization 4 Mgal Primary Clarifiers 10,000 sf (2 in total @ 80 ft diameter each) Secondary Treatment Aeration Basin Volume (total) SRT (Aerobic) Contact Stabilization Mode Aeration Blowers (total) Methanol Addition (Liquid) * Alkalinity Addition (Magnesium Hydroxide) Final Clarifiers 2.5 Mgal 6.5 days At flows > 14.2 mgd 1,100 hp 200 gpd 140 gpd 15,000 sf (4 in total @ 80’ dia each) Filtration Filters Type Surface Area (total) Hydraulic Loading (1 off line) Granular Mono-Media 2,600 sf (11 total units) 5 gpm/sq ft *Methanol facility needs requires additional data analysis The advantages and disadvantages for the BioMag® Treatment Alternative are provided in Table 12. Table 12. Evaluation of BioMag® Advantages Disadvantages • Accommodates peak flows the best of the alternatives considered • Flexibility to meet more stringent permit limitations • Might result in few final clarifiers than the other alternatives • Proprietary system • Additional energy use to keep magnetite suspended • More equipment maintenance • Less operating experience than MLE or VertiCel® • Existing operating plants have smaller design flows than WRRF WR R F P r o j e c t TM N o . 1 2 – P r o c e s s A l t e r n a t i v e s A n a l y s i s Pa g e 2 0 o f 2 2 Fig u r e 1 0 . A l t e r n a t i v e 4 - B i o M a g ® P r o c e s s S i t e L a y o u t WRRF Project TM No. 12 – Process Alternatives Analysis Page 21 of 22 Alternatives Evaluation The facility needs comparison for all four treatment alternatives is provided in Table 13. Alternative 2 (VertiCel®) has the largest aeration basin footprint, while Alternative 3 (High Rate A/B) has the smallest aeration basin footprint. Alternatives 2 and 3 have the lowest annual energy demands, while BioMag® was found to have the highest energy demand. While Alternative 3 has the one of the lowest energy demands, it also potentially has the highest requirements for an external carbon source. Table 13. Facility Needs Comparison of Alternatives Area/Unit Process Unit Alt 1: MLE Alt 2: VertiCel® Alt 3: High Rate A/B Alt 4: BioMag® BNR: Addt’l Units Number 4 6 2 4 BNR & A-Stage (Addt'l Vol) Mgal 1.7 3.0 1.0 1.7 Sludge age (aerobic) Days 6.5 10.0 6.5 6.5 Blower: BNR & A- Stage hp 900 700 700 1,100 Methanol Vol. gal/d 200 200 250 200 Clarifiers – BNR & A-Stage Addt’l Clarifiers Number 2 2 2 1 Filters - Addt'l Units Number 6 6 6 6 Hydraulic Loading gpm/sf 5 5 5 5 *Methanol facility needs requires additional data analysis Based on the facility needs presented in Table 12, an economic (construction and operating cost) analysis was performed. The life cycle analysis calculations are provided in Appendix D. The construction costs exclude unit processes that are common to all 4 alternatives, such as flow equalization modifications, filter complex expansion, and UV disinfection. Non-economic criteria were also evaluated and are described in detail in Appendix E. The non-economic criteria were weighted and scored and Table 10 includes the results of the non-economic analysis. Refer to Appendix E for details on the non-economic analysis. Table 14. Non-Economic and Economic Comparison of Alternatives Criteria Alt 1: MLE Alt 2: VertiCel® Alt 3: High Rate A/B Alt 4: BioMag® Non-Economic Criteria Non-Weighted Comparison (Scoring) 30 29 24 21 Weighted Comparison (Scoring) 94 95 80 71 Economic Comparison *,** Construction Cost $26.4M $32.4M $26.3M $26.5M Present Value O&M Cost $14.5M $11.9M $10.8M $19.9M Net Present Value $40.9M $44.3M $37.1M $46.4M * Includes average annual energy and chemicals required for new equipment (excludes labor and maintenance) ** Assumes 30 years, 5 percent discount rate, and a 3.5 percent inflation rate WRRF Project TM No. 12 – Process Alternatives Analysis Page 22 of 22 The MLE and VertiCel® have the most favorable non-economic scores. However, the VertiCel® has the largest footprint, is not flexible with the existing aeration basins, and is more expensive than MLE. As a result, VertiCel® was not recommended as the selected technology. The BioMag® had the least favorable non-economic score and it was the most expensive alternative. As a result, it is not recommended as the selected technology. The High Rate A/B Process had the second least favorable non-economic score but it was the least expensive. The workshop attendees discussed why the High Rate A/B process ranked lower in the non-economic evaluation. It was concluded that the lower scores on criteria such as Ease of Operation, Maintenance, and Level of Confidence and Piloting Recommended were due to the uncertainties associated with the process because it has not been widely implemented. Furthermore, the group concluded that due to the potential long term benefits, including O&M cost savings and GHG emissions, that this alternative should be further explored before it is ruled out. Based on the evaluation that was performed, it was determined that MLE (Alternative 1) and High- Rate A/B (Alternative 3) would be carried forward for further analysis and consideration. A phased approach is recommended that could allow for MLE to be constructed first with conversion to High Rate A/B second. Project phasing was recommended to be further developed at a follow-on workshop, and for the purposes of preparing the Facility Plan, MLE was recommended as the secondary treatment alternative; flexibility could be provided to enable changing to High Rate A/B during subsequent project phases. Conclusions Two workshops were conducted with the City to evaluate secondary treatment alternatives that could be implemented at the WRRF. The first workshop screened twelve technologies using economic and non-economic criteria, and identified the top four alternatives. The four alternatives were further developed and evaluated against economic and non-economic criteria in Workshop 2. Two of the four alternatives were recommended for implementation at the WRRF (MLE and High Rate A/B). High Rate A/B did not score as high as MLE primarily due to a lack of familiarity with the process and a lack of operational experience. Additional consideration for High Rate A/B is recommended; literature review, site visits and development of a bench-scale test and/or pilot test is recommended to address the lack of familiarity with the process. Until additional information can be gathered, the MLE and High Rate A/B processes will be carried forward. A phased approach to implementing MLE now and High-Rate A/B in the future will be considered. Until a decision can be made, the Facility Plan will carry forward MLE, with the ability to change to High Rate A/B during subsequent project phases. WRRF Project TM No. 12 – Process Alternatives Analysis Appendix A – Workshop Meeting Minutes and Presentation Slides WRRF Project TM No. 12 – Process Alternatives Analysis Page intentionally blank. Water Systems Consulting Inc 3765 S. Higuera Street, Suite 102 San Luis Obispo, California 93401 Phone: (805) 457-8833 Project: 0001- City of San Luis Obispo Water Resource Recovery Facility Project 35 Prado Road San Luis Obispo, California 93401 Phone: (805) 457-8833 Process Alternatives Screening Minutes MEETING DATE:07/17/2014 MEETING TIME:1:00 - 5:00 MEETING LOCATION:WSC Offices - 3765 South Higuera St. Suite 102 (accessed from Hind Lane) OVERVIEW: The purpose of this workshop is to review screening criteria, present process technologies, and screen the viable technologies to 3 to 4 for further evaluation. NOTES: ATTACHMENTS: WRRF_TreatmentAlts_Workshop_20140717.pptx SCHEDULED ATTENDEES: Name Company Phone Number Email Attendance Matthew Anderson City of San Luis Obispo 805-431-0109 manderso@slocity.org Present Howard Brewen City of San Luis Obispo 805-781-7240 hbrewen@slocity.org Present Anne Fairchild City of San Luis Obispo 805-781-7242 afairchi@slocity.org Present Dave Hix City of San Luis Obispo 805-781-7039 dhix@slocity.org Present Marty Maloney City of San Luis Obispo 805-781-7245 mmaloney@slocity.org Present Carrie Mattingly City of San Luis Obispo 805-781-7205 cmatting@slocity.org Present Joe O'Donnell City of San Luis Obispo 805-431-0109 jodonnel@slocity.org Present Pam Ouellette City of San Luis Obispo 805-781-7241 pouellet@slocity.org Present Vance Trimble City of San Luis Obispo 805-781-7245 vtrimble@slocity.org Present Mike Falk HDR 916-817-4916 michael.falk@hdrinc.com Present J. B. Neethling HDR (916) 817-4830 jb.neethling@hdrinc.com Present Mallika Ramanathan HDR (925) 974-2523 mallika.ramanathan@hdrinc.com Present Jasmine Diaz Water Systems Consulting, Inc. 805-457-8833 X109 jdiaz@wsc-inc.com Present Matthew Rodrigues Water Systems Consulting, Inc. 909-483-3200 X203 mrodrigues@wsc-inc.com Present Jeffery Szytel Water Systems Consulting, Inc. 805-457-8833 X101 jszytel@wsc-inc.com Present Lianne Williams Water Systems Consulting, Inc. 805-457-8833 X108 lwilliams@wsc-inc.com Present These meeting minutes are believed to be an accurate reflection of those items discussed and the conclusions that were reached during the referenced meeting. Please contact Water Systems Consulting Inc if there are any discrepancies or questions with the content of these minutes. Water Systems Consulting Inc Page 1 of 5 Printed On: 07/26/2014 01:44 PM Meeting #1 Uncategorized Items No Title Assignment Due Date Priority Status 1.1 Workshop Objectives Closed Official Documented Meeting Minutes:The workshop objectives were discussed as follows: 1. Consensus of treatment objectives and criteria 2. Screen mainstream technologies to 3 to 4 Alternatives 3. Discuss sidestream technologies 4. Review schedule and next steps 1.2 Overview of Process Evaluation Closed Official Documented Meeting Minutes:The workshop presentation is attached and provides an overview of the process taken to first screen and then evaluate treatment technologies. HDR identified a number of potential technologies prior to the workshop. In the first step of the process evaluation, these initial technologies are screened down to 3 or 4 top ranked alternatives (focus of this workshop). Then in a next step those alternatives will be evaluated in greater detail (results will be the focus of the second workshop). Then finally, the recommended alternative will be developed and included in the facility plan. 1.3 Treatment Objectives Closed Official Documented Meeting Minutes:The following treatment objectives were discussed and agreed upon: 1. Meet ammonia and nitrate limits – the focus of today’s meeting is to review/screen technologies that can meet ammonia and nitrate limits. 2. Odor control 3. Disinfection (THM, NDMA, coliforms, etc.) – ability to meet disinfection limitations in draft permit (this is being covered under the disinfection task). 4. Facilitate flow equalization. The intent is to continue to equalize flows diurnally. The existing flow equalization basin may be modified to facilitate O&M associated with flow equalization. Flow routing will also be considered. 5. Minimize chemical addition 6. Flexibility to accommodate reduced flows from I&I control, scalping plants, conservation, etc. 7. Ability to meet other permit limits (pentachlorophenol, DO, BOD, TDS, turbidity) 8. Cooling towers (flow routing) Screening criteria were developed based on triple bottom line criteria (Environmental, Social and Economic) and are included in the attached presentation. A total of twelve criteria were developed and are described in the meeting handout. During the workshop, two additional criteria were identified and added: (1) Compatibility with UV disinfection (at the Disinfection workshop, UV disinfection was selected), and (2) Ability to meet future endocrine disruptors (EDCs) regulations. Future peak wet weather flows were discussed. Improvements have been (and will be) made to the collection system, which should reduce peak wet weather flows. The 2011 Master Plan projected a peak hour flow of 32 mgd. The City would like this number to be revisited to make sure the treatment facilities are sized correctly to reflect modifications that have already been made to the collection system as well as modifications that will be made to the collection system. WSC is working on the collection system model and is using flow monitoring data collected by V&A. The capacity of the tertiary filters was discussed. With the replacement of the filter media, the capacity of the filters is expected to double to 8 mgd. 1.4 Screening Criteria Closed Attachments: ScreeningCriteria_Handout.docx These meeting minutes are believed to be an accurate reflection of those items discussed and the conclusions that were reached during the referenced meeting. Please contact Water Systems Consulting Inc if there are any discrepancies or questions with the content of these minutes. Water Systems Consulting Inc Page 2 of 5 Printed On: 07/26/2014 01:44 PM Meeting #1 Official Documented Meeting Minutes:A hand-out was provided at the Workshop (see attachment) that describes the criteria that were used to screen treatment technologies. The criteria included: 1.Meet Permit Limits 2.Technology Status 3.Good Neighbor (odor) 4.Minimize Chemicals (safety and TDS concerns) 5.Ability to Meet Lower Limits 6.Compatibility with Biosolids Treatment 7.Facilitate Flow Equalization 8.Ease of Operation 9.Relative capital Cost 10.Relative O&M Cost 11.GHG Emissions 12.Ease of Implementation In addition to these 12 criteria, 2 additional criteria were added based on discussions during the workshop: 1. Compatibility with UV disinfection (selected as the disinfection technology at a prior workshop) 2. Ability to meet future endocrine disrupting compounds (EDCs) The group discussed the relative importance of the 14 screening criteria. The result of the discussion was that each criteria was assigned a weighting factor (1, 3 or 5) to represent its relative importance, with 5 being the most important and 1 being the least important. The criteria were assigned as follows: •Weight 5: Meet Permit Limits; Good Neighbor (Odor); Ability to Meet Lower Limits; Facilitate Flow Equalization; Relative O&M Cost; Compatibility with UV Disinfection •Weight 3: Technology Status; Minimize Chemicals; Compatibility with Biosolids Treatment; Ease of Operation; GHG Emissions; Ease of Implementation; Ability to meet future EDC regulations. •Weight 1: Relative Capital Cost 1.5 Mainstream Process Screening Open Attachments: TreatmentAlts_ScreeningMatrix_4thAltRescreen_20140722.pdf TreatmentAlts_ScreeningMatrix_20140722.pdf Official Documented Meeting Minutes:The following twelve treatment technologies were described (descriptions are included in the attached presentation): 1.MLE (Conventional with and w/out re-aeration) (evaluated in 2011 Master Plan) 2.Oxidation Ditch (Verticel) (evaluated in 2011 Master Plan) 3.High Rate A/B Process 4.Integrated Fixed-Film Act Sludge (IFAS) 5.BioMag 6.Nereda Granular Sludge 7.BioBrimstone 8.Denite Filters These meeting minutes are believed to be an accurate reflection of those items discussed and the conclusions that were reached during the referenced meeting. Please contact Water Systems Consulting Inc if there are any discrepancies or questions with the content of these minutes. Water Systems Consulting Inc Page 3 of 5 Printed On: 07/26/2014 01:44 PM Meeting #1 9.Wetlands 10.MBR (Parallel Treatment w/Bioaugmentation) 11.MBR (Stand Alone) 12.Mainstream Anaerobic Treatment Wetlands treatment was discussed. The ability for wetlands alone to be the mainstream treatment process would require additional land and would not reliably meet permit limitations. Therefore, it may be more advantageous to provide wetlands as a demonstration facility near the interpretive center. The demonstration wetlands could also be done as a partnership with Cal Poly. The wetlands could also be designed to treat plant sidestreams as well. The twelve technologies were screened by scoring each treatment technology against the screening criteria. MLE was used a baseline for comparison purposes, because it was the recommended alternative in the 2011 Master Plan. The results of the screening analysis are illustrated in the attached table. The following technologies had the highest final score: 1.High Rate A/B 2.MLE 3.Oxidation Ditch (Verticel) Although wetlands was the fourth highest scored technology, it was agreed that due to its inability to reliably meet permit limitations, it was eliminated from further consideration for mainstream treatment (i.e., it was fatally flawed). The next highest score was the Nereda process; however the group agreed that this process may not be best suited for peak wet weather flows because it is a batch process. The group requested that HDR revisit the fourth alternative and select either Nereda, BioMag, or IFAS. Following the workshop, HDR revisited the scoring of these three alternatives as such: Treatment Alternative Non-Weighted Score Weighted Score Nereda Granular Sludge 27 99 IFAS (Attached Growth Media)28 102 BioMag (Magnetite)28 104 Details of this additional analysis are included in the attached table. Based on this evaluation, HDR recommends that BioMag be the fourth treatment alternative. The major benefit for BioMag over IFAS and Nereda is it’s ability to handle peak flows without compromising process performance. 1.6 Sidestream Discussion Closed Official Documented Meeting Minutes:Sidestream treatment options were discussed. Because sidestream treatment alone will not be adequate to meet permit limitations, sidestream treatment will be considered as a potential way to optimize the recommended treatment train and could be implemented as a future project. 1.7 Next Steps Open Official Documented Meeting Minutes:HDR will further develop the four alternatives selected and develop capital and operating costs for the alternatives. A list of advantages and disadvantages for each These meeting minutes are believed to be an accurate reflection of those items discussed and the conclusions that were reached during the referenced meeting. Please contact Water Systems Consulting Inc if there are any discrepancies or questions with the content of these minutes. Water Systems Consulting Inc Page 4 of 5 Printed On: 07/26/2014 01:44 PM Meeting #1 alternative will be developed. The information will be presented in Treatment Process Evaluation Workshop 2. A recommended treatment alternative will be selected at Treatment Process Evaluation Workshop 2. This alternative will then be further developed as part of the Facilities Plan. These meeting minutes are believed to be an accurate reflection of those items discussed and the conclusions that were reached during the referenced meeting. Please contact Water Systems Consulting Inc if there are any discrepancies or questions with the content of these minutes. Water Systems Consulting Inc Page 5 of 5 Printed On: 07/26/2014 01:44 PM Meeting #1 Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t En g a g e . Tr a n s f o r m . Su s t a i n . July 17, 2014 Tr e a t m e n t Al t s Wo r k s h o p Ag e n d a ME E T I N G OB J E C T I V E S OV E R V I E W OF PR O C E S S EV A L U A T I O N TR E A T M E N T OB J E C T I V E S SC R E E N I N G CR I T E R I A MA I N S T R E A M PR O C E S S SC R E E N I N G SI D E S T R E A M DI S C U S S I O N NE X T ST E P S Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t WO R K S H O P OB J E C T I V E S Wo r k s h o p Ob j e c t i v e s 1. C o n s e n s u s of tr e a t m e n t ob j e c t i v e s an d cr i t e r i a 2. S c r e e n ma i n s t r e a m te c h n o l o g i e s to 4 Al t s 3. D i s c u s s si d e s t r e a m te c h n o l o g i e s 4. R e v i e w sc h e d u l e an d ne x t st e p s Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t OV E R V I E W OF PR O C E S S EV A L U A T I O N Te c h n o l o g y Sc r e e n i n g / E v a l u a t i o n Ap p r o a c h Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t De v e l o p Pr o s p e c t i v e Te c h n o l o g i e s Li s t Te c h n o l o g i e s Sc r e e n i n g Al t e r n a t i v e De v e l o p m e n t an d Ev a l u a t i o n Fa c i l i t y Ne e d s Ec o n o m i c An a l y s i s No n ‐Ec o n o m i c An a l y s i s Recommended Alternative Te c h n o l o g y Sc r e e n i n g / E v a l u a t i o n Ap p r o a c h Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t De v e l o p Pr o s p e c t i v e Te c h n o l o g i e s Li s t Te c h n o l o g i e s Sc r e e n i n g Al t e r n a t i v e De v e l o p m e n t an d Ev a l u a t i o n Fa c i l i t y Ne e d s Ec o n o m i c An a l y s i s No n ‐Ec o n o m i c An a l y s i s Recommended Alternative To d a y ’ s Wo r k s h o p TR E A T M E N T OB J E C T I V E S Tr e a t m e n t Ob j e c t i v e s Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t ‐ Me e t am m o n i a an d ni t r a t e li m i t s ‐ Od o r co n t r o l ‐ Di s i n f e c t i o n (T H M , ND M A , co l i f o r m s , et c . ) ‐ Pe a k fl o w ma n a g e m e n t ‐ Mi n i m i z e ch e m i c a l ad d i t i o n ‐ Fl e x i b i l i t y to ac c o m m o d a t e re d u c e d fl o w s fr o m I& I co n t r o l , sc a l p i n g pl a n t s , co n s e r v a t i o n , et c . ‐ Ot h e r pe r m i t li m i t s (D O , BO D , TD S , tu r b i d i t y , pe n t a c h l o r o p h e n o l ) ‐ Co o l i n g to w e r s (f l o w ro u t i n g ) Re g u l a t o r y Re q u i r e m e n t s Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t Pa r a m e t e r U n i t Av e r a g e Dr y We a t h e r Fl o w Av e r a g e Mo n t h l y Av e r a g e We e k l y Ma x i m u m Da i l y In s t a n t a n e o u s Mi n i m u m Instantaneous Maximum Ra t e d Ca p a c i t y mg d 5. 1 ‐‐ ‐ ‐ ‐‐ ‐‐‐‐ BO D 5 mg / L ‐‐ 10 3 0 5 0 ‐‐‐‐ lb / d ‐‐ 42 5 1 , 2 7 5 2 , 1 2 5 TS S mg / L ‐‐ 10 3 0 7 5 ‐‐‐‐ lb / d ‐‐ 42 5 1 , 2 7 5 3 , 1 9 0 Un ‐io n i z e d Am m o n i a mg N/ L ‐‐ ‐ ‐ ‐ ‐ 0. 0 2 5 (I n ‐St r e a m ) ‐‐‐‐ Fi n a l Ni t r a t e mg N/ L ‐‐ 10 ‐‐ ‐‐ ‐‐‐‐ pH s. u . ‐‐ ‐ ‐ ‐ ‐ ‐‐ 6.58.3 Pe n t a c h l o r o p h e n o l µg / L ‐‐ 0. 2 8 ‐‐ 0. 5 6 ‐‐‐‐ ND M A ng / L ‐‐ 0. 69 ‐‐ 1. 4 ‐‐‐‐ lb / d ‐‐ 0. 0 0 0 0 2 9 ‐‐ 0. 0 0 0 0 6 0 ‐‐‐‐ Di s s o l v e d O x y g e n mg / L -- - - - - 7 ---- Od o r Co n c e r n s Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t Co o l i n g To w e r s Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t Pe a k Fl o w Ma n a g e m e n t Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t 0510152025 Jan-09 Mar-09 May-09 Jul-09 Sep-09 Nov-09 Jan-10 Mar-10 May-10 Jul-10 Sep-10 Nov-10 Jan-11 Mar-11 May-11 Jul-11 Sep-11 Nov-11 Jan-12 Mar-12 May-12 Jul-12 Sep-12 Nov-12 Jan-13 Mar-13 May-13 Jul-13 Sep-13 Nov-13 Jan-14 Flow (mgd) Da i l y I n f l u e n t P e a k F l o w f o r J a n u a r y 2 0 0 9 - J a n u a r y 2 0 1 4 SC R E E N I N G CR I T E R I A Sc r e e n i n g Cr i t e r i a ‐ Me e t pe r m i t li m i t s ‐ Re l a t i v e Ca p i t a l an d O& M ‐ Sa f e t y ‐ Go o d ne i g h b o r (o d o r co n t r o l ) ‐ Fl e x i b i l i t y to me e t mo r e st r i n g e n t li m i t s ‐ Mi n i m i z e ch e m i c a l s (T D S an d GH G s ) ‐ Co m p a t i b i l i t y wi t h bi o s o l i d s tr e a t m e n t ‐ Ea s e of Op e r a t i o n ‐ Op e r a t i o n du r i n g co n s t r u c t i o n (e a s e of im p l e m e n t a t i o n ) ‐ Fa c i l i t a t e fl o w eq u a l i z a t i o n ‐ Te c h n o l o g y St a t u s : Es t a b l i s h e d , Em e r g i n g , or Em b r y o n i c Su s t a i n a b i l i t y Te c h n o l o g y St a t u s Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t ‐ Es t a b l i s h e d : A pr o v e n technology wi t h nu m e r o u s fu l l ‐scale in s t a l l a t i o n s th a t span various de s i g n fl o w s ‐ Em e r g i n g : Up an d coming te c h n o l o g y th a t has several pilots an d a fe w fu l l ‐sc a l e installations. ‐ Em b r y o n i c : Li m i t e d to bench‐ sc a l e an d pi l o t s with zero or one fu l l ‐sc a l e in s t a l l a t i o n Fi r s t De m o n s t r a t i o n Em e r g i n g St a t u s Em b r y o n i c St a t u s Pi l o t Es t a b l i s h e d St a t u s Ti m e Development/ Number Installed Te c h n o l o g y St a t u s S‐Cu r v e (A d a p t e d fr o m Pa r k e r et al . , 20 1 1 ) MA I N S T R E A M PR O C E S S SC R E E N I N G 20 1 1 Ma s t e r Pl a n Al t e r n a t i v e s Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t ML E Re c o m m e n d e d Al t e r n a t i v e # Ad d t ’ l Pr i m a r i e s # Ad d t ’ l Ae r a t i o n Ta n k s # Ad d t ’ l Cl a r i f i e r s Ox i d a t i o n Di t c h 1 2 4 Mo d i f i e d Lu d z a c k ‐ Et t i n g e r ( M L E ) 15 2 ML E w/ S l u d g e Re ‐Ae r a t i o n 12 2 Ba r d e n p h o 1 7 2 Bi o f i l t e r s a n d Ac t Sl u d g e (s t a t u s qu o ) 12 2 Te c h n o l o g i e s Co n s i d e r e d Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t 1) M L E (C o n v e n t i o n a l wi t h an d w/ o u t re ‐ae r a t i o n ) 2) O x i d a t i o n Di t c h (V e r t i c e l ) 3) H i g h Ra t e A/ B Pr o c e s s 4) I n t e g r a t e Fi x e d ‐Fi l m Ac t Sl u d g e (I F A S ) 5) B i o M a g 6) N e r e d a G r a n u l a r Sl u d g e 7) B i o B r i m s t o n e 8) D e n i t e Fi l t e r s 9) W e t l a n d s 10 ) M B R (P a r a l l e l Tr e a t m e n t w/ B i o a u g m e n t a t i o n ) 11 ) M B R (S t a n d Al o n e ) 12 ) M a i n s t r e a m An a e r o b i c Tr e a t m e n t Te c h n o l o g i e s Co n s i d e r e d Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t 1) M L E (C o n v e n t i o n a l wi t h an d w/ o u t re ‐ae r a t i o n ) 2) O x i d a t i o n Di t c h (V e r t i ‐ce l ) 3) H i g h Ra t e A/ B Pr o c e s s 4) I n t e g r a t e Fi x e d ‐Fi l m Ac t Sl u d g e (I F A S ) 5) B i o M a g 6) N e r e d a G r a n u l a r Sl u d g e 7) B i o B r i m s t o n e 8) D e n i t r i f y i n g Fi l t e r s 9) W e t l a n d s 10 ) M B R (P a r a l l e l Tr e a t m e n t w/ B i o a u g m e n t a t i o n ) 11 ) M B R (S t a n d Al o n e ) 12 ) M a i n s t r e a m An a e r o b i c Tr e a t m e n t From 2011 Master Plan Mo d i f i e d Lu d z a c k ‐Et t i n g e r ( M L E ) • Es t a b l i s h e d te c h n o l o g y • 20 1 1 MP Re c o m m e n d a t i o n • In d u s t r y st a n d a r d • Ab i l i t y to re m o v e mo r e N an d re m o v e P (w / c h e m ) • Re a e r a t i o n o p t i o n fo r pe a k s IN F Pr i C l a r AN X Fi n a l C l a r ML R RA S AE R Ox i d a t i o n Di t c h (V e r t i ‐Ce l ) • Es t a b l i s h e d te c h n o l o g y • Co n s i d e r e d in 20 1 1 MP • Si m p l e to op e r a t e • Ef f i c i e n t ae r a t i o n • Re l a t i v e l y lo w so l i d s yi e l d • Co n t a c t st a b i l i z a t i o n fo r pe a k s IN F Pr i C l a r Fi n a l C l a r ML R RA S Ox i d a t i o n D i t c h Hi g h Ra t e A/ B Pr o c e s s • Em e r g i n g te c h n o l o g y in US • En e r g y ef f i c i e n t • Co m p a c t fo o t p r i n t • Lo w so l i d s yi e l d • Fu t u r e ma i n s t r e a m de a m m o n i f i c a t i o n Se c o n d a r y Cl a r i f i e r Fi n a l Cl a r i f i e r ML R RA S Lo w R a t e B P r o c e s s ; ML E IN F Hi g h R a t e A Pr o c e s s In t e g r a t e d Fi x e d ‐Fi l m Ac t Sl u d g e (IFAS) • Es t a b l i s h e d te c h n o l o g y • Co m p a c t fo o t p r i n t (a t t a c h e d gr o w t h sy s t e m ) • Me d i a sc r e e n s • Me d i a st o r a g e (w h e n of f ‐li n e ) • No ne w fi n a l cl a r i f i e r s ? • Ab i l i t y to ha n d l e pe a k fl o w s IN F Pr i C l a r AN X Fi n a l C l a r ML R RA S AE R Bi o M a g ( B a l l a s t e d Ac t i v a t e d Sl u d g e ) • Em e r g i n g te c h n o l o g y • Co m p a c t fo o t p r i n t (h e a v y / de n s e ba l l a s t e d fl o c s ) • Hi g h ML S S (8 , 0 0 0 mg / L ) • Hi g h cl a r i f i e r lo a d i n g ra t e s • De n s e sl u d g e bl a n k e t s IN F Pr i C l a r AN X Fi n a l C l a r ML R RA S AE R Ma g n e t i t e Re c y c l e Ma g n e t i t e Re c o v e r y WA S Ne r e d a G r a n u l a r Sl u d g e • Em e r g i n g te c h n o l o g y • Co m p a c t fo o t p r i n t (d e n s e / g r a n u l a r fl o c s ) • Hi g h ML S S (> 8 , 0 0 0 mg / L ) • Hi g h cl a r i f i e r lo a d i n g / s e t t l i n g ra t e s • Li m i t e d to se q u e n c i n g ba t c h re a c t o r IN F Pr i C l a r Se q u e n c i n g B a t c h Re a c t o r Bi o b r i m s t o n e • Em b r y o n i c s t a t u s • Ch e m i c a l tr e a t m e n t : tw o st e p pH ad j u s t m e n t • Ne e d s – Be t t e r te c h n o l o g y de s c r i p t i o n – Pe r f o r m a n c e da t a • Ap p l i c a t i o n at WR R F ? – Pl a n t – Sc a l p i n g pl a n t De n i t r i f y i n g Fi l t e r s • Es t a b l i s h e d te c h n o l o g y • Ex p a n d fi l t e r co m p l e x ? • Ad d ex t e r n a l ca r b o n so u r c e • Ca n me e t lo w ni t r a t e li m i t s • Ca n be us e d in ta n d e m w/ o t h e r Al t s Ae r a t i o n Ba s i n De n i t r i f y i n g Fi l t e r s Pr i C l a r SC L Tr i c k l i n g Fi l t e r Fi n a l C l a r Co o l i n g To w e r In f l u e n t Ma g n e s i u m Hy d r o x i d e Ex t e r n a l Ca r b o n So u r c e We t l a n d s • Em b r y o n i c , Em e r g i n g , an d Es t a b l i s h e d ( s e v e r a l te c h n o l o g i e s ) • Ap p l i c a t i o n : De n i t e OR N re m o v a l • La r g e fo o t p r i n t • Lo w en e r g y / c h e m i c a l s • Re l i a b l e pe r f o r m a n c e co n c e r n s • Lo c a t i o n at Pl a n t : – In pa r a l l e l wi t h Ac t Sl u d g e – U p s t r e a m of Fi l t e r s – Up s t r e a m of di s i n f e c t i o n Me m b r a n e Bi o r e a c t o r s • Es t a b l i s h e d te c h n o l o g y • Pa r a l l e l tr e a t m e n t or st a n d ‐al o n e • Pr o d u c e s Ti t l e 22 fi l t e r e d wa t e r • Co m p a c t fo o t p r i n t • En e r g y in t e n s i v e • Si z i n g ba s e d on pe a k fl o w s Me m b r a n e T a n k IN F Pr i C l a r AN X ML R RA S AE R Ma i n s t r e a m An a e r o b i c Tr e a t m e n t • Em b r y o n i c Te c h n o l o g y • En e r g y ne u t r a l i t y ? • Co m p a c t fo o t p r i n t • Si z i n g ba s e d on pe a k fl o w s • Re l i a b l y me e t pe r m i t ? An a e r o b i c Fl u i d i z e d MB R IN F Pr i C l a r RA S An a e r o b i c Fl u i d i z e d B e d Bi o r e a c t o r Te c h n o l o g y Sc r e e n i n g Pr o j e c t Ex c e l Wo r k b o o k an d Fi l t e r Re s u l t s to La n d on 4 Al t s to Ca r r y Fo r w a r d Cr i t e r i a We i g h t i n g Cr i t e r i a We i g h t i n g (1 , 2, or 3) Co s t (C a p i t a l an d O& M ) Sa f e t y Go o d Ne i g h b o r (O d o r s ) Me e t mo r e st r i n g e n t li m i t s Mi n i m i z e ch e m i c a l s Bi o s o l i d s tr e a t m e n t co m p a t i b i l i t y Ea s e of im p l e m e n t a t i o n Ea s e of op e r a t i o n Fa c i l i t a t e fl o w eq u a l i z a t i o n Te c h n o l o g y St a t u s SI D E S T R E A M DI S C U S S I O N Si d e s t r e a m Te c h n o l o g i e s ‐ Co n s i d e r as pa r t of re c o m m e n d e d al t e r n a t i v e ‐ Do e s it ma k e se n s e fo r WR R F ? ‐ Eq u a l i z e si d e s t r e a m or Tr e a t m e n t ? ‐ Ma i n s t r e a m + Si d e s t r e a m OR Ma i n s t r e a m (s t a n d ‐al o n e ) ‐ Si d e s t r e a m tr e a t m e n t be n e f i t s : ‐ Re d u c e ma i n s t r e a m fo o t p r i n t ‐ Re d u c e ma i n s t r e a m al k a l i n i t y de m a n d ‐ Re d u c e ma i n s t r e a m ex t e r n a l C de m a n d Si d e s t r e a m Te c h n o l o g i e s ‐ Es t a b l i s h e d : ‐ Co n v e n t i o n a l Se q u e n c i n g Ba t c h Re a c t o r ‐ Em e r g i n g : ‐ An a m m o x Te c h n o l o g i e s ‐ Em b r y o n i c : ‐ Ze o l i t e / A n a m m o x (W e t l a n d Te c h n o l o g y ) ‐ Am m o n i c Re c o v e r y Pr o c e s s (A R P ) NE X T ST E P S Ne x t St e p s Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t ‐ Su m m a r i z e sc r e e n i n g re s u l t s ‐ Ev a l u a t e te c h n o l o g i e s ca r r i e d fo r w a r d : ‐ Ev a l u a t e fa c i l i t y ne e d s ‐ Ca p i t a l , O& M , an d LC A ‐ No n ‐ec o n o m i c an a l y s i s ‐ Pr e p a r e re s u l t s fo r ne x t wo r k s h o p Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t En g a g e . Tr a n s f o r m . Su s t a i n . July 17, 2014 Tr e a t m e n t Al t s Wo r k s h o p Water Systems Consulting Inc 3765 S. Higuera Street, Suite 102 San Luis Obispo, California 93401 Phone: (805) 457-8833 Project: 0001- City of San Luis Obispo Water Resource Recovery Facility Project 35 Prado Road San Luis Obispo, California 93401 Phone: (805) 457-8833 Process Alternatives Screening Minutes MEETING DATE:08/21/2014 MEETING TIME:10:00 - 3:00 MEETING LOCATION:WSC Offices - 3765 South Higuera St. Suite 102 (accessed from Hind Lane) OVERVIEW: The purpose of this workshop is to present the results of the process alternatives evaluation and select a recommended alternative for further development. NOTES: ATTACHMENTS: TreatmentAlts_EvaluationMatrix_20140825.pdf TreatmentAlts_Workshop2Presentation_20140825.pdf ATTENDEES: Name Company Phone Number Email Attendance Howard Brewen City of San Luis Obispo Tel: 805-781-7240 hbrewen@slocity.org Present Dave Hix City of San Luis Obispo Tel: 805-781-7039 dhix@slocity.org Present Carrie Mattingly City of San Luis Obispo Tel: 805-781-7205 cmatting@slocity.org Present Rich Novick City of San Luis Obispo Tel: (805) 781- 7227 rnovick@slocity.org Present Joe O'Donnell City of San Luis Obispo Tel: 805-431-0109 jodonnel@slocity.org Present Pam Ouellette City of San Luis Obispo Tel: 805-781-7241 pouellet@slocity.org Present Ernie Redman City of San Luis Obispo Tel: 805-781-7245 eredman@slocity.org Present Vance Trimble City of San Luis Obispo Tel: 805-781-7245 vtrimble@slocity.org Present Mike Falk HDR Tel: 916-817-4916 michael.falk@hdrinc.com Present Holly Kennedy HDR Tel: 925-974-2617 holly.kennedy@hdrinc.com Present J. B. Neethling HDR Tel: (916) 817- 4830 jb.neethling@hdrinc.com Present Mallika Ramanathan HDR Tel: (925) 974- 2523 mallika.ramanathan@hdrinc.com Absent Jasmine Diaz Water Systems Consulting, Inc. Tel: 805-457-8833 X109 jdiaz@wsc-inc.com Present Matthew Rodrigues Water Systems Consulting, Inc. Tel: 909-483-3200 X203 mrodrigues@wsc-inc.com Present Jeffery Szytel Water Systems Consulting, Inc. Tel: 805-457-8833 X101 jszytel@wsc-inc.com Present Lianne Williams Water Systems Consulting, Inc. Tel: 805-457-8833 X108 lwilliams@wsc-inc.com Present These meeting minutes are believed to be an accurate reflection of those items discussed and the conclusions that were reached during the referenced meeting. Please contact Water Systems Consulting Inc if there are any discrepancies or questions with the content of these minutes. Water Systems Consulting Inc Page 1 of 4 Printed On: 09/03/2014 04:56 PM Meeting #2 Uncategorized Items No Title Assignment Due Date Priority Status 2.1 Meeting Objectives Closed Official Documented Meeting Minutes: Meeting objectives included: 1. Review rated capacity analysis 2. Reach consensus on the results of the alternatives evaluation 3. Select a preferred process alternative to carry forward to the facilities plan. 2.2 Summary from Process Screening Workshop Closed Official Documented Meeting Minutes: During Workshop 1: 1. Treatment objectives were reviewed and agreed upon. 2. Process screening criteria were defined and agreed upon (14 criteria in total). 3. The screening criteria were used to reduce the number of treatment technologies from 12 to 4, including MLE, Verti-cel, High Rate A/B, and BioMag. 2.3 Capacity Analysis Closed Description: . Official Documented Meeting Minutes: The capacity analysis included development of a steady state mass balance and an analysis of the existing unit processes for the current rated plant capacity. Refer to the attached presentation materials for the results of the capacity analysis. The required capacity of flow equalization under buildout conditions still needs to be confirmed. If the existing capacity (approximately 4 MGal) is not sufficient, there are two options to consider: 1) increase the volume of flow EQ storage either at the existing basin or at a new/alternative site, or 2) increase the peak equalized flow through the plant above 16 mgd. The WRRF currently cools both the effluent disposed of in SLO Creek as well as that used for recycled water. In the future, there may be opportunities to re-route recycled water flow such that cooling is only provided for the effluent t SLO Creek. 2.4 Process Alternatives Evaluation Closed Attachments: TreatmentAlts_EvaluationMatrix_20140825.pdf Official Documented Meeting Minutes: The evaluation of the four process alternatives was a comparative analysis that focused largely on the liquid stream processes. The following elements were common to each of the alternatives: •Flow Splits •Flow EQ Volume •Final clarifiers assumed to be 80' diameter for each new clarifier •Cooling Towers •Filtration •UV Disinfection •Reserve for future biosolids processing In addition, the following assumptions were made to facilitate the relative comparison (it is important to note that further analysis / detail will be developed for the recommended alternative): •Influent PWWF will overflow to the EQ basin at flows greater than 22 mgd. •The primary effluent diversion box will overflow to EQ at flows greater than 16 mgd. •The existing primary clarifiers can be rehabilitated. •For the purposes of being conservative and until additional BOD data is available, it was assumed that an additional carbon source is needed (e.g., methanol). These meeting minutes are believed to be an accurate reflection of those items discussed and the conclusions that were reached during the referenced meeting. Please contact Water Systems Consulting Inc if there are any discrepancies or questions with the content of these minutes. Water Systems Consulting Inc Page 2 of 4 Printed On: 09/03/2014 04:56 PM Meeting #2 •Tertiary filtration will be sized to accommodate flows up to 16 mgd at 5 gpm/sf with one unit off-line. This assumption is based on Title 22 requirements. However, there is room to optimize this and make a less conservative assumption. For each alternative, the following information was developed and presented for discussion: 1.General description 2.Process flow diagram 3.Design criteria 4.Facility needs 5.Preliminary site layout 6.Advantages and disadvantages 7.Summary of annual operations requirements, including both energy and chemical requirements. Once each of the alternatives were presented, a comparison of the relative capital, O&M, and net present value costs was presented. The capital costs for MLE, High Rate A/B, and BioMag are all about the same at approximately $26.4 million, while the capital cost for the Verti-Cel option is significantly higher at approximately $32.4M (23% more costly). Once the net present value for O&M costs (chemicals and energy) are factored in, the high rate A/B alternative is the lowest cost option ($37.1M), followed by MLE ($40.9M), Verti-Cel ($44.3M), and BioMag ($46.4M). Each of the alternatives was also scored against the screening criteria that were established during Workshop #1 (refer to attached table). The relative importance (weighting) for the criteria was also revisited during the workshop. The results of this non-economic analysis revealed that MLE and Verti-Cel were ranked highest, followed by High Rate A/B, and finally BioMag. Based on the results of the economic and non-economic evaluations, Verti-Cel and BioMag were eliminated from further consideration. The group discussed why the High Rate A/B process ranked lower in the non-economic evaluation and it was concluded that the lower scores on criteria such as Ease of Operation, Maintenance, and Level of Confidence and Piloting Recommended were due to the uncertainties associated with the process because it hasn’t been widely implemented. Furthermore, the group concluded that due to the potential long term benefits, including O&M cost savings and GHG emissions, that this alternative should be further explored before it is ruled out. Thus, the group agreed to carry forward both the MLE process and the High Rate A/B process for further analysis and consideration, including the development of a potential hybrid solution that may allow for a first of MLE followed by later implementation of High Rate A/B. 2.5 Recommended Alternative Closed Official Documented Meeting Minutes: See prior item As part of the analysis/development of the recommended alternative: •Evaluate the need for alkalinity (associated bulk storage) considering the impact that the City's raw water supply has on the alkalinity of the influent flow (e.g., raw water from Nacimiento Reservoir was reported to have only half the alkalinity of other raw water supplies). •Evaluate flow EQ volume for peak wet weather as well as diurnal EQ. •Evaluate flow routing through cooling towers. •Evaluate/optimize capacity requirements for filtration. •Consider ways to reduce energy demand spikes to better adapt to PGE rate schedule and reduce energy costs. •Include space for future expansion of facilities in the site layout. 2.6 Next Steps Closed Official Documented Meeting Minutes: Next steps include further development and evaluation of the MLE and High Rate A/B process, specifically including development of a hybrid approach in which an MLE process could be implemented in a first phase (perhaps at a lower capacity than plant buildout such that the basin would be sized appropriately for the High Rate A/B), followed by later implementation of High Rate A/B should it prove to viable and preferred over further expansion of MLE. These meeting minutes are believed to be an accurate reflection of those items discussed and the conclusions that were reached during the referenced meeting. Please contact Water Systems Consulting Inc if there are any discrepancies or questions with the content of these minutes. Water Systems Consulting Inc Page 3 of 4 Printed On: 09/03/2014 04:56 PM Meeting #2 In addition, the PM Team will reach out to Hampton Roads Sanitation District (HRSD) to obtain information regarding their High Rate A/B pilot. The PM Team will also develop a rough estimate of costs for a site visit to the HDSD pilot and to the full size plant operating in Strauss, Austria. A follow-up meeting will be scheduled in two to three weeks to report on the status of the potential hybrid approach and discuss additional steps going forward (e.g., site visits, piloting, etc.) These meeting minutes are believed to be an accurate reflection of those items discussed and the conclusions that were reached during the referenced meeting. Please contact Water Systems Consulting Inc if there are any discrepancies or questions with the content of these minutes. Water Systems Consulting Inc Page 4 of 4 Printed On: 09/03/2014 04:56 PM Meeting #2 Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t En g a g e . Tr a n s f o r m . Su s t a i n . August 21, 2014 Tr e a t m e n t Al t s Wo r k s h o p 2 Ag e n d a ME E T I N G OB J E C T I V E S SU M M A R Y FR O M WO R K S H O P 1 CA P A C I T Y AN A L Y S I S PR O C E S S AL T E R N A T I V E S EV A L U A T I O N RE C O M M E N D E D AL T E R N A T I V E NE X T ST E P S Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t WO R K S H O P OB J E C T I V E S Wo r k s h o p Ob j e c t i v e s 1. R e v i e w Ra t e d Ca p a c i t y An a l y s i s 2. C o n s e n s u s on Al t e r n a t i v e s Ev a l u a t i o n Re s u l t s 3. S e l e c t a Pr e f e r r e d Al t e r n a t i v e 4. R e v i e w Ne x t St e p s Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t WO R K S H O P 1 SU M M A R Y Pr o c e s s Sc r e e n i n g / E v a l u a t i o n Ap p r o a c h Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t De v e l o p Pr o s p e c t i v e Te c h n o l o g i e s Li s t Te c h n o l o g i e s Sc r e e n i n g Al t e r n a t i v e De v e l o p m e n t an d Ev a l u a t i o n Fa c i l i t y Ne e d s Ec o n o m i c An a l y s i s No n ‐Ec o n o m i c An a l y s i s Recommended Alternative Wo r k s h o p 1 Su m m a r y 1. R e v i e w e d tr e a t m e n t ob j e c t i v e s 2. A g r e e d up o n pr o c e s s sc r e e n i n g cr i t e r i a and re l a t i v e im p o r t a n c e 3. S c r e e n e d te c h n o l o g y al t e r n a t i v e s fr o m 12 to 4 4. D i s c u s s e d si d e s t r e a m t r e a t m e n t te c h n o l o g i e s an d ap p r o a c h an a l y s i s as pa r t of pr e f e r r e d al t e r n a t i v e Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t Sc r e e n i n g Cr i t e r i a Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t 1) M e e t Pe r m i t Li m i t s 2) T e c h n o l o g y St a t u s (E m e r g i n g , Es t a b l i s h e d ) 3) G o o d Ne i g h b o r (o d o r ) 4) M i n i m i z e Ch e m i c a l s (s a f e t y an d TD S co n c e r n s ) 5) A b i l i t y to Me e t Lo w e r Li m i t s 6) C o m p a t i b i l i t y wi t h Bi o s o l i d s T r e a t m e n t 7) F a c i l i t a t e Fl o w Eq u a l i z a t i o n 8) E a s e of Op e r a t i o n 9) R e l a t i v e Ca p i t a l Co s t 10 ) R e l a t i v e O& M Co s t 11 ) G H G Em i s s i o n s 12 ) E a s e of Im p l e m e n t a t i o n 13 ) C o m p a t i b i l i t y wi t h UV di s i n f e c t i o n 14 ) A b i l i t y to tr e a t ED C s Te c h n o l o g i e s Co n s i d e r e d Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t 1) M L E (C o n v e n t i o n a l wi t h an d w/ o u t re ‐ae r a t i o n ) 2) O x i d a t i o n Di t c h (V e r t i c e l ) 3) H i g h Ra t e A/ B Pr o c e s s 4) I n t e g r a t e Fi x e d ‐Fi l m Ac t Sl u d g e (I F A S ) 5) B i o M a g 6) N e r e d a G r a n u l a r Sl u d g e 7) B i o B r i m s t o n e 8) D e n i t e Fi l t e r s 9) W e t l a n d s 10 ) M B R (P a r a l l e l Tr e a t m e n t w/ B i o a u g m e n t a t i o n ) 11 ) M B R (S t a n d Al o n e ) 12 ) M a i n s t r e a m An a e r o b i c Tr e a t m e n t Se l e c t e d Te c h n o l o g i e s Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t 1) M L E (C o n v e n t i o n a l wi t h an d w/ o u t re ‐ae r a t i o n ) 2) O x i d a t i o n Di t c h (V e r t i ‐ce l ) 3) H i g h Ra t e A/ B Pr o c e s s 4) I n t e g r a t e Fi x e d ‐Fi l m Ac t Sl u d g e (I F A S ) 5) B i o M a g 6) N e r e d a G r a n u l a r Sl u d g e 7) B i o B r i m s t o n e 8) D e n i t r i f y i n g Fi l t e r s 9) W e t l a n d s 10 ) M B R (P a r a l l e l Tr e a t m e n t w/ B i o a u g m e n t a t i o n ) 11 ) M B R (S t a n d Al o n e ) 12 ) M a i n s t r e a m An a e r o b i c Tr e a t m e n t Pr o c e s s Sc r e e n i n g / E v a l u a t i o n Ap p r o a c h Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t De v e l o p Pr o s p e c t i v e Te c h n o l o g i e s Li s t Te c h n o l o g i e s Sc r e e n i n g Al t e r n a t i v e De v e l o p m e n t an d Ev a l u a t i o n Fa c i l i t y Ne e d s Ec o n o m i c An a l y s i s No n ‐Ec o n o m i c An a l y s i s Recommended Alternative To d a y ’ s Wo r k s h o p RA T E D CA P A C I T Y RE S U L T S Ba s i s fo r Ca p a c i t y Ev a l u a t i o n Ca l i b r a t e St e a d y St a t e Ma s s Ba l a n c e Ru n Sc e n a r i o s fo r 5. 4 mg d AD W F Co m p a r e Un i t Pr o c e s s Va l u e s ag a i n s t Cr i t e r i a St e a d y St a t e Ma s s Ba l a n c e WR R F Mo d e l – E N V i s i o n So f t w a r e Ba s i s fo r Ca p a c i t y Ev a l u a t i o n Ca l i b r a t e St e a d y St a t e Ma s s Ba l a n c e Ru n Sc e n a r i o s fo r 5. 4 mg d AD W F Co m p a r e Un i t Pr o c e s s Va l u e s ag a i n s t Cr i t e r i a Sc e n a r i o s Pa r a m e t e r U n i t A D W F A v e r a g e An n u a l Ma x i m u m Mo n t h Ma x i m u m Da y Pe a k Hour Fl o w mg d 5. 4 6 . 6 9 . 7 1 4 . 2 32.8 * TS S lb / d 15 , 0 0 0 1 8 , 0 0 0 27 , 0 0 0 33 , 0 0 0 ‐‐ BO D lb / d 17 , 0 0 0 20 , 0 0 0 29 , 0 0 0 36 , 0 0 0 ‐‐ Am m o n i a lb N/ d 1, 9 0 0 2, 2 0 0 3, 2 0 0 3, 7 0 0 ‐‐ TK N lb N/ d 2, 8 0 0 3, 4 0 0 4, 8 0 0 5, 6 0 0 ‐‐ * Eq u a l i z e d pe a k ho u r eq u a l s 16 mg d Ba s i s fo r Ca p a c i t y Ev a l u a t i o n Ca l i b r a t e St e a d y St a t e Ma s s Ba l a n c e Ru n Sc e n a r i o s fo r 5. 4 mg d AD W F Co m p a r e ag a i n s t Ca p a c i t y Cr i t e r i a Ca p a c i t y Cr i t e r i a : Pa r a m e t e r Un i t Va l u e A v e r a g i n g Pe r i o d fo r Ca p a c i t y As s e s s m e n t Pr i m a r y Cl a r i f i e r s (H R T ) hr 1. 6 A v e r a g e An n u a l Pr i m a r y Cl a r i f i e r s (O F R ‐1) gp d / s f 12 6 5 M a x i m u m Mo n t h Pr i m a r y Cl a r i f i e r s (O F R ‐2) gp d / s f 25 0 0 Pe a k Ho u r Ca p a c i t y Ev a l u a t i o n Re s u l t s Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t 6. 7 6. 8 5. 1 6. 3 5.8 32 . 0 58 . 6 22 . 0 24 . 3 16 . 0 8. 6 10 . 4 16 010203040506070 Rated Capacity per Unit Process (mgd) Li q u i d S t r e a m C a p a c i t y AD W F C a p a c i t y PW W F C a p a c i t y Up d a t e d AD W F Capacity = 5.1 mg d AD W F Up d a t e d PW W F Ca p a c i t y = 32 . 0 mg d PW W F Ca p a c i t y Ev a l u a t i o n Re s u l t s Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t 6. 5 5. 1 01234567 DA F T A n a e r o b i c D i g e s t e r s Rated Capacity per Unit Process (mgd) So l i d s S t r e a m C a p a c i t y Up d a t e d AD W F Ca p a c i t y = 5. 1 mg d AD W F OV E R V I E W OF PR O C E S S EV A L U A T I O N Fa c i l i t y Ne e d s Sc r e e n Gr i t Ae r a t i o n Ba s i n s Sand Filters PC L SC L Tr i c k l i n g Fi l t e r FC L Co o l i n g To w e r s Ra w In f l u e n t Ma g n e s i u m Hy d r o x i d e To Disinfect EQ B >2 2 mg d >1 6 mg d Ov e r v i e w of Ke y As s u m p t i o n s • Ev a l u a t i o n is Re l a t i v e • Fl o w an d Lo a d Co n d i t i o n s Pa r a m e t e r U n i t A D W F AA M M M W M D P H Fl o w mg d 5 . 4 6 . 6 9 . 7 1 1 . 9 1 4 . 5 3 2 . 8 TS S lb / d 1 5 , 0 0 0 18 , 0 0 0 27 , 0 0 0 33 , 0 0 0 40,000 ‐‐ BO D lb / d 1 7 , 0 0 0 20 , 0 0 0 2 9 , 0 0 0 36 , 0 0 0 4 4 , 0 0 0 ‐‐ NH 3 lb N/ d 1 , 9 0 0 2 , 2 0 0 3 , 2 0 0 3 , 7 0 0 4 , 5 0 0 ‐‐ TK N lb N/ d 2 , 8 0 0 3, 4 0 0 4, 8 0 0 5, 6 0 0 6,800 ‐‐ * Eq u a l i z e d pe a k ho u r eq u a l s 16 mg d Ov e r v i e w of Ke y As s u m p t i o n s • Co m m o n El e m e n t s : – Fl o w sp l i t s – Fl o w EQ vo l u m e (4 MG mo d i f i e d ) – Fi n a l cl a r i f i e r s (8 0 ’ di a f o r ea c h ne w cl a r i f i e r ) – Co o l i n g to w e r s – Fi l t r a t i o n – UV di s i n f e c t i o n – Re s e r v e fo r fu t u r e bi o s o l i d s Ov e r v i e w of Ke y As s u m p t i o n s • Di u r n a l an d We t We a t h e r Eq u a l i z a t i o n – He a d w o r k s o v e r f l o w to EQ at fl o w s >2 2 mg d – Pr i m a r y ef f l u e n t di v e r s i o n bo x ov e r f l o w s to EQ at fl o w s >16 mg d • Pr i m a r i e s ca n be re h a b i l i t a t e d • Ex t e r n a l ca r b o n so u r c e as s u m e d re q u i r e d un t i l more BO D da t a ma d e av a i l a b l e • Te r t i a r y Fi l t r a t i o n si z e d fo r fl o w s up to 16 mg d a t 5 gp m / s f ( 1 un i t of f ‐li n e ) Al t 1: Mo d i f i e d Lu d z a c k ‐Et t i n g e r ( M L E ) • Es t a b l i s h e d te c h n o l o g y • 20 1 1 MP Re c o m m e n d a t i o n • In d u s t r y st a n d a r d • Ab i l i t y to re m o v e mo r e N an d re m o v e P (w / c h e m ) • Co n t a c t st a b i l i z a t i o n fo r pe a k fl o w s IN F Pr i C l a r AN X Fi n a l C l a r IM L R RA S AE R Co n t a c t S t a b i l i z a t i o n B y p a s s f o r W e t W e a t h e r E v e n t s DA F T AD AN X AE R SC L IM L R RA S Cooling Towers/Filter To Disinfection PC L Cake Al t 1: Mo d i f i e d Lu d z a c k E t t i n g e r ( M L E ) Sc r e w P r e s s La g o o n Co n t a c t S t a b i l i z a t i o n B y p a s s f o r W e t We a t h e r E v e n t s ( F l o w > 1 4 . 2 m g d ) Ra w In f l u e n t EQ B >2 2 mg d >1 6 mg d Al t 1 ML E : De s i g n Cr i t e r i a Un i t Pr o c e s s Ar e a De s i g n C r i t e r i a Eq u a l i z a t i o n 4 MG Pr i m a r y Cl a r i f i e r s 10 , 0 0 0 sf (2 in to t a l @ 80 ’ diaeach) Se c o n d a r y Tr e a t m e n t Ae r a t i o n Ba s i n Vo l u m e (t o t a l ) SR T (A e r o b i c ) 2. 5 MG 6. 5 da y s Co n t a c t St a b i l i z a t i o n Mo d e At fl o w s > 14 . 2 mgd Ae r a t i o n Bl o w e r s (t o t a l ) 93 0 h p Me t h a n o l Ad d i t i o n (L i q u i d ) * Al k a l i n i t y Ad d i t i o n (M g ( O H ) 2) 20 0 gp d 14 0 gp d Fi n a l Cl a r i f i e r s 20 , 0 0 0 sf (4 in to t a l @ 8 0 ’ diaeach) Fi l t e r s Ty p e Su r f a c e A r e a (t o t a l ) Gr a n u l a r M o n o ‐Media 2, 6 0 0 sf (1 1 to t a l units) Hy d r a u l i c Lo a d i n g (1 of f li n e ) 5 gp m / s f * Me t h a n o l fa c i l i t y ne e d s re q u i r e s ad d i t i o n a l da t a an a l y s i s Al t 1 ML E : Fa c i l i t y Ne e d s Un i t Pr o c e s s M a i n t a i n / Re h a b Ex i s t i n g Ex p a n d D e m o / R e ‐Purpose Ex i s t i n g Pr i m a r y Cl a r i f i e r s X Tr i c k l i n g F i l t e r s X Se c o n d a r y C l a r i f i e r s X Ae r a t i o n Ba s i n s X X Fi n a l Cl a r i f i e r s X X Ae r a t i o n B l o w e r s X X RA S / W A S Pu m p i n g X X Fi l t r a t i o n X X Ne w Ae r a t i o n Ba s i n s UV Co o l i n g To w e r s Re s e r v e fo r Fu t u r e Bi o s o l i d s Ne w Fi n a l Cl a r i f i e r s Al t 1 ML E Flow EQ Basin Co m p a r t m e n t a l i z a t i o n De m o / R e ‐Purpose Bi o t o w e r s / S e c o n d a r y PE Diversion Box Rehab Ch e m i c a l St o r a g e Ex i s t i n g Ae r a t i o n Ba s i n s Co m m o n El e m e n t Un i q u e El e m e n t Ne w Te r t i a r y Fi l t e r s Ne w Bl o w e r Bu i l d i n g Al t 1 ML E Co n s i d e r a t i o n s Ad v a n t a g e s • Es t a b l i s h e d te c h n o l o g y (o p e r a t i o n a l hi s t o r y ) • Ca n ac c o m m o d a t e pe a k fl o w s • Ab i l i t y to me e t mo r e st r i n g e n t li m i t s • No pr o p r i e t a r y sy s t e m Di s a d v a n t a g e s • Fr e q u e n t ro u t i n e eq u i p m e n t maintenance • La r g e fo o t p r i n t • Nu m b e r of ad d i t i o n a l cl a r i f i e r s Al t 1 ML E : An n u a l Op e r a t i o n s It e m An n u a l Va l u e A n n u a l Cost En e r g y 1, 2 1, 8 0 0 , 0 0 0 kW h / y e a r $ 2 9 0 , 0 0 0 Ch e m i c a l s Me t h a n o l 70 , 0 0 0 gp y $ 20 0 , 0 0 0 Al k a l i n i t y (M g ( O H ) 2) 50 , 0 0 0 gp y $ 13 0 , 0 0 0 Ma g n e t i t e ‐‐ ‐ ‐ 1 ‐ En e r g y in c l u d e s ae r a t i o n bl o w e r s , RA S pu m p s , mi x e d li q u o r re t u r n pu m p s , and bi o g a s 2 ‐ En e r g y co s t s ar e ba s e d on $0 . 1 6 / k w h AL T 2 VE R T I ‐CE L Al t 2: Ve r t i ‐Ce l ( O x i d a t i o n Di t c h ) • Op e r a t i o n a l hi s t o r y • Co n s i d e r e d in 20 1 1 MP • Si m p l e to op e r a t e • Lo w sl u d g e yi e l d • Ef f i c i e n t ae r a t i o n • Co n t a c t st a b i l i z a t i o n fo r pe a k s IN F Pr i C l a r Fi n a l C l a r IM L R RA S Ox i d a t i o n D i t c h Co n t a c t S t a b i l i z a t i o n B y p a s s f o r W e t W e a t h e r E v e n t s DA F T AD SC L IM L R RA S Cooling Towers/Filter PC L Cake Al t 2: Ve r t i ‐Ce l ( O x i d a t i o n Di t c h ) Sc r e w P r e s s La g o o n Ve r t i c a l L o o p R e a c t o r EQ B >2 2 mg d Ra w In f l u e n t To Disinfection Co n t a c t S t a b i l i z a t i o n B y p a s s f o r W e t We a t h e r E v e n t s ( F l o w > 1 4 . 2 m g d ) >1 6 mg d Al t 2 Ve r t i ‐Ce l : De s i g n Cr i t e r i a Un i t Pr o c e s s Ar e a De s i g n C r i t e r i a Eq u a l i z a t i o n 4 MG Pr i m a r y Cl a r i f i e r s 10 , 0 0 0 sf (2 in to t a l @ 80 ’ diaeach) Se c o n d a r y Tr e a t m e n t Ae r a t i o n Ba s i n Vo l u m e (t o t a l ) SR T (A e r o b i c ) 3. 8 MG 10 da y s Co n t a c t St a b i l i z a t i o n Mo d e At fl o w s > 14 . 2 mgd Ae r a t i o n Bl o w e r s (t o t a l ) 70 0 hp Me t h a n o l Ad d i t i o n (L i q u i d ) * Al k a l i n i t y Ad d i t i o n (M g ( O H ) 2) 20 0 gp d 14 0 gp d Fi n a l Cl a r i f i e r s 20 , 0 0 0 sf (4 in to t a l @ 8 0 ’ diaeach) Fi l t e r s Ty p e Su r f a c e A r e a (t o t a l ) Gr a n u l a r M o n o ‐Media 2, 6 0 0 sf (1 1 un i t s in total) Hy d r a u l i c Lo a d i n g (1 of f li n e ) 5 gp m / s f * Me t h a n o l fa c i l i t y ne e d s re q u i r e s ad d i t i o n a l da t a an a l y s i s Al t 2 Ve r t i ‐Ce l : Fa c i l i t y Ne e d s Un i t Pr o c e s s M a i n t a i n / Re h a b Ex i s t i n g Ex p a n d D e m o / R e ‐Pu r p o s e Ex i s t i n g Pr i m a r y Cl a r i f i e r s X Tr i c k l i n g F i l t e r s X Se c o n d a r y C l a r i f i e r s X Ae r a t i o n Ba s i n s XX Fi n a l Cl a r i f i e r s XX Ae r a t i o n B l o w e r s X X RA S / W A S Pu m p i n g X X Fi l t r a t i o n XX Ne w Ae r a t i o n Ba s i n s Ch e m i c a l St o r a g e UV Re s e r v e fo r Fu t u r e Bi o s o l i d s Ex i s t i n g Ae r a t i o n Ba s i n s Ne w Fi n a l Cl a r i f i e r s Al t 2 Ve r t i ‐Ce l Flow EQ Basin Co m p a r t m e n t a l i z a t i o n De m o / R e ‐Purpose Bi o t o w e r s / S e c o n d a r y PE Diversion Box Rehab Co m m o n El e m e n t Un i q u e El e m e n t Ne w Te r t i a r y Fi l t e r s Co o l i n g To w e r s Ne w Bl o w e r Bu i l d i n g Al t 2 Ve r t i ‐Ce l C o n s i d e r a t i o n s Ad v a n t a g e s • Ca n ac c o m m o d a t e PW W F • Ro b u s t pr o c e s s • Ab i l i t y to me e t mo r e st r i n g e n t li m i t s • Lo w sl u d g e pr o d u c t i o n Di s a d v a n t a g e s • Le s s op e r a t i o n a l history th a n ML E • Pr o p r i e t a r y sy s t e m • La r g e s t fo o t p r i n t of the op t i o n s • Le v e r a g i n g ex i s t i n g ae r a t i o n ba s i n s • Fr e q u e n t ro u t i n e eq u i p m e n t maintenance Al t 2 Ve r t i ‐Ce l : An n u a l Op e r a t i o n s It e m An n u a l Va l u e A n n u a l Cost En e r g y 1, 2 1, 1 0 0 , 0 0 0 kW h / y e a r $ 1 8 0 , 0 0 0 Ch e m i c a l s Me t h a n o l 70 , 0 0 0 gp y $ 20 0 , 0 0 0 Al k a l i n i t y (M g ( O H ) 2) 50 , 0 0 0 gp y $ 13 0 , 0 0 0 Ma g n e t i t e ‐‐ ‐ ‐ 1 ‐ En e r g y in c l u d e s ae r a t i o n bl o w e r s , RA S pu m p s , mi x e d li q u o r re t u r n pu m p s , and bi o g a s 2 ‐ En e r g y co s t s ar e ba s e d on $0 . 1 3 6 / k w h Hi g h Ra t e A/ B Pr o c e s s • Em e r g i n g te c h n o l o g y in US • En e r g y ef f i c i e n t • Co m p a c t fo o t p r i n t • Lo w so l i d s yi e l d • Fl e x i b i l i t y fo r fu t u r e ma i n s t r e a m de a m m o n i f i c a t i o n Se c o n d a r y Cl a r i f i e r Fi n a l Cl a r i f i e r ML R RA S Lo w R a t e B P r o c e s s ; M L E IN F Hi g h R a t e A Pr o c e s s Co n t a c t S t a b i l i z a t i o n B y p a s s f o r W e t W e a t h e r E v e n t s Al t 3 –H i g h Ra t e A/ B SC L IM L R RA S Lo w R a t e B Pr o c e s s ; M L E Cooling Towers/Filters DA F T AD Hi g h R a t e A Pr o c e s s To Disinfection CakeScrew Press La g o o n Ra w In f l u e n t EQ B >2 2 mg d SC L Co n t a c t S t a b i l i z a t i o n B y p a s s f o r W e t We a t h e r E v e n t s ( F l o w > 1 4 . 2 m g d ) >1 6 mg d Al t 3 Hi g h Ra t e A/ B : De s i g n Cr i t e r i a Un i t Pr o c e s s Ar e a De s i g n C r i t e r i a Eq u a l i z a t i o n 4 MG A‐St a g e Ae r a t i o n Ba s i n s / C l a r i f i e r s To Fl o w EQ 0. 3 MG (2 in to t a l ; u s e ex i s t i n g primaries) At f l o w s >1 6 . 0 mgd B‐St a g e Ae r a t i o n Ba s i n Vo l u m e (t o t a l ) SR T (A e r o b i c ) 1. 8 MG 6. 5 da y s Co n t a c t St a b i l i z a t i o n Mo d e At fl o w s > 14 . 2 mgd Ae r a t i o n Bl o w e r s (t o t a l ) 70 0 hp Me t h a n o l Ad d i t i o n (L i q u i d ) * Al k a l i n i t y Ad d i t i o n (M g ( O H ) 2) 25 0 gp d 14 0 gp d Fi n a l Cl a r i f i e r s 20 , 0 0 0 sf (4 in to t a l @ 8 0 ’ diaeach) Fi l t e r s Ty p e Su r f a c e A r e a (t o t a l ) Gr a n u l a r M o n o ‐Media 2, 6 0 0 sf (1 1 un i t s ) Hy d r a u l i c Lo a d i n g (1 of f li n e ) 5 gp m / s f * Me t h a n o l fa c i l i t y ne e d s re q u i r e s ad d i t i o n a l da t a an a l y s i s Al t 3 Hi g h Ra t e A/ B : Fa c i l i t y Ne e d s Un i t Pr o c e s s M a i n t a i n / Re h a b Ex i s t i n g Ex p a n d D e m o / R e ‐ Pu r p o s e E x i s t i n g Pr i m a r y Cl a r i f i e r s X (F o r A‐St a g e ) Tr i c k l i n g F i l t e r s X Se c o n d a r y C l a r i f i e r s X Ae r a t i o n Ba s i n s XX (B o t h A‐ an d B‐St a g e s ) Fi n a l Cl a r i f i e r s XX Ae r a t i o n B l o w e r s X X RA S / W A S Pu m p i n g X X Fi l t r a t i o n XX UV Re s e r v e fo r Fu t u r e Bi o s o l i d s Ne w B‐St a g e Fi n a l Cl a r i f i e r s Al t 3 Hi g h Ra t e A/ B Ne w Ae r a t i o n Flow EQ Basin Co m p a r t m e n t a l i z a t i o n De m o / R e ‐Purpose Bi o t o w e r s / S e c o n d a r y PE Diversion Box Rehab Ch e m i c a l St o r a g e Ex i s t i n g Ae r a t i o n Ba s i n s Co m m o n El e m e n t Un i q u e El e m e n t Ne w Te r t i a r y Fi l t e r s Co o l i n g To w e r s Ne w Bl o w e r Bu i l d i n g Re b a b E x i s t i n g Pr i m a r i e s an d co n s t r u c t A‐St a g e ba s i n Al t 3 Hi g h Ra t e A/ B Co n s i d e r a t i o n s Ad v a n t a g e s • Fl e x i b i l i t y fo r fu t u r e ma i n s t r e a m de a m m o n i f i c a t i o n • Di v e r t mo r e ca r b o n to so l i d s ha n d l i n g (i . e . , mo r e bi o g a s pr o d u c t i o n ) • Lo w e r ae r a t i o n re q u i r e m e n t s Di s a d v a n t a g e s • Li m i t e d op e r a t i n g ex p e r i e n c e • Ch a l l e n g e to im p l e m e n t wi t h i n TS O da t e s (pilot te s t i n g ne e d e d ) • Mo r e di f f i c u l t to operate • Re l i a n c e on in s t r u m e n t a t i o n Al t 3 Hi g h Ra t e A/ B : An n u a l Op e r a t i o n s It e m An n u a l Va l u e A n n u a l Cost En e r g y 1, 2 50 0 , 0 0 0 kW h / y e a r $ 9 0 , 0 0 0 Ch e m i c a l s Me t h a n o l 90 , 0 0 0 gp y $ 25 0 , 0 0 0 Al k a l i n i t y (M g ( O H ) 2) 50 , 0 0 0 gp y $ 13 0 , 0 0 0 1 ‐ En e r g y in c l u d e s ae r a t i o n bl o w e r s , RA S pu m p s , mi x e d li q u o r re t u r n pu m p s , and bi o g a s 2 ‐ En e r g y co s t s ar e ba s e d on $0 . 1 6 / k w h Al t 4: Bi o M a g (B a l l a s t e d Ac t i v a t e d Sludge) • Em e r g i n g te c h n o l o g y • Co m p a c t fo o t p r i n t (h e a v y / de n s e ba l l a s t e d fl o c s ) • Hi g h ML S S (8 , 0 0 0 mg / L ) • Hi g h cl a r i f i e r lo a d i n g ra t e s • De n s e sl u d g e bl a n k e t s IN F AN X Fi n a l C l a r IM L R RA S AE R Ma g n e t i t e Re c y c l e WA S Pr i C l a r Co n t a c t S t a b i l i z a t i o n f o r W e t W e a t h e r E v e n t s Al t 4: Bi o M a g AD AN X AE R SC L IM L R RA S Cooling Towers/Filter To Disinfection PC L Cake Sc r e w P r e s s Co n t a c t S t a b i l i z a t i o n B y p a s s fo r W e t W e a t h e r E v e n t s Ma g n e t i t e Re c y c l e Magnetite Recovery Ra w In f l u e n t EQ B >2 2 mg d La g o o n DA F T >1 6 mg d Al t 4 Bi o M a g : De s i g n Cr i t e r i a Un i t Pr o c e s s Ar e a De s i g n C r i t e r i a Eq u a l i z a t i o n 4 MG Pr i m a r y Cl a r i f i e r s 10 , 0 0 0 sf (2 in to t a l @ 80 ’ diaeach) Se c o n d a r y Tr e a t m e n t Ae r a t i o n Ba s i n Vo l u m e (t o t a l ) SR T (A e r o b i c ) 2. 5 MG 6. 5 da y s Co n t a c t St a b i l i z a t i o n Mo d e At fl o w s > 14 . 2 mgd Ae r a t i o n Bl o w e r s (t o t a l ) 1, 1 0 0 hp Me t h a n o l Ad d i t i o n (L i q u i d ) * Al k a l i n i t y Ad d i t i o n (M g ( O H ) 2) 20 0 gp d 14 0 gp d Fi n a l Cl a r i f i e r s 15 , 0 0 0 sf (3 in to t a l @ 8 0 ’ diaeach) Fi l t e r s Ty p e Su r f a c e A r e a (t o t a l ) Gr a n u l a r M o n o ‐Media 2, 6 0 0 sf (1 1 un i t s in total) Hy d r a u l i c Lo a d i n g (1 of f li n e ) 5 gp m / s f * Me t h a n o l fa c i l i t y ne e d s re q u i r e s ad d i t i o n a l da t a an a l y s i s Al t 4 Bi o M a g : Fa c i l i t y Ne e d s Un i t Pr o c e s s M a i n t a i n / Re h a b Ex i s t i n g Ex p a n d D e m o / R e ‐Purpose Ex i s t i n g Pr i m a r y Cl a r i f i e r s X Tr i c k l i n g F i l t e r s X Se c o n d a r y C l a r i f i e r s X Ae r a t i o n Ba s i n s XX Fi n a l Cl a r i f i e r s XX Ae r a t i o n B l o w e r s XX RA S / W A S Pu m p i n g XX Fi l t r a t i o n XX Ne w Ae r a t i o n Ba s i n s Ch e m i c a l St o r a g e UV Flow EQ Basin Co m p a r t m e n t a l i z a t i o n Re s e r v e fo r Fu t u r e Bi o s o l i d s Ex i s t i n g Ae r a t i o n Ba s i n s Ne w Fi n a l Cl a r i f i e r s Al t 4 Bi o M a g Bi o M a g Dr u m PE Diversion Box Rehab De m o / R e ‐Purpose Bi o t o w e r s / S e c o n d a r y Co m m o n El e m e n t Un i q u e El e m e n t Ne w Te r t i a r y Fi l t e r s Ne w Bl o w e r Bu i l d i n g Co o l i n g To w e r s Al t 4 Bi o M a g C o n s i d e r a t i o n s Ad v a n t a g e s • Ac c o m m o d a t e s pe a k fl o w s th e be s t of th e Al t s • Ab i l i t y to me e t st r i n g e n t pe r m i t li m i t a t i o n s Di s a d v a n t a g e s • Pr o p r i e t a r y sy s t e m • Ad d i t i o n a l en e r g y use • Mo r e eq u i p m e n t ma i n t e n a n c e • Le s s op e r a t i n g ex p e r i e n c e th a n MLE or Ve r t i ‐Ce l • Ex i s t i n g op e r a t i n g pl a n t s ar e sm a l l Al t 4 Bi o M a g : An n u a l Op e r a t i o n s It e m An n u a l Va l u e A n n u a l Cost En e r g y 1, 2 2, 4 0 0 , 0 0 0 kW h / y e a r $ 38 0 , 0 0 0 Ch e m i c a l s Me t h a n o l 70 , 0 0 0 gp y $ 20 0 , 0 0 0 Al k a l i n i t y (M g ( O H ) 2) 50 , 0 0 0 gp y $ 13 0 , 0 0 0 Ma g n e t i t e 65 0 l b / d $ 14 0 , 0 0 0 1 ‐ En e r g y in c l u d e s ae r a t i o n bl o w e r s , RA S pu m p s , mi x e d li q u o r re t u r n pu m p s , and bi o g a s 2 ‐ En e r g y co s t s ar e ba s e d on $0 . 1 6 / k w h Fa c i l i t y Ne e d s Co m p a r i s o n Fa c i l i t i e s Un i t Al t 1: ML E Al t 2 : Ve r t i - C e l Al t 3 : High RateAlt 4: BioMag BN R ‐ Ad d t ’ l Un i t s Nu m b e r 4 6 2 4 BN R & A‐St a g e (A d d t ' l Vo l ) Mg a l 1 . 7 3. 0 1.0 1.7 Sl u d g e ag e (a e r o b i c ) Da y s 6 . 5 10 . 0 6.5 6.5 Bl o w e r – B N R & A‐St a g e hp 9 0 0 70 0 7 0 0 1 , 1 0 0 Me t h a n o l Vo l . ga l / d 2 0 0 2 0 0 250 200 Cl a r i f i e r s – B N R & A‐St a g e Ad d t ’ l Cl a r i f i e r s Nu m b e r 2 2 2 1 Fi l t e r s ‐ Ad d t ' l Un i t s Nu m b e r 6 6 6 6 Hy d r a u l i c Lo a d i n g gp m / s f 5 5 5 5 Op e r a t i o n s an d Ma i n t e n a n c e Co m p a r i s o n Un i t Al t 1: ML E Al t 2 : V C Al t 3 : Hi g h R a t e Alt 4: BioMag En e r g y Bl o w e r : BN R &A ‐St a g e MW h / y r 2 , 8 0 0 2 , 1 0 0 1 , 9 0 0 3 , 4 0 0 RA S : BN R & A‐St a g e MW h / y r 2 0 0 2 0 0 3 0 0 2 0 0 BN R : IM L R MW h / y r 2 0 0 2 0 0 2 0 0 2 0 0 Bi o g a s MW h / y r ‐1, 4 0 0 ‐1, 4 0 0 ‐1, 9 0 0 ‐1,400 To t a l En e r g y MW h / y r 1 , 8 0 0 1 , 1 0 0 5 0 0 2 , 4 0 0 Op e r a t i o n s an d Ma i n t e n a n c e Co m p a r i s o n Un i t Al t 1: ML E Al t 2 : V C Al t 3 : Hi g h R a t e Alt 4: BioMag Ch e m i c a l s Me t h a n o l $/ y r 2 0 0 , 0 0 0 20 0 , 0 0 0 25 0 , 0 0 0 200,000 Al k a l i n i t y $/ y r 1 3 0 , 0 0 0 13 0 , 0 0 0 13 0 , 0 0 0 130,000 Ma g n e t i t e $/ y r 0 0 0 1 4 0 , 0 0 0 To t a l Ch e m i c a l C o s t $/ y r 3 3 0 , 0 0 0 3 3 0 , 0 0 0 3 8 0 , 0 0 0 4 7 0 , 0 0 0 No n ‐Ec o n o m i c Co m p a r i s o n Ec o n o m i c Co m p a r i s o n * I n c l u d e s av e r a g e an n u a l en e r g y an d ch e m i c a l s re q u i r e d fo r ne w eq u i p m e n t (e x c l u d e s la b o r an d ma i n t e n a n c e ) ** As s u m e s 30 ye a r s , 5 pe r c e n t di s c o u n t ra t e , an d a 3. 5 pe r c e n t in f l a t i o n ra t e Cr i t e r i a Al t 1: ML E Al t 2 : Ve r t i - C e l Al t 3 : H R AB Alt 4: BioMag Co n s t r u c t i o n Co s t $2 6 . 4 M $ 3 2 . 4 M $ 2 6 . 3 M $ 2 6 . 5 M Pr e s e n t V a l u e O& M Co s t $1 4 . 5 M $ 1 1 . 9 M $ 1 0 . 8 M $ 1 9 . 9 M Ne t P r e s e n t Va l u e $4 0 . 9 M $ 4 4 . 3 M $ 3 7 . 1 M $ 4 6 . 4 M RE C O M M E N D E D AL T E R N A T I V E NE X T ST E P S Ne x t St e p s Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t ‐ Fu r t h e r De v e l o p an d Re f i n e th e Re c o m m e n d e d Al t e r n a t i v e ‐ Fa c i l i t y Si z i n g ‐ Pl a n t La y o u t ‐ Fl o w EQ St r a t e g y ‐ Hy d r a u l i c s ‐ Op e r a t i o n a l St r a t e g y ‐ As s e t Re n e w a l / Re h a b i l i t a t i o n ‐ In f r a s t r u c t u r e Re q u i r e m e n t s (S t o r m w a t e r , SC A D A , El e c t r i c a l , Access) ‐ Ca p i t a l an d O& M Co s t s Wa t e r Re s o u r c e Re c o v e r y Fa c i l i t y Pr o j e c t En g a g e . Tr a n s f o r m . Su s t a i n . August 21, 2014 Tr e a t m e n t Al t s Wo r k s h o p 2 WRRF Project TM No. 12 – Process Alternatives Analysis Appendix B – Technology Status Write-Up The timeline for wastewater treatment technology development and implementation has been observed to follow the shape of an S-curve as shown in Figure ES 1. The curve describes three different levels of technology status: established, emerging, and embryonic as defined below: 1. Established – A proven technology with numerous full-scale installations. The installations span a range of plant sizes (small 1 mgd; medium = 1 to 10 mgd; large 10 mgd). 2. Emerging - Up and coming technology that has several pilots and a few full-scale installations. Most likely, the installations do not cover all the plant sizes which can cause concern for smaller or larger plants without a similarly sized installation. 3. Embryonic - Limited to bench-scale and pilots with zero or one full-scale installation. As the curve indicates, initial demonstrations increase at a modest (though non-linear) rate during the piloting/testing period (e.g., embryonic status). Following the first full-scale application, a technology transitions from the embryonic to emerging status, and is considered to impart lower risk to the adopter. Subsequently, the technology is implemented a rapid, exponential rate. Over time, the technology becomes mature (or established) and the rate of installation levels off to a constant value. Figure ES 1. Technology Status S-Curve (Adapter from Parker et al., 2011) First Demonstration Emerging Status Embryonic Status Pilot Established Status Time De v e l o p m e n t / Nu m b e r I n s t a l l e d WRRF Project TM No. 12 – Process Alternatives Analysis Page intentionally blank. WRRF Project TM No. 12 – Process Alternatives Analysis Appendix C – Mass Balance Results for each Alternative WRRF Project TM No. 12 – Process Alternatives Analysis Page intentionally blank. St r e a m S u m m a r y f o r M L E A A EN V _ M L E _ A A St r e a m S u m m a r y f o r M L E A A Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oP TPAlk mg d g p m m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 6 . 1 0 4 , 2 3 6 7 5 3 , 8 1 6 2 7 8 1 4 , 1 4 0 2 7 2 1 3 , 8 4 0 2 1 8 1 1 , 0 7 0 3 2 1 , 6 2 8 4 8 2 , 4 4 2 0 0 4 8 2 , 4 4 2 4 2 0 4 6 3 0 5 2 4 3 1 2 , 3 6 0 1a He a d w o r k s t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 2 Ra w I n f l u e n t P l u s R e c y c l e s 6 . 8 0 4 , 7 2 2 6 8 3 , 8 3 0 2 5 3 1 4 , 3 7 0 2 5 9 1 4 , 6 6 0 2 0 6 1 1 , 6 8 0 3 2 1 , 7 9 7 4 7 2 , 6 7 5 1 3 6 4 8 2 , 7 1 1 5 2 9 1 7 4 0 8 2 4 7 1 4 , 0 0 0 3 Pr i m a r y E f f l u e n t 6 . 1 3 4 , 2 5 7 6 8 3 , 4 5 3 1 0 9 5 , 5 6 0 5 7 2 , 9 3 3 4 6 2 , 3 3 6 3 2 1 , 6 2 0 3 5 1 , 7 9 5 0 0 3 5 1 , 7 9 5 5 2 6 2 6 2 8 5 2 4 9 1 2 , 7 4 0 3a PE t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 6 . 1 3 4 , 2 5 7 6 8 3 , 4 5 3 1 0 9 5 , 5 6 0 5 7 2 , 9 3 3 4 6 2 , 3 3 6 3 2 1 , 6 2 0 3 5 1 , 7 9 5 0 0 3 5 1 , 7 9 5 5 2 6 2 6 2 8 5 2 4 9 1 2 , 7 4 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 6 . 9 3 4 , 8 1 0 6 6 3 , 7 8 5 1 3 2 7 , 6 1 6 9 9 5 , 7 0 6 7 8 4 , 5 1 7 3 1 1 , 7 9 2 3 7 2 , 1 4 2 0 8 3 7 2 , 1 5 0 5 2 9 6 6 3 4 7 3 6 4 2 1 , 0 1 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 1 0 . 9 5 7 , 6 0 1 4 2 3 , 8 5 1 5 0 9 4 6 , 4 5 0 1 , 9 6 2 1 7 9 , 1 0 0 1 , 4 6 5 1 3 3 , 7 0 0 2 0 1 , 8 0 1 1 6 5 1 5 , 0 7 0 2 2 2 3 1 6 8 1 5 , 2 9 0 5 4 5 6 4 1 3 , 7 4 1 3 1 4 2 8 , 6 4 0 9a Ae r a t i o n E f f l u e n t 1 0 . 9 5 7 , 6 0 1 2 1 7 9 4 3 6 3 9 , 8 0 0 1 , 9 4 1 1 7 7 , 2 0 0 1 , 4 4 7 1 3 2 , 1 0 0 0 2 3 1 4 5 1 3 , 2 3 0 6 5 8 5 1 5 1 1 3 , 8 1 0 5 4 3 7 4 1 3 , 7 4 1 2 2 7 2 0 , 7 6 0 10 Fi n a l C l a r i f i e r s E f f l 6 . 7 8 4 , 7 0 6 2 1 1 1 6 3 2 0 1 7 9 3 3 1 2 6 9 5 0 1 4 1 8 4 6 3 6 2 8 4 4 6 5 2 7 0 5 2 8 8 2 2 7 1 2 , 8 5 0 11 Ae r a t i o n R A S F l o w 4 . 0 2 2 , 7 9 2 2 6 6 1 , 1 5 8 3 8 , 8 3 0 5 , 1 7 1 1 7 3 , 4 0 0 3 , 8 5 4 1 2 9 , 2 0 0 0 8 3 8 6 1 2 , 9 3 0 6 2 1 5 3 9 2 1 3 , 1 5 0 5 1 6 0 1 0 1 3 , 3 9 4 2 2 7 7 , 6 2 5 12 Fi l t r a t i o n F e e d 6 . 7 8 4 , 7 0 6 2 1 1 1 6 3 2 0 1 7 9 3 3 1 2 6 9 5 0 1 4 1 8 4 6 3 6 2 8 4 4 6 5 2 7 0 5 2 8 8 2 2 7 1 2 , 8 5 0 13 Fi l t r a t i o n E f f l 6 . 1 0 4 , 2 3 4 2 1 0 0 3 1 3 2 3 1 4 2 2 1 0 6 0 1 3 0 2 3 6 3 2 6 7 3 4 9 5 2 4 3 5 2 4 6 2 2 7 1 1 , 5 6 0 13 a Fi l t r a t i o n B a c k w a s h 0 . 6 8 4 7 3 2 1 1 3 3 1 8 8 1 3 9 7 9 0 1 0 4 5 8 9 0 1 1 1 6 0 6 3 6 1 7 9 7 5 2 7 7 4 2 2 2 7 1 , 2 9 0 14 UV F e e d 6 . 1 0 4 , 2 3 4 2 1 0 0 3 1 3 2 3 1 4 2 2 1 0 6 0 1 3 0 2 3 6 3 2 6 7 3 4 9 5 2 4 3 5 2 4 6 2 2 7 1 1 , 5 6 0 14 a Pl a n t D i s c h a r g e 6 . 1 0 4 , 2 3 4 2 1 0 0 3 1 3 2 3 1 4 2 2 1 0 6 0 1 3 0 2 3 6 3 2 6 7 3 4 9 5 2 4 3 5 2 4 6 2 3 8 1 2 , 1 2 0 20 Pr i m a r y S l u d g e 0 . 6 7 4 6 5 6 8 3 7 7 1 , 5 7 7 8 , 8 0 8 2 , 1 0 0 1 1 , 7 3 0 1 , 6 7 3 9 , 3 4 3 3 2 1 7 7 1 5 7 8 7 9 0 0 1 5 7 8 7 9 5 2 9 2 2 1 2 3 2 4 9 1 , 3 9 2 22 WA S 0 . 1 5 1 0 3 2 2 5 2 0 6 4 4 2 , 3 1 5 2 , 8 6 9 1 , 7 2 6 2 , 1 3 8 0 0 1 7 3 2 1 4 6 8 1 7 9 2 2 2 5 6 4 8 5 9 2 2 7 2 8 2 30 DA F T F e e d 0 . 8 2 5 6 8 5 6 3 8 0 1 , 3 8 5 9 , 4 5 2 2 , 1 3 9 1 4 , 6 0 0 1 , 6 8 2 1 1 , 4 8 0 2 6 1 7 7 1 6 0 1 , 0 9 4 1 8 1 6 1 1 , 1 0 2 5 3 5 2 7 1 8 2 2 4 5 1 , 6 7 4 31 DA F T T h i c k e n e d S l u d g e 0 . 0 2 1 5 5 0 9 4 0 , 4 4 0 7 , 3 5 8 6 5 , 0 0 0 1 1 , 8 3 0 5 1 , 1 2 0 9 , 3 0 0 2 6 5 4 , 1 0 6 7 4 7 1 0 4 , 1 0 7 7 4 7 5 1 6 6 2 1 2 0 2 4 6 4 5 32 DA F T T h i c k e n e r R e t u r n 0 . 8 0 5 5 3 5 0 3 3 2 3 1 0 2 , 0 5 6 4 1 8 2 , 7 7 4 3 2 8 2 , 1 8 1 2 6 1 7 3 5 2 3 4 7 1 8 5 3 3 5 4 5 3 4 9 6 2 2 4 5 1 , 6 2 9 33 An a e r o b i c D i g e s t i o n F e e d 0 . 0 2 1 5 5 0 9 4 0 , 4 4 0 7 , 3 5 8 6 5 , 0 2 0 1 1 , 8 3 0 5 1 , 1 2 0 9 , 3 0 0 2 6 5 4 , 1 0 6 7 4 7 1 0 4 , 1 0 7 7 4 7 1 0 6 6 2 1 2 0 2 2 8 4 1 34 An a e r o b i c D i g e s t e d S o l i d s 0 . 0 2 1 5 5 0 0 9 1 1 0 , 0 4 0 1 , 8 2 6 3 1 , 8 0 0 5 , 7 8 4 1 7 , 8 9 0 3 , 2 5 5 2 , 6 7 8 4 8 7 4 , 1 0 6 7 4 7 0 0 4 , 1 0 6 7 4 7 3 8 4 7 0 6 6 2 1 2 0 9 , 6 9 4 1 , 7 6 4 41 De w a t e r i n g F e e d 0 . 0 2 1 5 5 0 0 9 1 1 0 , 0 4 0 1 , 8 2 6 3 1 , 8 0 0 5 , 7 8 4 1 7 , 8 9 0 3 , 2 5 5 2 , 6 7 8 4 8 7 4 , 1 0 6 7 4 7 0 0 4 , 1 0 6 7 4 7 3 8 4 7 0 6 6 2 1 2 0 9 , 6 9 4 1 , 7 6 4 42 CA K E 0 . 0 0 2 2 0 1 6 6 , 0 2 0 1 , 7 0 1 2 2 0 , 0 0 0 5 , 6 6 9 1 2 3 , 8 0 0 3 , 1 9 0 2 , 6 7 8 6 9 1 2 , 5 6 0 3 2 4 0 0 1 2 , 5 6 0 3 2 4 3 8 4 1 0 2 , 3 0 6 5 9 9 , 6 9 4 2 5 0 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0 . 0 2 1 3 2 0 3 2 4 2 3 8 7 4 1 1 1 6 4 1 7 6 5 2 , 6 7 8 4 1 8 2 , 7 1 1 4 2 3 0 0 2 , 7 1 1 4 2 3 3 8 4 6 0 3 9 1 6 1 9 , 6 9 4 1 , 5 1 4 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0 . 0 2 1 3 2 0 3 2 4 2 3 8 2 2 2 3 5 1 2 5 2 0 1 , 0 7 1 1 6 7 1 , 1 0 4 1 7 3 0 0 1 , 1 0 4 1 7 3 3 8 4 6 0 3 9 1 6 1 2 , 2 3 0 3 4 8 50 A- S t a g e B y p a s s t o B - S t a g e 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 54 A- S t a g e F e e d ( w / R A S ) 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 56 A- S t a g e E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 58 A- S t a g e R A S 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 59 A- S t a g e W A S 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 60 A- S t a g e E f f l t o B - S t a g e 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 62 A- S t a g e E f f l t o F l o w E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . St r e a m S u m m a r y f o r M L E M M EN V _ M L E _ M M St r e a m S u m m a r y f o r M L E M M Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 8 . 4 0 5 , 8 3 3 7 5 5 , 2 5 4 2 8 5 1 9 , 9 7 0 2 6 1 1 8 , 2 8 0 2 0 9 1 4 , 6 3 0 3 1 2 , 1 7 2 4 7 3 , 2 9 3 0 0 4 7 3 , 2 9 3 4 2 8 0 6 4 2 0 2 4 2 1 6 , 9 5 0 1a He a d w o r k s t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 2 Ra w I n f l u e n t P l u s R e c y c l e s 9 . 1 1 6 , 3 2 3 7 0 5 , 2 8 0 2 6 7 2 0 , 2 8 0 2 5 5 1 9 , 3 8 0 2 0 4 1 5 , 4 5 0 3 2 2 , 4 0 8 4 8 3 , 6 1 6 0 3 6 4 8 3 , 6 5 2 5 3 9 2 7 5 5 4 2 4 7 1 8 , 7 3 0 3 Pr i m a r y E f f l u e n t 8 . 2 2 5 , 7 0 9 7 0 4 , 7 6 7 1 1 3 7 , 7 6 6 5 7 3 , 8 7 7 4 5 3 , 0 9 0 3 2 2 , 1 7 4 3 5 2 , 4 1 6 0 0 3 5 2 , 4 1 6 5 3 5 4 6 3 8 7 2 4 8 1 7 , 0 3 0 3a PE t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 8 . 2 2 5 , 7 0 9 7 0 4 , 7 6 7 1 1 3 7 , 7 6 6 5 7 3 , 8 7 7 4 5 3 , 0 9 0 3 2 2 , 1 7 4 3 5 2 , 4 1 6 0 0 3 5 2 , 4 1 6 5 3 5 4 6 3 8 7 2 4 8 1 7 , 0 3 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 9 . 2 7 6 , 4 4 0 6 7 5 , 2 0 6 1 3 8 1 0 , 6 7 0 9 9 7 , 6 3 0 7 8 6 , 0 5 0 3 1 2 , 4 0 2 3 7 2 , 8 8 9 0 1 0 3 7 2 , 8 9 9 5 3 9 9 6 4 7 1 3 6 3 2 8 , 0 9 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 1 7 . 8 1 1 2 , 3 7 0 3 7 5 , 4 8 0 7 0 3 1 0 4 , 4 0 0 2 , 8 1 9 4 1 8 , 7 0 0 2 , 1 3 7 3 1 7 , 5 0 0 1 6 2 , 4 2 0 2 2 9 3 4 , 0 5 0 3 4 6 4 2 3 2 3 4 , 5 1 0 5 7 3 6 5 8 8 , 6 0 2 2 9 8 4 4 , 3 1 0 9a Ae r a t i o n E f f l u e n t 17 . 8 1 1 2 , 3 7 0 4 5 7 1 6 4 1 9 5 , 2 4 0 2 , 8 0 4 4 1 6 , 6 0 0 2 , 1 2 4 3 1 5 , 6 0 0 0 3 7 2 1 3 3 1 , 5 9 0 6 9 4 6 2 1 9 3 2 , 5 4 0 5 7 0 5 5 8 8 , 6 0 2 2 2 8 3 3 , 8 2 0 10 Fi n a l C l a r i f i e r s E f f l 9. 0 8 6 , 3 0 3 4 2 9 1 8 5 7 5 1 7 1 , 2 4 9 1 3 9 4 6 0 1 9 2 1 1 4 6 4 8 2 8 5 9 6 5 3 5 9 5 3 8 3 2 2 8 1 7 , 2 4 0 11 Ae r a t i o n R A S F l o w 8. 5 4 5 , 9 2 9 4 2 7 4 1 , 3 1 6 9 3 , 7 0 0 5 , 7 7 3 4 1 1 , 1 0 0 4 , 3 7 4 3 1 1 , 4 0 0 0 1 8 4 3 8 3 1 , 1 6 0 6 4 5 4 4 4 4 3 1 , 6 1 0 5 3 3 7 1 1 4 8 , 1 3 1 2 2 8 1 6 , 2 1 0 12 Fi l t r a t i o n F e e d 9. 0 8 6 , 3 0 3 4 2 9 1 8 5 7 5 1 7 1 , 2 4 9 1 3 9 4 6 0 1 9 2 1 1 4 6 4 8 2 8 5 9 6 5 3 5 9 5 3 8 3 2 2 8 1 7 , 2 4 0 13 Fi l t r a t i o n E f f l 8. 4 0 5 , 8 3 0 4 2 6 9 4 3 1 4 3 1 9 6 2 1 4 9 0 1 8 0 3 2 6 4 4 6 7 4 7 8 5 3 3 2 5 3 3 6 2 2 8 1 5 , 9 4 0 13 a Fi l t r a t i o n B a c k w a s h 0. 6 8 4 7 3 4 2 2 4 6 2 6 1 1 8 6 1 , 0 5 3 1 4 1 7 9 8 0 1 1 4 8 1 6 3 6 2 1 1 1 7 5 2 7 8 4 7 2 2 8 1 , 2 9 2 14 UV F e e d 8. 4 0 5 , 8 3 0 4 2 6 9 4 3 1 4 3 1 9 6 2 1 4 9 0 1 8 0 3 2 6 4 4 6 7 4 7 8 5 3 3 2 5 3 3 6 2 2 8 1 5 , 9 4 0 14 a Pl a n t D i s c h a r g e 8. 4 0 5 , 8 3 0 4 2 6 9 4 3 1 4 3 1 9 6 2 1 4 9 0 1 8 0 3 2 6 4 4 6 7 4 7 8 5 3 3 2 5 3 3 6 2 3 9 1 6 , 7 1 0 20 Pr i m a r y S l u d g e 0. 8 9 6 1 5 7 0 5 1 3 1 , 6 9 4 1 2 , 5 1 0 2 , 1 0 0 1 5 , 5 1 0 1 , 6 7 4 1 2 , 3 6 0 3 2 2 3 4 1 6 3 1 , 2 0 1 0 0 1 6 3 1 , 2 0 1 5 3 8 2 3 1 6 7 2 4 8 1 , 8 3 4 22 WA S 0. 2 0 1 3 8 4 6 5 8 8 9 7 1 2 , 5 6 9 4 , 2 4 3 1 , 9 4 6 3 , 2 1 5 0 0 1 9 5 3 2 2 6 1 1 2 0 1 3 3 2 5 8 5 3 8 8 2 2 8 3 7 6 30 DA F T F e e d 1. 0 8 7 5 2 5 8 5 2 0 1 , 4 9 2 1 3 , 4 8 0 2 , 1 8 6 1 9 , 7 5 0 1 , 7 2 4 1 5 , 5 8 0 2 6 2 3 5 1 6 9 1 , 5 2 2 1 1 1 1 7 0 1 , 5 3 3 5 4 6 2 8 2 5 6 2 4 5 2 , 2 1 0 31 DA F T T h i c k e n e d S l u d g e 0. 0 3 2 0 5 0 1 2 4 2 , 7 1 0 1 0 , 5 1 0 6 5 , 0 0 0 1 6 , 0 0 0 5 1 , 2 6 0 1 2 , 6 2 0 2 6 6 4 , 2 6 4 1 , 0 5 0 1 0 4 , 2 6 5 1 , 0 5 0 5 1 6 9 5 1 7 1 2 4 5 6 0 32 DA F T T h i c k e n e r R e t u r n 1. 0 5 7 3 2 5 0 4 4 0 3 3 0 2 , 9 0 2 4 2 7 3 , 7 5 3 3 3 7 2 , 9 5 9 2 6 2 2 8 5 4 4 7 3 1 1 0 5 5 4 8 3 5 4 5 1 0 8 5 2 4 5 2 , 1 5 0 33 An a e r o b i c D i g e s t i o n F e e d 0. 0 3 2 0 5 0 1 2 4 2 , 7 1 0 1 0 , 5 1 0 6 5 , 0 2 0 1 6 , 0 0 0 5 1 , 2 6 0 1 2 , 6 2 0 2 6 6 4 , 2 6 4 1 , 0 5 0 1 0 4 , 2 6 5 1 , 0 5 0 1 0 6 9 5 1 7 1 2 2 7 5 6 34 An a e r o b i c D i g e s t e d S o l i d s 0. 0 3 2 0 5 0 0 1 2 3 1 0 , 0 1 0 2 , 4 6 4 3 1 , 7 0 0 7 , 8 0 3 1 7 , 9 4 0 4 , 4 1 6 2 , 7 8 1 6 8 4 4 , 2 6 4 1 , 0 5 0 0 0 4 , 2 6 4 1 , 0 5 0 4 0 4 9 9 6 9 5 1 7 1 1 0 , 0 6 0 2 , 4 7 6 41 De w a t e r i n g F e e d 0. 0 3 2 0 5 0 0 1 2 3 1 0 , 0 1 0 2 , 4 6 4 3 1 , 7 0 0 7 , 8 0 3 1 7 , 9 4 0 4 , 4 1 6 2 , 7 8 1 6 8 4 4 , 2 6 4 1 , 0 5 0 0 0 4 , 2 6 4 1 , 0 5 0 4 0 4 9 9 6 9 5 1 7 1 1 0 , 0 6 0 2 , 4 7 6 42 CA K E 0. 0 0 3 2 0 1 6 6 , 0 2 0 2 , 2 9 5 2 2 0 , 0 0 0 7 , 6 4 7 1 2 4 , 5 0 0 4 , 3 2 8 2 , 7 8 1 9 7 1 3 , 0 7 0 4 5 5 0 0 1 3 , 0 7 0 4 5 5 4 0 4 1 4 2 , 4 2 7 8 4 1 0 , 0 6 0 3 5 0 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0. 0 3 1 8 2 0 4 2 4 2 5 1 7 3 8 1 5 6 4 1 8 8 8 2 , 7 8 1 5 8 8 2 , 8 1 5 5 9 5 0 0 2 , 8 1 5 5 9 5 4 0 4 8 5 4 1 0 8 7 1 0 , 0 6 0 2 , 1 2 7 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0. 0 3 1 8 2 0 4 2 4 2 5 1 2 2 2 4 7 1 2 5 2 6 1 , 1 1 2 2 3 5 1 , 1 4 7 2 4 2 0 0 1 , 1 4 7 2 4 2 4 0 4 8 5 4 1 0 8 7 2 , 3 1 4 4 8 9 50 A- S t a g e B y p a s s t o B - S t a g e 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 54 A- S t a g e F e e d ( w / R A S ) 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 56 A- S t a g e E f f l u e n t 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 58 A- S t a g e R A S 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 59 A- S t a g e W A S 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 60 A- S t a g e E f f l t o B - S t a g e 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 62 A- S t a g e E f f l t o F l o w E Q 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . St r e a m S u m m a r y f o r M L E M D EN V _ M L E _ M D St r e a m S u m m a r y f o r M L E M D Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 1 7 . 3 0 1 2 , 0 1 0 7 4 1 0 , 6 8 0 2 5 2 3 6 , 3 6 0 2 3 1 3 3 , 3 3 0 1 8 5 2 6 , 6 6 0 2 2 3 , 1 7 4 3 3 4 , 7 6 1 0 0 3 3 4 , 7 6 1 4 5 7 7 6 8 6 6 2 4 3 3 5 , 0 6 0 1a He a d w o r k s t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 2 Ra w I n f l u e n t P l u s R e c y c l e s 1 8 . 0 2 1 2 , 5 2 0 7 1 1 0 , 7 4 0 2 4 6 3 6 , 9 7 0 2 3 6 3 5 , 4 8 0 1 8 8 2 8 , 2 6 0 2 3 3 , 5 2 5 3 5 5 , 2 7 8 0 2 6 3 5 5 , 3 0 4 5 7 7 1 7 1 , 1 0 1 2 4 8 3 7 , 3 2 0 3 Pr i m a r y E f f l u e n t 1 6 . 7 1 1 1 , 6 0 0 7 1 9 , 9 5 3 1 3 7 1 9 , 1 3 0 8 9 1 2 , 4 2 0 7 1 9 , 8 9 1 2 3 3 , 2 6 7 2 8 3 , 8 8 1 0 0 2 8 3 , 8 8 1 5 7 1 5 6 8 3 0 2 4 9 3 4 , 6 8 0 3a PE t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 1 6 . 7 1 1 1 , 6 0 0 7 1 9 , 9 5 3 1 3 7 1 9 , 1 3 0 8 9 1 2 , 4 2 0 7 1 9 , 8 9 1 2 3 3 , 2 6 7 2 8 3 , 8 8 1 0 0 2 8 3 , 8 8 1 5 7 1 5 6 8 3 0 2 4 9 3 4 , 6 8 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 1 8 . 2 7 1 2 , 6 8 0 7 0 1 0 , 6 0 0 1 5 4 2 3 , 4 7 0 1 2 3 1 8 , 7 7 0 9 8 1 4 , 8 6 0 2 3 3 , 5 1 7 3 0 4 , 4 9 6 0 1 1 3 0 4 , 5 0 6 5 7 8 0 6 9 7 4 3 6 8 5 6 , 0 8 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 2 9 . 8 8 2 0 , 7 5 0 4 6 1 1 , 5 1 0 1 , 5 6 3 3 8 9 , 6 0 0 6 , 5 9 0 1 , 6 4 2 , 0 0 0 4 , 9 4 5 1 , 2 3 2 , 0 0 0 1 4 3 , 5 4 2 5 0 7 1 2 6 , 3 0 0 2 4 5 7 5 0 9 1 2 6 , 7 0 0 5 1 , 2 4 6 1 2 8 3 1 , 9 1 0 3 3 0 8 2 , 2 5 0 9a Ae r a t i o n E f f l u e n t 29 . 8 8 2 0 , 7 5 0 9 2 , 3 4 1 1 , 4 8 7 3 7 0 , 5 0 0 6 , 5 6 6 1 , 6 3 6 , 0 0 0 4 , 9 2 4 1 , 2 2 7 , 0 0 0 0 6 2 4 9 3 1 2 2 , 8 0 0 5 1 , 1 4 6 4 9 7 1 2 3 , 9 0 0 5 1 , 1 9 8 1 2 8 3 1 , 9 1 0 2 7 0 6 7 , 3 2 0 10 Fi n a l C l a r i f i e r s E f f l 17 . 9 7 1 2 , 4 8 0 9 1 , 4 0 8 1 3 1 , 9 6 4 1 7 2 , 4 7 3 1 2 1 , 8 5 5 0 3 7 1 2 2 3 5 6 9 0 6 9 1 3 5 7 2 1 5 7 6 7 2 7 0 4 0 , 4 9 0 11 Ae r a t i o n R A S F l o w 11 . 6 2 8 , 0 6 7 9 9 1 0 3 , 7 7 9 3 6 6 , 1 0 0 1 6 , 7 6 0 1 , 6 2 4 , 0 0 0 1 2 , 5 7 0 1 , 2 1 7 , 0 0 0 0 2 4 1 , 2 5 7 1 2 1 , 8 0 0 5 4 4 6 1 , 2 6 2 1 2 2 , 2 0 0 5 4 6 5 3 1 9 3 0 , 9 4 0 2 7 0 2 6 , 1 7 0 12 Fi l t r a t i o n F e e d 17 . 9 7 1 2 , 4 8 0 9 1 , 4 0 8 1 3 1 , 9 6 4 1 7 2 , 4 7 3 1 2 1 , 8 5 5 0 3 7 1 2 2 3 5 6 9 0 6 9 1 3 5 7 2 1 5 7 6 7 2 7 0 4 0 , 4 9 0 13 Fi l t r a t i o n E f f l 17 . 2 9 1 2 , 0 1 0 9 1 , 3 5 5 1 0 1 , 4 4 5 3 4 0 4 2 3 0 3 0 3 6 0 6 6 5 6 6 4 5 7 3 0 5 6 9 3 5 7 0 1 2 7 0 3 8 , 9 6 0 13 a Fi l t r a t i o n B a c k w a s h 0. 6 8 4 7 3 9 5 3 9 1 5 1 9 3 6 5 2 , 0 6 9 2 7 4 1 , 5 5 2 0 1 2 8 1 5 7 5 2 6 3 2 1 8 3 5 2 7 1 2 6 6 2 7 0 1 , 5 3 3 14 UV F e e d 17 . 2 9 1 2 , 0 1 0 9 1 , 3 5 5 1 0 1 , 4 4 5 3 4 0 4 2 3 0 3 0 3 6 0 6 6 5 6 6 4 5 7 3 0 5 6 9 3 5 7 0 1 2 7 0 3 8 , 9 6 0 14 a Pl a n t D i s c h a r g e 17 . 2 9 1 2 , 0 1 0 9 1 , 3 5 5 1 0 1 , 4 4 5 3 4 0 4 2 3 0 3 0 3 6 0 6 6 5 6 6 4 5 7 3 0 5 6 9 3 5 7 0 1 2 8 1 4 0 , 5 3 0 20 Pr i m a r y S l u d g e 1. 3 2 9 1 4 7 1 7 8 4 1 , 6 2 4 1 7 , 8 3 0 2 , 1 0 0 2 3 , 0 6 0 1 , 6 7 3 1 8 , 3 7 0 2 3 2 5 8 1 2 7 1 , 3 9 7 0 0 1 2 7 1 , 3 9 7 5 5 6 2 5 2 7 1 2 4 9 2 , 7 3 4 22 WA S 0. 2 9 2 0 3 9 2 3 9 6 8 2 , 3 6 0 4 , 2 6 0 1 0 , 3 9 0 3 , 1 9 4 7 , 7 8 9 0 1 3 2 0 7 8 0 5 1 1 3 2 4 7 9 1 5 1 2 8 5 2 0 7 2 7 0 6 5 9 30 DA F T F e e d 1. 6 1 1 , 1 1 7 6 0 8 0 7 1 , 5 0 5 2 0 , 1 9 0 2 , 4 9 2 3 3 , 4 5 0 1 , 9 4 9 2 6 , 1 6 0 1 9 2 5 8 1 6 2 2 , 1 7 7 1 1 1 1 6 3 2 , 1 8 8 5 6 8 3 6 4 7 8 2 5 3 3 , 3 9 2 31 DA F T T h i c k e n e d S l u d g e 0. 0 5 3 5 5 0 2 1 3 7 , 7 2 0 1 5 , 7 2 0 6 5 , 0 0 0 2 7 , 0 9 0 5 0 , 8 3 0 2 1 , 1 9 0 1 9 8 3 , 7 4 7 1 , 5 6 2 1 0 3 , 7 4 8 1 , 5 6 2 5 2 8 0 1 3 3 4 2 5 3 1 0 5 32 DA F T T h i c k e n e r R e t u r n 1. 5 6 1 , 0 8 3 5 0 6 5 0 3 3 3 4 , 3 3 3 4 8 9 6 , 3 5 5 3 8 2 4 , 9 7 0 1 9 2 5 0 4 7 6 1 5 1 1 1 4 8 6 2 6 5 6 6 1 1 1 4 4 2 5 3 3 , 2 8 7 33 An a e r o b i c D i g e s t i o n F e e d 0. 0 5 3 5 5 0 2 1 3 7 , 7 2 0 1 5 , 7 2 0 6 5 , 0 2 0 2 7 , 1 0 0 5 0 , 8 3 0 2 1 , 1 9 0 1 9 8 3 , 7 4 7 1 , 5 6 2 1 0 3 , 7 4 8 1 , 5 6 2 1 0 8 0 1 3 3 4 2 3 5 9 8 34 An a e r o b i c D i g e s t e d S o l i d s 0. 0 5 3 5 5 0 0 2 0 8 1 0 , 0 9 0 4 , 2 0 8 3 1 , 9 8 0 1 3 , 3 3 0 1 7 , 7 9 0 7 , 4 1 6 2 , 4 4 3 1 , 0 1 8 3 , 7 4 7 1 , 5 6 2 0 0 3 , 7 4 7 1 , 5 6 2 4 6 6 1 9 4 8 0 1 3 3 4 8 , 8 8 6 3 , 7 0 4 41 De w a t e r i n g F e e d 0. 0 5 3 5 5 0 0 2 0 8 1 0 , 0 9 0 4 , 2 0 8 3 1 , 9 8 0 1 3 , 3 3 0 1 7 , 7 9 0 7 , 4 1 6 2 , 4 4 3 1 , 0 1 8 3 , 7 4 7 1 , 5 6 2 0 0 3 , 7 4 7 1 , 5 6 2 4 6 6 1 9 4 8 0 1 3 3 4 8 , 8 8 6 3 , 7 0 4 42 CA K E 0. 0 1 5 2 0 1 6 6 , 0 2 0 3 , 9 2 0 2 2 0 , 0 0 0 1 3 , 0 6 0 1 2 2 , 4 0 0 7 , 2 6 7 2 , 4 4 3 1 4 5 1 1 , 4 2 0 6 7 8 0 0 1 1 , 4 2 0 6 7 8 4 6 6 2 8 2 , 7 7 3 1 6 5 8 , 8 8 6 5 2 8 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0. 0 4 3 0 2 0 7 2 4 4 8 7 7 4 6 2 6 7 4 1 5 1 4 8 2 , 4 4 3 8 7 3 2 , 4 7 3 8 8 4 0 0 2 , 4 7 3 8 8 4 4 6 6 1 6 6 4 7 3 1 6 9 8 , 8 8 6 3 , 1 7 6 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0. 0 4 3 0 2 0 7 2 4 4 8 7 2 2 4 8 0 1 2 5 4 4 9 7 7 3 4 9 1 , 0 0 7 3 6 0 0 0 1 , 0 0 7 3 6 0 4 6 6 1 6 6 4 7 3 1 6 9 2 , 0 4 4 7 3 1 50 A- S t a g e B y p a s s t o B - S t a g e 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 54 A- S t a g e F e e d ( w / R A S ) 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 56 A- S t a g e E f f l u e n t 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 58 A- S t a g e R A S 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 59 A- S t a g e W A S 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 60 A- S t a g e E f f l t o B - S t a g e 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 62 A- S t a g e E f f l t o F l o w E Q 0. 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . St r e a m S u m m a r y f o r M L E P H EN V _ M L E _ P H St r e a m S u m m a r y f o r M L E P H Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 3 3 . 5 0 2 3 , 2 6 0 1a He a d w o r k s t o E Q 1 1 . 5 0 7 , 9 8 6 2 Ra w I n f l u e n t P l u s R e c y c l e s 2 2 . 7 1 1 5 , 7 7 0 3 Pr i m a r y E f f l u e n t 2 1 . 8 1 1 5 , 1 5 0 3a PE t o E Q 1 6 . 3 1 1 1 , 3 3 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 1 7 . 0 0 1 1 , 8 1 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 1 8 . 1 4 1 2 , 6 0 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 2 8 . 0 6 1 9 , 4 8 0 9a Ae r a t i o n E f f l u e n t 2 8 . 0 6 1 9 , 4 8 0 10 Fi n a l C l a r i f i e r s E f f l 1 7 . 8 6 1 2 , 4 0 0 11 Ae r a t i o n R A S F l o w 9 . 9 2 6 , 8 8 6 12 Fi l t r a t i o n F e e d 1 7 . 8 6 1 2 , 4 0 0 13 Fi l t r a t i o n E f f l 1 7 . 1 8 1 1 , 9 3 0 13 a Fi l t r a t i o n B a c k w a s h 0 . 6 8 4 7 3 14 UV F e e d 1 7 . 1 8 1 1 , 9 3 0 14 a Pl a n t D i s c h a r g e 1 7 . 1 8 1 1 , 9 3 0 20 Pr i m a r y S l u d g e 0 . 9 0 6 2 2 22 WA S 0 . 2 8 1 9 3 30 DA F T F e e d 1 . 1 7 8 1 5 31 DA F T T h i c k e n e d S l u d g e 0 . 0 3 2 3 32 DA F T T h i c k e n e r R e t u r n 1 . 1 4 7 9 2 33 An a e r o b i c D i g e s t i o n F e e d 0 . 0 3 2 3 34 An a e r o b i c D i g e s t e d S o l i d s 0 . 0 3 2 3 41 De w a t e r i n g F e e d 0 . 0 3 2 3 42 CA K E 0 . 0 0 3 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0 . 0 3 2 0 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0 . 0 3 2 0 50 A- S t a g e B y p a s s t o B - S t a g e 0 . 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 0 . 0 0 0 54 A- S t a g e F e e d ( w / R A S ) 0 . 0 0 0 56 A- S t a g e E f f l u e n t 0 . 0 0 0 58 A- S t a g e R A S 0 . 0 0 0 59 A- S t a g e W A S 0 . 0 0 0 60 A- S t a g e E f f l t o B - S t a g e 0 . 0 0 0 62 A- S t a g e E f f l t o F l o w E Q 0 . 0 0 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . St r e a m S u m m a r y f o r V e r t i C e l A A EN V _ O D _ A A St r e a m S u m m a r y f o r O D A A Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 6 . 1 0 4 , 2 3 6 7 5 3 , 8 1 6 2 7 8 1 4 , 1 4 0 2 7 2 1 3 , 8 4 0 2 1 8 1 1 , 0 7 0 3 2 1 , 6 2 8 4 8 2 , 4 4 2 0 0 4 8 2 , 4 4 2 4 2 0 4 6 3 0 5 2 4 3 1 2 , 3 6 0 1a He a d w o r k s t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 2 Ra w I n f l u e n t P l u s R e c y c l e s 6 . 8 0 4 , 7 2 1 6 7 3 , 8 2 7 2 5 3 1 4 , 3 6 0 2 5 9 1 4 , 6 6 0 2 0 6 1 1 , 6 7 0 3 2 1 , 7 9 3 4 7 2 , 6 7 1 1 5 5 4 8 2 , 7 2 6 5 2 8 9 7 4 0 6 2 4 6 1 3 , 9 2 0 3 Pr i m a r y E f f l u e n t 6 . 1 3 4 , 2 5 6 6 7 3 , 4 5 0 1 0 9 5 , 5 5 7 5 7 2 , 9 3 2 4 6 2 , 3 3 4 3 2 1 , 6 1 7 3 5 1 , 7 9 2 0 0 3 5 1 , 7 9 2 5 2 6 0 6 2 8 4 2 4 9 1 2 , 7 3 0 3a PE t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 6 . 1 3 4 , 2 5 6 6 7 3 , 4 5 0 1 0 9 5 , 5 5 7 5 7 2 , 9 3 2 4 6 2 , 3 3 4 3 2 1 , 6 1 7 3 5 1 , 7 9 2 0 0 3 5 1 , 7 9 2 5 2 6 0 6 2 8 4 2 4 9 1 2 , 7 3 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 6 . 9 3 4 , 8 0 9 6 5 3 , 7 8 2 1 3 2 7 , 6 0 2 9 8 5 , 6 6 6 7 8 4 , 4 8 1 3 1 1 , 7 8 9 3 7 2 , 1 3 5 0 1 2 3 7 2 , 1 4 7 5 2 9 4 6 3 4 5 3 6 3 2 0 , 9 8 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 1 1 . 5 7 8 , 0 3 4 4 0 3 , 8 3 9 5 1 0 4 9 , 2 4 0 2 , 0 0 8 1 9 3 , 7 0 0 1 , 4 8 3 1 4 3 , 1 0 0 1 9 1 , 7 9 9 1 6 6 1 6 , 0 1 0 4 3 8 7 1 7 0 1 6 , 3 9 0 5 4 8 0 4 1 4 , 0 0 0 3 0 4 2 9 , 3 0 0 9a Ae r a t i o n E f f l u e n t 1 1 . 5 7 8 , 0 3 4 1 1 4 1 4 4 1 4 2 , 5 2 0 1 , 9 8 7 1 9 1 , 7 0 0 1 , 4 6 4 1 4 1 , 3 0 0 0 2 4 1 4 7 1 4 , 1 5 0 1 0 9 3 6 1 5 6 1 5 , 0 9 0 5 4 6 5 4 1 4 , 0 0 0 2 1 5 2 0 , 7 2 0 10 Fi n a l C l a r i f i e r s E f f l 6 . 7 8 4 , 7 0 6 1 8 3 5 2 8 9 1 7 9 3 3 1 2 6 8 7 0 1 4 1 8 3 1 0 5 4 8 1 1 6 3 1 5 2 7 2 5 2 9 0 2 1 5 1 2 , 1 4 0 11 Ae r a t i o n R A S F l o w 4 . 6 4 3 , 2 2 5 1 5 7 1 , 0 7 5 4 1 , 6 4 0 4 , 8 5 6 1 8 8 , 1 0 0 3 , 5 7 9 1 3 8 , 6 0 0 0 1 0 3 5 8 1 3 , 8 7 0 1 0 3 7 6 3 6 8 1 4 , 2 5 0 5 1 8 6 9 4 3 , 6 5 5 2 1 5 8 , 3 1 6 12 Fi l t r a t i o n F e e d 6 . 7 8 4 , 7 0 6 1 8 3 5 2 8 9 1 7 9 3 3 1 2 6 8 7 0 1 4 1 8 3 1 0 5 4 8 1 1 6 3 1 5 2 7 2 5 2 9 0 2 1 5 1 2 , 1 4 0 13 Fi l t r a t i o n E f f l 6 . 1 0 4 , 2 3 4 1 7 4 2 1 0 6 3 1 4 2 2 1 0 5 0 1 3 0 2 3 1 0 4 9 3 1 0 5 1 6 5 2 4 5 5 2 4 8 2 1 5 1 0 , 9 2 0 13 a Fi l t r a t i o n B a c k w a s h 0 . 6 8 4 7 3 1 8 3 2 1 8 3 1 3 9 7 9 0 1 0 3 5 8 2 0 1 1 1 6 0 1 0 5 5 2 0 1 1 5 5 2 7 7 4 2 2 1 5 1 , 2 1 8 14 UV F e e d 6 . 1 0 4 , 2 3 4 1 7 4 2 1 0 6 3 1 4 2 2 1 0 5 0 1 3 0 2 3 1 0 4 9 3 1 0 5 1 6 5 2 4 5 5 2 4 8 2 1 5 1 0 , 9 2 0 14 a Pl a n t D i s c h a r g e 6 . 1 0 4 , 2 3 4 1 7 4 2 1 0 6 3 1 4 2 2 1 0 5 0 1 3 0 2 3 1 0 4 9 3 1 0 5 1 6 5 2 4 5 5 2 4 8 2 2 6 1 1 , 4 7 0 20 Pr i m a r y S l u d g e 0 . 6 7 4 6 5 6 7 3 7 7 1 , 5 7 7 8 , 8 0 6 2 , 1 0 0 1 1 , 7 3 0 1 , 6 7 2 9 , 3 3 7 3 2 1 7 7 1 5 7 8 7 9 0 0 1 5 7 8 7 9 5 2 8 2 2 1 2 2 2 4 9 1 , 3 9 1 22 WA S 0 . 1 5 1 0 3 1 2 4 7 9 5 9 0 2 , 1 5 9 2 , 6 6 0 1 , 5 9 1 1 , 9 6 0 0 0 1 5 9 1 9 6 1 0 1 2 1 6 9 2 0 8 5 6 4 5 5 5 2 1 5 2 6 5 30 DA F T F e e d 0 . 8 2 5 6 8 5 6 3 7 9 1 , 3 7 8 9 , 3 9 6 2 , 1 1 1 1 4 , 3 9 0 1 , 6 5 7 1 1 , 3 0 0 2 6 1 7 7 1 5 8 1 , 0 7 5 2 1 2 1 5 9 1 , 0 8 7 5 3 4 2 6 1 7 7 2 4 3 1 , 6 5 5 31 DA F T T h i c k e n e d S l u d g e 0 . 0 2 1 5 5 0 9 4 0 , 7 8 0 7 , 3 1 3 6 5 , 0 0 0 1 1 , 6 6 0 5 1 , 0 3 0 9 , 1 5 1 2 6 5 4 , 0 8 2 7 3 2 2 0 4 , 0 8 3 7 3 2 5 1 6 5 1 1 1 7 2 4 3 4 4 32 DA F T T h i c k e n e r R e t u r n 0 . 8 0 5 5 3 5 0 3 3 2 3 0 8 2 , 0 4 5 4 1 2 2 , 7 3 4 3 2 3 2 , 1 4 7 2 6 1 7 2 5 2 3 4 3 2 1 2 5 3 3 5 5 5 3 3 9 6 1 2 4 3 1 , 6 1 2 33 An a e r o b i c D i g e s t i o n F e e d 0 . 0 2 1 5 5 0 9 4 0 , 7 8 0 7 , 3 1 3 6 5 , 0 2 0 1 1 , 6 6 0 5 1 , 0 3 0 9 , 1 5 1 2 6 5 4 , 0 8 2 7 3 2 2 0 4 , 0 8 3 7 3 2 1 0 6 5 1 1 1 7 2 2 5 4 0 34 An a e r o b i c D i g e s t e d S o l i d s 0 . 0 2 1 5 5 0 0 9 0 1 0 , 0 6 0 1 , 8 0 3 3 1 , 8 5 0 5 , 7 1 1 1 7 , 8 6 0 3 , 2 0 3 2 , 6 6 2 4 7 7 4 , 0 8 2 7 3 2 0 0 4 , 0 8 2 7 3 2 3 7 8 6 8 6 5 1 1 1 7 9 , 6 3 7 1 , 7 2 8 41 De w a t e r i n g F e e d 0 . 0 2 1 5 5 0 0 9 0 1 0 , 0 6 0 1 , 8 0 3 3 1 , 8 5 0 5 , 7 1 1 1 7 , 8 6 0 3 , 2 0 3 2 , 6 6 2 4 7 7 4 , 0 8 2 7 3 2 0 0 4 , 0 8 2 7 3 2 3 7 8 6 8 6 5 1 1 1 7 9 , 6 3 7 1 , 7 2 8 42 CA K E 0 . 0 0 2 2 0 1 6 6 , 0 2 0 1 , 6 8 0 2 2 0 , 0 0 0 5 , 5 9 7 1 2 3 , 4 0 0 3 , 1 3 9 2 , 6 6 2 6 8 1 2 , 4 7 0 3 1 7 0 0 1 2 , 4 7 0 3 1 7 3 7 8 1 0 2 , 2 6 3 5 8 9 , 6 3 7 2 4 5 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0 . 0 2 1 3 2 0 3 2 4 3 3 7 7 4 2 1 1 4 4 1 6 6 4 2 , 6 6 2 4 1 0 2 , 6 9 5 4 1 5 0 0 2 , 6 9 5 4 1 5 3 7 8 5 8 3 8 4 5 9 9 , 6 3 7 1 , 4 8 3 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0 . 0 2 1 3 2 0 3 2 4 3 3 7 2 2 3 3 4 1 2 5 1 9 1 , 0 6 5 1 6 4 1 , 0 9 8 1 6 9 0 0 1 , 0 9 8 1 6 9 3 7 8 5 8 3 8 4 5 9 2 , 2 1 6 3 4 1 50 A- S t a g e B y p a s s t o B - S t a g e 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 54 A- S t a g e F e e d ( w / R A S ) 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 56 A- S t a g e E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 58 A- S t a g e R A S 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 59 A- S t a g e W A S 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 60 A- S t a g e E f f l t o B - S t a g e 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 62 A- S t a g e E f f l t o F l o w E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . St r e a m S u m m a r y f o r V e r t i C e l M M EN V _ O D _ M M St r e a m S u m m a r y f o r O D M M Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 8 . 4 5 , 8 3 3 7 5 5 , 2 5 4 2 8 5 1 9 , 9 7 0 2 6 1 1 8 , 2 8 0 2 0 9 1 4 , 6 3 0 3 1 2 , 1 7 2 4 7 3 , 2 9 3 0 0 4 7 3 , 2 9 3 4 2 8 0 6 4 2 0 2 4 2 1 6 , 9 5 0 1a He a d w o r k s t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 2 Ra w I n f l u e n t P l u s R e c y c l e s 9 . 1 6 , 3 2 3 6 9 5 , 2 7 5 2 6 7 2 0 , 2 7 0 2 5 5 1 9 , 3 8 0 2 0 3 1 5 , 4 4 0 3 2 2 , 4 0 2 4 8 3 , 6 0 9 1 5 5 4 8 3 , 6 6 4 5 3 8 9 7 5 5 1 2 4 6 1 8 , 6 5 0 3 Pr i m a r y E f f l u e n t 8 . 2 5 , 7 0 8 6 9 4 , 7 6 2 1 1 3 7 , 7 6 1 5 7 3 , 8 7 7 4 5 3 , 0 8 8 3 2 2 , 1 6 9 3 5 2 , 4 1 0 0 0 3 5 2 , 4 1 0 5 3 5 2 6 3 8 4 2 4 8 1 7 , 0 1 0 3a PE t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 8 . 2 5 , 7 0 8 6 9 4 , 7 6 2 1 1 3 7 , 7 6 1 5 7 3 , 8 7 7 4 5 3 , 0 8 8 3 2 2 , 1 6 9 3 5 2 , 4 1 0 0 0 3 5 2 , 4 1 0 5 3 5 2 6 3 8 4 2 4 8 1 7 , 0 1 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 9 . 3 6 , 4 3 5 6 7 5 , 1 9 8 1 3 8 1 0 , 6 4 0 9 8 7 , 5 6 1 7 7 5 , 9 8 8 3 1 2 , 3 9 6 3 7 2 , 8 7 6 0 1 5 3 7 2 , 8 9 1 5 3 9 6 6 4 6 6 3 6 3 2 8 , 0 4 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 1 7 . 8 1 2 , 3 6 0 3 6 5 , 4 0 3 7 0 2 1 0 4 , 3 0 0 2 , 8 5 4 4 2 3 , 8 0 0 2 , 1 3 8 3 1 7 , 5 0 0 1 6 2 , 4 1 4 2 2 9 3 4 , 0 4 0 5 7 0 3 2 3 4 3 4 , 7 5 0 5 7 3 6 5 8 8 , 6 0 3 2 9 2 4 3 , 3 3 0 9a Ae r a t i o n E f f l u e n t 1 7 . 8 1 2 , 3 6 0 3 4 2 7 6 4 0 9 5 , 0 3 0 2 , 8 3 8 4 2 1 , 4 0 0 2 , 1 2 4 3 1 5 , 3 0 0 0 3 7 2 1 3 3 1 , 5 7 0 1 0 1 , 4 3 4 2 2 2 3 3 , 0 1 0 5 7 1 1 5 8 8 , 6 0 4 2 1 5 3 1 , 8 9 0 10 Fi n a l C l a r i f i e r s E f f l 9 . 1 6 , 3 0 3 3 2 1 8 7 4 9 8 1 7 1 , 2 4 9 1 2 9 3 5 0 1 9 1 1 1 2 1 0 7 3 1 1 1 8 4 4 5 3 6 3 5 3 8 6 2 1 5 1 6 , 2 6 0 11 Ae r a t i o n R A S F l o w 8 . 5 5 , 9 2 9 3 2 0 5 1 , 3 1 5 9 3 , 6 6 0 5 , 8 4 6 4 1 6 , 2 0 0 4 , 3 7 5 3 1 1 , 5 0 0 0 1 8 4 3 8 3 1 , 1 7 0 1 0 6 8 8 4 4 7 3 1 , 8 6 0 5 3 4 1 1 1 4 8 , 1 3 7 2 1 5 1 5 , 2 9 0 12 Fi l t r a t i o n F e e d 9 . 1 6 , 3 0 3 3 2 1 8 7 4 9 8 1 7 1 , 2 4 9 1 2 9 3 5 0 1 9 1 1 1 2 1 0 7 3 1 1 1 8 4 4 5 3 6 3 5 3 8 6 2 1 5 1 6 , 2 6 0 13 Fi l t r a t i o n E f f l 8 . 4 5 , 8 3 0 3 2 0 1 4 2 4 5 3 1 9 6 2 1 4 7 0 1 8 0 3 2 1 0 6 7 6 1 0 7 0 9 5 3 3 5 5 3 3 9 2 1 5 1 5 , 0 4 0 13 a Fi l t r a t i o n B a c k w a s h 0 . 7 4 7 3 3 1 6 4 5 2 5 3 1 8 6 1 , 0 5 3 1 3 9 7 8 8 0 1 1 4 8 0 1 0 5 5 2 4 1 3 5 5 2 7 8 4 7 2 1 5 1 , 2 1 9 14 UV F e e d 8 . 4 5 , 8 3 0 3 2 0 1 4 2 4 5 3 1 9 6 2 1 4 7 0 1 8 0 3 2 1 0 6 7 6 1 0 7 0 9 5 3 3 5 5 3 3 9 2 1 5 1 5 , 0 4 0 14 a Pl a n t D i s c h a r g e 8 . 4 5 , 8 3 0 3 2 0 1 4 2 4 5 3 1 9 6 2 1 4 7 0 1 8 0 3 2 1 0 6 7 6 1 0 7 0 9 5 3 3 5 5 3 3 9 2 2 6 1 5 , 8 0 0 20 Pr i m a r y S l u d g e 0 . 9 6 1 5 6 9 5 1 3 1 , 6 9 4 1 2 , 5 1 0 2 , 1 0 0 1 5 , 5 1 0 1 , 6 7 3 1 2 , 3 5 0 3 2 2 3 4 1 6 2 1 , 1 9 9 0 0 1 6 2 1 , 1 9 9 5 3 8 2 3 1 6 7 2 4 8 1 , 8 3 2 22 WA S 0 . 2 1 3 2 3 5 5 5 4 8 7 6 2 , 4 5 6 3 , 8 8 3 1 , 8 3 8 2 , 9 0 6 0 0 1 8 4 2 9 1 1 0 1 5 1 9 4 3 0 6 5 8 5 1 8 0 2 1 5 3 4 0 30 DA F T F e e d 1 . 1 7 4 7 5 8 5 1 8 1 , 4 9 3 1 3 , 3 8 0 2 , 1 6 3 1 9 , 3 9 0 1 , 7 0 2 1 5 , 2 6 0 2 6 2 3 4 1 6 6 1 , 4 9 0 2 1 5 1 6 8 1 , 5 0 5 5 4 5 2 8 2 4 7 2 4 2 2 , 1 7 2 31 DA F T T h i c k e n e d S l u d g e 0 . 0 2 0 5 0 1 2 4 3 , 1 8 0 1 0 , 4 3 0 6 5 , 0 0 0 1 5 , 7 1 0 5 1 , 1 5 0 1 2 , 3 6 0 2 6 6 4 , 2 3 7 1 , 0 2 4 2 0 4 , 2 3 8 1 , 0 2 4 5 1 6 8 1 1 6 5 2 4 3 5 9 32 DA F T T h i c k e n e r R e t u r n 1 . 0 7 2 6 5 0 4 3 6 3 3 0 2 , 8 8 1 4 2 2 3 , 6 8 4 3 3 2 2 , 8 9 9 2 6 2 2 8 5 3 4 6 6 2 1 5 5 5 4 8 1 5 4 4 9 8 3 2 4 2 2 , 1 1 4 33 An a e r o b i c D i g e s t i o n F e e d 0 . 0 2 0 5 0 1 2 4 3 , 1 8 0 1 0 , 4 3 0 6 5 , 0 2 0 1 5 , 7 1 0 5 1 , 1 5 0 1 2 , 3 6 0 2 6 6 4 , 2 3 7 1 , 0 2 4 2 0 4 , 2 3 8 1 , 0 2 4 1 0 6 8 1 1 6 5 2 2 5 5 4 34 An a e r o b i c D i g e s t e d S o l i d s 0 . 0 2 0 5 0 0 1 2 1 1 0 , 0 3 0 2 , 4 2 4 3 1 , 7 7 0 7 , 6 7 7 1 7 , 9 0 0 4 , 3 2 6 2 , 7 6 3 6 6 8 4 , 2 3 7 1 , 0 2 4 0 0 4 , 2 3 7 1 , 0 2 4 3 9 5 9 6 6 8 1 1 6 5 9 , 9 9 5 2 , 4 1 5 41 De w a t e r i n g F e e d 0 . 0 2 0 5 0 0 1 2 1 1 0 , 0 3 0 2 , 4 2 4 3 1 , 7 7 0 7 , 6 7 7 1 7 , 9 0 0 4 , 3 2 6 2 , 7 6 3 6 6 8 4 , 2 3 7 1 , 0 2 4 0 0 4 , 2 3 7 1 , 0 2 4 3 9 5 9 6 6 8 1 1 6 5 9 , 9 9 5 2 , 4 1 5 42 CA K E 0 . 0 3 2 0 1 6 6 , 0 2 0 2 , 2 5 8 2 2 0 , 0 0 0 7 , 5 2 4 1 2 4 , 0 0 0 4 , 2 3 9 2 , 7 6 3 9 4 1 2 , 9 7 0 4 4 4 0 0 1 2 , 9 7 0 4 4 4 3 9 5 1 4 2 , 3 7 4 8 1 9 , 9 9 5 3 4 2 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0 . 0 1 7 2 0 4 2 4 2 5 0 7 4 0 1 5 4 4 1 7 8 7 2 , 7 6 3 5 7 3 2 , 7 9 7 5 8 0 0 0 2 , 7 9 7 5 8 0 3 9 5 8 2 4 0 2 8 3 9 , 9 9 5 2 , 0 7 3 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0 . 0 1 7 2 0 4 2 4 2 5 0 2 2 2 4 6 1 2 5 2 6 1 , 1 0 5 2 2 9 1 , 1 4 0 2 3 6 0 0 1 , 1 4 0 2 3 6 3 9 5 8 2 4 0 2 8 3 2 , 2 9 9 4 7 7 50 A- S t a g e B y p a s s t o B - S t a g e 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 54 A- S t a g e F e e d ( w / R A S ) 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 56 A- S t a g e E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 58 A- S t a g e R A S 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 59 A- S t a g e W A S 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 60 A- S t a g e E f f l t o B - S t a g e 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 62 A- S t a g e E f f l t o F l o w E Q 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . St r e a m S u m m a r y f o r V e r t i C e l M D EN V _ O D _ M D St r e a m S u m m a r y f o r O D M D Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 1 7 . 3 0 1 2 , 0 1 0 7 4 1 0 , 6 8 0 2 5 2 3 6 , 3 6 0 2 3 1 3 3 , 3 3 0 1 8 5 2 6 , 6 6 0 2 2 3 , 1 7 4 3 3 4 , 7 6 1 0 0 3 3 4 , 7 6 1 4 5 7 7 6 8 6 6 2 4 3 3 5 , 0 6 0 1a He a d w o r k s t o E Q 0 . 0 0 00 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 2 Ra w I n f l u e n t P l u s R e c y c l e s 1 8 . 0 2 1 2 , 5 2 0 7 1 1 0 , 7 2 0 2 4 6 3 6 , 9 4 0 2 3 6 3 5 , 4 8 0 1 8 8 2 8 , 2 4 0 2 3 3 , 5 1 2 3 5 5 , 2 6 3 0 4 0 3 5 5 , 3 0 3 5 7 6 4 7 1 , 0 9 4 2 4 8 3 7 , 2 4 0 3 Pr i m a r y E f f l u e n t 1 6 . 7 1 1 1 , 6 0 0 7 1 9 , 9 4 1 1 3 7 1 9 , 1 2 0 8 9 1 2 , 4 2 0 7 1 9 , 8 8 4 2 3 3 , 2 5 6 2 8 3 , 8 6 8 0 0 2 8 3 , 8 6 8 5 7 0 8 6 8 2 4 2 4 9 3 4 , 6 5 0 3a PE t o E Q 0 . 0 0 00 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 00 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 00 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 1 6 . 7 1 1 1 , 6 0 0 7 1 9 , 9 4 1 1 3 7 1 9 , 1 2 0 8 9 1 2 , 4 2 0 7 1 9 , 8 8 4 2 3 3 , 2 5 6 2 8 3 , 8 6 8 0 0 2 8 3 , 8 6 8 5 7 0 8 6 8 2 4 2 4 9 3 4 , 6 5 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 1 8 . 2 6 1 2 , 6 8 0 7 0 1 0 , 5 9 0 1 5 4 2 3 , 4 1 0 1 2 2 1 8 , 6 2 0 9 7 1 4 , 7 2 0 2 3 3 , 5 0 5 2 9 4 , 4 6 9 0 1 6 2 9 4 , 4 8 5 5 7 7 4 6 9 6 3 3 6 8 5 6 , 0 1 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 00 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 2 9 . 8 8 2 0 , 7 5 0 4 5 1 1 , 2 7 0 1 , 5 7 0 3 9 1 , 3 0 0 6 , 7 0 5 1 , 6 7 1 , 0 0 0 4 , 9 7 2 1 , 2 3 9 , 0 0 0 1 4 3 , 5 2 9 5 0 9 1 2 6 , 9 0 0 3 6 9 4 5 1 2 1 2 7 , 6 0 0 5 1 , 2 4 4 1 2 9 3 2 , 0 7 0 3 2 6 8 1 , 2 4 0 9a Ae r a t i o n E f f l u e n t 29 . 8 8 2 0 , 7 5 0 7 1 , 7 6 4 1 , 4 9 2 3 7 1 , 7 0 0 6 , 6 7 9 1 , 6 6 4 , 0 0 0 4 , 9 4 8 1 , 2 3 3 , 0 0 0 0 6 2 4 9 5 1 2 3 , 4 0 0 7 1 , 7 4 4 5 0 2 1 2 5 , 1 0 0 5 1 , 2 1 0 1 2 9 3 2 , 0 7 0 2 6 0 6 4 , 8 7 0 10 Fi n a l C l a r i f i e r s E f f l 17 . 9 7 1 2 , 4 8 0 7 1 , 0 6 1 1 1 1 , 6 1 1 1 7 2 , 4 7 3 1 2 1 , 8 3 2 0 3 7 1 2 2 1 7 1 , 0 4 9 8 1 , 2 7 0 5 7 2 8 5 7 7 4 2 6 0 3 9 , 0 2 0 11 Ae r a t i o n R A S F l o w 11 . 6 2 8 , 0 6 8 7 6 8 6 3 , 7 9 7 3 6 7 , 9 0 0 1 7 , 0 5 0 1 , 6 5 2 , 0 0 0 1 2 , 6 3 0 1 , 2 2 4 , 0 0 0 0 2 4 1 , 2 6 4 1 2 2 , 4 0 0 7 6 7 8 1 , 2 7 1 1 2 3 , 1 0 0 5 4 7 0 3 2 1 3 1 , 1 1 0 2 6 0 2 5 , 2 3 0 12 Fi l t r a t i o n F e e d 17 . 9 7 1 2 , 4 8 0 7 1 , 0 6 1 1 1 1 , 6 1 1 1 7 2 , 4 7 3 1 2 1 , 8 3 2 0 3 7 1 2 2 1 7 1 , 0 4 9 8 1 , 2 7 0 5 7 2 8 5 7 7 4 2 6 0 3 9 , 0 2 0 13 Fi l t r a t i o n E f f l 17 . 2 9 1 2 , 0 1 0 7 1 , 0 2 1 8 1 , 1 1 1 3 4 0 4 2 2 9 9 0 3 6 0 6 6 7 1 , 0 0 9 7 1 , 0 7 5 5 7 0 0 5 7 0 8 2 6 0 3 7 , 5 4 0 13 a Fi l t r a t i o n B a c k w a s h 0. 6 8 4 7 3 7 4 0 8 8 5 0 0 3 6 5 2 , 0 6 9 2 7 0 1 , 5 3 3 0 1 2 7 1 5 5 7 4 0 3 4 1 9 5 5 2 8 1 2 6 6 2 6 0 1 , 4 7 7 14 UV F e e d 17 . 2 9 1 2 , 0 1 0 7 1 , 0 2 1 8 1 , 1 1 1 3 4 0 4 2 2 9 9 0 3 6 0 6 6 7 1 , 0 0 9 7 1 , 0 7 5 5 7 0 0 5 7 0 8 2 6 0 3 7 , 5 4 0 14 a Pl a n t D i s c h a r g e 17 . 2 9 1 2 , 0 1 0 7 1 , 0 2 1 8 1 , 1 1 1 3 4 0 4 2 2 9 9 0 3 6 0 6 6 7 1 , 0 0 9 7 1 , 0 7 5 5 7 0 0 5 7 0 8 2 7 1 3 9 , 1 2 0 20 Pr i m a r y S l u d g e 1. 3 2 9 1 4 7 1 7 8 4 1 , 6 2 3 1 7 , 8 3 0 2 , 1 0 0 2 3 , 0 6 0 1 , 6 7 2 1 8 , 3 6 0 2 3 2 5 7 1 2 7 1 , 3 9 5 0 0 1 2 7 1 , 3 9 5 5 5 6 2 5 2 7 0 2 4 9 2 , 7 3 1 22 WA S 0. 2 9 1 9 8 7 1 7 9 0 3 2 , 1 5 2 4 , 0 3 2 9 , 6 0 5 2 , 9 8 7 7 , 1 1 6 0 1 2 9 9 7 1 2 7 1 7 3 0 6 7 2 9 5 1 2 8 0 1 9 0 2 6 0 6 2 0 30 DA F T F e e d 1. 6 0 1 , 1 1 3 6 0 8 0 0 1 , 4 9 5 1 9 , 9 8 0 2 , 4 4 4 3 2 , 6 6 0 1 , 9 0 6 2 5 , 4 7 0 1 9 2 5 7 1 5 8 2 , 1 0 7 1 1 7 1 5 9 2 , 1 2 4 5 6 7 3 4 4 6 0 2 5 1 3 , 3 5 1 31 DA F T T h i c k e n e d S l u d g e 0. 0 5 3 4 5 0 2 0 3 8 , 2 1 0 1 5 , 5 5 0 6 5 , 0 0 0 2 6 , 4 6 0 5 0 , 6 9 0 2 0 , 6 3 0 1 9 8 3 , 7 0 0 1 , 5 0 6 1 0 3 , 7 0 1 1 , 5 0 7 5 2 7 8 6 3 2 0 2 5 1 1 0 2 32 DA F T T h i c k e n e r R e t u r n 1. 5 5 1 , 0 7 9 5 0 6 4 8 3 3 1 4 , 2 9 2 4 7 9 6 , 2 0 6 3 7 4 4 , 8 4 0 1 9 2 4 9 4 6 6 0 1 1 1 6 4 8 6 1 7 5 6 5 1 1 1 4 0 2 5 1 3 , 2 4 9 33 An a e r o b i c D i g e s t i o n F e e d 0. 0 5 3 4 5 0 2 0 3 8 , 2 1 0 1 5 , 5 5 0 6 5 , 0 2 0 2 6 , 4 7 0 5 0 , 6 9 0 2 0 , 6 3 0 1 9 8 3 , 7 0 0 1 , 5 0 6 1 0 3 , 7 0 1 1 , 5 0 7 1 0 7 8 6 3 2 0 2 3 3 9 5 34 An a e r o b i c D i g e s t e d S o l i d s 0. 0 5 3 4 5 0 0 2 0 4 1 0 , 1 2 0 4 , 1 2 1 3 2 , 0 8 0 1 3 , 0 6 0 1 7 , 7 4 0 7 , 2 2 1 2 , 4 1 2 9 8 2 3 , 7 0 0 1 , 5 0 6 0 0 3 , 7 0 0 1 , 5 0 6 4 5 7 1 8 6 7 8 6 3 2 0 8 , 7 7 4 3 , 5 7 2 41 De w a t e r i n g F e e d 0. 0 5 3 4 5 0 0 2 0 4 1 0 , 1 2 0 4 , 1 2 1 3 2 , 0 8 0 1 3 , 0 6 0 1 7 , 7 4 0 7 , 2 2 1 2 , 4 1 2 9 8 2 3 , 7 0 0 1 , 5 0 6 0 0 3 , 7 0 0 1 , 5 0 6 4 5 7 1 8 6 7 8 6 3 2 0 8 , 7 7 4 3 , 5 7 2 42 CA K E 0. 0 1 5 2 0 1 6 6 , 0 2 0 3 , 8 4 0 2 2 0 , 0 0 0 1 2 , 8 0 0 1 2 1 , 7 0 0 7 , 0 7 7 2 , 4 1 2 1 4 0 1 1 , 2 5 0 6 5 4 0 0 1 1 , 2 5 0 6 5 4 4 5 7 2 7 2 , 7 1 4 1 5 8 8 , 7 7 4 5 1 0 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0. 0 4 2 9 2 0 7 2 4 5 8 5 7 4 9 2 6 1 4 1 4 1 4 4 2 , 4 1 2 8 4 1 2 , 4 4 2 8 5 2 0 0 2 , 4 4 2 8 5 2 4 5 7 1 5 9 4 6 4 1 6 2 8 , 7 7 4 3 , 0 6 1 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0. 0 4 2 9 2 0 7 2 4 5 8 5 2 2 5 7 8 1 2 4 4 3 9 6 5 3 3 7 9 9 5 3 4 7 0 0 9 9 5 3 4 7 4 5 7 1 5 9 4 6 4 1 6 2 2 , 0 1 8 7 0 4 50 A- S t a g e B y p a s s t o B - S t a g e 0. 0 0 00 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 0. 0 0 00 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 54 A- S t a g e F e e d ( w / R A S ) 0. 0 0 00 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 56 A- S t a g e E f f l u e n t 0. 0 0 00 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 58 A- S t a g e R A S 0. 0 0 00 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 59 A- S t a g e W A S 0. 0 0 00 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 60 A- S t a g e E f f l t o B - S t a g e 0. 0 0 00 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 62 A- S t a g e E f f l t o F l o w E Q 0. 0 0 00 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . St r e a m S u m m a r y f o r V e r t i C e l P H EN V _ O D _ P H St r e a m S u m m a r y f o r O D P H Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 3 3 . 5 0 2 3 , 2 6 0 1a He a d w o r k s t o E Q 1 1 . 5 0 7 , 9 8 6 2 Ra w I n f l u e n t P l u s R e c y c l e s 2 2 . 7 1 1 5 , 7 7 0 3 Pr i m a r y E f f l u e n t 2 1 . 8 1 1 5 , 1 5 0 3a PE t o E Q 1 6 . 3 1 1 1 , 3 3 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 1 7 . 0 0 1 1 , 8 1 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 1 8 . 1 3 1 2 , 5 9 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 2 8 . 0 5 1 9 , 4 8 0 9a Ae r a t i o n E f f l u e n t 2 8 . 0 5 1 9 , 4 8 0 10 Fi n a l C l a r i f i e r s E f f l 1 7 . 8 6 1 2 , 4 0 0 11 Ae r a t i o n R A S F l o w 9 . 9 2 6 , 8 8 8 12 Fi l t r a t i o n F e e d 1 7 . 8 6 1 2 , 4 0 0 13 Fi l t r a t i o n E f f l 1 7 . 1 8 1 1 , 9 3 0 13 a Fi l t r a t i o n B a c k w a s h 0 . 6 8 4 7 3 14 UV F e e d 1 7 . 1 8 1 1 , 9 3 0 14 a Pl a n t D i s c h a r g e 1 7 . 1 8 1 1 , 9 3 0 20 Pr i m a r y S l u d g e 0 . 9 0 6 2 2 22 WA S 0 . 2 7 1 8 9 30 DA F T F e e d 1 . 1 7 8 1 1 31 DA F T T h i c k e n e d S l u d g e 0 . 0 3 2 3 32 DA F T T h i c k e n e r R e t u r n 1 . 1 4 7 8 8 33 An a e r o b i c D i g e s t i o n F e e d 0 . 0 3 2 3 34 An a e r o b i c D i g e s t e d S o l i d s 0 . 0 3 2 3 41 De w a t e r i n g F e e d 0 . 0 3 2 3 42 CA K E 0 . 0 0 3 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0 . 0 3 2 0 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0 . 0 3 2 0 50 A- S t a g e B y p a s s t o B - S t a g e 0 . 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 0 . 0 0 0 54 A- S t a g e F e e d ( w / R A S ) 0 . 0 0 0 56 A- S t a g e E f f l u e n t 0 . 0 0 0 58 A- S t a g e R A S 0 . 0 0 0 59 A- S t a g e W A S 0 . 0 0 0 60 A- S t a g e E f f l t o B - S t a g e 0 . 0 0 0 62 A- S t a g e E f f l t o F l o w E Q 0 . 0 0 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . St r e a m S u m m a r y f o r B i o M a g A A EN V _ B i o M a g _ A A St r e a m S u m m a r y f o r B i o M a g A A Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 6 . 1 0 4 , 2 3 6 7 5 3 , 8 1 6 2 7 8 1 4 , 1 4 0 2 7 2 1 3 , 8 4 0 2 1 8 1 1 , 0 7 0 3 2 1 , 6 2 8 4 8 2 , 4 4 2 0 0 4 8 2 , 4 4 2 4 2 0 4 6 3 0 5 2 4 3 1 2 , 3 6 0 1a He a d w o r k s t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 2 Ra w I n f l u e n t P l u s R e c y c l e s 6 . 8 0 4 , 7 2 2 6 8 3 , 8 3 3 2 5 4 1 4 , 3 7 0 2 5 9 1 4 , 6 6 0 2 0 6 1 1 , 6 8 0 3 2 1 , 7 9 7 4 7 2 , 6 7 5 1 5 5 4 8 2 , 7 3 0 5 2 9 1 7 4 0 8 2 4 6 1 3 , 9 4 0 3 Pr i m a r y E f f l u e n t 6 . 1 3 4 , 2 5 7 6 8 3 , 4 5 6 1 0 9 5 , 5 6 3 5 7 2 , 9 3 3 4 6 2 , 3 3 6 3 2 1 , 6 2 0 3 5 1 , 7 9 6 0 0 3 5 1 , 7 9 6 5 2 6 2 6 2 8 6 2 4 9 1 2 , 7 4 0 3a PE t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 6 . 1 3 4 , 2 5 7 6 8 3 , 4 5 6 1 0 9 5 , 5 6 3 5 7 2 , 9 3 3 4 6 2 , 3 3 6 3 2 1 , 6 2 0 3 5 1 , 7 9 6 0 0 3 5 1 , 7 9 6 5 2 6 2 6 2 8 6 2 4 9 1 2 , 7 4 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 6 . 9 2 4 , 8 0 4 6 6 3 , 7 8 5 1 3 2 7 , 6 1 7 9 9 5 , 7 1 2 7 8 4 , 5 2 2 3 1 1 , 7 9 3 3 7 2 , 1 4 3 0 1 1 3 7 2 , 1 5 4 5 2 9 6 6 3 4 7 3 6 4 2 0 , 9 9 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 1 1 . 5 6 8 , 0 3 1 4 0 3 , 8 8 3 6 1 0 5 8 , 8 7 0 2 , 4 2 8 2 3 4 , 2 0 0 1 , 8 1 5 1 7 5 , 0 0 0 1 9 1 , 8 0 2 1 9 9 1 9 , 2 0 0 4 3 8 4 2 0 3 1 9 , 5 9 0 5 4 8 0 5 0 4 , 7 9 9 3 0 4 2 9 , 3 6 0 9a Ae r a t i o n E f f l u e n t 1 1 . 5 6 8 , 0 3 1 3 2 4 6 5 4 2 5 2 , 2 5 0 2 , 4 0 8 2 3 2 , 3 0 0 1 , 7 9 7 1 7 3 , 4 0 0 0 2 4 1 8 0 1 7 , 3 6 0 1 0 9 3 0 1 9 0 1 8 , 2 9 0 5 4 6 1 5 0 4 , 7 9 9 2 1 6 2 0 , 8 3 0 10 Fi n a l C l a r i f i e r s E f f l 6 . 7 8 4 , 7 0 6 3 1 4 4 6 3 5 3 1 7 9 3 3 1 2 6 9 6 0 1 4 1 8 4 1 0 5 4 5 1 1 6 2 9 5 2 7 0 5 2 8 7 2 1 6 1 2 , 2 1 0 11 Ae r a t i o n R A S F l o w 4 . 6 5 3 , 2 2 6 3 9 9 1 , 3 2 3 5 1 , 2 5 0 5 , 8 9 6 2 2 8 , 4 0 0 4 , 4 0 0 1 7 0 , 5 0 0 0 1 0 4 4 0 1 7 , 0 6 0 1 0 3 7 3 4 5 0 1 7 , 4 3 0 5 1 8 5 1 1 5 4 , 4 5 2 2 1 6 8 , 3 7 0 12 Fi l t r a t i o n F e e d 6 . 7 8 4 , 7 0 6 3 1 4 4 6 3 5 3 1 7 9 3 3 1 2 6 9 6 0 1 4 1 8 4 1 0 5 4 5 1 1 6 2 9 5 2 7 0 5 2 8 7 2 1 6 1 2 , 2 1 0 13 Fi l t r a t i o n E f f l 6 . 1 0 4 , 2 3 4 3 1 3 0 3 1 6 1 3 1 4 2 2 1 0 6 0 1 3 0 2 3 1 0 4 9 0 1 0 5 1 3 5 2 4 3 5 2 4 6 2 1 6 1 0 , 9 8 0 13 a Fi l t r a t i o n B a c k w a s h 0 . 6 8 4 7 3 3 1 4 3 4 1 9 1 1 3 9 7 9 0 1 0 4 5 9 0 0 1 1 1 6 0 1 0 5 5 2 0 1 1 5 5 2 7 7 4 2 2 1 6 1 , 2 2 6 14 UV F e e d 6 . 1 0 4 , 2 3 4 3 1 3 0 3 1 6 1 3 1 4 2 2 1 0 6 0 1 3 0 2 3 1 0 4 9 0 1 0 5 1 3 5 2 4 3 5 2 4 6 2 1 6 1 0 , 9 8 0 14 a Pl a n t D i s c h a r g e 6 . 1 0 4 , 2 3 4 3 1 3 0 3 1 6 1 3 1 4 2 2 1 0 6 0 1 3 0 2 3 1 0 4 9 0 1 0 5 1 3 5 2 4 3 5 2 4 6 2 2 7 1 1 , 5 4 0 20 Pr i m a r y S l u d g e 0 . 6 7 4 6 5 6 8 3 7 8 1 , 5 7 7 8 , 8 0 9 2 , 1 0 0 1 1 , 7 3 0 1 , 6 7 3 9 , 3 4 4 3 2 1 7 7 1 5 8 8 8 0 0 0 1 5 8 8 8 0 5 2 9 2 2 1 2 3 2 4 9 1 , 3 9 2 22 WA S 0 . 1 4 9 8 3 3 5 5 4 6 5 1 2 , 4 6 3 2 , 8 9 6 1 , 8 3 8 2 , 1 6 1 0 0 1 8 4 2 1 6 1 0 1 1 1 9 4 2 2 8 5 6 5 1 6 0 2 1 6 2 5 4 30 DA F T F e e d 0 . 8 1 5 6 3 5 6 3 8 1 1 , 3 9 9 9 , 4 6 0 2 , 1 6 3 1 4 , 6 3 0 1 , 7 0 2 1 1 , 5 1 0 2 6 1 7 7 1 6 2 1 , 0 9 6 2 1 1 1 6 4 1 , 1 0 7 5 3 4 2 7 1 8 2 2 4 4 1 , 6 4 6 31 DA F T T h i c k e n e d S l u d g e 0 . 0 2 1 5 5 0 9 4 0 , 4 0 0 7 , 3 6 4 6 5 , 0 0 0 1 1 , 8 5 0 5 1 , 1 3 0 9 , 3 1 9 2 6 5 4 , 1 0 9 7 4 9 2 0 4 , 1 1 1 7 4 9 5 1 6 6 3 1 2 1 2 4 4 4 4 32 DA F T T h i c k e n e r R e t u r n 0 . 7 9 5 4 8 5 0 3 2 9 3 1 2 2 , 0 5 4 4 2 2 2 , 7 7 9 3 3 2 2 , 1 8 6 2 6 1 7 3 5 3 3 4 7 2 1 1 5 4 3 5 8 5 3 3 9 6 1 2 4 4 1 , 6 0 2 33 An a e r o b i c D i g e s t i o n F e e d 0 . 0 2 1 5 5 0 9 4 0 , 4 0 0 7 , 3 6 4 6 5 , 0 2 0 1 1 , 8 5 0 5 1 , 1 3 0 9 , 3 1 9 2 6 5 4 , 1 0 9 7 4 9 2 0 4 , 1 1 1 7 4 9 1 0 6 6 3 1 2 1 2 2 6 4 1 34 An a e r o b i c D i g e s t e d S o l i d s 0 . 0 2 1 5 5 0 0 9 1 1 0 , 0 4 0 1 , 8 2 9 3 1 , 7 9 0 5 , 7 9 4 1 7 , 9 0 0 3 , 2 6 2 2 , 6 8 0 4 8 9 4 , 1 0 9 7 4 9 0 0 4 , 1 0 9 7 4 9 3 8 5 7 0 6 6 3 1 2 1 9 , 7 0 0 1 , 7 6 8 41 De w a t e r i n g F e e d 0 . 0 2 1 5 5 0 0 9 1 1 0 , 0 4 0 1 , 8 2 9 3 1 , 7 9 0 5 , 7 9 4 1 7 , 9 0 0 3 , 2 6 2 2 , 6 8 0 4 8 9 4 , 1 0 9 7 4 9 0 0 4 , 1 0 9 7 4 9 3 8 5 7 0 6 6 3 1 2 1 9 , 7 0 0 1 , 7 6 8 42 CA K E 0 . 0 0 2 2 0 1 6 6 , 0 2 0 1 , 7 0 4 2 2 0 , 0 0 0 5 , 6 7 8 1 2 3 , 8 0 0 3 , 1 9 6 2 , 6 8 0 6 9 1 2 , 5 7 0 3 2 4 0 0 1 2 , 5 7 0 3 2 4 3 8 5 1 0 2 , 3 1 1 6 0 9 , 7 0 0 2 5 0 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0 . 0 2 1 3 2 0 3 2 4 2 3 8 7 4 1 1 1 6 4 1 7 6 5 2 , 6 8 0 4 1 9 2 , 7 1 3 4 2 5 0 0 2 , 7 1 3 4 2 5 3 8 5 6 0 3 9 1 6 1 9 , 7 0 0 1 , 5 1 8 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0 . 0 2 1 3 2 0 3 2 4 2 3 8 2 2 2 3 5 1 2 5 2 0 1 , 0 7 2 1 6 8 1 , 1 0 5 1 7 3 0 0 1 , 1 0 5 1 7 3 3 8 5 6 0 3 9 1 6 1 2 , 2 3 1 3 4 9 50 A- S t a g e B y p a s s t o B - S t a g e 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 54 A- S t a g e F e e d ( w / R A S ) 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 56 A- S t a g e E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 58 A- S t a g e R A S 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 59 A- S t a g e W A S 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 60 A- S t a g e E f f l t o B - S t a g e 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 62 A- S t a g e E f f l t o F l o w E Q 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . St r e a m S u m m a r y f o r B i o M a g M M EN V _ B i o M a g _ M M St r e a m S u m m a r y f o r B i o M a g M M Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 8 . 4 0 5 , 8 3 3 7 5 5 , 2 5 4 2 8 5 1 9 , 9 7 0 2 6 1 1 8 , 2 8 0 2 0 9 1 4 , 6 3 0 3 1 2 , 1 7 2 4 7 3 , 2 9 3 0 0 4 7 3 , 2 9 3 4 2 8 0 6 4 2 0 2 4 2 1 6 , 9 5 0 1a He a d w o r k s t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 2 Ra w I n f l u e n t P l u s R e c y c l e s 9 . 1 1 6 , 3 2 3 7 0 5 , 2 8 7 2 6 7 2 0 , 2 8 0 2 5 5 1 9 , 3 8 0 2 0 4 1 5 , 4 5 0 3 2 2 , 4 0 9 4 8 3 , 6 1 7 1 5 4 4 8 3 , 6 7 1 5 3 9 3 7 5 5 4 2 4 6 1 8 , 6 7 0 3 Pr i m a r y E f f l u e n t 8 . 2 2 5 , 7 0 9 7 0 4 , 7 7 3 1 1 3 7 , 7 7 2 5 7 3 , 8 7 7 4 5 3 , 0 9 1 3 2 2 , 1 7 5 3 5 2 , 4 1 6 0 0 3 5 2 , 4 1 6 5 3 5 5 6 3 8 7 2 4 8 1 7 , 0 3 0 3a PE t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 8 . 2 2 5 , 7 0 9 7 0 4 , 7 7 3 1 1 3 7 , 7 7 2 5 7 3 , 8 7 7 4 5 3 , 0 9 1 3 2 2 , 1 7 5 3 5 2 , 4 1 6 0 0 3 5 2 , 4 1 6 5 3 5 5 6 3 8 7 2 4 8 1 7 , 0 3 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 9 . 2 6 6 , 4 2 9 6 7 5 , 2 0 5 1 3 8 1 0 , 6 7 0 9 9 7 , 6 3 6 7 8 6 , 0 5 6 3 1 2 , 4 0 3 3 7 2 , 8 9 0 0 1 4 3 8 2 , 9 0 4 5 3 9 9 6 4 7 1 3 6 3 2 8 , 0 5 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 1 7 . 8 0 1 2 , 3 6 0 3 7 5 , 5 5 9 8 5 7 1 2 7 , 2 0 0 3 , 4 9 2 5 1 8 , 3 0 0 2 , 6 5 0 3 9 3 , 3 0 0 1 6 2 , 4 2 1 2 8 1 4 1 , 6 3 0 5 6 9 6 2 8 5 4 2 , 3 3 0 5 7 3 6 7 1 1 0 , 5 0 0 2 9 3 4 3 , 4 6 0 9a Ae r a t i o n E f f l u e n t 17 . 8 0 1 2 , 3 6 0 5 7 3 7 7 9 6 1 1 8 , 2 0 0 3 , 4 7 8 5 1 6 , 2 0 0 2 , 6 3 7 3 9 1 , 5 0 0 0 3 7 2 6 4 3 9 , 1 8 0 1 0 1 , 4 2 2 2 7 4 4 0 , 6 0 0 5 7 0 4 7 1 1 0 , 5 0 0 2 1 6 3 2 , 1 1 0 10 Fi n a l C l a r i f i e r s E f f l 9. 0 8 6 , 3 0 3 5 3 7 6 9 6 6 0 1 7 1 , 2 4 9 1 3 9 4 7 0 1 9 2 1 1 4 1 0 7 2 5 1 1 8 3 9 5 3 5 9 5 3 8 3 2 1 6 1 6 , 3 8 0 11 Ae r a t i o n R A S F l o w 8. 5 4 5 , 9 2 9 5 3 5 4 1 , 6 3 6 1 1 6 , 5 0 0 7 , 1 7 1 5 1 0 , 6 0 0 5 , 4 3 8 3 8 7 , 3 0 0 0 1 8 5 4 4 3 8 , 7 4 0 1 0 6 8 2 5 5 4 3 9 , 4 3 0 5 3 3 7 1 4 1 1 0 , 0 3 0 2 1 6 1 5 , 4 1 0 12 Fi l t r a t i o n F e e d 9. 0 8 6 , 3 0 3 5 3 7 6 9 6 6 0 1 7 1 , 2 4 9 1 3 9 4 7 0 1 9 2 1 1 4 1 0 7 2 5 1 1 8 3 9 5 3 5 9 5 3 8 3 2 1 6 1 6 , 3 8 0 13 Fi l t r a t i o n E f f l 8. 4 0 5 , 8 3 0 5 3 4 8 6 3 9 2 3 1 9 6 2 1 4 9 0 1 8 0 3 2 1 0 6 7 1 1 0 7 0 3 5 3 3 2 5 3 3 6 2 1 6 1 5 , 1 5 0 13 a Fi l t r a t i o n B a c k w a s h 0. 6 8 4 7 3 5 2 8 4 7 2 6 8 1 8 6 1 , 0 5 3 1 4 1 7 9 9 0 1 1 4 8 1 1 0 5 4 2 4 1 3 6 5 2 7 8 4 7 2 1 6 1 , 2 2 8 14 UV F e e d 8. 4 0 5 , 8 3 0 5 3 4 8 6 3 9 2 3 1 9 6 2 1 4 9 0 1 8 0 3 2 1 0 6 7 1 1 0 7 0 3 5 3 3 2 5 3 3 6 2 1 6 1 5 , 1 5 0 14 a Pl a n t D i s c h a r g e 8. 4 0 5 , 8 3 0 5 3 4 8 6 3 9 2 3 1 9 6 2 1 4 9 0 1 8 0 3 2 1 0 6 7 1 1 0 7 0 3 5 3 3 2 5 3 3 6 2 2 7 1 5 , 9 1 0 20 Pr i m a r y S l u d g e 0. 8 9 6 1 5 7 0 5 1 4 1 , 6 9 4 1 2 , 5 1 0 2 , 1 0 0 1 5 , 5 1 0 1 , 6 7 4 1 2 , 3 6 0 3 2 2 3 4 1 6 3 1 , 2 0 1 0 0 1 6 3 1 , 2 0 1 5 3 8 2 3 1 6 7 2 4 8 1 , 8 3 4 22 WA S 0. 1 8 1 2 6 5 8 6 4 8 9 8 1 2 , 8 2 6 4 , 2 8 0 2 , 1 4 4 3 , 2 4 6 0 0 2 1 5 3 2 5 1 0 1 5 2 2 4 3 3 9 5 7 5 8 8 8 2 1 6 3 2 8 30 DA F T F e e d 1. 0 7 7 4 1 5 9 5 2 2 1 , 5 1 6 1 3 , 4 9 0 2 , 2 2 4 1 9 , 7 9 0 1 , 7 5 4 1 5 , 6 1 0 2 6 2 3 5 1 7 1 1 , 5 2 6 2 1 5 1 7 3 1 , 5 4 0 5 4 5 2 9 2 5 6 2 4 3 2 , 1 6 2 31 DA F T T h i c k e n e d S l u d g e 0. 0 3 2 1 5 0 1 2 4 2 , 6 6 0 1 0 , 5 2 0 6 5 , 0 0 0 1 6 , 0 3 0 5 1 , 2 7 0 1 2 , 6 4 0 2 6 7 4 , 2 6 7 1 , 0 5 2 2 0 4 , 2 6 9 1 , 0 5 3 5 1 6 9 6 1 7 2 2 4 3 6 0 32 DA F T T h i c k e n e r R e t u r n 1. 0 4 7 2 0 5 0 4 3 3 3 3 5 2 , 8 9 7 4 3 5 3 , 7 6 0 3 4 3 2 , 9 6 5 2 6 2 2 8 5 5 4 7 3 2 1 4 5 6 4 8 8 5 4 4 1 0 8 4 2 4 3 2 , 1 0 2 33 An a e r o b i c D i g e s t i o n F e e d 0. 0 3 2 1 5 0 1 2 4 2 , 6 6 0 1 0 , 5 2 0 6 5 , 0 2 0 1 6 , 0 3 0 5 1 , 2 7 0 1 2 , 6 4 0 2 6 7 4 , 2 6 7 1 , 0 5 2 2 0 4 , 2 6 9 1 , 0 5 3 1 0 6 9 6 1 7 2 2 2 5 5 6 34 An a e r o b i c D i g e s t e d S o l i d s 0. 0 3 2 1 5 0 0 1 2 3 1 0 , 0 1 0 2 , 4 6 8 3 1 , 7 0 0 7 , 8 1 6 1 7 , 9 4 0 4 , 4 2 5 2 , 7 8 3 6 8 6 4 , 2 6 7 1 , 0 5 2 0 0 4 , 2 6 7 1 , 0 5 2 4 0 4 1 0 0 6 9 6 1 7 2 1 0 , 0 7 0 2 , 4 8 2 41 De w a t e r i n g F e e d 0. 0 3 2 1 5 0 0 1 2 3 1 0 , 0 1 0 2 , 4 6 8 3 1 , 7 0 0 7 , 8 1 6 1 7 , 9 4 0 4 , 4 2 5 2 , 7 8 3 6 8 6 4 , 2 6 7 1 , 0 5 2 0 0 4 , 2 6 7 1 , 0 5 2 4 0 4 1 0 0 6 9 6 1 7 2 1 0 , 0 7 0 2 , 4 8 2 42 CA K E 0. 0 0 3 2 0 1 6 6 , 0 2 0 2 , 2 9 8 2 2 0 , 0 0 0 7 , 6 5 9 1 2 4 , 6 0 0 4 , 3 3 6 2 , 7 8 3 9 7 1 3 , 0 9 0 4 5 6 0 0 1 3 , 0 9 0 4 5 6 4 0 4 1 4 2 , 4 3 2 8 5 1 0 , 0 7 0 3 5 1 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0. 0 3 1 8 2 0 4 2 4 1 5 1 7 3 8 1 5 6 4 1 8 8 9 2 , 7 8 3 5 8 9 2 , 8 1 8 5 9 7 0 0 2 , 8 1 8 5 9 7 4 0 4 8 6 4 1 1 8 7 1 0 , 0 7 0 2 , 1 3 2 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0. 0 3 1 8 2 0 4 2 4 1 5 1 2 2 1 4 7 1 2 5 2 7 1 , 1 1 3 2 3 6 1 , 1 4 8 2 4 3 0 0 1 , 1 4 8 2 4 3 4 0 4 8 6 4 1 1 8 7 2 , 3 1 5 4 9 0 50 A- S t a g e B y p a s s t o B - S t a g e 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 54 A- S t a g e F e e d ( w / R A S ) 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 56 A- S t a g e E f f l u e n t 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 58 A- S t a g e R A S 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 59 A- S t a g e W A S 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 60 A- S t a g e E f f l t o B - S t a g e 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 62 A- S t a g e E f f l t o F l o w E Q 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . St r e a m S u m m a r y f o r B i o M a g M D EN V _ B i o M a g _ M D St r e a m S u m m a r y f o r B i o M a g M D Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 1 7 . 3 0 1 2 , 0 1 0 7 4 1 0 , 6 8 0 2 5 2 3 6 , 3 6 0 2 3 1 3 3 , 3 3 0 1 8 5 2 6 , 6 6 0 2 2 3 , 1 7 4 3 3 4 , 7 6 1 0 0 3 3 4 , 7 6 1 4 5 7 7 6 8 6 6 2 4 3 3 5 , 0 6 0 1a He a d w o r k s t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 2 Ra w I n f l u e n t P l u s R e c y c l e s 1 8 . 0 2 1 2 , 5 2 0 7 2 1 0 , 7 5 0 2 4 6 3 6 , 9 8 0 2 3 6 3 5 , 4 8 0 1 8 8 2 8 , 2 6 0 2 3 3 , 5 2 5 3 5 5 , 2 7 8 0 3 9 3 5 5 , 3 1 8 5 7 7 1 7 1 , 1 0 1 2 4 8 3 7 , 2 8 0 3 Pr i m a r y E f f l u e n t 1 6 . 7 1 1 1 , 6 0 0 7 2 9 , 9 6 7 1 3 7 1 9 , 1 5 0 8 9 1 2 , 4 2 0 7 1 9 , 8 9 1 2 3 3 , 2 6 8 2 8 3 , 8 8 1 0 0 2 8 3 , 8 8 1 5 7 1 5 6 8 3 0 2 4 9 3 4 , 6 8 0 3a PE t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 1 6 . 7 1 1 1 , 6 0 0 7 2 9 , 9 6 7 1 3 7 1 9 , 1 5 0 8 9 1 2 , 4 2 0 7 1 9 , 8 9 1 2 3 3 , 2 6 8 2 8 3 , 8 8 1 0 0 2 8 3 , 8 8 1 5 7 1 5 6 8 3 0 2 4 9 3 4 , 6 8 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 1 8 . 2 5 1 2 , 6 7 0 7 0 1 0 , 6 1 0 1 5 4 2 3 , 4 7 0 1 2 3 1 8 , 7 8 0 9 8 1 4 , 8 6 0 2 3 3 , 5 1 8 3 0 4 , 4 9 6 0 1 6 3 0 4 , 5 1 2 5 7 8 0 6 9 7 4 3 6 8 5 6 , 0 3 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 2 9 . 8 7 2 0 , 7 4 0 4 7 1 1 , 7 7 0 1 , 9 1 0 4 7 5 , 9 0 0 8 , 1 2 5 2 , 0 2 4 , 0 0 0 6 , 0 9 7 1 , 5 1 9 , 0 0 0 1 4 3 , 5 4 2 6 2 2 1 5 4 , 9 0 0 3 6 8 6 6 2 5 1 5 5 , 6 0 0 5 1 , 2 4 5 1 5 7 3 9 , 0 9 0 3 2 7 8 1 , 4 2 0 9a Ae r a t i o n E f f l u e n t 29 . 8 7 2 0 , 7 4 0 1 2 2 , 9 9 2 1 , 8 3 5 4 5 7 , 1 0 0 8 , 1 0 1 2 , 0 1 8 , 0 0 0 6 , 0 7 6 1 , 5 1 4 , 0 0 0 0 6 2 6 0 8 1 5 1 , 4 0 0 7 1 , 7 2 2 6 1 5 1 5 3 , 2 0 0 5 1 , 1 9 8 1 5 7 3 9 , 0 9 0 2 6 2 6 5 , 2 5 0 10 Fi n a l C l a r i f i e r s E f f l 17 . 9 7 1 2 , 4 8 0 1 2 1 , 8 0 0 1 6 2 , 3 5 6 1 7 2 , 4 7 3 1 2 1 , 8 5 5 0 3 7 1 2 2 3 7 1 , 0 3 6 8 1 , 2 5 9 5 7 2 1 5 7 6 7 2 6 2 3 9 , 2 6 0 11 Ae r a t i o n R A S F l o w 11 . 6 2 8 , 0 7 0 1 2 1 , 1 6 4 4 , 6 6 8 4 5 2 , 4 0 0 2 0 , 6 9 0 2 , 0 0 5 , 0 0 0 1 5 , 5 2 0 1 , 5 0 4 , 0 0 0 0 2 4 1 , 5 5 2 1 5 0 , 4 0 0 7 6 7 0 1 , 5 5 9 1 5 1 , 1 0 0 5 4 6 6 3 9 3 3 8 , 1 1 0 2 6 2 2 5 , 3 8 0 12 Fi l t r a t i o n F e e d 17 . 9 7 1 2 , 4 8 0 1 2 1 , 8 0 0 1 6 2 , 3 5 6 1 7 2 , 4 7 3 1 2 1 , 8 5 5 0 3 7 1 2 2 3 7 1 , 0 3 6 8 1 , 2 5 9 5 7 2 1 5 7 6 7 2 6 2 3 9 , 2 6 0 13 Fi l t r a t i o n E f f l 17 . 2 9 1 2 , 0 1 0 1 2 1 , 7 3 2 1 3 1 , 8 2 3 3 4 0 4 2 3 0 3 0 3 6 0 6 6 7 9 9 7 7 1 , 0 6 3 5 6 9 3 5 7 0 1 2 6 2 3 7 , 7 7 0 13 a Fi l t r a t i o n B a c k w a s h 0. 6 8 4 7 3 1 2 6 8 9 4 5 3 4 3 6 5 2 , 0 6 9 2 7 4 1 , 5 5 2 0 1 2 8 1 5 7 7 3 9 3 5 1 9 6 5 2 7 1 2 6 6 2 6 2 1 , 4 8 6 14 UV F e e d 17 . 2 9 1 2 , 0 1 0 1 2 1 , 7 3 2 1 3 1 , 8 2 3 3 4 0 4 2 3 0 3 0 3 6 0 6 6 7 9 9 7 7 1 , 0 6 3 5 6 9 3 5 7 0 1 2 6 2 3 7 , 7 7 0 14 a Pl a n t D i s c h a r g e 17 . 2 9 1 2 , 0 1 0 1 2 1 , 7 3 2 1 3 1 , 8 2 3 3 4 0 4 2 3 0 3 0 3 6 0 6 6 7 9 9 7 7 1 , 0 6 3 5 6 9 3 5 7 0 1 2 7 3 3 9 , 3 4 0 20 Pr i m a r y S l u d g e 1. 3 2 9 1 4 7 2 7 8 6 1 , 6 2 4 1 7 , 8 3 0 2 , 1 0 0 2 3 , 0 6 0 1 , 6 7 3 1 8 , 3 7 0 2 3 2 5 8 1 2 7 1 , 3 9 7 0 0 1 2 7 1 , 3 9 7 5 5 6 2 5 2 7 1 2 4 9 2 , 7 3 4 22 WA S 0. 2 8 1 9 3 1 2 2 8 1 , 0 2 0 2 , 3 6 9 4 , 4 8 1 1 0 , 4 1 0 3 , 3 6 1 7 , 8 0 4 0 1 3 3 6 7 8 1 7 1 6 3 4 3 7 9 7 5 1 1 8 9 2 0 7 2 6 2 6 0 8 30 DA F T F e e d 1. 6 0 1 , 1 0 8 6 1 8 1 3 1 , 5 1 9 2 0 , 2 0 0 2 , 5 1 6 3 3 , 4 7 0 1 , 9 6 7 2 6 , 1 7 0 1 9 2 5 8 1 6 4 2 , 1 7 8 1 1 6 1 6 5 2 , 1 9 4 5 6 7 3 6 4 7 8 2 5 1 3 , 3 4 2 31 DA F T T h i c k e n e d S l u d g e 0. 0 5 3 5 5 0 2 1 3 7 , 7 1 0 1 5 , 7 3 0 6 5 , 0 0 0 2 7 , 1 1 0 5 0 , 8 4 0 2 1 , 2 0 0 1 9 8 3 , 7 4 9 1 , 5 6 3 1 0 3 , 7 5 0 1 , 5 6 4 5 2 8 0 1 3 3 4 2 5 1 1 0 5 32 DA F T T h i c k e n e r R e t u r n 1. 5 5 1 , 0 7 3 5 0 6 4 4 3 3 6 4 , 3 2 8 4 9 3 6 , 3 5 9 3 8 6 4 , 9 7 3 1 9 2 5 0 4 8 6 1 5 1 1 6 4 9 6 3 0 5 6 5 1 1 1 4 3 2 5 1 3 , 2 3 7 33 An a e r o b i c D i g e s t i o n F e e d 0. 0 5 3 5 5 0 2 1 3 7 , 7 1 0 1 5 , 7 3 0 6 5 , 0 2 0 2 7 , 1 2 0 5 0 , 8 4 0 2 1 , 2 0 0 1 9 8 3 , 7 4 9 1 , 5 6 3 1 0 3 , 7 5 0 1 , 5 6 4 1 0 8 0 1 3 3 4 2 3 3 9 7 34 An a e r o b i c D i g e s t e d S o l i d s 0. 0 5 3 5 5 0 0 2 0 9 1 0 , 0 9 0 4 , 2 1 0 3 1 , 9 8 0 1 3 , 3 4 0 1 7 , 7 9 0 7 , 4 2 0 2 , 4 4 3 1 , 0 1 9 3 , 7 4 9 1 , 5 6 3 0 0 3 , 7 4 9 1 , 5 6 3 4 6 6 1 9 4 8 0 1 3 3 4 8 , 8 8 7 3 , 7 0 6 41 De w a t e r i n g F e e d 0. 0 5 3 5 5 0 0 2 0 9 1 0 , 0 9 0 4 , 2 1 0 3 1 , 9 8 0 1 3 , 3 4 0 1 7 , 7 9 0 7 , 4 2 0 2 , 4 4 3 1 , 0 1 9 3 , 7 4 9 1 , 5 6 3 0 0 3 , 7 4 9 1 , 5 6 3 4 6 6 1 9 4 8 0 1 3 3 4 8 , 8 8 7 3 , 7 0 6 42 CA K E 0. 0 1 5 2 0 1 6 6 , 0 2 0 3 , 9 2 2 2 2 0 , 0 0 0 1 3 , 0 7 0 1 2 2 , 4 0 0 7 , 2 7 2 2 , 4 4 3 1 4 5 1 1 , 4 2 0 6 7 9 0 0 1 1 , 4 2 0 6 7 9 4 6 6 2 8 2 , 7 7 4 1 6 5 8 , 8 8 7 5 2 8 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0. 0 4 3 0 2 0 7 2 4 4 8 7 7 4 6 2 6 7 4 1 5 1 4 8 2 , 4 4 3 8 7 4 2 , 4 7 4 8 8 5 0 0 2 , 4 7 4 8 8 5 4 6 6 1 6 7 4 7 4 1 6 9 8 , 8 8 7 3 , 1 7 8 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0. 0 4 3 0 2 0 7 2 4 4 8 7 2 2 4 8 0 1 2 5 4 5 9 7 7 3 5 0 1 , 0 0 8 3 6 0 0 0 1 , 0 0 8 3 6 0 4 6 6 1 6 7 4 7 4 1 6 9 2 , 0 4 4 7 3 1 50 A- S t a g e B y p a s s t o B - S t a g e 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 54 A- S t a g e F e e d ( w / R A S ) 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 56 A- S t a g e E f f l u e n t 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 58 A- S t a g e R A S 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 59 A- S t a g e W A S 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 60 A- S t a g e E f f l t o B - S t a g e 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 62 A- S t a g e E f f l t o F l o w E Q 0. 0 0 0 0 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . St r e a m S u m m a r y f o r B i o M a g P H EN V _ B i o M a g _ P H St r e a m S u m m a r y f o r B i o M a g P H Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 3 3 . 5 0 2 3 , 2 6 0 1a He a d w o r k s t o E Q 1 1 . 5 0 7 , 9 8 6 2 Ra w I n f l u e n t P l u s R e c y c l e s 2 2 . 7 1 1 5 , 7 7 0 3 Pr i m a r y E f f l u e n t 2 1 . 8 1 1 5 , 1 5 0 3a PE t o E Q 1 6 . 3 1 1 1 , 3 3 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 1 7 . 0 0 1 1 , 8 1 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 1 8 . 1 3 1 2 , 5 9 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 2 8 . 0 5 1 9 , 4 8 0 9a Ae r a t i o n E f f l u e n t 2 8 . 0 5 1 9 , 4 8 0 10 Fi n a l C l a r i f i e r s E f f l 1 7 . 8 6 1 2 , 4 0 0 11 Ae r a t i o n R A S F l o w 9 . 9 2 6 , 8 8 9 12 Fi l t r a t i o n F e e d 1 7 . 8 6 1 2 , 4 0 0 13 Fi l t r a t i o n E f f l 1 7 . 1 8 1 1 , 9 3 0 13 a Fi l t r a t i o n B a c k w a s h 0 . 6 8 4 7 3 14 UV F e e d 1 7 . 1 8 1 1 , 9 3 0 14 a Pl a n t D i s c h a r g e 1 7 . 1 8 1 1 , 9 3 0 20 Pr i m a r y S l u d g e 0 . 9 0 6 2 2 22 WA S 0 . 2 7 1 8 5 30 DA F T F e e d 1 . 1 6 8 0 7 31 DA F T T h i c k e n e d S l u d g e 0 . 0 3 2 3 32 DA F T T h i c k e n e r R e t u r n 1 . 1 3 7 8 4 33 An a e r o b i c D i g e s t i o n F e e d 0 . 0 3 2 3 34 An a e r o b i c D i g e s t e d S o l i d s 0 . 0 3 2 3 41 De w a t e r i n g F e e d 0 . 0 3 2 3 42 CA K E 0 . 0 0 3 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0 . 0 3 2 0 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0 . 0 3 2 0 50 A- S t a g e B y p a s s t o B - S t a g e 0 . 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 0 . 0 0 0 54 A- S t a g e F e e d ( w / R A S ) 0 . 0 0 0 56 A- S t a g e E f f l u e n t 0 . 0 0 0 58 A- S t a g e R A S 0 . 0 0 0 59 A- S t a g e W A S 0 . 0 0 0 60 A- S t a g e E f f l t o B - S t a g e 0 . 0 0 0 62 A- S t a g e E f f l t o F l o w E Q 0 . 0 0 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . St r e a m S u m m a r y f o r H i g h R a t e A / B A A EN V _ H R _ A A St r e a m S u m m a r y f o r H R A A Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L lb / d mg / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 6 . 1 0 4 , 2 3 6 7 5 3 , 8 1 6 2 7 8 1 4 , 1 4 0 2 7 2 1 3 , 8 4 0 2 1 8 1 1 , 0 7 0 3 2 1 , 6 2 8 4 8 2 , 4 4 2 0 0 4 8 2 , 4 4 2 4 2 0 4 6 3 0 5 2 4 3 1 2 , 3 6 0 1a He a d w o r k s t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 2 Ra w I n f l u e n t P l u s R e c y c l e s 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 3 Pr i m a r y E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 3a PE t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 6 . 6 1 4 , 5 8 7 3 1 1 , 7 3 3 4 9 2 , 6 8 8 7 0 3 , 8 5 6 5 8 3 , 1 8 3 2 1 1 , 1 4 8 2 7 1 , 4 6 7 1 3 0 2 7 1 , 4 9 7 2 8 7 3 1 6 6 2 5 4 1 4 , 0 0 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 6 . 9 0 4 , 7 9 3 3 2 1 , 8 5 8 6 3 3 , 6 2 6 1 2 6 7 , 2 2 3 1 0 2 5 , 8 9 3 2 1 1 , 1 8 0 3 1 1 , 7 6 9 1 3 6 3 1 1 , 8 0 6 2 9 2 4 2 4 0 3 7 9 2 1 , 8 0 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 1 1 . 5 5 8 , 0 2 3 2 0 1 , 9 1 8 5 7 7 5 5 , 5 5 0 2 , 7 3 8 2 6 3 , 8 0 0 1 , 8 5 6 1 7 8 , 8 0 0 1 2 1 , 1 9 0 1 9 8 1 9 , 0 7 0 3 2 4 7 2 0 1 1 9 , 3 2 0 2 2 1 5 4 9 4 , 6 9 8 3 3 4 3 2 , 1 4 0 9a Ae r a t i o n E f f l u e n t 1 1 . 5 5 8 , 0 2 3 2 1 4 9 5 4 7 5 2 , 6 9 0 2 , 6 9 8 2 5 9 , 9 0 0 1 , 8 1 8 1 7 5 , 1 0 0 0 2 4 1 8 2 1 7 , 5 4 0 5 5 2 4 1 8 8 1 8 , 0 6 0 3 3 0 6 4 9 4 , 6 9 9 2 6 7 2 5 , 7 0 0 10 Fi n a l C l a r i f i e r s E f f l 6 . 7 8 4 , 7 0 6 2 8 7 5 2 7 6 1 7 9 3 3 1 1 6 2 8 0 1 4 1 7 7 5 3 0 7 7 3 8 4 3 1 8 0 3 1 9 6 2 6 7 1 5 , 0 7 0 11 Ae r a t i o n R A S F l o w 4 . 6 5 3 , 2 2 9 2 6 0 1 , 3 3 9 5 1 , 9 3 0 6 , 6 1 6 2 5 6 , 6 0 0 4 , 4 5 8 1 7 2 , 9 0 0 0 1 0 4 4 6 1 7 , 3 0 0 5 2 1 1 4 5 2 1 7 , 5 1 0 3 1 2 3 1 1 5 4 , 4 5 9 2 6 7 1 0 , 3 4 0 12 Fi l t r a t i o n F e e d 6 . 7 8 4 , 7 0 6 2 8 7 5 2 7 6 1 7 9 3 3 1 1 6 2 8 0 1 4 1 7 7 5 3 0 7 7 3 8 4 3 1 8 0 3 1 9 6 2 6 7 1 5 , 0 7 0 13 Fi l t r a t i o n E f f l 6 . 1 0 4 , 2 3 4 2 7 9 2 1 0 7 3 1 4 2 2 9 6 0 1 3 0 2 2 5 2 7 7 6 2 9 9 3 1 6 2 3 1 6 4 2 6 7 1 3 , 5 6 0 13 a Fi l t r a t i o n B a c k w a s h 0 . 6 8 4 7 3 2 9 3 0 1 6 9 1 3 9 7 9 0 9 4 5 3 2 0 1 1 0 5 5 5 3 1 1 5 8 6 3 1 8 6 3 1 2 6 7 1 , 5 1 3 14 UV F e e d 6 . 1 0 4 , 2 3 4 2 7 9 2 1 0 7 3 1 4 2 2 9 6 0 1 3 0 2 2 5 2 7 7 6 2 9 9 3 1 6 2 3 1 6 4 2 6 7 1 3 , 5 6 0 14 a Pl a n t D i s c h a r g e 6 . 1 0 4 , 2 3 4 2 7 9 2 1 0 7 3 1 4 2 2 9 6 0 1 3 0 2 2 5 2 7 7 6 2 9 9 3 1 6 2 3 1 6 4 2 7 8 1 4 , 1 1 0 20 Pr i m a r y S l u d g e 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 22 WA S 0 . 1 3 8 7 2 2 4 6 7 4 9 0 2 , 3 0 1 2 , 4 1 6 1 , 5 5 1 1 , 6 2 8 0 0 1 5 5 1 6 3 5 6 1 6 1 1 6 9 3 3 4 2 4 4 2 6 7 2 8 0 30 DA F T F e e d 0 . 3 2 2 2 5 2 0 5 4 1 , 6 0 2 4 , 3 3 3 6 , 5 5 3 1 7 , 7 2 0 5 , 2 7 4 1 4 , 2 6 0 1 3 3 5 5 4 0 1 , 4 6 1 2 7 5 4 3 1 , 4 6 8 2 6 1 3 4 3 6 3 2 5 9 7 0 0 31 DA F T T h i c k e n e d S l u d g e 0 . 0 3 1 8 5 0 1 1 1 5 , 7 5 0 3 , 4 7 7 6 5 , 0 0 0 1 4 , 3 5 0 5 2 , 3 2 0 1 1 , 5 5 0 1 3 3 5 , 2 4 5 1 , 1 5 8 2 1 5 , 2 4 7 1 , 1 5 9 2 0 1 , 3 1 2 2 9 0 2 5 9 5 7 32 DA F T T h i c k e n e r R e t u r n 0 . 3 0 2 0 7 5 0 1 2 4 3 7 7 9 3 7 1 , 3 5 6 3 , 3 6 7 1 , 0 9 1 2 , 7 1 0 1 3 3 2 1 2 2 3 0 3 2 6 1 2 4 3 0 9 2 5 3 0 7 3 2 5 9 6 4 3 33 An a e r o b i c D i g e s t i o n F e e d 0 . 0 3 1 8 5 0 1 1 1 5 , 7 5 0 3 , 4 7 7 6 5 , 0 2 0 1 4 , 3 6 0 5 2 , 3 2 0 1 1 , 5 5 0 1 3 3 5 , 2 4 5 1 , 1 5 8 2 1 5 , 2 4 7 1 , 1 5 9 1 0 1 , 3 1 2 2 9 0 2 4 1 5 3 34 An a e r o b i c D i g e s t e d S o l i d s 0 . 0 3 1 8 5 0 0 1 1 0 9 , 8 0 5 2 , 1 6 5 3 1 , 0 2 0 6 , 8 4 9 1 8 , 3 1 0 4 , 0 4 4 3 , 4 1 3 7 5 4 5 , 2 4 5 1 , 1 5 8 0 0 5 , 2 4 5 1 , 1 5 8 7 7 0 1 7 0 1 , 3 1 2 2 9 0 1 2 , 3 8 0 2 , 7 3 4 41 De w a t e r i n g F e e d 0 . 0 3 1 8 5 0 0 1 1 0 9 , 8 0 5 2 , 1 6 5 3 1 , 0 2 0 6 , 8 4 9 1 8 , 3 1 0 4 , 0 4 4 3 , 4 1 3 7 5 4 5 , 2 4 5 1 , 1 5 8 0 0 5 , 2 4 5 1 , 1 5 8 7 7 0 1 7 0 1 , 3 1 2 2 9 0 1 2 , 3 8 0 2 , 7 3 4 42 CA K E 0 . 0 0 3 2 0 1 6 6 , 0 2 0 2 , 0 1 4 2 2 0 , 0 0 0 6 , 7 1 2 1 2 9 , 9 0 0 3 , 9 6 3 3 , 4 1 3 1 0 4 1 6 , 4 0 0 5 0 0 0 0 1 6 , 4 0 0 5 0 0 7 7 0 2 3 4 , 6 1 5 1 4 1 1 2 , 3 8 0 3 7 8 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0 . 0 2 1 6 2 0 4 2 3 6 4 5 7 2 0 1 3 7 4 2 5 8 1 3 , 4 1 3 6 5 0 3 , 4 5 6 6 5 8 0 0 3 , 4 5 6 6 5 8 7 7 0 1 4 7 7 8 2 1 4 9 1 2 , 3 8 0 2 , 3 5 6 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0 . 0 2 1 6 2 0 4 2 3 6 4 5 2 1 6 4 1 1 2 8 2 4 1 , 3 6 5 2 6 0 1 , 4 0 8 2 6 8 0 0 1 , 4 0 8 2 6 8 7 7 0 1 4 7 7 8 2 1 4 9 2 , 8 4 8 5 4 2 50 A- S t a g e B y p a s s t o B - S t a g e 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 6 . 8 0 4 , 7 2 4 6 7 3 , 8 2 8 2 5 3 1 4 , 3 6 0 2 5 9 1 4 , 6 7 0 2 0 5 1 1 , 6 3 0 3 3 1 , 8 8 9 4 9 2 , 7 6 5 1 3 1 4 9 2 , 7 9 5 6 3 6 8 9 4 8 5 2 5 4 1 4 , 4 2 0 54 A- S t a g e F e e d ( w / R A S ) 1 0 . 0 1 6 , 9 4 9 5 6 4 , 6 6 9 9 1 6 7 6 , 4 0 0 3 , 1 3 7 2 6 1 , 8 0 0 2 , 5 8 4 2 1 5 , 7 0 0 2 9 2 , 4 4 6 2 8 4 2 3 , 7 2 0 1 4 5 2 8 5 2 3 , 7 7 0 5 4 1 0 6 8 5 , 6 3 3 2 5 4 2 1 , 2 1 0 56 A- S t a g e E f f l u e n t 6 . 6 1 4 , 5 8 7 3 1 1 , 7 3 3 4 9 2 , 6 8 8 7 0 3 , 8 5 6 5 8 3 , 1 8 3 2 1 1 , 1 4 8 2 7 1 , 4 6 7 1 3 0 2 7 1 , 4 9 7 2 8 7 3 1 6 6 2 5 4 1 4 , 0 0 0 58 A- S t a g e R A S 3 . 2 0 2 , 2 2 4 3 1 8 4 1 2 , 3 2 3 6 2 , 0 5 0 9 , 2 5 1 2 4 7 , 1 0 0 7 , 6 3 7 2 0 4 , 0 0 0 2 1 5 5 7 7 8 5 2 0 , 9 6 0 1 1 5 7 8 5 2 0 , 9 7 0 2 4 2 1 9 3 5 , 1 4 8 2 5 4 6 , 7 8 8 59 A- S t a g e W A S 0 . 2 0 1 3 8 3 1 5 2 2 , 3 2 3 3 , 8 4 3 9 , 2 5 1 1 5 , 3 0 0 7 , 6 3 7 1 2 , 6 4 0 2 1 3 4 7 8 5 1 , 2 9 8 1 1 7 8 5 1 , 2 9 9 2 3 1 9 3 3 1 9 2 5 4 4 2 0 60 A- S t a g e E f f l t o B - S t a g e 6 . 6 1 4 , 5 8 7 3 1 1 , 7 3 3 4 9 2 , 6 8 8 7 0 3 , 8 5 6 5 8 3 , 1 8 3 2 1 1 , 1 4 8 2 7 1 , 4 6 7 1 3 0 2 7 1 , 4 9 7 2 8 7 3 1 6 6 2 5 4 1 4 , 0 0 0 62 A- S t a g e E f f l t o F l o w E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . St r e a m S u m m a r y f o r H i g h R a t e A / B M M EN V _ H R _ M M St r e a m S u m m a r y f o r H R M M Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L lb / d mg / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 8 . 4 0 5 , 8 3 3 7 5 5 , 2 5 4 2 8 5 1 9 , 9 7 0 2 6 1 1 8 , 2 8 0 2 0 9 1 4 , 6 3 0 3 1 2 , 1 7 2 4 7 3 , 2 9 3 0 0 4 7 3 , 2 9 3 4 2 8 0 6 4 2 0 2 4 2 1 6 , 9 5 0 1a He a d w o r k s t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 2 Ra w I n f l u e n t P l u s R e c y c l e s 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 3 Pr i m a r y E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 3a PE t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 8 . 9 9 6 , 2 4 3 4 9 3 , 6 4 6 6 5 4 , 8 9 2 7 0 5 , 2 4 8 5 5 4 , 1 5 3 2 9 2 , 1 4 9 3 4 2 , 5 6 5 0 3 7 3 5 2 , 6 0 2 3 2 3 1 4 3 3 5 2 4 7 1 8 , 5 3 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 9 . 2 4 6 , 4 1 6 4 9 3 , 7 4 9 7 4 5 , 6 9 3 1 0 7 8 , 2 5 2 8 4 6 , 4 7 8 2 8 2 , 1 7 4 3 7 2 , 8 2 1 1 4 6 3 7 2 , 8 6 7 3 2 3 9 5 4 0 1 3 7 4 2 8 , 7 7 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 1 7 . 7 8 1 2 , 3 5 0 2 7 3 , 9 8 9 7 7 3 1 1 4 , 6 0 0 3 , 5 3 4 5 2 4 , 0 0 0 2 , 4 8 7 3 6 8 , 8 0 0 1 5 2 , 1 9 1 2 6 4 3 9 , 0 7 0 3 5 1 6 2 6 7 3 9 , 5 8 0 4 5 3 9 6 6 9 , 7 8 1 3 0 8 4 5 , 6 1 0 9a Ae r a t i o n E f f l u e n t 17 . 7 8 1 2 , 3 5 0 3 4 9 8 7 4 3 1 1 0 , 1 0 0 3 , 5 0 8 5 2 0 , 2 0 0 2 , 4 6 4 3 6 5 , 3 0 0 0 3 7 2 4 7 3 6 , 5 7 0 7 9 7 8 2 5 3 3 7 , 5 5 0 4 6 2 5 6 6 9 , 7 8 1 2 3 6 3 5 , 0 4 0 10 Fi n a l C l a r i f i e r s E f f l 9. 0 8 6 , 3 0 3 3 2 5 4 7 51 8 1 7 1 , 2 4 9 1 2 8 7 7 0 1 9 1 1 0 7 7 5 0 0 8 6 0 6 4 3 1 9 5 3 4 1 2 3 6 1 7 , 8 9 0 11 Ae r a t i o n R A S F l o w 8. 5 4 5 , 9 3 1 3 2 3 9 1 , 5 2 9 1 0 8 , 9 0 0 7 , 2 4 1 5 1 5 , 8 0 0 5 , 0 8 6 3 6 2 , 3 0 0 0 1 8 5 0 9 3 6 , 2 5 0 7 4 7 0 5 1 6 3 6 , 7 2 0 4 3 0 0 1 3 2 9 , 3 7 9 2 3 6 1 6 , 8 3 0 12 Fi l t r a t i o n F e e d 9. 0 8 6 , 3 0 3 3 2 5 4 7 51 8 1 7 1 , 2 4 9 1 2 8 7 7 0 1 9 1 1 0 7 7 5 0 0 8 6 0 6 4 3 1 9 5 3 4 1 2 3 6 1 7 , 8 9 0 13 Fi l t r a t i o n E f f l 8. 4 0 5 , 8 3 1 3 2 3 5 4 27 7 3 1 9 6 2 1 3 8 0 1 8 0 3 1 7 4 6 2 7 4 9 3 4 2 9 5 4 2 9 8 2 3 6 1 6 , 5 5 0 13 a Fi l t r a t i o n B a c k w a s h 0. 6 8 4 7 3 3 1 9 4 2 24 1 1 8 6 1 , 0 5 3 1 3 0 7 4 0 0 1 1 3 7 5 7 3 7 2 0 1 1 3 4 2 4 7 4 2 2 3 6 1 , 3 4 1 14 UV F e e d 8. 4 0 5 , 8 3 1 3 2 3 5 4 27 7 3 1 9 6 2 1 3 8 0 1 8 0 3 1 7 4 6 2 7 4 9 3 4 2 9 5 4 2 9 8 2 3 6 1 6 , 5 5 0 14 a Pl a n t D i s c h a r g e 8. 4 0 5 , 8 3 1 3 2 3 5 4 27 7 3 1 9 6 2 1 3 8 0 1 8 0 3 1 7 4 6 2 7 4 9 3 4 2 9 5 4 2 9 8 2 4 7 1 7 , 3 1 0 20 Pr i m a r y S l u d g e 0. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 22 WA S 0. 1 6 1 1 2 3 5 4 8 9 65 9 2 , 3 0 7 3 , 1 0 6 1 , 6 2 0 2 , 1 8 1 0 0 1 6 2 2 1 9 7 9 1 6 9 2 2 7 4 6 4 5 6 0 2 3 6 3 1 8 30 DA F T F e e d 0. 2 7 1 8 9 2 2 4 9 1 , 6 4 0 3 , 7 2 0 6 , 9 7 2 1 5 , 8 1 0 5 , 3 9 5 1 2 , 2 3 0 1 2 2 7 5 5 1 1 , 2 5 0 4 9 5 5 5 1 , 2 6 0 4 9 1 3 9 3 1 5 2 4 1 5 4 6 31 DA F T T h i c k e n e d S l u d g e 0. 0 2 1 6 5 0 1 0 1 5 , 1 4 0 2 , 9 8 3 6 5 , 0 0 0 1 2 , 8 1 0 5 0 , 3 0 0 9 , 9 1 0 1 2 2 5 , 0 4 2 9 9 3 4 1 5 , 0 4 6 9 9 4 4 1 1 , 2 6 3 2 4 9 2 4 2 4 8 32 DA F T T h i c k e n e r R e t u r n 0. 2 5 1 7 2 5 0 1 0 4 3 8 7 80 1 1 , 4 5 1 3 , 0 0 4 1 , 1 2 3 2 , 3 2 5 1 2 2 4 1 2 4 2 5 7 4 9 1 2 8 2 6 5 4 8 3 2 6 6 2 4 1 4 9 9 33 An a e r o b i c D i g e s t i o n F e e d 0. 0 2 1 6 5 0 1 0 1 5 , 1 4 0 2 , 9 8 3 6 5 , 0 2 0 1 2 , 8 1 0 5 0 , 3 0 0 9 , 9 1 0 1 2 2 5 , 0 4 2 9 9 3 4 1 5 , 0 4 6 9 9 4 1 0 1 , 2 6 3 2 4 9 2 2 4 4 4 34 An a e r o b i c D i g e s t e d S o l i d s 0. 0 2 1 6 5 0 0 9 9 1 0 , 2 0 0 2 , 0 0 9 3 2 , 3 3 0 6 , 3 6 9 1 7 , 6 1 0 3 , 4 6 8 3 , 2 8 1 6 4 7 5 , 0 4 2 9 9 3 0 0 5 , 0 4 2 9 9 3 7 4 0 1 4 6 1 , 2 6 3 2 4 9 1 1 , 9 0 0 2 , 3 4 4 41 De w a t e r i n g F e e d 0. 0 2 1 6 5 0 0 9 9 1 0 , 2 0 0 2 , 0 0 9 3 2 , 3 3 0 6 , 3 6 9 1 7 , 6 1 0 3 , 4 6 8 3 , 2 8 1 6 4 7 5 , 0 4 2 9 9 3 0 0 5 , 0 4 2 9 9 3 7 4 0 1 4 6 1 , 2 6 3 2 4 9 1 1 , 9 0 0 2 , 3 4 4 42 CA K E 0. 0 0 2 2 0 1 6 6 , 0 2 0 1 , 8 7 3 2 2 0 , 0 0 0 6 , 2 4 1 1 1 9 , 8 0 0 3 , 3 9 9 3 , 2 8 1 9 3 1 5 , 2 6 0 4 3 3 0 0 1 5 , 2 6 0 4 3 3 7 4 0 2 1 4 , 2 9 9 1 2 2 1 1 , 9 0 0 3 3 8 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0. 0 2 1 4 2 0 3 2 4 7 42 7 5 5 1 2 7 4 1 1 6 9 3 , 2 8 1 5 5 3 3 , 3 2 3 5 6 0 0 0 3 , 3 2 3 5 6 0 7 4 0 1 2 5 7 5 2 1 2 7 1 1 , 9 0 0 2 , 0 0 6 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0. 0 2 1 4 2 0 3 2 4 7 42 2 2 7 3 8 1 2 3 2 1 1 , 3 1 3 2 2 1 1 , 3 5 4 2 2 8 0 0 1 , 3 5 4 2 2 8 7 4 0 1 2 5 7 5 2 1 2 7 2 , 7 3 6 4 6 1 50 A- S t a g e B y p a s s t o B - S t a g e 0. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 9. 1 0 6 , 3 2 0 7 0 5 , 2 7 7 2 6 7 2 0 , 2 5 0 2 5 5 1 9 , 3 8 0 2 0 3 1 5 , 3 9 0 3 2 2 , 3 9 5 4 7 3 , 5 9 6 0 3 7 4 8 3 , 6 3 4 6 4 2 9 8 5 9 0 2 4 7 1 8 , 7 6 0 54 A- S t a g e F e e d ( w / R A S ) 13 . 5 4 9 , 4 0 3 6 3 7 , 0 7 7 1 , 2 6 8 1 4 3 , 2 0 0 4 , 6 9 2 5 2 9 , 9 0 0 3 , 7 1 4 4 1 9 , 4 0 0 3 1 3 , 4 5 6 3 9 9 4 5 , 0 5 0 0 5 6 4 0 0 4 5 , 1 1 0 5 5 4 3 9 6 1 0 , 8 1 0 2 4 7 2 7 , 9 1 0 56 A- S t a g e E f f l u e n t 8. 9 9 6 , 2 4 3 4 9 3 , 6 4 6 6 5 4 , 8 9 2 7 0 5 , 2 4 8 5 5 4 , 1 5 3 2 9 2 , 1 4 9 3 4 2 , 5 6 5 0 3 7 3 5 2 , 6 0 2 3 2 3 1 4 3 3 5 2 4 7 1 8 , 5 3 0 58 A- S t a g e R A S 4. 4 4 3 , 0 8 3 4 9 1 , 8 0 1 3 , 3 2 2 1 2 3 , 0 0 0 1 3 , 7 9 0 5 1 0 , 5 0 0 1 0 , 9 1 0 4 0 4 , 0 0 0 2 9 1 , 0 6 1 1 , 1 2 0 4 1 , 4 6 0 0 1 8 1 , 1 2 0 4 1 , 4 8 0 3 1 1 4 2 7 6 1 0 , 2 2 0 2 4 7 9 , 1 5 0 59 A- S t a g e W A S 0. 1 1 7 7 4 9 4 5 3 , 3 2 2 3 , 0 6 1 1 3 , 7 9 0 1 2 , 7 0 0 1 0 , 9 1 0 1 0 , 0 5 0 2 9 2 6 1 , 1 2 0 1 , 0 3 2 0 0 1 , 1 2 0 1 , 0 3 2 3 3 2 7 6 2 5 4 2 4 7 2 2 8 60 A- S t a g e E f f l t o B - S t a g e 8. 9 9 6 , 2 4 3 4 9 3 , 6 4 6 6 5 4 , 8 9 2 7 0 5 , 2 4 8 5 5 4 , 1 5 3 2 9 2 , 1 4 9 3 4 2 , 5 6 5 0 3 7 3 5 2 , 6 0 2 3 2 3 1 4 3 3 5 2 4 7 1 8 , 5 3 0 62 A- S t a g e E f f l t o F l o w E Q 0. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . St r e a m S u m m a r y f o r H i g h R a t e A / B M D EN V _ H R _ M D St r e a m S u m m a r y f o r H R M D Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L lb / d mg / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 1 7 . 3 0 1 2 , 0 1 0 7 4 1 0 , 6 8 0 2 5 2 3 6 , 3 6 0 2 3 1 3 3 , 3 3 0 1 8 5 2 6 , 6 6 0 2 2 3 , 1 7 4 3 3 4 , 7 6 1 0 0 3 3 4 , 7 6 1 4 5 7 7 6 8 6 6 2 4 3 3 5 , 0 6 0 1a He a d w o r k s t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 2 Ra w I n f l u e n t P l u s R e c y c l e s 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 3 Pr i m a r y E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 3a PE t o E Q 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 1 6 . 0 0 1 1 , 1 1 0 7 9 1 0 , 6 0 0 1 1 0 1 4 , 6 5 0 1 3 0 1 7 , 3 5 0 1 0 1 1 3 , 4 9 0 1 9 2 , 5 6 2 2 9 3 , 9 1 1 0 2 5 2 9 3 , 9 3 6 3 4 4 7 6 7 8 4 2 4 7 3 2 , 9 9 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 1 6 . 2 7 1 1 , 3 0 0 7 9 1 0 , 7 1 0 1 1 5 1 5 , 5 6 0 1 5 4 2 0 , 9 4 0 1 1 9 1 6 , 1 6 0 1 9 2 , 5 7 0 3 1 4 , 1 8 6 0 3 4 3 1 4 , 2 2 0 3 4 5 7 6 8 6 1 3 7 5 5 0 , 9 3 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 2 6 . 6 3 1 8 , 4 9 0 5 2 1 1 , 5 8 0 2 , 0 1 1 4 4 6 , 6 0 0 9 , 2 1 0 2 , 0 4 5 , 0 0 0 6 , 5 2 9 1 , 4 5 0 , 0 0 0 1 2 2 , 5 9 1 6 6 5 1 4 7 , 6 0 0 2 4 6 5 6 6 7 1 4 8 , 1 0 0 4 8 7 7 1 6 8 3 7 , 1 9 0 3 3 5 7 4 , 3 0 0 9a Ae r a t i o n E f f l u e n t 26 . 6 3 1 8 , 4 9 0 1 0 2 , 2 3 9 1 , 9 5 8 4 3 4 , 8 0 0 9 , 1 6 7 2 , 0 3 6 , 0 0 0 6 , 4 9 3 1 , 4 4 2 , 0 0 0 0 5 6 6 5 0 1 4 4 , 2 0 0 5 1 , 1 0 7 6 5 5 1 4 5 , 4 0 0 5 1 , 0 8 0 1 6 8 3 7 , 1 9 0 2 7 1 6 0 , 0 7 0 10 Fi n a l C l a r i f i e r s E f f l 16 . 0 2 1 1 , 1 3 0 1 0 1 , 3 4 7 1 4 1 , 8 1 6 1 7 2 , 2 0 5 1 2 1 , 5 6 2 0 3 3 1 1 9 0 5 6 6 6 6 8 5 6 5 6 5 0 5 6 8 9 2 7 1 3 6 , 1 5 0 11 Ae r a t i o n R A S F l o w 10 . 3 6 7 , 1 9 6 1 0 8 7 1 4 , 9 8 7 4 3 1 , 0 0 0 2 3 , 4 2 0 2 , 0 2 4 , 0 0 0 1 6 , 5 9 0 1 , 4 3 4 , 0 0 0 0 2 2 1 , 6 5 9 1 4 3 , 4 0 0 5 4 3 1 1 , 6 6 4 1 4 3 , 8 0 0 5 4 2 0 4 2 0 3 6 , 3 3 0 2 7 1 2 3 , 3 8 0 12 Fi l t r a t i o n F e e d 16 . 0 2 1 1 , 1 3 0 1 0 1 , 3 4 7 1 4 1 , 8 1 6 1 7 2 , 2 0 5 1 2 1 , 5 6 2 0 3 3 1 1 9 0 5 6 6 6 6 8 5 6 5 6 5 0 5 6 8 9 2 7 1 3 6 , 1 5 0 13 Fi l t r a t i o n E f f l 15 . 3 4 1 0 , 6 5 0 1 0 1 , 2 9 0 1 1 1 , 3 6 6 3 3 5 8 2 2 5 4 0 3 2 0 5 7 5 6 3 8 5 6 9 5 5 6 2 2 5 6 2 9 2 7 1 3 4 , 6 1 0 13 a Fi l t r a t i o n B a c k w a s h 0. 6 8 4 7 3 1 0 5 7 7 9 45 0 3 2 5 1 , 8 4 7 2 3 1 1 , 3 0 8 0 1 2 3 1 3 2 5 2 8 2 8 1 6 1 5 2 8 1 1 6 0 2 7 1 1 , 5 3 5 14 UV F e e d 15 . 3 4 1 0 , 6 5 0 1 0 1 , 2 9 0 1 1 1 , 3 6 6 3 3 5 8 2 2 5 4 0 3 2 0 5 7 5 6 3 8 5 6 9 5 5 6 2 2 5 6 2 9 2 7 1 3 4 , 6 1 0 14 a Pl a n t D i s c h a r g e 15 . 3 4 1 0 , 6 5 0 1 0 1 , 2 9 0 1 1 1 , 3 6 6 3 3 5 8 2 2 5 4 0 3 2 0 5 7 5 6 3 8 5 6 9 5 5 6 2 2 5 6 2 9 2 8 1 3 6 , 0 1 0 20 Pr i m a r y S l u d g e 0. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 22 WA S 0. 2 4 1 6 8 1 0 2 0 9 7 8 1 , 9 7 0 4 , 5 5 6 9 , 1 7 4 3 , 2 2 7 6 , 4 9 8 0 1 3 2 3 6 5 0 5 1 0 3 2 8 6 6 0 5 1 0 8 6 1 7 3 2 7 1 5 4 5 30 DA F T F e e d 0. 2 9 2 0 4 2 2 5 5 1 , 7 4 9 4 , 2 7 8 7 , 7 3 5 1 8 , 9 2 0 5 , 7 5 5 1 4 , 0 8 0 4 9 5 7 9 1 , 4 1 6 4 1 0 5 8 3 1 , 4 2 7 5 1 1 1 4 9 3 6 4 2 6 6 6 5 2 31 DA F T T h i c k e n e d S l u d g e 0. 0 3 2 0 5 0 1 2 1 4 , 5 6 0 3 , 4 3 2 6 5 , 0 0 0 1 5 , 3 3 0 4 8 , 3 6 0 1 1 , 4 0 0 4 1 4 , 8 3 9 1 , 1 4 1 4 1 4 , 8 4 3 1 , 1 4 2 5 1 1 , 2 1 5 2 8 7 2 6 7 6 3 32 DA F T T h i c k e n e r R e t u r n 0. 2 7 1 8 4 5 0 1 1 1 4 1 3 91 3 1 , 6 2 6 3 , 5 9 5 1 , 2 1 0 2 , 6 7 5 4 8 1 2 5 2 7 5 4 9 1 2 9 2 8 5 5 1 0 3 5 7 7 2 6 6 5 8 9 33 An a e r o b i c D i g e s t i o n F e e d 0. 0 3 2 0 5 0 1 2 1 4 , 5 6 0 3 , 4 3 2 6 5 , 0 2 0 1 5 , 3 3 0 4 8 , 3 6 0 1 1 , 4 0 0 4 1 4 , 8 3 9 1 , 1 4 1 4 1 4 , 8 4 3 1 , 1 4 2 1 0 1 , 2 1 5 2 8 7 2 4 9 5 9 34 An a e r o b i c D i g e s t e d S o l i d s 0. 0 3 2 0 5 0 0 1 1 8 1 0 , 5 8 0 2 , 4 9 4 3 3 , 5 9 0 7 , 9 2 0 1 6 , 9 3 0 3 , 9 9 1 3 , 1 4 7 7 4 2 4 , 8 3 9 1 , 1 4 1 0 0 4 , 8 3 9 1 , 1 4 1 7 1 2 1 6 8 1 , 2 1 5 2 8 7 1 1 , 4 7 0 2 , 7 0 5 41 De w a t e r i n g F e e d 0. 0 3 2 0 5 0 0 1 1 8 1 0 , 5 8 0 2 , 4 9 4 3 3 , 5 9 0 7 , 9 2 0 1 6 , 9 3 0 3 , 9 9 1 3 , 1 4 7 7 4 2 4 , 8 3 9 1 , 1 4 1 0 0 4 , 8 3 9 1 , 1 4 1 7 1 2 1 6 8 1 , 2 1 5 2 8 7 1 1 , 4 7 0 2 , 7 0 5 42 CA K E 0. 0 0 3 2 0 1 6 6 , 0 2 0 2 , 3 2 9 2 2 0 , 0 0 0 7 , 7 6 1 1 1 0 , 9 0 0 3 , 9 1 1 3 , 1 4 7 1 1 1 1 4 , 2 3 0 5 0 2 0 0 1 4 , 2 3 0 5 0 2 7 1 2 2 5 4 , 0 1 0 1 4 2 1 1 , 4 7 0 4 0 5 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0. 0 2 1 7 2 0 4 2 5 7 52 7 9 0 1 5 8 3 9 8 8 0 3 , 1 4 7 6 3 1 3 , 1 8 7 6 3 9 0 0 3 , 1 8 7 6 3 9 7 1 2 1 4 3 7 2 3 1 4 5 1 1 , 4 7 0 2 , 3 0 0 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0. 0 2 1 7 2 0 4 2 5 7 52 2 3 7 4 8 1 1 9 2 4 1 , 2 5 9 2 5 2 1 , 2 9 9 2 6 0 0 0 1 , 2 9 9 2 6 0 7 1 2 1 4 3 7 2 3 1 4 5 2 , 6 3 8 5 2 9 50 A- S t a g e B y p a s s t o B - S t a g e 0. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 18 . 0 0 1 2 , 5 0 0 7 2 1 0 , 7 4 0 2 4 6 3 6 , 8 6 0 2 3 5 3 5 , 2 2 0 1 8 6 2 8 , 0 0 0 2 3 3 , 4 2 8 3 4 5 , 1 5 4 0 2 8 3 5 5 , 1 8 2 5 7 4 7 7 1 , 0 7 1 2 4 7 3 7 , 1 2 0 54 A- S t a g e F e e d ( w / R A S ) 26 . 9 5 1 8 , 7 2 0 7 4 1 6 , 6 7 0 1 , 9 3 6 4 3 5 , 2 0 0 7 , 6 4 1 1 , 7 1 8 , 0 0 0 5 , 9 4 4 1 , 3 3 6 , 0 0 0 2 2 4 , 8 6 1 6 1 1 1 3 7 , 4 0 0 0 4 2 6 1 1 1 3 7 , 4 0 0 4 9 9 7 1 5 2 3 4 , 0 5 0 2 4 7 5 5 , 5 8 0 56 A- S t a g e E f f l u e n t 17 . 9 5 1 2 , 4 7 0 7 9 1 1 , 9 0 0 1 1 0 1 6 , 4 4 0 1 3 0 1 9 , 4 6 0 1 0 1 1 5 , 1 3 0 1 9 2 , 8 7 4 2 9 4 , 3 8 8 0 2 8 2 9 4 , 4 1 6 3 5 0 1 6 8 8 0 2 4 7 3 7 , 0 2 0 58 A- S t a g e R A S 8. 9 5 6 , 2 1 6 7 9 5 , 9 3 1 5 , 3 3 7 3 9 8 , 4 0 0 2 2 , 5 4 0 1 , 6 8 2 , 0 0 0 1 7 , 5 3 0 1 , 3 0 8 , 0 0 0 1 9 1 , 4 3 3 1 , 7 7 2 1 3 2 , 3 0 0 0 1 4 1 , 7 7 2 1 3 2 , 3 0 0 3 2 5 0 4 4 2 3 2 , 9 8 0 2 4 7 1 8 , 4 6 0 59 A- S t a g e W A S 0. 0 5 3 6 7 9 3 4 5 , 3 3 7 2 , 3 0 8 2 2 , 5 4 0 9 , 7 4 6 1 7 , 5 3 0 7 , 5 7 8 1 9 8 1 , 7 7 2 7 6 6 0 0 1 , 7 7 2 7 6 6 3 1 4 4 2 1 9 1 2 4 7 1 0 7 60 A- S t a g e E f f l t o B - S t a g e 16 . 0 0 1 1 , 1 1 0 7 9 1 0 , 6 0 0 1 1 0 1 4 , 6 5 0 1 3 0 1 7 , 3 5 0 1 0 1 1 3 , 4 9 0 1 9 2 , 5 6 2 2 9 3 , 9 1 1 0 2 5 2 9 3 , 9 3 6 3 4 4 7 6 7 8 4 2 4 7 3 2 , 9 9 0 62 A- S t a g e E f f l t o F l o w E Q 1. 9 5 1 , 3 5 6 7 9 1 , 2 9 4 1 1 0 1 , 7 8 8 1 3 0 2 , 1 1 7 1 0 1 1 , 6 4 6 1 9 3 1 3 2 9 4 7 7 0 3 2 9 4 8 0 3 5 5 6 9 6 2 4 7 4 , 0 2 6 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . St r e a m S u m m a r y f o r H i g h R a t e A / B P H EN V _ H R _ P H St r e a m S u m m a r y f o r H R P H Li n e Na m e Fl o w sB O D BO D TS S VS S NH 4 TK N TO N TN oPTPAlk mg d g p m m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d m g / L l b / d 1 Ra w i n f l u e n t 3 3 . 5 2 3 , 2 6 0 1a He a d w o r k s t o E Q 1 1 . 5 7 , 9 8 6 2 Ra w I n f l u e n t P l u s R e c y c l e s 0 . 0 0 3 Pr i m a r y E f f l u e n t 0 . 0 0 3a PE t o E Q 0 . 0 0 4 Bi o f i l t e r s E f f l u e n t 0 . 0 0 5 Se c C l a r i f i e r E f f l u e n t 0 . 0 0 6 Ae r a t i o n B a s i n F e e d ( w / o u t D A F T R e t u r n ) 2 7 . 5 1 9 , 1 0 0 7 Ae r a t i o n B a s i n F e e d ( w / D A F T R e t u r n ) 2 7 . 9 1 9 , 3 5 0 8 Ae r a t i o n B a s i n B y p a s s 0 . 0 0 9 Ae r a t i o n B a s i n F e e d ( w / R A S ) 4 4 . 3 3 0 , 7 3 0 9a Ae r a t i o n E f f l u e n t 4 4 . 3 3 0 , 7 3 0 10 Fi n a l C l a r i f i e r s E f f l 2 7 . 5 1 9 , 0 8 0 11 Ae r a t i o n R A S F l o w 1 6 . 4 1 1 , 3 8 0 12 Fi l t r a t i o n F e e d 2 7 . 5 1 9 , 0 8 0 13 Fi l t r a t i o n E f f l 2 6 . 8 1 8 , 6 1 0 13 a Fi l t r a t i o n B a c k w a s h 0 . 7 4 7 3 14 UV F e e d 2 6 . 8 1 8 , 6 1 0 14 a Pl a n t D i s c h a r g e 2 6 . 8 1 8 , 6 1 0 20 Pr i m a r y S l u d g e 0 . 0 0 22 WA S 0 . 4 2 6 2 30 DA F T F e e d 0 . 4 2 6 2 31 DA F T T h i c k e n e d S l u d g e 0 . 0 1 4 32 DA F T T h i c k e n e r R e t u r n 0 . 4 2 4 8 33 An a e r o b i c D i g e s t i o n F e e d 0 . 0 1 4 34 An a e r o b i c D i g e s t e d S o l i d s 0 . 0 1 4 41 De w a t e r i n g F e e d 0 . 0 1 4 42 CA K E 0 . 0 2 43 De w a t e r i n g C e n t r a t e t o L a g o o n 0 . 0 1 2 44 La g o o n R e c y c l e t o P r i m a r y I n f l u e n t 0 . 0 1 2 50 A- S t a g e B y p a s s t o B - S t a g e 0 . 0 0 52 A- S t a g e F e e d ( w / o u t R A S ) 2 2 . 7 1 5 , 7 6 0 54 A- S t a g e F e e d ( w / R A S ) 3 4 . 1 2 3 , 6 7 0 56 A- S t a g e E f f l u e n t 2 2 . 7 1 5 , 7 9 0 58 A- S t a g e R A S 1 1 . 4 7 , 9 1 0 59 A- S t a g e W A S ( 0 . 0 ) ( 2 9 ) 60 A- S t a g e E f f l t o B - S t a g e 1 6 . 0 1 1 , 1 1 0 62 A- S t a g e E f f l t o F l o w E Q 6 . 7 4 , 6 8 0 Ma s s B a l a n c e N o t e s Th e f l o w a n d l o a d i n g s a b o v e a r e da i l y a v e r a g e v a l u e s . Fo r s o l i d s s t r e a m s , t h e a c t u a l f l o w s m a y b e d i f f e r e n t i f t h e u n i t p e r f o r m a n c e d o e s n o t m e e t t h e c o n c e n t r a t i o n l i m i t s . B r a c k e t f l o w s b a s e d o n ma s s l o a d i n g w i t h a c c o m o d a t i o n f o r l o w e r / h i g h e r co n c e n t r a t i o n s . I n s t a n t a n e o u s f l o w f o r s o l i d s s t r e a m s i s o f t e n i n t e r m i t t e n t a n d h i g h e r t o m a t c h m i n i m u m p i p e v e l o c i t i e s a n d a c t u a l o p e r a t i n g c o n d i t i o n s . A d j u s t t o m a t c h m a s s l o a d i n g . Fi l t e r b a c k w a s h i s c a l c u l a t e d a s a 2 4 - h o u r a v e r a g e f l o w . I n s t a n t a n e o u s f l o w s w i l l b e h i g h e r , p e n d i n g t h e o p e r a t i n g s t r a t e g y . A d j u s t i n s t a n t a n e o u s f l o w s a s n e e d e d . WRRF Project TM No. 12 – Process Alternatives Analysis Appendix D – Life Cycle Analysis Results for each Alternative WRRF Project TM No. 12 – Process Alternatives Analysis Page intentionally blank. Alt 1 : M L E Ra t e s Di s c o u n t R a t e 5 . 0 0 0 % Ca p i t a l I n f l a t i o n R a t e ( M R ) 1 . 0 3 5 En e r g y I n f l a t i o n R a t e 1 . 0 3 5 No n - E n e r g y I n f l a t i o n R a t e 1 . 0 3 5 Ca p i t a l C o s t s ( $ i n 2 0 1 4 d o l l a r s ) ($ / y e a r i n 2 0 1 4 d o l l a r s ) ( $ / y e a r i n 2 0 1 4 d o l l a r s ) C a p i t a l C o s t = 2 6 , 4 0 0 , 0 0 0 $ E n e r g y 29 0 , 0 0 0 C h e m i c a l s 3 3 0 , 0 0 0 Yea r b y Y e a r L i f e C y c l e C o s t T a b l e NP V Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r 12 3 4 5 6 7 8 9 1 0 C a p i t a l C o s t 2 6 , 4 0 0 , 0 0 0 $ - - - - - - - - - ‐ E n e r g y 6, 7 7 7 , 7 1 1 $ 2 9 0 , 0 0 0 3 0 0 , 1 5 0 3 1 0 , 6 5 5 3 2 1 , 5 2 8 3 3 2 , 7 8 2 3 4 4 , 4 2 9 3 5 6 , 4 8 4 3 6 8 , 9 6 1 3 8 1 , 8 7 5 395,240 C h e m i c a l s 7 , 7 1 2 , 5 6 7 $ 3 3 0 , 0 0 0 3 4 1 , 5 5 0 3 5 3 , 5 0 4 3 6 5 , 8 7 7 3 7 8 , 6 8 3 3 9 1 , 9 3 6 40 5 , 6 5 4 419,852 434,547 449,756 To t a l P r e s e n t W o r t h 40 , 8 9 0 , 2 7 8 $ 62 0 , 0 0 0 64 1 , 7 0 0 66 4 , 1 6 0 68 7 , 4 0 5 71 1 , 4 6 4 73 6 , 3 6 6 76 2 , 1 3 8 788,813 816,422 844,996 Ann u a l O p e r a t i n g C o s t s $ 62 0 , 0 0 0 64 1 , 7 0 0 66 4 , 1 6 0 68 7 , 4 0 5 71 1 , 4 6 4 73 6 , 3 6 6 76 2 , 1 3 8 788,813 816,422 844,996 To t a l A n n u a l i z e d C a p i t a l C o s t $ 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2,118,404 2,118,404 Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r YearYear 11 12 13 14 15 16 17 18 1920 C a p i t a l C o s t $ - - - - - - - - - ‐ E n e r g y $ 40 9 , 0 7 4 42 3 , 3 9 1 43 8 , 2 1 0 45 3 , 5 4 7 46 9 , 4 2 1 48 5 , 8 5 1 50 2 , 8 5 6 520,456 538,672 557,525 C h e m i c a l s $ 46 5 , 4 9 8 48 1 , 7 9 0 49 8 , 6 5 3 51 6 , 1 0 5 53 4 , 1 6 9 55 2 , 8 6 5 57 2 , 2 1 5 592,243 612,971 634,425 To t a l P r e s e n t W o r t h 87 4 , 5 7 1 90 5 , 1 8 1 93 6 , 8 6 3 96 9 , 6 5 3 1, 0 0 3 , 5 9 1 1, 0 3 8 , 7 1 6 1, 0 7 5 , 0 7 1 1, 1 1 2 , 6 9 9 1,151,643 1,191,951 Ann u a l O p e r a t i n g C o s t s $ 87 4 , 5 7 1 90 5 , 1 8 1 93 6 , 8 6 3 96 9 , 6 5 3 1, 0 0 3 , 5 9 1 1, 0 3 8 , 7 1 6 1, 0 7 5 , 0 7 1 1, 1 1 2 , 6 9 9 1,151,643 1,191,951 To t a l A n n u a l i z e d C a p i t a l C o s t $ 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2,118,404 2,118,404 Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r YearYear 21 22 23 24 25 26 27 28 2930 C a p i t a l C o s t $ - - - - - - - - - ‐ E n e r g y $ 57 7 , 0 3 9 59 7 , 2 3 5 61 8 , 1 3 8 63 9 , 7 7 3 66 2 , 1 6 5 68 5 , 3 4 1 70 9 , 3 2 8 734,154 759,850 786,445 C h e m i c a l s $ 65 6 , 6 3 0 67 9 , 6 1 2 70 3 , 3 9 9 72 8 , 0 1 8 75 3 , 4 9 8 77 9 , 8 7 1 80 7 , 1 6 6 835,417 864,657 894,920 To t a l P r e s e n t W o r t h 1, 2 3 3 , 6 6 9 1, 2 7 6 , 8 4 8 1, 3 2 1 , 5 3 7 1, 3 6 7 , 7 9 1 1, 4 1 5 , 6 6 4 1, 4 6 5 , 2 1 2 1, 5 1 6 , 4 9 4 1, 5 6 9 , 5 7 2 1,624,507 1,681,364 Ann u a l O p e r a t i n g C o s t s $ 1, 2 3 3 , 6 6 9 1, 2 7 6 , 8 4 8 1, 3 2 1 , 5 3 7 1, 3 6 7 , 7 9 1 1, 4 1 5 , 6 6 4 1, 4 6 5 , 2 1 2 1, 5 1 6 , 4 9 4 1, 5 6 9 , 5 7 2 1,624,507 1,681,364 To t a l A n n u a l i z e d C a p i t a l C o s t $ 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2, 1 1 8 , 4 0 4 2,118,404 2,118,404 An n u a l E n e r g y C o s t s Ch e m i c a l C o s t s Co s t C a t e g o r y Co s t C a t e g o r y Co s t C a t e g o r y Alt 2 : V e r t i C e l Ra t e s D i s c o u n t R a t e 5 . 0 0 % Ca p i t a l I n f l a t i o n R a t e ( M R ) 1 . 0 3 5 E n e r g y I n f l a t i o n R a t e 1 . 0 3 5 N o n - E n e r g y I n f l a t i o n R a t e 1 . 0 3 5 Ca p i t a l C o s t s ( $ i n 2 0 1 4 d o l l a r s ) ($ / y e a r i n 2 0 1 4 d o l l a r s ) ( $ / y e a r i n 2 0 1 4 d o l l a r s ) C a p i t a l C o s t = 3 2 , 4 0 0 , 0 0 0 $ E n e r g y 18 0 , 0 0 0 C h e m i c a l s 3 3 0 , 0 0 0 Yea r b y Y e a r L i f e C y c l e C o s t T a b l e NP V Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r 12 3 4 5 6 7 8 9 1 0 C a p i t a l C o s t 3 2 , 4 0 0 , 0 0 0 $ - - - - - - - - - - E n e r g y 4, 2 0 6 , 8 5 5 $ 1 8 0 , 0 0 0 1 8 6 , 3 0 0 1 9 2 , 8 2 1 1 9 9 , 5 6 9 2 0 6 , 5 5 4 2 1 3 , 7 8 4 2 2 1 , 2 6 6 2 2 9 , 0 1 0 2 3 7 , 0 2 6 245,322 C h e m i c a l s 7 , 7 1 2 , 5 6 7 $ 3 3 0 , 0 0 0 3 4 1 , 5 5 0 3 5 3 , 5 0 4 3 6 5 , 8 7 7 3 7 8 , 6 8 3 3 9 1 , 9 3 6 40 5 , 6 5 4 419,852 434,547 449,756 To t a l P r e s e n t W o r t h 44 , 3 1 9 , 4 2 2 $ 51 0 , 0 0 0 52 7 , 8 5 0 54 6 , 3 2 5 56 5 , 4 4 6 58 5 , 2 3 7 60 5 , 7 2 0 62 6 , 9 2 0 648,862 671,573 695,078 Ann u a l O p e r a t i n g C o s t s $ 51 0 , 0 0 0 52 7 , 8 5 0 54 6 , 3 2 5 56 5 , 4 4 6 58 5 , 2 3 7 60 5 , 7 2 0 62 6 , 9 2 0 648,862 671,573 695,078 To t a l A n n u a l i z e d C a p i t a l C o s t $ 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2,599,860 2,599,860 Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r YearYear 11 12 13 14 15 16 17 18 1920 C a p i t a l C o s t $ - - - - - - - - - - E n e r g y $ 25 3 , 9 0 8 26 2 , 7 9 5 27 1 , 9 9 2 28 1 , 5 1 2 29 1 , 3 6 5 30 1 , 5 6 3 31 2 , 1 1 7 323,042 334,348 346,050 C h e m i c a l s $ 46 5 , 4 9 8 48 1 , 7 9 0 49 8 , 6 5 3 51 6 , 1 0 5 53 4 , 1 6 9 55 2 , 8 6 5 57 2 , 2 1 5 592,243 612,971 634,425 To t a l P r e s e n t W o r t h 71 9 , 4 0 5 74 4 , 5 8 5 77 0 , 6 4 5 79 7 , 6 1 8 82 5 , 5 3 4 85 4 , 4 2 8 88 4 , 3 3 3 915,285 947,319 980,476 Ann u a l O p e r a t i n g C o s t s $ 71 9 , 4 0 5 74 4 , 5 8 5 77 0 , 6 4 5 79 7 , 6 1 8 82 5 , 5 3 4 85 4 , 4 2 8 88 4 , 3 3 3 915,285 947,319 980,476 To t a l A n n u a l i z e d C a p i t a l C o s t $ 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2,599,860 2,599,860 Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r YearYear 21 22 23 24 25 26 27 28 2930 C a p i t a l C o s t $ - - - - - - - - - - E n e r g y $ 35 8 , 1 6 2 37 0 , 6 9 8 38 3 , 6 7 2 39 7 , 1 0 1 41 0 , 9 9 9 42 5 , 3 8 4 44 0 , 2 7 3 455,682 471,631 488,138 C h e m i c a l s $ 65 6 , 6 3 0 67 9 , 6 1 2 70 3 , 3 9 9 72 8 , 0 1 8 75 3 , 4 9 8 77 9 , 8 7 1 80 7 , 1 6 6 835,417 864,657 894,920 To t a l P r e s e n t W o r t h 1, 0 1 4 , 7 9 2 1, 0 5 0 , 3 1 0 1, 0 8 7 , 0 7 1 1, 1 2 5 , 1 1 8 1, 1 6 4 , 4 9 8 1, 2 0 5 , 2 5 5 1, 2 4 7 , 4 3 9 1, 2 9 1 , 0 9 9 1,336,288 1,383,058 Ann u a l O p e r a t i n g C o s t s $ 1, 0 1 4 , 7 9 2 1, 0 5 0 , 3 1 0 1, 0 8 7 , 0 7 1 1, 1 2 5 , 1 1 8 1, 1 6 4 , 4 9 8 1, 2 0 5 , 2 5 5 1, 2 4 7 , 4 3 9 1, 2 9 1 , 0 9 9 1,336,288 1,383,058 To t a l A n n u a l i z e d C a p i t a l C o s t $ 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2, 5 9 9 , 8 6 0 2,599,860 2,599,860 An n u a l E n e r g y C o s t s Ch e m i c a l C o s t s Co s t C a t e g o r y Co s t C a t e g o r y Co s t C a t e g o r y Alt 3 : H i g h R a t e A B Ra t e s D i s c o u n t R a t e 5 . 0 0 % Ca p i t a l I n f l a t i o n R a t e ( M R ) 1 . 0 3 5 E n e r g y I n f l a t i o n R a t e 1 . 0 3 5 N o n - E n e r g y I n f l a t i o n R a t e 1 . 0 3 5 Ca p i t a l C o s t s ( $ i n 2 0 1 4 d o l l a r s ) ($ / y e a r i n 2 0 1 4 d o l l a r s ) ( $ / y e a r i n 2 0 1 4 d o l l a r s ) C a p i t a l C o s t = 2 6 , 3 0 0 , 0 0 0 $ E n e r g y 90 , 0 0 0 C h e m i c a l s 3 7 0 , 0 0 0 Yea r b y Y e a r L i f e C y c l e C o s t T a b l e NP V Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r 12 3 4 5 6 7 8 9 1 0 C a p i t a l C o s t 2 6 , 3 0 0 , 0 0 0 $ - - - - - - - - - - E n e r g y 2, 1 0 3 , 4 2 7 $ 9 0 , 0 0 0 9 3 , 1 5 0 9 6 , 4 1 0 9 9 , 7 8 5 1 0 3 , 2 7 7 1 0 6 , 8 9 2 1 1 0 , 6 3 3 1 1 4 , 5 0 5 1 1 8 , 5 1 3 122,661 C h e m i c a l s 8 , 6 4 7 , 4 2 4 $ 3 7 0 , 0 0 0 3 8 2 , 9 5 0 3 9 6 , 3 5 3 4 1 0 , 2 2 6 4 2 4 , 5 8 4 4 3 9 , 4 4 4 45 4 , 8 2 4 470,743 487,219 504,272 To t a l P r e s e n t W o r t h 37 , 0 5 0 , 8 5 1 $ 46 0 , 0 0 0 47 6 , 1 0 0 49 2 , 7 6 4 51 0 , 0 1 0 52 7 , 8 6 1 54 6 , 3 3 6 56 5 , 4 5 7 585,248 605,732 626,933 Ann u a l O p e r a t i n g C o s t s $ 46 0 , 0 0 0 47 6 , 1 0 0 49 2 , 7 6 4 51 0 , 0 1 0 52 7 , 8 6 1 54 6 , 3 3 6 56 5 , 4 5 7 585,248 605,732 626,933 To t a l A n n u a l i z e d C a p i t a l C o s t $ 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2,110,380 2,110,380 Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r YearYear 11 12 13 14 15 16 17 18 1920 C a p i t a l C o s t $ - - - - - - - - - - E n e r g y $ 12 6 , 9 5 4 13 1 , 3 9 7 13 5 , 9 9 6 14 0 , 7 5 6 14 5 , 6 8 3 15 0 , 7 8 1 15 6 , 0 5 9 161,521 167,174 173,025 C h e m i c a l s $ 52 1 , 9 2 2 54 0 , 1 8 9 55 9 , 0 9 5 57 8 , 6 6 4 59 8 , 9 1 7 61 9 , 8 7 9 64 1 , 5 7 5 664,030 687,271 711,325 To t a l P r e s e n t W o r t h 64 8 , 8 7 5 67 1 , 5 8 6 69 5 , 0 9 2 71 9 , 4 2 0 74 4 , 5 9 9 77 0 , 6 6 0 79 7 , 6 3 4 825,551 854,445 884,351 Ann u a l O p e r a t i n g C o s t s $ 64 8 , 8 7 5 67 1 , 5 8 6 69 5 , 0 9 2 71 9 , 4 2 0 74 4 , 5 9 9 77 0 , 6 6 0 79 7 , 6 3 4 825,551 854,445 884,351 To t a l A n n u a l i z e d C a p i t a l C o s t $ 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2,110,380 2,110,380 Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r YearYear 21 22 23 24 25 26 27 28 2930 C a p i t a l C o s t $ - - - - - - - - - - E n e r g y $ 17 9 , 0 8 1 18 5 , 3 4 9 19 1 , 8 3 6 19 8 , 5 5 0 20 5 , 5 0 0 21 2 , 6 9 2 22 0 , 1 3 6 227,841 235,815 244,069 C h e m i c a l s $ 73 6 , 2 2 2 76 1 , 9 9 0 78 8 , 6 5 9 81 6 , 2 6 2 84 4 , 8 3 2 87 4 , 4 0 1 90 5 , 0 0 5 936,680 969,464 1,003,395 To t a l P r e s e n t W o r t h 91 5 , 3 0 3 94 7 , 3 3 8 98 0 , 4 9 5 1, 0 1 4 , 8 1 3 1, 0 5 0 , 3 3 1 1, 0 8 7 , 0 9 3 1, 1 2 5 , 1 4 1 1, 1 6 4 , 5 2 1 1,205,279 1,247,464 Ann u a l O p e r a t i n g C o s t s $ 91 5 , 3 0 3 94 7 , 3 3 8 98 0 , 4 9 5 1, 0 1 4 , 8 1 3 1, 0 5 0 , 3 3 1 1, 0 8 7 , 0 9 3 1, 1 2 5 , 1 4 1 1, 1 6 4 , 5 2 1 1,205,279 1,247,464 To t a l A n n u a l i z e d C a p i t a l C o s t $ 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2, 1 1 0 , 3 8 0 2,110,380 2,110,380 An n u a l E n e r g y C o s t s Ch e m i c a l C o s t s Co s t C a t e g o r y Co s t C a t e g o r y Co s t C a t e g o r y Alt 4 : B i o M a g Ra t e s D i s c o u n t R a t e 5 . 0 0 % Ca p i t a l I n f l a t i o n R a t e ( M R ) 1 . 0 3 5 E n e r g y I n f l a t i o n R a t e 1 . 0 3 5 N o n - E n e r g y I n f l a t i o n R a t e 1 . 0 3 5 Ca p i t a l C o s t s ( $ i n 2 0 1 4 d o l l a r s ) ($ / y e a r i n 2 0 1 4 d o l l a r s ) ( $ / y e a r i n 2 0 1 4 d o l l a r s ) C a p i t a l C o s t = 2 6 , 5 0 0 , 0 0 0 $ E n e r g y 38 0 , 0 0 0 C h e m i c a l s 4 7 0 , 0 0 0 Yea r b y Y e a r L i f e C y c l e C o s t T a b l e NP V Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r Y e a r 12 3 4 5 6 7 8 9 1 0 C a p i t a l C o s t 2 6 , 5 0 0 , 0 0 0 $ - - - - - - - - - E n e r g y 8, 8 8 1 , 1 3 8 $ 3 8 0 , 0 0 0 3 9 3 , 3 0 0 4 0 7 , 0 6 6 4 2 1 , 3 1 3 4 3 6 , 0 5 9 4 5 1 , 3 2 1 4 6 7 , 1 1 7 4 8 3 , 4 6 6 5 0 0 , 3 8 7 517,901 C h e m i c a l s 1 0 , 9 8 4 , 5 6 5 $ 4 7 0 , 0 0 0 4 8 6 , 4 5 0 5 0 3 , 4 7 6 5 2 1 , 0 9 7 5 3 9 , 3 3 6 5 5 8 , 2 1 3 57 7 , 7 5 0 597,971 618,900 640,562 To t a l P r e s e n t W o r t h 46 , 3 6 5 , 7 0 3 $ 85 0 , 0 0 0 87 9 , 7 5 0 91 0 , 5 4 1 94 2 , 4 1 0 97 5 , 3 9 5 1, 0 0 9 , 5 3 3 1, 0 4 4 , 8 6 7 1, 0 8 1 , 4 3 7 1,119,288 1,158,463 Ann u a l O p e r a t i n g C o s t s $ 85 0 , 0 0 0 87 9 , 7 5 0 91 0 , 5 4 1 94 2 , 4 1 0 97 5 , 3 9 5 1, 0 0 9 , 5 3 3 1, 0 4 4 , 8 6 7 1, 0 8 1 , 4 3 7 1,119,288 1,158,463 To t a l A n n u a l i z e d C a p i t a l C o s t $ 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2,126,429 2,126,429 Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r YearYear 11 12 13 14 15 16 17 18 1920 C a p i t a l C o s t $ - - - - - - - - - E n e r g y $ 53 6 , 0 2 8 55 4 , 7 8 8 57 4 , 2 0 6 59 4 , 3 0 3 61 5 , 1 0 4 63 6 , 6 3 3 65 8 , 9 1 5 681,977 705,846 730,551 C h e m i c a l s $ 66 2 , 9 8 1 68 6 , 1 8 6 71 0 , 2 0 2 73 5 , 0 5 9 76 0 , 7 8 6 78 7 , 4 1 4 81 4 , 9 7 3 843,498 873,020 903,576 To t a l P r e s e n t W o r t h 1, 1 9 9 , 0 0 9 1, 2 4 0 , 9 7 4 1, 2 8 4 , 4 0 8 1, 3 2 9 , 3 6 3 1, 3 7 5 , 8 9 0 1, 4 2 4 , 0 4 7 1, 4 7 3 , 8 8 8 1, 5 2 5 , 4 7 4 1,578,866 1,634,126 Ann u a l O p e r a t i n g C o s t s $ 1, 1 9 9 , 0 0 9 1, 2 4 0 , 9 7 4 1, 2 8 4 , 4 0 8 1, 3 2 9 , 3 6 3 1, 3 7 5 , 8 9 0 1, 4 2 4 , 0 4 7 1, 4 7 3 , 8 8 8 1, 5 2 5 , 4 7 4 1,578,866 1,634,126 To t a l A n n u a l i z e d C a p i t a l C o s t $ 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2,126,429 2,126,429 Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r Ye a r YearYear 21 22 23 24 25 26 27 28 2930 C a p i t a l C o s t $ - - - - - - - - - E n e r g y $ 75 6 , 1 2 0 78 2 , 5 8 4 80 9 , 9 7 4 83 8 , 3 2 4 86 7 , 6 6 5 89 8 , 0 3 3 92 9 , 4 6 4 961,996 995,665 1,030,514 C h e m i c a l s $ 93 5 , 2 0 1 96 7 , 9 3 3 1, 0 0 1 , 8 1 0 1, 0 3 6 , 8 7 4 1, 0 7 3 , 1 6 4 1, 1 1 0 , 7 2 5 1, 1 4 9 , 6 0 1 1, 1 8 9 , 8 3 7 1,231,481 1,274,583 To t a l P r e s e n t W o r t h 1, 6 9 1 , 3 2 1 1, 7 5 0 , 5 1 7 1, 8 1 1 , 7 8 5 1, 8 7 5 , 1 9 7 1, 9 4 0 , 8 2 9 2, 0 0 8 , 7 5 8 2, 0 7 9 , 0 6 5 2, 1 5 1 , 8 3 2 2,227,146 2,305,096 Ann u a l O p e r a t i n g C o s t s $ 1, 6 9 1 , 3 2 1 1, 7 5 0 , 5 1 7 1, 8 1 1 , 7 8 5 1, 8 7 5 , 1 9 7 1, 9 4 0 , 8 2 9 2, 0 0 8 , 7 5 8 2, 0 7 9 , 0 6 5 2, 1 5 1 , 8 3 2 2,227,146 2,305,096 To t a l A n n u a l i z e d C a p i t a l C o s t $ 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2, 1 2 6 , 4 2 9 2,126,429 2,126,429 An n u a l E n e r g y C o s t s Ch e m i c a l C o s t s Co s t C a t e g o r y Co s t C a t e g o r y Co s t C a t e g o r y WRRF Project TM No. 12 – Process Alternatives Analysis (Draft) Appendix E – Non-Economic Criteria Results for each Alternative WRRF Project TM No. 12 – Process Alternatives Analysis (Draft) Page intentionally blank. Alternatives Evaluation Non‐Economic CriteriaAlt 1Alt 2Alt 3Alt 4WeightAlt 1Alt 2Alt 3Alt 4 MLEVerti‐CelHR ABBioMag MLEVerti‐CelHR ABBioMag Meet Permit Limits 3333515151515 EDCs Removal 222212222 Biosolids/UV Compatibility 3333515151515 Ease of Operation 23115101555 Maintenance 322139663 GHG Emissions 223136693 Level of Confidence/Proven 321139633 Piloting Recommended 331113311 Ease of Implementation 322213222 Good Neighbor (Odor)2222510101010 Minimize Chemicals (Safety)222236666 Ability to Meet Lower Limits 232236966 Technology Status 000000000 Total (Non‐Economic)30292421 94958071 Economic Criteria Capital Cost 26.4$ 32.4$ 26.3$ 26.5$ 26.4$ 32.4$ 26.3$ 26.5$ O&M Present Value 14.5$ 11.9$ 10.8$ 19.9$ 14.5$ 11.9$ 10.8$ 19.9$ Total Present Value 40.9$ 44.3$ 37.1$ 46.4$ 40.9$ 44.3$ 37.1$ 46.4$ Percent Difference NPV 10%19%0%25%10%19%0%25% Ranking Non‐Economic Ranking 1134 Capital Ranking 1411 NPV Ranking 2314 Appendix P TM No. 13 - Filter Technology Evaluation Page 1 of 15 Date: 6/26/2014 Prepared by: Cynthia Greene, PE; Michael Falk, PhD, PE Reviewed by: Mallika Ramanathan, PE; Holly Kennedy, PE Project: WRRF Project SUBJECT: TM NO. 13 – FILTER TECHNOLOGY EVALUATION (FINAL) The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long-term strategy for resource management. The purpose of this technical memorandum (TM) is to provide an overview of filtration technologies under consideration for expanding the filter complex at the WRRF. Contents Introduction .............................................................................................................................. 3 Background .............................................................................................................................. 3 Technologies ............................................................................................................................ 3 Granular Media Filter Technology ............................................................................................................ 6 Disk Filter Technology .............................................................................................................................. 7 Compressed Media Filter Technology .................................................................................................... 10 Summary and Conclusions ....................................................................................................14 List of Tables Table 1. Granular Media Filtration Technology Advantages and Disadvantages......................................... 7 Table 2. Disk Filter Technology Advantages and Disadvantages .............................................................. 10 Table 3. Compressed Media Filter Technology Advantages and Disadvantages ...................................... 12 Table 4. Compressible Media Filter Installations in CA .............................................................................. 13 Table 5. Filter Technology Comparison ...................................................................................................... 15 List of Figures Figure 1. SLO WRRF Existing Process Schematic (includes WRRF Energy Efficiency Project) ................ 4 Figure 2. Existing Filter Cell Complex ........................................................................................................... 5 Figure 3. Empty Filter Cell ............................................................................................................................. 5 WRRF Project TM NO. 13 – Filter Technology Evaluation (FINAL) Page 2 of 15 Figure 4. Aqua-Aerobic Systems , Inc. Aqua-Disk® Filter ............................................................................ 8 Figure 5. Kruger/Hydrotech Diskfilter ............................................................................................................ 8 Figure 6. NOVA/Ultrascreen Disk Filter ........................................................................................................ 9 Figure 7. Schreiber® Fuzzy Filter Filtration, Wash, and Flush Cycles ....................................................... 11 Figure 8. Schreiber® Fuzzy Filter Installation in Linda, CA (7’x7’ filter size and 12.7 mgd capacity)......... 12 WRRF Project TM NO. 13 – Filter Technology Evaluation (FINAL) Page 3 of 15 Introduction The City of San Luis Obispo’s Water Resource Recovery Facility (WRRF) treats municipal wastewater flow from the City, California Polytechnic State University (Cal Poly), and the San Luis Obispo County Airport. The WRRF has a permitted average dry weather flow (ADWF) capacity of 5.1 million gallons per day (mgd). Currently, the W RRF treats an ADWF of approximately 3.2 mgd. Buildout ADWF and peak hour flows are projected to be 5.4 mgd and 33.5 mgd, respectively (HDR 2014; WSC 2014). In September 2014, the WRRF’s National Pollutant Discharge Elimination System (NPDES) permit (Order R3-2014-0033) was renewed. In order to meet the limits, the WRRF will no longer be able to bypass peak flows around the advanced treatment system during wet weather events. All the flow must be treated through the advanced treatment system. As a result, the advanced treatment facilities will need to be expanded to treat the peak flows. This TM identifies filtration technologies under consideration for adding additional filtration capacity at the WRRF. Background A general process schematic of the existing treatment plant is shown in Figure 1. During wet weather events, the WRRF currently bypasses advanced treatment (aeration basins, tertiary treatment and cooling towers). In order to meet the renewed discharge permit limits, the WRRF will need to treat all the water through the activated sludge and filtration. The existing filter cells will need to be expanded as they are not sized to treat all the attenuated peak flows (upwards of 16 mgd). The plant currently uses granular media filtration (GMF) for tertiary treatment. A picture of the existing filter cells is provided in Figure 2 and Figure 3. There are currently four filters of 240 sf surface area (960 sf total; 240 sf per cell) capable of treating up to 8.3 mgd with one unit out of service at a filter loading rate of 8.0 gpm/sf. The anthracite and sand dual-media was replaced in 2014 with mono-media sand (1/8” x No. 12 with a uniformity coefficient of 1.4) and is at a filter depth of 72 inches. This evaluation considers three different filter technologies for filter expansion. The subsections below will describe each filter technology and make a recommendation for the WRRF Project. Technologies Three different filter technologies were considered to expand the filter complex: i) mono-media filters, ii) disk filters, and iii) compressible media filters. A description for each technology is provided in the subsections below. WR R F P r o j e c t TM N O . 1 3 – F i l t e r T e c h n o l o g y E v a l u a t i o n ( F I N A L ) Pa g e 4 o f 1 5 Fi g u r e 1 . S L O W R R F E x i s t i n g P r o c e s s S c h e m a t i c ( i n c l ud e s W R R F E n e r g y E f f i c i e n c y P r o j e c t ) He a d w o r k s (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) Ae r a t i o n Ba s i n Mo n o M e d i a Fi l t e r ( W R R F En e r g y E f f i c i e n c y Pr o j e c t ) CC T SLO Creek Emergency Storage3W Water System Recycled Water PC L SC L Bi o t o w e r FC L Co o l i n g To w e r DA F T AD AD AD St o r a g e Vo r t e x Cl a s s i f i e r Dr y i n g B e d Su p e r n a t a n t St o r a g e La g o o n Di s p o s a l Fe r r o u s Ch l o r i d e Po l y m e r Ra w In f l u e n t So d i u m Hy p o c h l o r i t e Ma g n e s i u m Hy d r o x i d e Fi l t e r B a c k w a s h Li q u i d S t r e a m s Sl u d g e S t r e a m s Re t u r n S t r e a m s Ch e m i c a l S t r e a m s Pr i m a r y C l a r i f i c a t i o n PC L Se c o n d a r y C l a r i f i c a t i o n SC L Fi n a l C l a r i f i c a t i o n FC L Ch l o r i n e C o n t a c t T a n k CC T Di s s o l v e d A i r F l o a t a t i o n T h i c k e n e r DA F T An a e r o b i c D i g e s t i o n AD Be l t F i l t e r P r e s s BF P DA F T S u p e r n a t a n t La g o o n R e t u r n Sodium Bisulfite Sc r e w P r e s s (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) RA S (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) WA S Fl o w s > 3 2 m g d to F l o w E Q Fl o w s > 2 2 m g d to F l o w E Q Bi o t o w e r B y p a s s Ad v a n c e d T r e a t m e n t B y p a s s ( F l o w s > 5 . 1 m g d ) Fl o w s C u r r e n t l y >1 6 m g d t o F l o w E Q WRRF Project TM NO. 13 – Filter Technology Evaluation (FINAL) Page 5 of 15 Figure 2. Existing Filter Cell Complex Figure 3. Empty Filter Cell WRRF Project TM NO. 13 – Filter Technology Evaluation (FINAL) Page 6 of 15 Granular Media Filter Technology The existing filtration facilities at the WRRF are granular media filters (GMF). A logical expansion of filtration capacity is to add two additional GMF filter cells. For a conventional GMF, influent is applied to the top of the filter bed and migrates in a downward fashion through the media. Typically, sand or anthracite is utilized as the filter media. The existing GMF units at the plant were designed for dual-media filtration. The media was replaced as part of the WRRF Energy Efficiency Project with mono-media sand because mono-media can sustain higher loading rates and have reduced backwash frequency compared to dual-media. The benefits of these improvements are additional capacity and a more energy efficient process. The backwash frequency was reduced from daily with dual-media to about every five days with mono-media. The backwash cycling with the mono-media is currently done manually, but the plan is to automate the process. During the back wash stage, stored filtered water is used to remove the particles that were collected in the filter bed by flowing from the bottom of the bed to the top. Additionally, backwash air blowers scour the media during this back wash cycle at five scfm/sf of media. As the filter is brought back on- line following the backwash cycle, the initial few minutes of filtered water produced needs to be wasted as the filter ripens. The existing filters with mono-media are subjected to a 20 to 30 minute backwash with air scour. The advantages and disadvantages of using GMF for filtration expansion are summarized in Table 1 below. The major advantages of GMF technology are it is a proven technology and the least complex option for expansion. The plant was designed for future filter expansion and adequate space has been provided adjacent to the existing filters. Operators are familiar with this technology and expansion will minimize changes in operational procedures. Additionally, the GMF is Title 22 compliant and the filtration technology lends itself to phosphorus removal (if required in the future). Additionally, the deep media bed translates to the highest quality filtered water of the considered technologies. The major disadvantages of GMF technology are the high capital cost, relative large footprint, and higher headloss and energy requirements when compared to disk and compressible media filters. Continuous backwash filters (CBFs) were not included in the evaluation. CBFs use the same media as conventional GMF and operate at comparable loading rates. However, the CBF does not offer any practical advantages over the GMF from a capital cost or operational perspective. Because redundancy is already provided in the existing GMF, there would be no real capital cost savings with adding CBF independently. Operationally, the continuous backwash process is more complex, as it would require operating two different filtration technologies. In addition, the CBF has a lower overall recovery, higher backwash and energy needs, and more frequent media replacement requirements. WRRF Project TM NO. 13 – Filter Technology Evaluation (FINAL) Page 7 of 15 Table 1. Granular Media Filtration Technology Advantages and Disadvantages Advantages Disadvantages Proven technology. Highest capital cost. Ease of construction - Most straight-forward option for expansion. Large footprint at 8.0 gpm/sf loading. Least complex – Maintains the existing filtration technology that operations is already familiarity with. Higher backwash (air/ water scour), energy requirements, and higher headloss requirements through filters compared to the other technologies considered. 1,000’s of installations in the U.S. Full cell shutdown during a backwash cycle. Several manufacturers so sole sourcing and state revolving fund (SRF) funding are not a concern. Post backwash recover is slower than the other technologies considered. GMF can be used for future phosphorous using metal salts (if required in the future). Unrestricted State of California Title 22 compliant. No piloting required (existing process at plant). Produces the highest quality filtered water of the technologies considered (benefit to downstream disinfection). Lower expected media replacement costs ($2,000 per year). No additional infrastructure-intensive pretreatment facilities required. Can add coagulant and chemicals directly to influent pipelines. Deep bed granular media filtration is compatible with potential future indirect or direct potable reuse treatment requirements. Disk Filter Technology A disk filter is a technology that has been around for a couple decades. This established technology uses a cloth piling, a metal mesh, or a plastic mesh to remove particles as water passes through the separation medium. Regardless of medium type, the solids removal mechanism for all disk filter technologies relies on surface filtration. In contrast, the GMF technology offers “in depth” filtration. As a result, disk filters are thought to produce lower quality water than GMF technology. Several different disk configurations exist and vary by manufacturer. In some configurations, the disk is submerged in the influent stream and influent passes from the outside, depositing solids on the surface, and through the media where effluent is collected. Effluent is collected via laterals inside the media and discharged by gravity. In other configurations, influent is carried through the center of the filter segments by an influent drum. As the water moves through the disk to the outside effluent tank, solids catch on the inside of the filter media. In both configurations, periodic backwashes remove solids from the media. The backwash requirements are typically lower than GMF and compressible media filters, both of which employ air scour and have higher headloss through the filters. During the backwash process, only a few disks are taken off-line and the rest of the units remain on-line. Three different media disk filter configurations are recommended for consideration: pile cloth media, polyester sheet media, or woven stainless steel screen media. Pile media is carpet-like cloth affixed to support structures using an outside to inside flow direction, as manufactured by Aqua Aerobics (see Figure 4). Polyester cloth can also be stretched across a frame, where filtration occurs from WRRF Project TM NO. 13 – Filter Technology Evaluation (FINAL) Page 8 of 15 inside to outside flow direction, as manufactured by Kruger and others (see Figure 5). Finally, stainless steel media can also be used, where influent flows into the filters in between a pair of disks and then out through the steel mesh, as manufactured by Nova (see Figure 6). Figure 4. Aqua-Aerobic Systems , Inc. Aqua-Disk® Filter Figure 5. Kruger/Hydrotech Diskfilter WRRF Project TM NO. 13 – Filter Technology Evaluation (FINAL) Page 9 of 15 Figure 6. NOVA/Ultrascreen Disk Filter Solids removal varies by application and manufacturer and is highly dependent on filter feed water quality. One of the differentiators between disk type and flow path is solids loading in an extreme event. The outside-in flow path of the pile disk filters allows for handling of a much higher solids spike than the inside-out flow path of the polyester media. Title 22 certified cloth with 5-micron and 10-micron pore sizes is available for pile media cloth. The smaller 5-micron pore cloth will reject a greater proportion of smaller particles but will require approximately 10% higher backwash and energy requirements compared to traditional 10-micron size media. The stainless steel mesh media (which has a nominal size rating of 10 micron) is able to handle a higher solids spike than cloth media filters, as the steel media is manufactured to have a narrower pore size distribution that rejects a larger proportion of smaller particles. Advantages and disadvantages of using Disk Filters for expansion at the plant are summarized in Table 2. The major advantages of using disk filters are lower capital cost, smaller footprint, and lower backwash requirements when compared to GMF. The major disadvantages of the disk filters are the propensity for pre-treatment chemicals, their operational complexity, and lack of filter depth to remove finer particles. As evidenced during the site visit to the City of Santa Cruz, CA, the operators need to constantly feed pre-treatment chemicals in order to reliably operate. Since the Santa Cruz, CA site visit, an evaluation of disk filter installations in the state found wide ranging pre-treatment requirements. There are over 30 installations of the Aqua-Aerobic and Kruger technologies in California. A portion of facilities report operating the technology as advertised (six gpm/sf with one WRRF Project TM NO. 13 – Filter Technology Evaluation (FINAL) Page 10 of 15 unit out of service), whereas others require large doses of pre-treatment chemicals, such as hypochlorite, and frequent backwashing. For example, the Eastern Municipal San Jacinto Plant in Hemet, CA, uses the Aqua-Aerobics AquaDisk filter technology and they are limited to a filter loading rate of between two and three gpm/sf. The additional operator complexity refers to operators having to maintain two different filtration systems at the plant (including the existing conventional mono-media sand filters) during wet weather conditions. Operating two filtrations systems is inherently more complex than operating a single system. Disk filters do not provide in depth filtration and they only provide marginal phosphorus removal. Disk filters have marginal capacity to reliably remove phosphorus. The filter can reduce TSS, but has very limited capability to handle the solids loading associated with chemical phosphorus removal. The chemicals have a propensity to “blind” the filters. Table 2. Disk Filter Technology Advantages and Disadvantages Advantages Disadvantages Low capital cost assuming no additional pretreatment required. This benefit would be offset if pre-treatment facilities are required. High complexity – Process consists of several moving parts; operator unfamiliarity. Adoption would entail two tertiary filtration processes at the plant. Low backwash and associated energy requirements (lower headloss). Construction more complex - Plant was designed to expand GMF. Medium footprint – The media is rated for a lower design flux than granular media but surface area is in a more compact arrangement. Unreliable for nutrient (phosphorous) removal as “blinding” can occur on the filter surface. Accepted Title 22 technology for several configurations. No in depth filtration: Possible particle pass-through 10 micron pores during wet weather events; pretreatment likely required. Several manufacturers available (e.g. Kruger, Aqua Aerobics, Parkson, Siemens). Piloting required. Filter unit remains in service during backwash – only a few disks backwashed at a time. Lower chemical tolerance than granular media – tolerance to metal salts and polymer is acceptable. Special disk may be required if free chlorine is added upstream of filters. Several installations in California, in particular for recycled water applications. Expensive media replacement (every 5-7 years). Pilot testing would be recommended to determine the pretreatment needs for wet weather performance, capability to remove phosphorus (for potential future phosphorous limits), and to provide an accurate life-cycle cost. Compressed Media Filter Technology The Compressed Media Filter (CMF) Technology has been around for several decades but there are very few tertiary treatment installations in California. The CMF uses a synthetic compressible media installed in a compact, modular cell. CMFs can use either a downflow or upflow configuration. In either configuration, influent flows though the media as opposed to around the media. The filter media is compressible so that the porosity of the filter bed can be changed as influent characteristics change. Compression of the media creates a porosity gradient in the filter that allows stratification and removal of particles of varying size as solids move through the filter. The CMF is capable of very high rate filtration (up to 40 gpm/sf is rated for Title 22 reuse). Figure 7 provides a cross-sectional view of a unit manufactured by Schreiber. WRRF Project TM NO. 13 – Filter Technology Evaluation (FINAL) Page 11 of 15 Figure 7. Schreiber® Fuzzy Filter Filtration, Wash, and Flush Cycles Both air scour and influent water are used during the backwash cycle. Under normal conditions, the backwash process would be initiated once or twice daily and each unit would be offline for approximately half an hour. Although there are a few manufacturers of the CMF technology, only one manufacturer (Schreiber) has Title 22 certification in California, which has a few installations in California, including a small installation (0.63 mgd) in Yountville, CA used for tertiary filtration and rated for Title 22 reuse. Generally, the filters are arranged in a single row, as shown in Figure 8. The WRRF installation would likely use a similar 7 foot by 7 foot filter size, arrangement, and footprint. WRRF Project TM NO. 13 – Filter Technology Evaluation (FINAL) Page 12 of 15 Figure 8. Schreiber® Fuzzy Filter Installation in Linda, CA (7’x7’ filter size and 12.7 mgd capacity) The advantages and disadvantages of using CMFs for expansion at the plant are summarized in Table 3. Table 3. Compressed Media Filter Technology Advantages and Disadvantages Advantages Disadvantages Lowest capital cost assuming no additional pretreatment required. This benefit would be offset if pre-treatment facilities are required. High complexity. Operators are unfamiliar with newer technology. Adoption would entail two tertiary filtration processes at the plant. Very small footprint (based on very high flux, up to 40 gpm/sf). Construction is more complex - Plant was designed to expand GMF. Suitable for wet weather events – Can maintain effluent quality. Very few installation in California (two installations >1 mgd; one installation for tertiary treatment to meet Title 22 requirements of 0.6 mgd). Ability to change porosity by compressing media. Sole source requirement: Only one manufacturer is Title 22 compliant (Schreiber). Low backwash requirements. Pilot testing required to determine pretreatment requirements and verify nutrient removal capability. Medium energy requirements (medium headloss). Lower chemical tolerance than granular media. Shorter filter downtime during backwash than GMF. Expensive media replacement (10-year life). Nutrient (phosphorous) removal with upstream chemical addition. The major advantages of the CMFs are the very small footprint and low capital cost compared to the GMF. The major disadvantage is that there are very few installations and a proven record of reliability has not yet been established in California. An evaluation of CMF installations throughout CA was carried out as presented in Table 4. WR R F P r o j e c t TM N O . 1 3 – F i l t e r T e c h n o l o g y E v a l u a t i o n ( F I N A L ) Pa g e 1 3 o f 1 5 Ta b l e 4 . C o m p r e s s i b l e M e d i a F i l t e r I n s t a l l a t i o n s i n C A Lo c a t i o n De s i g n F l o w , mg d Pr e - T r e a t m e n t Ch e m i c a l T y p e Pr e - T r e a t m e n t Ch e m i c a l D o s e Pr e - T r e a t m e n t Re a c t i o n T a n k s Di s i n f e c t i o n Co m m e n t Yo u n t v i l l e S a n i t a r y Di s t r i c t 0. 4 P o l y A l u m 1 2 g p d Y e s S o d i u m H y p o c h l o r i t e Ma l a g a 0 . 4 5 P o l y A l u m u n k n o w n N o U V • Di d n o t u s e t h e p r i o r y e a r a n d l i m i t e d b e f o r e th a t . • Ea s y t o m a i n t a i n a n d f u n c t i o n a l . Ca n a d a W o o d s , Ca r m e l 0. 1 5 u n k n o w n u n k n o w n u n k n o w n • Cu r r e n t l y n o t u s e d o r u n d e r u t i l i z e d . • Sa t i s f i e d w i t h p a s t p e r f o r m a n c e . • Su s c e p t i b l e t o f a i l u r e a n d p r o b a b l y n o t su s t a i n a b l e f o r t h e n e x t 2 0 y e a r s . So l e d a d 5 . 5 P o l y A l u m < 0 . 5 p p m Y e s ; 3 0 m i n s w i t h cu r r e n t f l o w s UV • Sa t i s f i e d . • De s i g n e d f o r 3 0 g p m / s f . • Th e k e y t o s u c c e s s f u l o p e r a t i o n i s t h e 3 0 mi n u t e s r e a c t i o n t i m e i n t h e p r e - t r e a t m e n t re a c t i o n t a n k . Li n d a 1 2 . 7 u n k n o w n u n k n o w n u n k n o w n • Pr e t t y s t r a i g h t - f o r w a r d . Gr a t o n 0 . 5 P r o p r i e t a r y P o l y m e r an d S u r f a c t a n t 1 m L / h r Y e s , S A F P a s t e u r i z a t i o n • Fi l t e r s p e r f o r m i n g f a i r l y w e l l b u t p o s s i b l y un d e r s i z e d . • Pr o b l e m s w i t h c o m p u t e r i n t e r f a c i n g . • On c e p e r w e e k c l e a n i n g r e q u i r e d . WRRF Project TM NO. 13 – Filter Technology Evaluation (FINAL) Page 14 of 15 In general, the installations all seemed satisfied with the performance. In all cases, pre-treatment chemicals were used but at wide ranging doses. The operator at Soledad reported that key to a CMF technology is the pre-treatment reaction tank residence time (30 mins residence time). The CMF will also add operational complexity, as the operation of two different filtration systems, including the existing mono-media sand filters, would need to be synchronized at the plant. In addition, only one CMF manufacturer has achieved Title 22 compliance and would therefore require sole-source procurement of the technology. Piloting of the CMF is necessary to determine treatability and performance during wet weather events. Results of pilot testing would verify whether additional infrastructure would be necessary (i.e. pretreatment flocculation basins) to meet stringent disinfection and permit requirements and to obtain more accurate life-cycle costs. Summary and Conclusions A comparison matrix that considers economic and non-economic parameters is presented in Table 5. Only the GMF technology is capable of in-depth filtration and providing a reliable filter effluent quality for wet weather flows without requiring pilot testing before plant predesign. The plant was designed to accommodate expansion of the GMFs and so will be the least difficult option to both construct and operate. Both disk filters and compressed media filters have attractive attributes, but selection of these technologies will complicate current filtration operations at the plant. Startup and coordination of two types of filtration technologies will be more challenging than simply maintaining and expanding the existing GMF at the plant. Another major disadvantage of the disk filters and CMF is that both are very susceptible to small particle flow-through during peak wet weather events due to their limitation for in-depth filtration. Downstream processes, such as cooling towers and UV disinfection, are susceptible to fouling by these small particles. Adoption of these technologies will likely require pretreatment upstream of filtration to meet downstream disinfection requirements, increasing the overall capital cost for the option. Piloting and site visits would be recommended for evaluating the disk filter and CMF performance and obtaining a more accurate life-cycle cost estimate. Since expansion of GMF is well understood (no piloting and operators are familiar) and would be compatible with a future indirect or direct potable reuse treatment scheme, the recommended plan presented in the Facilities Plan is based on GMF.. WR R F P r o j e c t TM N O . 1 3 – F i l t e r T e c h n o l o g y E v a l u a t i o n ( F I N A L ) Pa g e 1 5 o f 1 5 Ta b l e 5 . F i l t e r T e c h n o l o g y C o m p a r i s o n Te c h n o l o g y G r a n u l a r M e d i a F i l t e r D i s k F i l t e r C o m p r e ss i b l e M e d i a F i l t e r Fi l t e r M e d i a / M a t e r i a l Sa n d P o l y e s t e r m i c r o f i b e r w o v e n p i l e c l o t h f a b r i c P ol y p h e n y l e n e s u l p h i d e w / a l u m i n u m p i n Fi l t e r P o r o s i t y Fl o w a r o u n d : S a n d 1 / 8 ” x N o 12 . U C = 1 . 4 0 Fl o w t h r o u g h : 5 a n d 1 0 m i c r o n , b o t h T i t l e 2 2 ce r t i f i e d Fl o w t h r o u g h : 4 micron. Variable porosity up o n c o m p r e s s i o n . Fi l t e r D e p t h 72 ” N / A No r m a l c o m p r e s s i o n d e p t h 3 0 ” Ca p i t a l C o s t Hi g h Lo w (a s s u m e s n o a d d i t i o n a l p r e t r e a t m e n t re q u i r e m e n t s ) Lo w (a s s u m e s n o a d d i t i o n a l p r e t r e a t m e n t re q u i r e m e n t s ) Op e r a t i o n a l C o m p l e x i t y Lo w c o m p l e x i t y Hi g h ; Re q u i r e s o p e r a t i n g G M F p l u s t h i s te c h n o l o g y Hi g h ; R e q u i r e s o p e r a t i n g G M F p l u s t h i s te c h n o l o g y Co n s t r u c t a b i l i t y Ea s i e r M o r e d i f f i c u l t M o r e d i f f i c u l t Fo o t p r i n t La r g e M e d i u m S m a l l Ov e r a l l P r o c e s s Re l i a b i l i t y Hi g h L o w ( r e q u i r e s p i l o t i n g ) L o w ( r e q u i r e s p i l o t i n g ) Ef f l u e n t Q u a l i t y - Pe a k Lo a d i n g Go o d P o o r ( r e q u i r e s p i l o t i n g ) M o d e r a t e ( r e q u i r e s p i loting) Re l i a b l e P h o s p h o r o u s Re m o v a l Hi g h L o w Mo d e r a t e Ti t l e 2 2 C o m p l i a n t ? Ye s Y e s Ye s ( b u t o n l y o n e m a n u f a c t u r e r ) Op e r a t i o n a l H i s t o r y Ma n y ( t h o u s a n d s ) S e v e r a l ( H u n d r e d s ) V e r y F e w Re q u i r e S o l e S o u r c e Fu n d i n g ? No N o Ye s * Ba c k w a s h R e q u i r e m e n t s 1- 5 % 1 - 3 % 2- 3 % Pi l o t i n g R e c o m m e n d e d ? No : Pr o v e n / E x i s t i n g Te c h n o l o g y Ye s Ye s En e r g y Hi g h L o w Me d i u m Me d i a 10 y e a r r e p l a c e m e n t 5 - 7 y e a r r e p l a c e m e n t 1 0 y e a r r e pl a c e m e n t Fi l t e r Dow n t i m e Dur i n g Ba c k w a s h Fu l l b a s i n s h u t d o w n , 2 0 m i n , on c e p e r d a y In d i v i d u a l c e l l s b a c k w a s h e d b u t c o n t i n u o u s fi l t r a t i o n t h r o u g h o t h e r s Ba c k w a s h d o w n t i m e 3 0 m i n , 2 x p e r d a y Ch e m i c a l T o l e r a n c e Hi g h L o w Mo d e r a t e * T h e r e a r e t w o C M F t e c h n o l o g i e s , b u t o n l y o n e o f t he m i s T i t l e 2 2 c o m p l i a n t . Appendix Q TM No. 14 - Cooling Technology Evaluation Page 1 of 14 Date: 11/14/2014 Prepared by: Irina Lukicheva, PhD, PE; Michael Falk, PhD, PE Reviewed by: Mallika Ramanathan, PE Project: WRRF Project SUBJECT: TM NO. 14 - COOLING TECHNOLOGIES TECHNICAL MEMORANDUM The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long-term strategy for resource management. The purpose of this technical memorandum (TM) is to provide an overview of cooling technologies to replace the existing cooling towers. Potential cooling technologies other than cooling towers are presented, and a technology is recommended for further evaluation. Contents Introduction .............................................................................................................................. 3 Background .............................................................................................................................. 3 Technologies ............................................................................................................................ 6 Cooling Towers System ............................................................................................................................ 6 Ground Source Heat Pump ...................................................................................................................... 8 Spray Pond Cooling System ..................................................................................................................... 9 Chiller Cooling System ........................................................................................................................... 10 Summary and Conclusions ....................................................................................................11 List of Tables Table 1. Cooling Tower System Advantages and Disadvantages ................................................................ 7 Table 2. Cooling Tower Location Impacts ..................................................................................................... 7 Table 3. Ground Source Heat Pump Advantages and Disadvantages ........................................................ 9 Table 4. Spray Pond Cooling System Advantages and Disadvantages ..................................................... 10 Table 5. Chiller Cooling System Advantages and Disadvantages ............................................................. 11 Table 6. Cooling Technologies Comparison Matrix .................................................................................... 12 WRRF Project TM No. 14 - Cooling Technologies Technical Memorandum Page 2 of 14 List of Figures Figure 1. SLO WRRF Existing Process Schematic (includes WRRF Energy Efficiency Project) ................ 4 Figure 2. Existing Cooling Towers at the WRRF .......................................................................................... 5 Figure 3. Number of Cooling Towers On-Line over Time ............................................................................. 5 Figure 4. Temperature over Time for i) SLO Creek, ii) WRRF Discharge, and iii) SLO Creek Temperature Increase from WRRF Discharge ..................................................................................... 6 Figure 5. Ground Source Heat Pump Treatment Schematic ........................................................................ 8 Figure 6. Spray Pond, Volgodonsk Nuclear Power Station, Russia ............................................................. 9 Figure 7. Photos of Pipe-In-Pipe Chiller System used in Conveyance Pipelines ....................................... 10 Figure 8. Recommended Cooling Configuration for the (A) Cooling Towers and (B) Heat Exchanger/Chillers ............................................................................................................................. 14 WRRF Project TM No. 14 - Cooling Technologies Technical Memorandum Page 3 of 14 Introduction The City of San Luis Obispo’s Water Resource Recovery Facility (WRRF) treats municipal wastewater flow from the City, California Polytechnic State University (Cal Poly), and the San Luis Obispo County Airport. The WRRF has a permitted average dry weather flow (ADWF) capacity of 5.1 million gallons per day (mgd). Currently, the W RRF treats an ADWF of approximately 3.2 mgd. Buildout ADWF and peak hour flows are projected to be 5.4 mgd and 33.5 mgd, respectively (HDR 2014; V&A, 2012; WSC 2014). In September 2014, the WRRF’s National Pollutant Discharge Elimination System (NPDES) permit (Order R3-2014-0033) was renewed. Effluent discharged shall not cause the receiving water temperature to increase more than 5 DegF above receiving water temperature. To meet the temperature requirements, either more cooling towers are required or a different technology is required to cool the water. This TM evaluates cooling technologies that could be used for expansion. The objective is to increase cooling capacity and consider different locations within the treatment train. Background A general process schematic of the existing treatment plant is shown in Figure 1. Three cooling towers are currently used to meet the discharge requirements and they are located upstream of filtration and disinfection. The cooled and treated effluent is discharged to San Luis Obispo Creek and/or distributed to recycled water customers. Under this configuration, the recycled water flows are also cooled. All three cooling towers are the same model, Baltimore Air Model 3868 CSR, each at 12 ft wide by 21 ft long by 14 ft tall. A picture of the existing cooling towers is provided in Figure 2. A sidestream flow of nitrified effluent is currently diverted to the cooling towers from the filter distribution box. The cooling tower effluent is then pumped back to the filter complex. The WRRF currently operates the cooling towers as single pass. However, the plumbing has the ability to return flows to top of the cooling towers and perform multiple pass cooling. The cooling tower media was replaced this past summer with Brentwood Industries Accu-Pac XF-75 Herringbone Film Fill Media. The media has integrated inlet louvers (XF75 IL) and drift eliminators (XF75 ID). The benefits of the new cooling tower media is improved cooling efficiencies coupled with the ability to maintain and clean biological growth/scaling on the media. The historical cooling tower data (January 2010 to present) was analyzed to confirm that additional cooling capacity is required under the WRRF Project build out flows and loads. A plot of the number of cooling towers on-line over time is provided in Figure 3. The use of all three cooling towers has typically occurred in the fall/shoulder months when wet weather events can occur. In more recent years (2013 and 2014) three cooling towers were operated for extended durations in summer and fall months, and almost 50 percent of the year. This additional use in recent years is attributed to concerns over reliably meeting the NPDES permit temperature limits. WR R F P r o j e c t TM N o . 1 4 - C o o l i n g T e c h n o l o g i e s T e c h n i c a l M e m o r a n d um Pa g e 4 o f 1 4 Fi g u r e 1 . S L O W R R F E x i s t i n g P r o c e s s S c h e m a t i c ( i n c l ud e s W R R F E n e r g y E f f i c i e n c y P r o j e c t ) He a d w o r k s (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) Ae r a t i o n Ba s i n Mo n o M e d i a Fi l t e r ( W R R F En e r g y E f f i c i e n c y Pr o j e c t ) CC T SLO Creek Emergency Storage3W Water System Recycled Water PC L SC L Bi o t o w e r FC L Co o l i n g To w e r DA F T AD AD AD St o r a g e Vo r t e x Cl a s s i f i e r Dr y i n g B e d Su p e r n a t a n t St o r a g e La g o o n Di s p o s a l Fe r r o u s Ch l o r i d e Po l y m e r Ra w In f l u e n t So d i u m Hy p o c h l o r i t e Ma g n e s i u m Hy d r o x i d e Fi l t e r B a c k w a s h Li q u i d S t r e a m s Sl u d g e S t r e a m s Re t u r n S t r e a m s Ch e m i c a l S t r e a m s Pr i m a r y C l a r i f i c a t i o n PC L Se c o n d a r y C l a r i f i c a t i o n SC L Fi n a l C l a r i f i c a t i o n FC L Ch l o r i n e C o n t a c t T a n k CC T Di s s o l v e d A i r F l o a t a t i o n T h i c k e n e r DA F T An a e r o b i c D i g e s t i o n AD Be l t F i l t e r P r e s s BF P DA F T S u p e r n a t a n t La g o o n R e t u r n Sodium Bisulfite Sc r e w P r e s s (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) RA S (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) WA S Fl o w s > 3 2 m g d to F l o w E Q Fl o w s > 2 2 m g d to F l o w E Q Bi o t o w e r B y p a s s Ad v a n c e d T r e a t m e n t B y p a s s ( F l o w s > 5 . 1 m g d ) Fl o w s C u r r e n t l y >1 6 m g d t o F l o w E Q WRRF Project TM No. 14 - Cooling Technologies Technical Memorandum Page 5 of 14 Figure 2. Existing Cooling Towers at the WRRF Figure 3. Number of Cooling Towers On-Line over Time 0 1 2 3 Jan-10Jul-10Feb-11Aug-11Mar-12Sep-12Apr-13Nov-13May-14Dec-14 Nu m b e r o f C o o l i n g T o w e r s O n - L i n e WRRF Project TM No. 14 - Cooling Technologies Technical Memorandum Page 6 of 14 Figure 4 presents the temperature values over time for several locations: San Luis Obispo (SLO) Creek upstream of the WRRF, the WRRF discharge, and SLO Creek temperature increase associated with the WRRF discharge. The data suggests that the WRRF occasionally exceeds the temperature delta limit, 5 DegF, as evidenced by four violations over the last three years. These violations have all occurred with two or three cooling towers on-line. In order to reliably meet the projected future flows and loads, additional cooling capacity is recommended to accommodate build out flows and loads. Figure 4. Temperature over Time for i) SLO Creek, ii) WRRF Discharge, and iii) SLO Creek Temperature Increase from WRRF Discharge Technologies Four different cooling technologies were considered for this planning level evaluation: i) status quo (cooling towers), ii) chillers using an in pipe heat exchanger, iii) ground heat source pumping (GHSP), or iv) spray pond cooling system. A description for each technology is provided in the sub-sections below. Cooling Towers System A cooling tower is a water-to-air heat exchanger, where air is blown through a falling spray of water. The type of heat rejection in a cooling tower is termed "evaporative" in that a small portion of the water being cooled evaporates into a moving air stream to provide cooling to the rest of the water stream. The evaporation from the water stream transferred to the air stream raises the wet bulb temperature and related relative humidity to near 100%, and this air is discharged to the 0 5 10 15 20 25 Jul-12Oct-12Jan-13May-13Aug-13Nov-13Mar-14Jun-14Sep-14Dec-14 Te m p e r a t u r e ( F ) Upstream Creek Temp WRRF Discharge Temp Temp Increase in Creek Renewed NPDES Permit Limit for Temperature Increase in Creek WRRF Project TM No. 14 - Cooling Technologies Technical Memorandum Page 7 of 14 atmosphere. Effluent temperature is limited to an approach temperature of about 5 DegF (the maximum difference between the effluent temperature and the ambient wet bulb temperature). Table 1 lists the advantages and disadvantages for the cooling tower technology. The technology is proven, has relatively low capital cost, but it suffers from biofouling which is difficult to control and the limitation of the approach temperature. The WRRF currently adds liquid chlorine in the filter feed channel to control biofouling. Chlorine addition is not feasible in the future due to concerns over violating the renewed NPDES permits trihalomethane (THM) limit. A new biofouling control strategy must be developed other than chlorine addition if the status quo is maintained under the WRRF Project. Table 1. Cooling Tower System Advantages and Disadvantages Advantages Disadvantages Proven technology at the WRRF. Effluent temperature is limited to 5 DegF above the wet bulb temperature. Moderate energy required. Periodic cleaning of the towers is required. The frequency is not known with the new media. Can be modulated by controlling feed flow to minimize energy usage. Using a disinfectant to control biofouling is a concern with the stringent THM limits. The WRRF currently uses chlorine but this is thought to not be an option under the WRRF Project. Relatively low capital cost as the system is already in place at the WRRF. The existing location is visual blight and noisy for those using the Bob Jones Bike Trail. The cooling tower system evaluation is focused on location within the WRRF treatment configuration. The options are to keep the system in its current location (upstream of filters), move downstream of the filters, or move downstream of disinfection. The advantages and disadvantages of each of these options are outlined in the table below: Table 2. Cooling Tower Location Impacts Location Upstream of filters (status quo) Downstream of filters Downstream of disinfection Ability to meet renewed NPDES permit. Yes Maybe No Cools recycled water. Yes Yes No Ability to capture biofouling material downstream. Yes No No Cost associated with moving towers. No Yes Yes Propensity for biofouling. High Medium Low Visual Blight and Noise. High Medium Low The key differences in Table 2 for locating cooling towers downstream of disinfection are cooling the recycled water and the ability to meet the renewed NPDES permit. Moving the cooling towers downstream of the filters or disinfection has an inherent risk in meeting the renewed NDPES permit. If downstream of filters, the recycled water is cooled and sloughed off biomass can negatively impact UV disinfection and the ability to meet disinfection requirements at the point of compliance. Mitigating the permit issues are possible if the point of compliance location is moved to immediately WRRF Project TM No. 14 - Cooling Technologies Technical Memorandum Page 8 of 14 following UV disinfection (i.e., upstream of the cooling towers). However, this likelihood of the Water Board accepting this are low given that the cooling towers provide a treatment. Maintaining the cooling towers in the existing location is recommended due to the ability to meet the renewed NDPES permit disinfection requirements. Placing the cooling towers downstream of the filters is possible and preferred to minimize biological fouling, but it would require pilot testing to determine the impact on disinfection. Moving the cooling towers downstream of disinfection is fatally flawed due to the inability to reliably meet discharge disinfection requirements. Ground Source Heat Pump A ground source heat pump (GSHP) circulates water through pipes buried in the ground in trenches or vertical boreholes, providing cooling of the flow stream. Figure 5 provides a schematic of the GSHP technology. In the case of cooling, a heat exchanger is used to transfer heat from the water to the refrigerant. The water is pumped through the underground pipes, losing latent heat to the earth, and then returned to the heat exchanger. Through this process, the water loses heat to a continuous stream of cooled refrigerant from the GSHP. The system would be located between the UV disinfection and the creek discharge. The GSHP would most likely not be deemed a treatment process as the cooling takes place within the discharge pipeline. Thus, the technology could be potentially located downstream of UV disinfection. A ground source heat pump at this location would require several thousand vertical bore-holes, each at about 400’ deep. These wells are necessary to investigate the most cost-effective locations (assuming the hydrogeologic conditions are favorable) for cooling the water. The footprint to drill all of these holes is on the order of four to five acres. Figure 5. Ground Source Heat Pump Treatment Schematic WRRF Project TM No. 14 - Cooling Technologies Technical Memorandum Page 9 of 14 The advantages and disadvantages of the GSHP are outlined in Table 3. Due to the disadvantages , the GSHP technology is not feasible for effluent cooling. Table 3. Ground Source Heat Pump Advantages and Disadvantages Advantages Disadvantages Most efficient technology of the technologies considered. Requires about 4 to 5 acres (about 1 acre per 400 ton capacity; about a 1,500 tons required for the WRRF). Potential to located downstream of disinfection and not cool recycled water. Requires a 1,000 or more 400’ deep wells. Invisible to the public on the Bob Jones Bike Trail. Expensive cooling technology. Can be modulated to meet demand. Typically used for heating/cooling buildings, not large water volumes such as those seen at the WRRF. The construction sequencing is straight-forward; this can be completed while the existing cooling towers are in operation. Mechanically intensive (still requires a heat exchanger and compressor). Energy recovered can be used for HVAC at the WRRF. Spray Pond Cooling System A spray pond is a body of water that has a system of pumps, piping and sprayers which spray pond water into the air using high pressure nozzles. The heat exchange between the spray water and the surrounding air lowers the water temperature. Figure 6 illustrates a spray pond at a Nuclear Power Station. In essence, a spray pond is evaporative cooling (e.g., cooling towers) without the media that provides a high surface area and forces the air flow. As a result, it requires a larger footprint than cooling towers and does not as reliably cool the water. The technology is more dependent on ambient conditions than cooling towers. Figure 6. Spray Pond, Volgodonsk Nuclear Power Station, Russia The spray pond would most likely be situated in the wetlands along the Bob Jones Bike Trail (between disinfection and SLO Creek). The spray ponds would need to be lined for pollution control. The wetlands themselves are an intrinsic part of the Bob Jones Bike Trail, so it might be difficult to obtain community support for making significant changes to this local landmark. WRRF Project TM No. 14 - Cooling Technologies Technical Memorandum Page 10 of 14 Operationally, water would be diverted to the spray ponds (most likely pre-filtered water), cooled and conveyed back to filtration for treatment prior to disinfection and discharge. This would require additional pumping beyond the current practice at the WRRF. Additionally, there are concerns over solids production in the spray ponds that might negatively impact filter performance when returned for polishing, disinfection, and discharge. The advantages and disadvantages for the spray pond cooling system are outlined in Table 4. Due to the disadvantages, spray ponds are not feasible for effluent cooling. Table 4. Spray Pond Cooling System Advantages and Disadvantages Advantages Disadvantages Low energy costs. Modifying the existing wetlands system could be challenging to get community support as this is along the Bob Jones Bike Trail. Relatively low capital costs. System performance highly dependent on wet bulb temperature. Concerns over reliably meeting the renewed NPDES permit temperature requirements. Low maintenance costs. Carryover of the misting spray. Can be modulated to meet demand. The construction sequencing is straight-forward; this can be completed while the existing cooling towers are in operation. Chiller Cooling System Water cooled chillers exchange heat between a low temperature water source (chilled water) and refrigerant with a vapor-compression cycle. The refrigerant cycle consists of an evaporative heat exchanger, a compressor, condenser coil and expansion valve. Return chilled water is passed through the evaporative exchanger where heat from the water is transferred to the cold refrigerant gas which cools the water. The refrigerant gas is then compressed and cooled in a condenser heat exchanger where the heat from the hot gas is transferred to the returning condensate water causing the gas to condense. As the condensed gas expands through the expansion valve the gas cools and the cycle is repeated. The condenser water circuit wlll be composed of a pumped loop between the chiller and cooling towers. The existing cooling towers can be used in the condenser loop. The discharge pipe from disinfection to the creek discharge point (about ¾ mile) could serve as the chiller cooling system. Figure 7 presents chiller systems configured within a conveyance pipeline - using pipe-in-pipe technology whereby the outer pipe carries the cooling fluid. The existing pipe would need to be replaced with a pipe-in-pipe configuration. Most likely, this pipeline would be placed next to the existing pipe. Figure 7. Photos of Pipe-In-Pipe Chiller System used in Conveyance Pipelines WRRF Project TM No. 14 - Cooling Technologies Technical Memorandum Page 11 of 14 A second option would be a series of plate and frame or shell and tube heat exchangers. Effluent would flow through the tubes and chilled water through the shell to cool the effluent. The heat exchangers can be sized to reduce the pressure drop and allow gravity flow through them, and eliminate the need to have additional pumping. The advantages and disadvantages for a chiller cooling system are outlined in Table 5. The technology is flexible in that the chillers can be cycled to regulate the temperature depending on the stream temperature conditions. However, the technology would have high capital and operations and maintenance costs. Of the technologies considered, the chilled water system or cooling tower technology are the only ones feasible for use at the WRRF. Table 5. Chiller Cooling System Advantages and Disadvantages Advantages Disadvantages Proven technology. High capital cost. Independent of wet bulb temperature as this all occurs in the discharge pipe. High energy demand. The temperature cooling can be modulated to meet demand. Need to replace existing discharge pipe. High maintenance costs. The construction sequencing is straight-forward; this can be completed while the existing cooling towers are in operation. Plate and frame or shell and tube heat exchanges will require periodic cleaning. Summary and Conclusions A cooling technology comparison matrix is provided in Table 6. The comparison considers both economic and non-economic parameters. The existing cooling towers in their current location are a viable method for cooling as long as they are well-maintained. However, keeping the cooling towers at their current location has significant drawbacks, as biofouling on the media will continue to be problematic, not feasible in the long-term to use chlorine at the filter feed, and the towers can be a visual blight along the Bob Jones Bike Trail for some locations. A fourth and possibly fifth cooling tower would most likely be required, but there appears to be sufficient space at all three prospective locations. Moving the cooling towers to either downstream location has an inherent risk in meeting the renewed NDPES permit. The attraction in moving downstream of disinfection is that only discharge water would be cooled (i.e., no recycled water) and the propensity for biofouling on cooling tower media would be reduced. However, the WRRF could violate their renewed permit coliform limits. If the WRRF is interested in pursuing siting cooling towers downstream of disinfection, it is critical to engage the Regional Water Quality Control Board (CCRWQCB) now to discuss the potential for moving their point of compliance immediately downstream of disinfection and excluding the cooling tower as a treatment. The probability of the CCRWQCB to accept this strategy is low, but it is worth a discussion nonetheless as the other benefits are attractive. Of the three other technologies considered, the only potentially viable option is the chiller cooling system. The ground source heat pump requires four to five acres, the drilling of upwards of 1,000 wells at 400’ deep, and it is equipment intensive. The spray ponds will most likely not be able to reliable meet the renewed NPDES permit requirements, as well as negatively affecting the existing wetland. WR R F P r o j e c t TM N o . 1 4 - C o o l i n g T e c h n o l o g i e s T e c h n i c a l M e m o r a n d um Pa g e 1 2 o f 1 4 Ta b l e 6 . C o o l i n g T e c h n o l o g i e s C o m p a r i s o n M a t r i x Lo c a t i o n Co o l i n g T o w e r Up s t r e a m o f f i l t e r s (s t a t u s q u o ) Co o l i n g T o w e r Do w n s t r e a m o f fi l t e r s Co o l i n g T o w e r Do w n s t r e a m o f di s i n f e c t i o n GS H P Sp r a y P o n d s Chiller Ab i l i t y t o m e e t r e n e w e d N P D E S pe r m i t Ye s Ma y b e No Ye s Pr o b a b l y N o t Yes Co o l s r e c y c l e d w a t e r Ye s Ye s No No Ye s No Ca p i t a l C o s t Lo w ($ 0 . 1 5 - 0 . 3 0 / g p d ) Lo w ($ 0 . 1 5 - 0 . 3 0 / g p d ) Lo w ($ 0 . 1 5 - 0 . 3 0 / g p d ) Hi g h Lo w High ($0.50-0.65/gpd) Op e r a t i o n s C o s t Me d i u m Me d i u m Me d i u m Lo w Lo w High Fo o t p r i n t Sm a l l Sm a l l Sm a l l Me d i u m (4 t o 5 o f ac r e s ) Hu g e (1 0 ’ s t o 1 0 0 ’ s o f ac r e s ) Large Ab i l i t y t o c a p t u r e bi o f o u l i n g m a t e r i a l do w n s t r e a m Ye s No No -- Ye s -- Pr o p e n s i t y f o r b i o f o u l i n g Hi g h Me d i u m Lo w -- Un k n o w n Medium Vi s u a l B l i g h t a n d N o i s e Hi g h Me d i u m Lo w -- Hi g h High Co n s t r u c t i o n S e q u e n c i n g No t a n i s s u e No t a n i s s u e No t a n i s s u e Ea s y Ea s y Easy WRRF Project TM No. 14 - Cooling Technologies Technical Memorandum Page 13 of 14 The chiller cooling system would provide the best temperature control to meet the effluent temperature requirements. However, this alternative comes at a price. As a point of reference, two other large WRRFs (>>150 mgd) did a similar analysis and found a chiller system to cost about $0.60/gpd capacity (about $0.20/gpd capacity for cooling towers). Furthermore, the annual operating cost for a chiller is about five times more costly than cooling towers. This additional energy demand might be problematic for maintaining the lower tier PG&E energy rates at the WRRF. Additional cooling capacity is required in the near-term as the WRRF struggles to meet the temperature limits, especially during the shoulder months. The use of cooling towers may not guarantee the lower effluent temperatures will always be reached, whereas chiller systems can be sized to meet the low effluent temperature requirements. Cooling towers in combination with a chiller system will allow the cooling towers to provide most of the cooling at a lower energy cost and the chiller system to provide additional cooling to meet regulatory requirements under worst-case scenario conditions. Additionally, the chiller will only cool water that is discharged to San Luis Obispo Creek. The recommended combined system is presented in Figure 8. The combined system includes adding a fourth and fifth cooling tower at the existing cooling towers coupled with a heat exchanger/chiller system to treat disinfected water that will be discharged to the San Luis Obispo Creek. The heat exchanger/chiller system includes a chiller with a water circuit recirculating water between the chiller and a sixth cooling tower and a refrigerant circuit between the chiller and a heat exchanger immersed in Plant effluent. Plant effluent will gravity flow through the heat exchanger and will be cooled by exchanging heat with the refrigerant. The sixth cooling tower will be collocated with and dedicated to the chiller operation. As it is on a separate loop, isolated from Plant effluent, there will be more flexibility to chemically condition the condenser water to inhibit fouling of the media. WRRF Project TM No. 14 - Cooling Technologies Technical Memorandum Page 14 of 14 Figure 8. Recommended Cooling Configuration for the (A) Cooling Towers and (B) Heat Exchanger/Chillers Appendix R TM No. 15 - Additional Sampling Page 1 of 20 Date: 6/10/2015 Prepared by: Irina Lukicheva, PhD, PE; Michael Falk, PhD, PE Reviewed by: Mallika Ramanathan, PE Project: WRRF Project SUBJECT: TM NO. 15 - ANALYSIS OF ADDITIONAL SAMPLING FOR THE WRRF PROJECT Contents Introduction .............................................................................................................................. 3 Sampling Results ..................................................................................................................... 6 Upstream of Bar Screens ......................................................................................................................... 6 Primary Effluent ........................................................................................................................................ 8 Secondary Clarifier Effluent .................................................................................................................... 10 Final Clarifier Effluent ............................................................................................................................. 11 Primary Solids ......................................................................................................................................... 11 Thickening Return ................................................................................................................................... 12 Lagoon Supernatant ............................................................................................................................... 13 Summary and Continued Sampling .......................................................................................13 Attachment A: Additional Data Plots .....................................................................................16 List of Tables Table 1: Additional Sampling Locations, Analyses and Basis for the Sampling ........................................... 3 Table 2. Sampling Matrix (Additional Sampling from May 2014 through May 2015).................................... 5 Table 3. Upstream of Bar Screen Additional Sampling Results (Time-Paced Composite Sampler) ............ 6 Table 4. Primary Effluent Additional Sampling Results (Time-Paced Composite Sampler) ......................... 8 Table 5. Secondary Clarifier Additional Sampling Results ......................................................................... 11 Table 6. Final Clarifier Effluent Additional Sampling Results ...................................................................... 11 Table 7. Primary Solids Additional Sampling Results ................................................................................. 11 Table 8. Thickening Return Additional Sampling Results ........................................................................... 12 Table 9. Lagoon Supernatant Additional Sampling Results ....................................................................... 13 Table 10. Continued Sampling Matrix (Weekly Sampling) ......................................................................... 15 WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Page 2 of 20 List of Figures Figure 1. SLO WRRF Existing Process Schematic with Sampling Locations (includes WRRF Energy Efficiency Project) .................................................................................................................... 4 Figure 2: Influent TSS, BOD and BOD:TSS Ratio (May 2014 - May 2015) ................................................. 7 Figure 3: Influent Ammonia-N, TKN and Ammonia-N:TKN Ratio (May-October 2014)................................ 7 Figure 4: Primary Effluent COD:BOD Ratio (May 2014 – May 2015) ........................................................... 9 Figure 5: Primary Effluent Soluble COD:TKN Ratio (May 2014 – May 2015) .............................................. 9 Figure 6: Primary Clarifier Soluble BOD Removal Performance (May 2014 – May 2015) ......................... 10 Figure 7: Primary Solids TSS (May 2014 - May 2014) ............................................................................... 12 WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Page 3 of 20 Introduction The purpose of this technical memorandum (TM) is to review the additional plant wide sampling that was performed from May 2014 through May 2015. The objectives of the additional sampling and analytical effort were to address data gaps and inconsistencies with historic plant wide data so that design criteria could be developed. A listing of the additional sampling locations and basis for the sampling are provided in Table 1. Each sampling location has an identification tag. Refer to Figure 1 for the schematic of sampling location identification tags. Table 2 contains the matrix of additional sampling. Table 1: Additional Sampling Locations, Analyses and Basis for the Sampling Identificatio n Tag for Figure 1 Sample Location Analyses * Basis/Reason 1 Raw Influent Ammonia, Alkalinity, BOD, Soluble BOD, COD, Soluble COD, TSS, TKN, Phosphorus - To calibrate mass balance - To verify TSS/BOD and Ammonia/TKN ratios for current and projected loads - To better understand seasonal variation 2 Primary Effluent Ammonia, BOD, Soluble BOD, COD, Soluble COD, TSS, TKN, Phosphorus - To calibrate mass balance - Required for nutrient removal design - To better understand seasonal variation 3 Secondary Effluent Ammonia, BOD, Soluble BOD, COD, Soluble COD, TSS, TKN, Phosphorus - To calibrate mass balance 4 Nitrified Effluent Ammonia, Alkalinity, TSS, TKN, Phosphorus, Nitrate - To calibrate mass balance 5 DAFT Return Ammonia, Alkalinity, BOD, Soluble BOD, COD, Soluble COD, TSS, TKN, Phosphorus - To calibrate mass balance 6 Lagoon Supernatant Ammonia, Alkalinity, BOD, Soluble BOD, COD, Soluble COD, TSS, TKN, Phosphorus - To calibrate mass balance - Required for nutrient removal design 7 Primary Solids TSS - To calibrate mass balance * BOD- Biological Oxygen Demand, COD-Chemical Oxygen Demand, TSS- Total Suspended Solids, TKN- Total Kjeldahl Nitrogen WR R F P r o j e c t TM N o . 1 5 - A n a l y s i s o f A d d i t i o n a l S a m p l i n g f o r t h e W R R F P r o j e c t Pa g e 4 o f 1 6 Fi g u r e 1 . S L O W R R F E x i s t i n g P r o c e s s S c h e m a t i c w i t h Sa m p l i n g L o c a t i o n s ( i n c l u d e s W R R F E n e r g y E f f i c i e n c y P r o j e c t ) He a d w o r k s (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) Ae r a t i o n Ba s i n Mo n o M e d i a Fi l t e r ( W R R F En e r g y E f f i c i e n c y Pr o j e c t ) CC T SLO Creek Emergency Storage3W Water System Recycled Water PC L SC L Bi o t o w e r FC L Co o l i n g To w e r DA F T AD AD AD St o r a g e Vo r t e x Cl a s s i f i e r Dr y i n g B e d Su p e r n a t a n t St o r a g e La g o o n Di s p o s a l Fe r r o u s Ch l o r i d e Po l y m e r Ra w In f l u e n t So d i u m Hy p o c h l o r i t e Ma g n e s i u m Hy d r o x i d e Fi l t e r B a c k w a s h Li q u i d S t r e a m s Sl u d g e S t r e a m s Re t u r n S t r e a m s Ch e m i c a l S t r e a m s Pr i m a r y C l a r i f i c a t i o n PC L Se c o n d a r y C l a r i f i c a t i o n SC L Fi n a l C l a r i f i c a t i o n FC L Ch l o r i n e C o n t a c t T a n k CC T Di s s o l v e d A i r F l o a t a t i o n T h i c k e n e r DA F T An a e r o b i c D i g e s t i o n AD Be l t F i l t e r P r e s s BF P DA F T S u p e r n a t a n t La g o o n R e t u r n Sodium Bisulfite Sc r e w P r e s s (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) RA S (W R R F E n e r g y Ef f i c i e n c y P r o j e c t ) WA S Fl o w s > 3 2 m g d to F l o w E Q Fl o w s > 2 2 m g d to F l o w E Q Bi o t o w e r B y p a s s Ad v a n c e d T r e a t m e n t B y p a s s ( F l o w s > 5 . 1 m g d ) Fl o w s C u r r e n t l y >1 6 m g d t o F l o w E Q 1 2 3 4 5 6 7 WR R F P r o j e c t TM N o . 1 5 - A n a l y s i s o f A d d i t i o n a l S a m p l i n g f o r t h e W R R F P r o j e c t Pa g e 5 o f 1 6 Ta b l e 2 . S a m p l i n g M a t r i x ( A d d i t i o n a l S a m p l i n g f r o m Ma y 2 0 1 4 t h r o u g h M a y 2 0 1 5 ) Lo c a t i o n 1, 2 : NH3-N mg/L NH3-N mg/L (WRRF Laboratory) Alkalinity as CaCO3 mg/L Alkalinity Bicarbonate mg/L Alkalinity Carbonate mg/L Alkalinity Hydroxide mg/L BOD mg/L Soluble BOD mg/L TSS mg/L (WRRF Laboratory) COD mg/L Soluble COD mg/L TKN mg/L Phosphate, Phosphorus Dissolved mg/L Phosphorus Total mg/L Nitrate as N mg/L Nitrate as N mg/L (WRRF Laboratory) (1 ) U p s t r e a m o f B a r s c r e e n s X X X X X X X X X X X X X X (2 ) P r i m a r y E f f l u e n t X X X X X X X X X X (3 ) S e c o n d a r y E f f l u e n t X X X X X X X X X X (4 ) N i t r i f i e d E f f l u e n t X X X X X X X X X X X (5 ) D A F T R e t u r n X X X X X X X X X X X X X X X (6 ) S u p e r n a t a n t L a g o o n X X X X X X X X X X X X X (7 ) P r i m a r y S e t t l e d S l u d g e X 1- Al l t h e s a m p l e s a r e c o l l e c t e d a s c o m p o s i t e e x c e p t f or P r i m a r y S l u d g e 2- Al l t h e s a m p l e s a r e a n a l y z e d a t F G L E n v i r o n m e n t a l L ab o r a t o r y e x c e p t w h e n i n d i c a t e d o t h e r w i s e WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Page 6 of 16 Sampling Results The sampling results by each monitoring location are presented in the sub-sections below. Upstream of Bar Screens The additional sampling objectives and key results for this location are as follows: • Confirm BOD:TSS ratio: the BOD to TSS ratio averaged 0.93, which is below the 1.09 ratio used for the WRRF Project Flows and Loads (HDR, 2015). Despite a reduced average value, the data in Figure 2 illustrates a relatively wide ranged in data (ranged from 0.5 to 1.3). The 30-day moving average had low values from mid-summer through the fall and has since maintained a ratio of between 0.9 to 1.1. • Confirm Ammonia:TKN ratio: the ammonia to TKN ratio averaged 0.76, which is above the 0.67 ratio used for the WRRF Project Flows and Loads (HDR, 2015). The data in Figure 3 is more stable than the BOD:TSS ratio (ranged from 0. 5 to 1.0). The ratio spiked over this past winter months but has since reduced back to around 0.70. This sampling location represents the WRRF raw influent. WRRF currently collects daily composite samples for reporting between the aerated grit and Parshall flumes, which is a different location than these additional samples collected upstream of the bar screens. Note: new screens were installed and operational in the winter of 2015 as part of the WRRF Energy Efficiency Project. There are no recycle streams added between these two sampling locations, so the two locations should be representative of raw influent. However, because the locations are different, TSS and ammonia samples are collected upstream of the bar screens so that an accurate ratio can be calculated. In the future, additional sampling should be collected between the aerated grit and Parshall flumes, if feasible because it would reduce analytical requirements (i.e., duplicate samples). A summary of the sampling efforts from May 2014 - May 2015 for this location is presented in Table 3. It is recommended that the WRRF continue weekly sampling for influent organics, TSS, Ammonia, TKN, and alkalinity to account for seasonal trends and build a larger, more robust database. As previously noted, the WRRF should use the raw influent auto-sampler for future sampling instead of the current location. This will reduce sampling locations and eliminate duplicate samples. Table 3. Upstream of Bar Screen Additional Sampling Results (Time-Paced Composite Sampler) Sampling Parameter Units Average Values Range of Values Number of Samples Future Sampling Frequency BOD mg/L 322 158-465 59 1/week Soluble BOD mg/L 116 50-185 57 1/week COD mg/L 526 170-820 60 1/week Soluble COD mg/L 174 100-310 57 1/week TSS mg/L 355 188-678 58 1/week NH3-N (FGL Environmental) mg N/L 45 30-69 61 1/week TKN mg N/L 60 40-88 60 1/week Soluble Phosphate mg P/L 4.3 2.7-7.0 60 --- Total Phosphorus mg P/L 8.0 5.0-15.0 60 --- Alkalinity mg/L 366 320-450 58 1/week WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Page 7 of 16 Figure 2: Influent TSS, BOD and BOD:TSS Ratio (May 2014 - May 2015) Figure 3: Influent Ammonia-N, TKN and Ammonia-N:TKN Ratio (May-October 2014) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 0 100 200 300 400 500 600 700 800 5/29/147/28/149/26/1411/25/141/24/153/25/155/24/15 Ra t i o mg / L Upstream of Barscreens, TSS Upstream of Barscreens, BOD Influent, BOD/TSS (calculated) 30 per. Mov. Avg. (Influent, BOD/TSS (calculated)) 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 0 20 40 60 80 100 5/29/147/28/149/26/1411/25/141/24/153/25/155/24/15 Ra t i o mg / L Upstream of Barscreens, Ammonia Nitrogen (FGL) Upstream of Barscreens, Ammonia Nitrogen (WQL) Upstream of Bar Screens, Ammonia/TKN (calculated) 30 per. Mov. Avg. (Upstream of Bar Screens, Ammonia/TKN (calculated)) WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Page 8 of 16 Additional raw influent (upstream of bar screens) sampling plots are provided in Appendix A (Figure A - 1 and Figure A - 2). In particular, the raw influent soluble BOD and phosphorus species are presented. The soluble BOD was collected to confirm the soluble BOD values used in the mass balance calibration. The phosphorus species data was collected to better understand the loads (if necessary for the future). Primary Effluent The primary objective for sampling primary effluent was to confirm future loading to the aeration basins, which is critical for developing design criteria for the downstream activated sludge process. Table 4 presents the average values and the range for the primary effluent parameters tested. Overall, the sampling yielded good results. The following parameters and ratios were reviewed and a summary of the conclusions is as follows: • Confirm COD:BOD ratio: the COD to BOD ratio was calculated to augment the lack of COD data available on primary effluent. Once a ratio is developed, this value can be applied to historical and future data. The calculated ratio is presented in Figure 4. The COD:BOD ratio has increased from about 1.5 on average in 2014 to about 2.1 on average in 2015. This increase to 2.1 is greater than industry accepted values of about 1.50. This abnormally high ratio might be a direct result of the drought and water conservation. • Confirm soluble COD:TKN Ratio: this ratio was calculated as it is critical for determining whether an external carbon source (e.g., methanol) is required for designing the downstream activated sludge process. The on average soluble COD:TKN ratio is 2.9, which is comparable to the theoretical 2.9 mg soluble COD per mg of nitrate as N removed. The 30-day moving average has occasional excursions below the 2.9 ratio threshold which suggests that an external carbon source may be required to meet the renewed NPDES permit nitrate limits. • Monitor soluble BOD removal across the primaries: soluble BOD was monitored as it is critical for designing the downstream biological process. The primary feed (minus the return streams), primary effluent, and removal across the primaries for soluble BOD are presented in Figure 6. About 43 percent of the soluble BOD is removed in the primaries. The soluble BOD is not expected to significantly reduce across the primaries. In contrast, the soluble COD reduces about 25 percent across the primaries (data not shown). This high removal rate of soluble material is attributed to a combination of the primary solids flow rates required to move thin sludge (<1,000 mg/L solids) and denitrification in the primaries from a nitrified supernatant lagoon. Table 4. Primary Effluent Additional Sampling Results (Time-Paced Composite Sampler) Sampling Parameter Units Average Values Range of Values Number of Samples Future Sampling Frequency BOD mg/L 172 95-233 59 1/week Soluble BOD mg/L 76 45-190 52 1/week COD mg/L 293 220-440 61 1/week Soluble COD mg/L 142 90-340 57 1/week TSS mg/L 71 41-123 63 1/week NH3-N (FGL Environmental) mg N/L 37 24-54 59 1/week TKN mg N/L 47 29-81 60 1/week Soluble Phosphate mg P/L 4.3 2.9-7.0 59 --- Total Phosphorus mg P/L 6.4 4.0-8.0 60 --- WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Page 9 of 16 Figure 4: Primary Effluent COD:BOD Ratio (May 2014 – May 2015) Figure 5: Primary Effluent Soluble COD:TKN Ratio (May 2014 – May 2015) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 5/29/147/28/149/26/1411/25/141/24/153/25/155/24/15 Ra t i o Primary Clarifier Effluent, COD/BOD (calculated) 30 per. Mov. Avg. (Primary Clarifier Effluent, COD/BOD (calculated)) 0.0 1.0 2.0 3.0 4.0 5.0 6.0 5/29/147/28/149/26/1411/25/141/24/153/25/155/24/15 mg / L Primary effluent, sCOD/TKN (calculated) 30 per. Mov. Avg. (Primary effluent, sCOD/TKN (calculated)) WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Page 10 of 16 Figure 6: Primary Clarifier Soluble BOD Removal Performance (May 2014 – May 2015) Additional primary effluent sampling plots are provided in Appendix A (Figure A - 3). In particular, the ammonia and TKN removal across the primaries is plotted. In a similar vein to the soluble BOD removal across the primaries, the ammonia removal across the primaries is larger than typically seen at WRRFs. As a cross-check, the TKN removal across the primaries was in-line with other values typically seen at WRRFs. This finding further supports the recommendation to continue weekly sampling. Given that the primary effluent values govern the downstream activated sludge process design, continued sampling is recommended to better understand seasonal trends and create a more robust database. The recommended sampling frequency on future sampling is once per week for those identified Table 4. Secondary Clarifier Effluent The objective for sampling the secondary clarifier effluent was to confirm the accuracy of the plant wide mass balance model calibration results against actual plant data. Table 5 summarizes the secondary clarifier effluent results. The necessary information was collected and additional sampling is not required. 0% 20% 40% 60% 80% 100% 120% 0 40 80 120 160 200 5/29/147/28/149/26/1411/25/141/24/153/25/155/24/15 % mg / L Upstream of Barscreens, Soluble BOD Primary Clarifier Effluent, Soluble BOD Removal Across Primaries, Soluble BOD 30 per. Mov. Avg. (Removal Across Primaries, Soluble BOD) WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Page 11 of 16 Table 5. Secondary Clarifier Additional Sampling Results Sampling Parameter Units Average Values Range of Values Number of Samples Future Sampling Frequency BOD mg/L 71 26-143 33 --- Soluble BOD mg/L 8 3-26 27 --- COD mg/L 99 80-130 34 --- Soluble COD mg/L 52 40-100 30 --- TSS mg/L 34 24-51 37 --- NH3-N (FGL Environmental) mg N/L 16 10-30 35 --- TKN mg N/L 21 12-41 34 --- Soluble Phosphate mg P/L 4.7 3.5-7.0 33 --- Total Phosphorus mg P/L 5.9 4.0-7.0 32 --- Final Clarifier Effluent The objective for sampling the final clarifier effluent was to compare the plant wide mass balance model calibration results against actual plant data. Table 6 summarizes the final clarifier effluent results. The key findings were the plant fully nitrifies except for periods of blending and the final clarifier effluent has relatively low solids and sufficient alkalinity to maintain a stable pH (>100 mg/L as CaCO3). Supplemental alkalinity is added as either sodium hydroxide or magnesium hydroxide in order to maintain a stable pH. Incorporating denitrification in the WRRF Upgrade will reduce supplemental alkalinity addition due to alkalinity recovery. The sampling produced sufficient results to discontinue sampling. Table 6. Final Clarifier Effluent Additional Sampling Results Sampling Parameter Units Average Values Range of Values Number of Samples Future Sampling Frequency TSS mg/L 13.3 2 - 32 105 --- NH3-N (FGL Environmental) mg N/L 1.33 0.3 - 9.5 19 --- Soluble Phosphate mg P/L 5.0 4.0 - 6.0 33 --- Total Phosphorus mg P/L 5.4 3.7 - 7.7 34 --- Alkalinity mg/L 174 100-220 34 --- Primary Solids The objective for sampling the primary clarifier solids was to compare the plant wide mass balance model calibration results against actual plant data. Specifically, there was a lack of information on the primary solids concentration going to thickening. Table 7 summarizes the primary solids data. The data is plotted in Figure 7 where there is wide variability in TSS levels (212 to 2,004 mg/L; average about 750 mg/L). This data is not critical for sizing facilities for the WRRF upgrade so discontinuing sampling is recommended. Table 7. Primary Solids Additional Sampling Results Sampling Parameter Units Average Values Range of Values Number of Samples Future Sampling Frequency TSS mg/L 724 212-2,004 30 -- WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Page 12 of 16 Figure 7: Primary Solids TSS (May 2014 - May 2014) Thickening Return The objective for sampling the dissolved air flotation thickening (DAFT) return stream was to compare the plant wide mass balance model calibration results against actual plant data. Specifically, there was a lack of information on the BOD and COD values which are essential to calibrating the mass balance. Table 8 summarizes the thickening return data. The sampling values, in particular the TSS values, were reproducible with marginal data variability. The necessary information was collected and thus, no more sampling is required. Table 8. Thickening Return Additional Sampling Results Sampling Parameter Units Average Values Range of Values Number of Samples Future Sampling Frequency1 BOD mg/L 193 78-363 34 --- Soluble BOD mg/L 14 3-25 30 --- COD mg/L 226 130-310 34 --- Soluble COD mg/L 79 40-110 31 --- TSS mg/L 162 121-206 57 --- NH3-N (FGL Environmental) mg N/L 25 13-46 34 --- TKN mg N/L 41 16-84 34 --- Soluble Phosphate mg P/L 4.8 3-10 34 --- Total Phosphorus mg P/L 7.9 5.0-9.0 34 --- Alkalinity mg/L 324 280-390 34 --- 0 500 1,000 1,500 2,000 2,500 5/29/147/28/149/26/1411/25/141/24/153/25/155/24/15 mg / L Primary Sludge, TSS WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Page 13 of 16 Lagoon Supernatant The lagoon supernatant is a highly concentrated return stream that introduces large nutrient loads just downstream of the influent Parshall flumes. The nutrient load from such streams typically represents about 15 to 25 percent of the plant ammonia load. The primary objectives for sampling the lagoon supernatant were to i) compare the plant wide mass balance model calibration results against actual plant data, ii) characterize the ammonia load, and iii) characterize the alkalinity load. Table 9 summarizes the lagoon supernatant data. The data exhibited significant variability which is most likely due to the nature of this stream. The key parameters for implementing the WRRF Project, ammonia and alkalinity, also had significant variability (see Figure A - 4 in Appendix A). This wide range in ammonia and alkalinity is attributed to occasional nitrification in the lagoons before returning downstream of the Parshall flumes. Table 9. Lagoon Supernatant Additional Sampling Results Sampling Parameter Units Average Values Range of Values Number of Samples Future Sampling Frequency BOD mg/L 172 74-349 18 ------- Soluble BOD mg/L 6 2-17 17 ------- COD mg/L 287 170-450 18 ------- Soluble COD mg/L 226 160-360 18 ------- TSS mg/L 121 41-448 20 ------- NH3-N (FGL Environmental) mg N/L 597 140-1,300 19 1/week TKN mg N/L 605 280-1,140 17 ------- Soluble Phosphate mg P/L 11 4-23 19 ------- Total Phosphorus mg P/L 14 7-22 19 ------- Alkalinity mg/L 1,726 90-3,040 19 1/week It is recommended that the WRRF continues sampling at this location, but only for ammonia, alkalinity, and nitrate (to monitor nitrification). The other parameters do not require any additional sampling. It is critical to have more information on ammonia and alkalinity throughout the year in order to develop design criteria for this stream (if the WRRF decides to treat) and the liquid stream nutrient removal process. To better understand the conditions that lead to nitrification in the lagoons, it is recommended that the WRRF start documenting lagoon operational information, such as mixer (aerator) on/off frequency or energy demand, daily volume of water returned to the WRRF, volume of 3W added, and any supplemental alkalinity addition. Summary and Continued Sampling Continued sampling is recommended with several modifications. The number of sampling points and parameters tested is reduced for each location. This continued sampling is vital for the WRRF Project design. Table 10 contains the proposed continued sampling locations and sampling frequency. WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Page 14 of 16 The recommendations for weekly sampling at each location are as follows: • Raw Influent: • Switch samplers to the influent composite sampler used for daily sample collection. This will eliminate any additional laboratory effort. • Continue sampling for nitrogen species, organics, solids, and alkalinity to account for seasonal trends and verify the projected flows and loads (HDR, 2015). • Primary Effluent: • The primary effluent levels are critical for developing the WRRF Project activated sludge design criteria. • Continue sampling for nitrogen species, organics, and solids to account for seasonal trends, confirm whether an external carbon source is required, and build an overall larger, more robust database. • Secondary Effluent: the necessary information was collected and thus, no more sampling is required. • Nitrified Effluent: the necessary information was collected and thus, no more sampling is required. • Primary Solids: the necessary information was collected and thus, no more sampling is required. • DAFT Return: the necessary information was collected and thus, no more sampling is required. • Lagoon Supernatant: • Continue sampling for ammonia, alkalinity, and nitrate (to monitor nitrification). The other parameters do not require any additional sampling. • It is critical to have more information on ammonia and alkalinity throughout the year in order to develop design criteria for this stream (if the WRRF decides to treat) and the liquid stream nutrient removal process. • To better understand occasional nitrification in the lagoons, document operational information on mixer (aerator) on/off frequency or energy demand, daily volume of water returned to the WRRF, volume of 3W added, and any supplemental alkalinity addition. WR R F P r o j e c t TM N o . 1 5 - A n a l y s i s o f A d d i t i o n a l S a m p l i n g f o r t h e W R R F P r o j e c t Pa g e 1 5 o f 1 6 Ta b l e 1 0 . C o n t i n u e d S a m p l i n g M a t r i x ( W e e k l y S a m p l i n g) Lo c a t i o n : NH3-N mg/L NH3-N mg/L (WRRF Laboratory) Alkalinity as CaCO3 mg/L Alkalinity Bicarbonate mg/L Alkalinity Carbonate mg/L Alkalinity Hydroxide mg/L BOD mg/L Soluble BOD mg/L TSS mg/L (WRRF Laboratory) COD mg/L Soluble COD mg/L TKN mg/L Phosphate, Phosphorus Dissolved mg/L Phosphorus Total mg/L Nitrate as N mg/L Nitrate as N mg/L (WRRF Laboratory) (1 ) R a w I n f l u e n t ( m o d i f i e d l o c a t i o n ) X X X X X X X X (2 ) P r i m a r y E f f l u e n t X X X X X X X (3 ) S e c o n d a r y E f f l u e n t (4 ) N i t r i f i e d E f f l u e n t (5 ) D A F T R e t u r n (6 ) L a g o o n S u p e r n a t a n t X X X (7 ) P r i m a r y S e t t l e d S l u d g e WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Page 16 of 16 Page intentionally blank. WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Attachment A: Additional Data Plots WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Page intentionally blank. WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Figure A - 1. Influent Soluble BOD (May 2014 - May 2015) Figure A - 2. Influent Phosphorus Species Concentrations (May 2014 – May 2015) 0 20 40 60 80 100 120 140 160 180 200 5/29/147/28/149/26/1411/25/141/24/153/25/155/24/15 mg / L Upstream of Barscreens, Soluble BOD 0 2 4 6 8 10 12 14 16 5/29/147/28/149/26/1411/25/141/24/153/25/155/24/15 mg / L Upstream of Barscreens, Phosphorus, Total Upstream of Barscreens, Phosphate - P Diss. WRRF Project TM No. 15 - Analysis of Additional Sampling for the WRRF Project Figure A - 3. Ammonia and TKN Removal across the Primaries (May 2014 – May 2015) Figure A - 4. Lagoon Supernatant Return Alkalinity, Ammonia-N and Alkalinity:Ammonia-N (May 2014 – May 2015) 0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50% 5/29/147/28/149/26/1411/25/141/24/153/25/155/24/15 % Removal Across Primaries, Ammonia Removal Across Primaries, TKN 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 0 500 1,000 1,500 2,000 2,500 3,000 3,500 05/29/1407/28/1409/26/1411/25/1401/24/1503/25/1505/24/15 Ra t i o Co n c e n t r a t i o n ( m g / L ) Supernatant Lagoon, Ammonia Nitrogen Supernatant Lagoon, Alkalinity (as CaCO3) Supernatant Lagoon, Alkalinity/Ammonia-N Appendix S TM No. 16 - High Rate A/B Bench Testing Protocol Date: 1/15/2015 Prepared by: Michael Falk, PhD, PE, Mallika Ramanathan, PE Reviewed by: Holly Kennedy, PE Project: WRRF Project SUBJECT: TM NO. 16 - BENCH SCALE TEST PROTOCOL The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo, CA. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long-term strategy for resource management. The purpose of this testing protocol is to present the steps associated with evaluating the benefits of the High Rate Adsorption/Bio-oxidation Technology at the WRRF. Contents Purpose and Objectives .......................................................................................................... 2 Overview of Methodology........................................................................................................ 3 Step 1: Biomass Seed Production ............................................................................................................ 4 Step 2: A-Stage Testing............................................................................................................................ 5 Materials and Equipment ......................................................................................................... 5 Seed Reactor ............................................................................................................................................ 5 A-Stage Reactor ....................................................................................................................................... 6 General and Laboratory Supplies ............................................................................................................. 6 Siting ......................................................................................................................................... 6 Detailed Procedures ................................................................................................................ 7 Step 1: Seed Reactor Startup and Operation ........................................................................................... 7 Reactor Daily Operation ....................................................................................................................... 8 Step 2: A-Stage Testing............................................................................................................................ 8 Reactor Set-Up and Trial Run .............................................................................................................. 8 Reactor Testing .................................................................................................................................... 8 Analytical Requirements ......................................................................................................... 9 Staffing and Schedule Estimates ............................................................................................................ 10 List of Attachments A - Seed Reactor and A-Stage Testing Details WRRF Project TM No. 16 - Bench Scale Test Protocol Page 2 of 12 List of Tables Table 1. Typical A-stage Operating Parameters ........................................................................................... 3 Table 2. Operating Parameters for Seed Reactor (Step 1) .......................................................................... 4 Table 3. Operating Parameters for the A-Stage Reactors (2 – 4 Liters per Reactor)................................... 5 Table 4. Analytical Requirements for A-Stage Testing (Six Reactors for Each Test Day) ........................... 9 Table 5. Bench-Scale Testing Staffing Estimate ........................................................................................ 12 List of Figures Figure 1. HR Technology – Process Flow Diagram ...................................................................................... 3 Figure 2. Bench Scale Test Schematic ......................................................................................................... 4 Figure 3. First Stage (Biomass Seed) Reactor Location (South of the Parshall Flumes) ............................ 7 Figure 4. HR Bench-Scale Testing Schedule ............................................................................................. 11 Purpose and Objectives For the development of the Facility Plan, two secondary treatment alternatives are under consideration: (1) Modified Ludzack Ettinger (MLE) and (2) High Rate Adsorption/Bio-oxidation (HR). Technical memorandum (TM) 12 provides details on both technologies and the basis for their selection.1 The HR technology comprises two processes in series (Figure 1), known as the Adsorption Stage (A-Stage) and the Bio-oxidation Stage (B-Stage). Improved organics removal in the A-Stage offers the following benefits over MLE: • Reduced B-stage energy demands due to lower organic loading to the B-stage • Increased digester gas production due to higher organic removal in the A-stage • Reduced capital cost due to a smaller footprint Despite the benefits of HR, the number of HR installations is limited to Europe (about 12 in total) and there is concern over performance and reliability at the City of San Luis Obispo’s Water Resource Recovery Facility (WRRF). Furthermore, the primary clarifiers at the WRRF achieve high TSS removal (greater than 80 percent). Therefore, the City would like to understand the HR A-stage performance relative to the current primary clarifier performance. The purpose of this bench scale protocol is to outline testing objectives, testing procedures, analytical requirements, schedule, and staffing requirements. This protocol is intended to be a working document that will be refined as modifications are made to accommodate field conditions. The bench-scale protocol has been developed to assess HR performance at the WRRF in comparison to primary clarifier performance. The bench-scale testing objectives are as follows: • Estimate solids and organics removal of the HR A-Stage process, and • Compare HR A-Stage performance to the WRRF’s existing primary clarifier performance. 1 HDR (2014) Technical Memorandum No. 12 – Process Alternatives Analysis (Draft). As part of the Water Resource Recovery Facility (WRRF) Facility Plan. City of San Luis Obispo, CA. WRRF Project TM No. 16 - Bench Scale Test Protocol Page 3 of 12 Figure 1. HR Technology – Process Flow Diagram The data collected with this bench scale testing will be used to evaluate the energy benefits of HR at the WRRF, and to assist the City in making a decision to carry the HR technology forward into subsequent project phases. If the HR results are attractive, the City should consider pilot testing the HR technology to further investigate various full-scale conditions (e.g., performance under storm flows) and develop design criteria. Overview of Methodology The HR A-Stage is typically designed with a short solids residence time (SRT) (i.e., less than 1-day) and a 30-minute hydraulic residence time (HRT). The A-stage is typically operated under low dissolved oxygen (DO) conditions. Table 1 lists typical HR A-Stage operating parameters. Table 1. Typical A-stage Operating Parameters Parameter Target Range2 Mixed Liquor Suspended Solids (MLSS) 500-2,000 mg/l Solids Residence Time (SRT) 6-12 hours Hydraulic Residence Time (HRT) 30 min Dissolved Oxygen (DO) < 2 mg/L* * Aeration provided to prevent septic conditions and maintain mixing The WRRF currently operates the activated sludge system at an SRT of approximately 7 days to achieve nitrification. Because the properties of a 7-day SRT sludge and a 0.5-day SRT sludge differ, it was determined that generating a 0.5-day SRT sludge is necessary. For this reason, the bench scale test protocol consists of the following steps (Figure 2): • Step 1: Biomass Seed Production: Generation of 0.5-day SRT biomass by operating a bench-scale reactor at a 0.5-day SRT. 2 Jimenez, Jose; Bott, Charles; Miller, Mark, et al.; High Rate Activated Sludge System for Carbon Removal – Pilot Results and Crucial Process Parameters. 2013 WEFTEC Proceedings. A-Stage Clarifier Final Clarifier Mixed Liquor Return Return Activated Sludge Low Rate “B-Stage”; MLE Influent High Rate “A-Stage” Wet Weather/Peak Flow Diversion WRRF Project TM No. 16 - Bench Scale Test Protocol Page 4 of 12 • Step 2: A-Stage Testing: The biomass generated in Step 1 is used to seed multiple A-stage reactors (2 to 4 liters per reactor). A side by side test to estimate traditional primary clarifier performance will be performed. As shown in Figure 2, the reactor operated under Step 1 will be referred to as the Seed Reactor. The reactors operated in Step 2 will be referred to as the A-Stage Reactors. Step 1: Biomass Seed Production The continuously operated Seed Reactor will be fed raw influent wastewater (downstream of screening and grit removal) by peristaltic pumps. The reactor will be designed as a complete mix reactor such that the SRT will equal the HRT. As a result, there is no clarification. The target SRT for the Seed Reactor is 0.5 day. The reactor will be operated for several days (> 3 SRTs) to provide steady state conditions prior to moving to Step 2 of the test plan. The operating volume for the Seed Reactor is 30 gallons per reactor (influent feed pumping rate of approximately 2.5 gph). Two Seed Reactors will be operated in parallel, with one reactor serving as a backup. The operating parameters for the Seed Reactor are listed in Table 2. Table 2. Operating Parameters for Seed Reactor (Step 1) Parameter Target Range MLSS Average 350 mg/L* SRT 12 to 24 hours HRT 12 to 24 hours Dissolved Oxygen >2 mg/L * Based on a sludge yield of 1 and average influent BOD concentration of 350 mg/L Figure 2. Bench Scale Test Schematic 0.5-day SRT Biomass Collected Influent, Raw Wastewater Step 1: Biomass Seed Production Influent, Raw Wastewater Seed Reactor Catchment Container Pumping Feed Rate = 30 gpd per Reactor Air Step 2: A-Stage Testing Reactor Volume = 2-4 L each A-Stage + Control Reactors Pri ClarA-Stage ControlA-StageA-StageA-StageA-Stage WRRF Project TM No. 16 - Bench Scale Test Protocol Page 5 of 12 Step 2: A-Stage Testing Step 2 consists of operating A-stage reactors at varying MLSS concentrations. Biomass from the seed reactor will be concentrated and then used to seed the A-stage reactors. Table 3 presents the operating conditions for the A-Stage Reactors. The MLSS concentrations in Table 3 are targets. The intent is to do a relative comparison. During Step 1, testing will be done to determine a strategy for meeting the target MLSS levels. The two strategies of interest are the rapid microwave test and developing a MLSS database during the acclimation period. Details on these methods are provided in the Detailed Procedures and Analytical Requirements sections below. Table 3. Operating Parameters for the A-Stage Reactors (2 – 4 Liters per Reactor) Test Target MLSS (mg/L) * Reaction Time Settling Time A 500 30 min 30 – 60 minutes B 1,000 30 min 30 – 60 minutes C 1,500 30 min 30 – 60 minutes D 2,000 30 min 30 – 60 minutes E No biomass seed **(Control Reactor) 30 min 30 – 60 minutes F No biomass seed *** (Control – Primary Clarifier) 0 min 30 – 60 minutes * The MLSS levels are targets. The intent is to provide a relative comparison. Strategies to meet the target will be evaluated during Step 1 acclimation period (Detailed Procedures and Analytical Requirements sections below). ** Reactor serves as the A-Stage Control (no biomass seed) *** Simulate Existing WRRF Primaries The A-stage reactors will be aerated for 30 minutes, while maintaining the reactor DO at less than 2 mg/L. After 30 minutes, the aeration will be stopped and the reactor will be allowed to settle for 30 to 60 minutes to achieve liquid-solids separation. This settling mimics the A-stage clarification step (Figure 1). The liquid stream will be decanted and collected for laboratory analyses and the concentrated solids stream will also be collected for laboratory analyses. Materials and Equipment A listing of required field supplies is described below. The volumes are based on preliminary calculations and will be further refined after construction and operation. The materials listed below represent larger/major equipment and materials. Coordination with the WRRF staff will be conducted to determine the availability of laboratory glassware, filters, etc. Seed Reactor - Four (4) 50-gallon reactors. A V-notch or overflow pipe will be inserted into the reactor to provide a constant volume in the reactor and a way for mixed liquor to overflow into the catchment. Two containers will serve as the catchment of mixed liquor and two will serve as the reactors. - Two (2) peristaltic pumps will be used for pumping screened, degritted raw wastewater (one pump per reactor). It is assumed that the WRRF has two peristaltic pumps that can be used for this study. The target operating range of the pumps will be 1 to 3 gallons per hour (gph). To minimize clogging potential, the influent intake will be constructed with a perforated basket inlet. If the WRRF does not have perforated basket inlets available, the PM Team will procure/construct a device. WRRF Project TM No. 16 - Bench Scale Test Protocol Page 6 of 12 - Four (4) sets of aeration stones (2 per reactor). Additional tubing, wye splits, and aeration stones will be ordered in the case that additional aeration stones are needed. HDR will order the additional equipment during the reactor construction phase. - One to two canopies procured by the PM Team to provide protection of the Seed Reactors from rain. - Optional: Two (2) plastic cones (2-4 L each) to concentrate biomass from the Seed Reactors on test days. If the WRRF does not have settling cones, the PM Team will procure the cones. A-Stage Reactor - Six (6) 2 to 4 liter (L) reactors or beakers. The PM Team will procure the reactors. - Five (5) to ten (10) sets of aeration stones (1 set per reactor). Additional stones may be needed to keep the system mixed and sufficiently aerated. Additional tubing, wye splits, and aeration stones will be ordered in the case that an aeration stone per reactor is not sufficient. The PM Team will procure the additional equipment during the reactor construction phase. - Sample bottles provided by the WRRF for laboratory analyses. General and Laboratory Supplies - DO probe (PM Team to confirm whether the WRRF has this equipment; if not, probe will be rented for duration of testing) - pH and temperature probe (PM Team to confirm if the WRRF has this equipment; if not, HDR to rent a DO probe for the studies duration) - Graduated Cylinders (250 mL and 1000 mL) provided by the WRRF - General lab glassware (e.g., beakers) provided by the WRRF - Access to lab and equipment to perform total suspended solids (TSS) and volatile suspended solids (VSS) tests. The WRRF will provide the necessary lab space and equipment to perform these studies, if needed. - Sample bottles provided by the WRRF for BOD, COD, TSS and VSS analyses - Disposable filters (0.45 and 1.2 µm) and syringes provided by the WRRF for soluble BOD, soluble COD, TSS, and VSS sample preparation. The PM Team will confirm if the WRRF has materials or will procure as needed. - PPE (gloves, towels) provided by the WRRF. The PM Team will confirm if the WRRF has materials or will procure as needed. Siting Operation of the Seed Reactor will require electrical connections for operation of the influent pumps as well as access to a compressed air line. It is assumed that a site at the WRRF can be located with both connections. For A-Stage Testing, access to a compressed air line will be needed. The PM Team will coordinate with the WRRF staff to confirm sizing of lines and confirm availability at test locations. Based on discussions with WRRF staff, the Seed Reactor and A-stage testing locations have been identified as follows: WRRF Project TM No. 16 - Bench Scale Test Protocol Page 7 of 12 - The Seed Reactors will be set-up adjacent to primary clarifier influent sampling points. An area of approximately 30’ X 20’ is required to accommodate the sampling containers, pumps and other equipment. Figure 3 shows an aerial graphic of where the reactors will be setup. - One to two canopies (provided by PM Team) will be set up to cover the reactors. - Electrical connection/power provided by the WRRF for two feed pumps (110 V). - Compressed air connection provided by the WRRF for aerating the Seed Reactors Figure 3. First Stage (Biomass Seed) Reactor Location (South of the Parshall Flumes) Detailed Procedures Step 1: Seed Reactor Startup and Operation Step by step procedures for Seed Reactor startup and operation are listed below. During startup and operation, TSS and VSS samples will be tested on a daily basis to confirm reactor operation. The exact number of samples is unclear as it is dependent on operational performance. It is anticipated that 1 to 3 TSS and VSS samples will be run per day during this period: 1. Set-up the Seed Reactors side by side. The reactors will be set-up with the aeration stones on the reactor bottom and feed water delivered to the lower part of the reactor. The aeration stones provide adequate mixing and target a DO of about 2 mg/L. The Seed Reactor will be equipped with the overflow to the Catchment Container. A V-notch weir or overflow pipe will be installed in the Seed Reactor wall to maintain a constant water level in the reactor. 2. The overflow from each Seed Reactor will flow into a second 50-gallon container (Catchment Container - refer to Figure 2). Initially the volume overflowing into the Catchment Container should be monitored three to four times per day to confirm that the feed pump flow rate is correct. The goal is to feed each Seed Reactor 30 to 60 gallons over a 24-hour period (or 1.3 to 2.5 gph). The final feed rate will be refined after the working volume of the reactor is finalized. WRRF Project TM No. 16 - Bench Scale Test Protocol Page 8 of 12 3. Calibrate the pump for each reactor using manufacturer instructions. Each reactor will have a dedicated feed pump (City’s Model M4 peristaltic pump- Blue-White Industries; Model M-425 MGK or similar). 4. Twice per day take DO and pH measurements. Reactor Daily Operation 1. Feed each reactor raw influent wastewater using a peristaltic pump at a rate of 30 to 60 gallons over a 24 hour period (1.3 to 2.5 gph). The volume overflowing into the Catchment Container should be monitored at least two times per day to confirm the accuracy of the feed pump flow rate. 2. Calibrate and adjust feed pump speed daily, as necessary. 3. Take DO measurements in the reactor at least two times per day. Adjust air flow rate to maintain a DO of about 2 mg/L. 4. Monitor pH daily to make sure it is within a reasonable range (6.8-8.2). 5. Inspect the reactors at least two times per day for grit/debris accumulation, clogging of aeration stones, and clogging of the feed pump. 6. Once per day, empty the Catchment Container and dispose of overflow to the plant drain. Run the Seed Reactors for 5 to 7 days to reach steady-state conditions, prior to initiating the A-Stage Reactor Testing. 7. Following the Catchment Container emptying, collect fresh samples of the Seed Reactor overflow (from each reactor) daily for TSS and VSS testing. Total sample volume required is about 250 mL. The number of samples might increase for periods of erratic operational performance. Additionally, there will be some additional TSS and VSS testing to test for the Step 2 testing, such as determining whether the microwave test is viable for rapidly measuring TSS in Step 2 or the volume can be based on the TSS and VSS database developed during Step 1. Step 2: A-Stage Testing Reactor Set-Up and Trial Run 1. Set-up six beakers side by side (2 to 4 L each). Five of the six reactors will be equipped with aeration stones. 2. Coordinate with laboratory for trial run analyses. Prior to starting the A-stage testing, performing a trial run test of the actual experiment (target DO of about 0.5 mg/L). Raw wastewater and RAS from the WRRF can be used to seed the reactor. The trial run shall be performed to confirm DO control and concentration and sampling procedures. Confirm if TSS concentration of the MLSS can be verified in field with real-time results. Reactor Testing 1. Coordinate testing with the laboratory staff prior to test day. Label sample bottles prior to test day. 2. Empty Catchment Container at each Seed Reactor. Allow overflow from Seed Reactors to collect into Catchment Container. After approximately 2 to 4 hours, collect fresh MLSS from each catchment container (about 2.5 to 10 gal from each Seed Reactor Catchment Container). 1. Transfer the collected mixed liquor to the lab and let it settle (about 30 min or less) 2. While MLSS is settling, collect approximately 5 to 10 gals of fresh primary influent. WRRF Project TM No. 16 - Bench Scale Test Protocol Page 9 of 12 3. After MLSS has settled, carefully discard the supernatant and mix the remaining MLSS. 4. If feasible, test the settled MLSS for TSS using the microwave test method. If microwave test method is not feasible, TSS concentration results from the Seed Reactor steady state operation will be used to estimate TSS concentration of settled MLSS. 5. Calculate the required first stage biomass seed (concentrated) and primary influent volume ratio for each test. Fill the six reactors with the determined volume ratios for the first stage biomass seed (concentrated) and primary influent. 6. Start aeration for the reactors A through E (HR A-stage reactors) and continue for 30 min while monitoring DO in each (target DO about 0.5 mg/L) 7. While aerating, take influent and effluent full-scale primary samples 8. Settle the non-aerated reactor for 30-60 min (the settling time will be updated based on field results during Step 1 testing) 9. Stop the aeration in the aerated reactors after 30 min and let it settle for 30-60 min (the settling time will be updated based on field results during Step 1 testing) 10. Collect decant and solids samples from each reactor 11. Repeat steps 1 through 9 for five consecutive days. Ideally, a weekend day is included as one of the test days. Make sure that the continuous operation reactor is operational for the duration of entire study. Analytical Requirements Table 4 demonstrates the anticipated number of samples for the Step 2 A-Stage Testing. There will be additional testing during the first stage setup and operation, which is summarized in Attachment A. Table 4. Analytical Requirements for A-Stage Testing (Six Reactors for Each Test Day) Parameter Infl* Infl/Effl Full-Scale Primaries Waste MLSS A-Stage Decant A-Stage Sludge PC Decant PC Sludge No. of Samples per Test Day Total No. of Samples ** COD 1 per Test 2 per Test 5 per Test 5 per Test 1 per Test 1 per Test 15 75 sCOD 1 per Test 2 per Test 5 per Test 1 per Test 9 45 TSS 1 per Test 2 per Test 1 per Test 5 per Test 5 per Test 1 per Test 1 per Test 16 80 VSS 1 per Test 2 per Test 1 per Test 5 per Test 1 per Test 10 50 BOD 1 per Test 2 per Test 5 per Test 1 per Test 9 45 sBOD 1 per Test 2 per Test 5 per Test 1 per Test 9 45 *The influent is the same for all six reactors so only one sample required per test day. ** Total number of samples assumes 5 test days. WRRF Project TM No. 16 - Bench Scale Test Protocol Page 10 of 12 Staffing and Schedule Estimates An overview of the testing schedule is provided in Figure 4. It is anticipated that the reactors will take one to two weeks to construct, which will be conducted in Folsom, CA at HDR, followed by one to three weeks to startup and test at the WRRF. The third week at the WRRF is for contingency. The staffing estimate for the testing at the WRRF is provided in Table 5. Remainder of page intentionally blank. WR R F P r o j e c t TM N o . 1 6 - B e n c h S c a l e T e s t P r o t o c o l Pa g e 1 1 o f 1 2 Fi g u r e 4 . H R B e n c h - S c a l e T e s t i n g S c h e d u l e Te s t i n g a t t h e W R R F ( i n c l u d e s c o n t i n g e n c y ) Se t u p / A c c l i m a t e R e a c t o r s a t t h e W R R F Re a c t o r C o n s t r u c t i o n / T r i a l R u n Te s t i n g W o r k p l a n R e v i e w / F i n a l i z e WR R F P r o j e c t TM N o . 1 6 - B e n c h S c a l e T e s t P r o t o c o l Pa g e 1 2 o f 1 2 Ta b l e 5 . B e n c h - S c a l e T e s t i n g S t a f f i n g E s t i m a t e Te s t i n g W R R F S t a f f PM T e a m S t a f f L e v e l o f E f f o r t C o m m e n t L e v e l o f E f f o r t C o m m e n t Re a c t o r D e s i g n / Co n s t r u c t i o n • La b o r a t o r y / O p e r a t i o n s s t a f f t o p r o v i d e pu m p , c o m p r e s s e d a i r a n d e l e c t r i c a l co n n e c t i o n d e t a i l s . • De s i g n / C o n s t r u c t i o n pe r f o r m e d i n F o l s o m by H D R • 1- 2 w e e k s • Co n s t r u c t e d b y s t a f f e n g i n e e r St a r t u p a n d O p e r a t i o n of S e e d R e a c t o r s (W e e k 1 ) • 1 O p e r a t i o n s s t a f f a t t h e b e g i n n i n g a n d en d o f e a c h s h i f t t o c h e c k r e a c t o r ( 1 pe r s o n , a v e r a g e o f 4 h o u r s p e r d a y ) • La b o r a t o r y o r O p e r a t i o n s s a f f P r o v i d e 3 - 6 hr s t o t a l p e r d a y ( a v e r a g e o f 4 h r s p e r da y , 7 d a y s p e r w e e k ) • La b o r a t o r y s t a f f a s s i s t w i t h e v a l u a t i n g TS S a n d V S S r a p i d m e t h o d s f o r A - S t a g e te s t i n g ( v i a b i l i t y o f m i c r o w a v e t e s t a n d / o r TS S / V S S d a t a b a s e ) • HD R / W S C o n s i t e f o r as s i s t a n c e w i t h re a c t o r o p e r a t i o n / tr o u b l e s h o o t i n g . • HD R o n s i t e f o r 2 d a y s ; H D R t o c o o r d i n a t e wi t h W R R F a n d W S C s t a f f t h e r e a f t e r o n a da i l y b a s i s • WS C o n s i t e f o r t r a i n i n g a n d r e a c t o r op e r a t i o n ( 1 s t a f f e n g i n e e r – o n s i t e a n av e r a g e o f 3 h r s / d a y ) • Ev a l u a t e T S S a n d V S S r a p i d m e t h o d s f o r A- S t a g e t e s t i n g ( v i a b i l i t y o f m i c r o w a v e te s t a n d / o r T S S / V S S d a t a b a s e ) • HD R / W S C t o a s s i s t w i t h re a c t o r o p e r a t i o n / m o n i t o r i n g Co n t i n g e n c y W e e k – Se e d R e a c t o r Op e r a t i o n ( W e e k 2 ) • 1 O p e r a t i o n s s t a f f a t t h e b e g i n n i n g a n d en d o f e a c h s h i f t t o c h e c k r e a c t o r ( 1 pe r s o n , a v e r a g e o f 4 h o u r s p e r d a y ) • La b o r a t o r y o r O p e r a t i o n s s t a f f p r o v i d e 3 - 6 hr s t o t a l p e r d a y ( a v e r a g e o f 4 h r s p e r da y , 7 d a y s p e r w e e k ) • La b o r a t o r y s t a f f a s s i s t w i t h e v a l u a t i n g TS S a n d V S S r a p i d m e t h o d s f o r A - S t a g e te s t i n g ( v i a b i l i t y o f m i c r o w a v e t e s t a n d / o r TS S / V S S d a t a b a s e ) • HD R / W S C o n s i t e f o r as s i s t a n c e w i t h re a c t o r o p e r a t i o n / tr o u b l e s h o o t i n g . • HD R t o c o o r d i n a t e w i t h W R R F a n d W S C on a d a i l y b a s i s r e g a r d i n g r e a c t o r op e r a t i o n ( 1 t o 2 h r s p e r d a y ) • WS C o n s i t e r e a c t o r m o n i t o r i n g ( 1 s t a f f en g i n e e r – o n s i t e a n a v e r a g e o f 2 h r s / d a y ) • Ev a l u a t e T S S a n d V S S r a p i d m e t h o d s f o r A- S t a g e t e s t i n g ( v i a b i l i t y o f m i c r o w a v e te s t a n d / o r T S S / V S S d a t a b a s e ) • HD R / W S C t o a s s i s t w i t h re a c t o r o p e r a t i o n / m o n i t o r i n g Co n d u c t A - S t a g e Te s t i n g a t W R R F (W e e k 3 ) • 1 O p e r a t i o n s s t a f f a t t h e b e g i n n i n g a n d en d o f e a c h s h i f t t o c h e c k r e a c t o r ( 1 pe r s o n , a v e r a g e o f 4 h o u r s p e r d a y ) • 2 L a b o r a t o r y s t a f f f o r 8 h o u r s p e r d a y t o as s i s t w i t h A - S t a g e T e s t i n g ; a s s u m e t o t a l of 5 t e s t d a y s • 1 O p e r a t i o n s o r L a b o r a t o r y s t a f f a s s i s t wi t h r e a c t o r c l e a n u p a t t e s t c o n c l u s i o n . • HD R / W S C o n s i t e t o le a d t e s t i n g e f f o r t • HD R o n s i t e f o r 2 . 5 d a y s o f t e s t i n g t o t r a i n an d c o n d u c t t e s t i n g • WS C o n s i t e ( 1 s t a f f , 8 h o u r s p e r d a y ) f o r te s t i n g • HD R / W S C t o l e a d t e s t i n g ef f o r t f o r 5 d a y s . C l e a n u p o f Se e d R e a c t o r s a f t e r co m p l e t i o n o f t e s t i n g . WRRF Project TM No. 16 - Bench Scale Test Protocol Attachment A: Seed Reactor and A-Stage Testing Details Table A - 1. Summary of Analytical Requirements – Seed Reactor Operation and A-Stage Testing Description No. of TSS Samples No. of VSS Samples No. of BOD Samples No. of sBOD Samples No. of COD Samples No. of sCOD Samples Seed Reactor Operation1 35 28 7 7 A-Stage Testing Trial 16 10 9 9 15 9 A-Stage Testing 80 50 45 45 75 45 Total 131 88 61 54 97 54 1 – Assumes 7 days of Seed Reactor Operation. TSS and VSS samples collected from two Seed Reactors, twice per day for 7 days. Reactor influent TSS, BOD and COD samples. *Volume of Seed Reactor sludge and influent wastewater into each reactor to be confirmed after startup of Seed Reactor. Figure A - 1. A-Stage Testing Setup A Influent, Raw Wastewater B A-Stage + Control Reactors Seed Reactor Sludge (0.5 to 1 day SRT) MLSS 500 mg/L C D E F MLSS 1,000 mg/L MLSS 1,500 mg/L MLSS 2,000 mg/L Control Primary Clarifier Sample Influent Wastewater (1 Sample analyzed for TSS, COD, sCOD, BOD, sBOD) Sample Each Reactor A thru F Decant -TSS, COD, sCOD, BOD, sBOD Solids –TSS, VSS, COD Appendix T Building Program Date: 6/9/2015 To: Carrie Mattingly Phone: (805) 781‐7205 Utilities Director 879 Morro St. San Luis Obispo, CA 93401 CC: Dave Hix; Howard Brewen Prepared by: Todd Hansen Reviewed by: Jasmine Diaz, Lianne Williams, Howard Brewen, Dave Hix, Carrie Mattingly, Site staff Project: WRRF Project SUBJECT: BUILDING PROGRAM The redevelopment of the water rescource recovery facility represents an opportunity that only comes once in a generation. With this redevelopment the goal is to create a facility that reinforces and supports the collaborative culture of the facility staff and that is an asset to the people of San Luis Obispo. The facility not only needs to serve the staff it needs to educate and inspire people regarding water use. The following building program for the San Luis Obispo Water Resource Recovery Facility was developed after extensive interviews with City staff, particularly facility staff and managers. The first draft was shared with operational staff and managers and revisions were made after discussions to review needs today and into the future. After review of the overall project budget and estimated costs it was decided to separate the Learning Center from the Water Resources Center as a stand alone facility that can be developed independently with community support. Narrative Water Resource Center ‐ Building Requirements Operations Facility operates 24 hours a day, 7 days a week all year Staff on site 7 days a week, 6am to 7pm Staff on site continuously during storm events Lab staff collects samples outside lab at times, particularly the creek. Operations staff divide time between central control area and field SCADA stations with limited lab facilities related to operations at that station. Facility to accommodate staff and interns Staff work 4 days weeks with one day a week when all staff are on site (typically Wedneday). Visitors Tours provided to groups including elementary schools, colleges, service groups Deliveries of supplies arrive regularly in variety of vehicles from Semi‐trucks with 40’ trailers to delivery vans. Adjacencies Lobby desk to direct visitors Management team offices to be located near each other Lab manager’s office to be located adjacent to the lab Maintenance manager to have small office adjacent to other managers and small office in shop building Kitchen area to be in close proximity to the conference rooms to facilitate refreshments for visitors and meetings Mud rooms to be adjacent to Lab and Operations entry from site Building to have public entry to lobby, staff entry adjacent to locker rooms, and entry adjacent to mud room Samples to enter building adjacent to mud room Operations, Lab, and Management functions to share a single facility Maintenance functions to be in a separate building due to noise but share locker and shower space with rest of staff. Machine shop and welding shop to share a common gantry crane but be separate spaces Structural Buildings to be designed and built to meet the current building codes and the Essential Services Act. WRRF Project Building Program 6/9/2015 Page 1 of 72 Narrative Mechanical Systems Background noise from generated by the mechanical system should be no more than 35 dB Return air to be filtered to MERV 13 Plumbing Examine the potential to use plant generated recycled water for toilets and urinals. Electrical Power Systems Provide a minimum of one dual electrical outlet per wall Provide a minimum of two quad electrical outlets at the desk areas in offices and workstations Lighting Systems Day lighting is desirable in all work areas High efficiency lighting is desired Emergency Power Systems Entire facility to be on emergency power. Can shed air conditioning of HVAC system except at computer equipment rooms Uninterruptible Power System No building wide UPS system. Select equipment to be protected by UPS during transition to generator Telecommunications System Wireless network access and coverage throughout buildings Conference rooms to have large wall mounted display screens for teleconferencing and SCADA display. Offices, workstations, and conference rooms to have one analog telephone line, one port for telephone and four ports for data and network as a minimum. Radio Systems NA WRRF Project Building Program 6/9/2015 Page 2 of 72 Narrative Security Systems Electronic keypad locks with unique access for each staff. Special keying at public access spaces for potential after hours use. Site Requirements Parking Visitor parking for 20 vehicles, accessible for bus Staff parking for 20 City vehicle parking for 3 full size vehicles and 3 electric carts Staff commute bicycle parking (not the same as facility bicycle parking) Solar panel covered parking Electric vehicle charging stations Security Fence to keep people out from creek path but views into site Full cut off lighting with no light source visible from off site, but all areas illuminated – possibly motion activated Outdoor Area Used by staff for informal meetings and meals Used by tour visitors as outdoor classroom space Demonstration landscaping with indigenous plants and reclaimed water Special Items Equipment Potential to use facility for City non‐emergency staff EOC – would require storage space for special equipment. May need to provide space for City wide communications equipment – telemetry from water system. WRRF Project Building Program 6/9/2015 Page 3 of 72 Narrative Learning Center – Building Requirements Operations Learning Center to host elementary through college school tour groups for hands on discovery utilizing water and lab equipment such as microscopes and fume hoods Center to host special events with room for large gatherings – indoor and outdoor Center to host school groups divided into groups of around 25 to 35 people Center to have facilities to support catered events – with commercial refrigerator and warming oven. Large meeting room to have facilities for coffee service. Facility to host a variety of events and users with various needs – storage for tables and chairs required. Adjacencies Center to be convenient to parking, particularly bus parking Center to be adjacent to outdoor meeting areas Center to be located along the plant tour route Adjacency to creek for collection of samples for education programs desirable. Structural Building to be compliant with current building codes Mechanical Systems Background noise generated by the mechanical system should be no more than 35 dB Return air to be filtered to MERV 13 Plumbing Examine the potential to use plant treated recycled water for toilets and urinals. Meeting room plumbed with water and sewer ports around the room for wet interactive displays is desirable. Electrical Power Systems Provide a minimum of one quad electrical outlet per 12’ of wall in meeting room. Provide a minimum of one duplex electrical outlet per 6’ of counter in lab. Lighting Systems Day lighting is desirable in all areas High efficiency lighting is desired Emergency Power Systems Not required WRRF Project Building Program 6/9/2015 Page 4 of 72 Narrative Uninterruptible Power System Not required Telecommunications System Wireless network access and coverage throughout. Video conferencing in the meeting room is desirable Meeting room and lab to have large wall mounted display screens for training video, feed from microscopes, and SCADA display. Ports for telephone and data to be distributed around lab and meeting room for future needs. Radio Systems NA Security Systems Electronic keypad locks with unique access for each staff. Site Requirements Parking Visitor parking for 20 vehicles, accessible for bus Solar panel covered parking Electric vehicle charging stations Security Fence to keep people out from creek path but views into site Full cut off lighting with no light source visible off site – possibly motion activated Outdoor Area Used by City staff for informal meetings Used by tour visitors as outdoor classroom space Demonstration landscaping with indigenous plants and reclaimed water WRRF Project Building Program 6/9/2015 Page 5 of 72 Common Lab‐Operations‐Management Spaces Management Staff Positions SizeCodeSFQty.SF Notes Facility Manager 12' x 14'PO‐31681168 Operations Manager 12' x 14'PO‐3 168 1168 Lab Manager 12' x 14'PO‐3168 1168 Adjacent to Lab Maintenance Manager 12' x 10'PO‐1120 1120 Lobby 22'x24'LBY 528 1528 Display area Total Management Spaces 5 Mangement SF Subtotal 1152 SF TOTAL WITH CIRCULATION (35%)1555 Testing Lab SizeCodeSFQty.SF Notes Testing Lab 23'x42'LAB 29661966 Lab Work Stations 5'x10'~504200 Adjacent to lab Lab Receiving 10'x22'~2201220 Adjacent to lab Lab Equipment Storage 8'x12'STOR1962192 Lab File Storage 8'x12'STOR2962192 Total Testing Lab Spaces 10 Testing Lab SF Subtotal 1770 SF TOTAL WITH CIRCULATION (35%)2390 Operations SizeCodeSFQty.SF Notes Control Room‐SCADA 16'x29'CTRL3921392 Operations Work Stations 8'x8'WRK‐S643192 Library Alcove 3'x12'LIB36136 Field ‐SCADA Station 12'x15'FLD1803~ Separate Buildings not included in subtotal Total Operations Spaces 8 Operations SF Subtotal 620 SF TOTAL WITH CIRCULATION (35%)837 Standard SpacesTotal Standard SpacesTotal Standard SpacesTotal WRRF Project Building Program 6/9/2015 Page 6 of 72 Common Lab‐Operations‐Management Spaces Support Spaces SizeCodeSFQty.SF Notes Kitchen / Break Room 22'x26'KIT‐DIN5721572 Work Room 10' x 15'WRK1501150 File Room 8' x 10'FILE80180 Large Conference Room 30' x 30'CONF‐L9001900 Adj to Kitchen Small Conference Room 12' x 17'CONF‐S2042408 Adj to Control room w bed Storage Room 8' x 10'STOR80180 Women's Restrooms 14' x24'LCKR3361336 Adj to Lockers Men's Restrooms 14' x 24'LCKR3361336 Adj to Lockers Mens's Locker Room 24'x35'LCKR8151815 Women's Locker Room 10'x23'LCKR5431543 Bicycle Storage 12'x18'STOR‐B2161216 Mud Room 9'x22'MUD1982396 Public Toilet Men 18'x11'PT‐M1981198 Public Toilet Women 18'x11'PT‐F1981198 Server Closet 6'x10'SERV60160 Communications Closet 6'x10'COM60160 For City water telementry Janitor Room 6'x10'60160 Electrical Room 6'x10'60160 Total Support Spaces 20 Support Spaces SF Total 5468 SF TOTAL WITH CIRCULATION (35%)7382 LAB‐OPERATIONS‐MANAGEMENT TOTAL 12164 Standard SpacesTotal WRRF Project Building Program 6/9/2015 Page 7 of 72 Maintenance Spaces Office Staff Positions SizeCodeSFQty.SF Notes Maintenance Manager 12'x10'PO‐1120 1120 Maintenace Work Stations 8'x8'WRK‐S643192 Library Alcove 2'x12'LIB242 48 Total Offices 6 Office SF Subtotal 360 SF TOTAL WITH CIRCULATION (35%)486 Shop Staff Positions SizeCodeSFQty.SF Notes Machine Shop 28'x50'M‐SHOP140011400 Welding Shop 28'x40'W‐SHOP112011120 Washdown Area 28'x16'WASH4481~Outdoor covered Parts Warehouse 30'x28'WARE8401840 Toilet 5'x8'TLT48148 Clean ‐Up Area 8'x11'CLN88188 Shower stall 5'x8'SHWR48148 Not intended for daily use Electronics Work Room 10'x12'E‐WRK1201120 Landscape Storage 12'x28'STOR‐L3361336 Covered Outdoor Storage 12'x28'STOR‐O3361~Outdoor covered Compressor 10'x8'COMP80180 Total Shop 11 Shop SF Subtotal 4080 SF TOTAL WITH CIRCULATION (35%)5508 MAINTENANCE SF GRAND TOTAL 5994 Standard Spaces Standard Spaces Total Total WRRF Project Building Program 6/9/2015 Page 8 of 72 Learning Center Learning Center SizeCodeSFQty.SF Notes Storage Room 8' x 10'STOR80180 Interactive Visitor Space 40'x43'VSTR118611186 Adjacent to Lab Microbiology Teaching Lab 12'x24'VSTR2881288 Chair Storage 8'x12'VSTR96196 Catering Alcove 12'x13'VSTR1601160 Public Toilet Men 18'x11'PT‐M1981198 Public Toilet Women 18'x11'PT‐F1981198 Janitor Room 6'x10'60160 Electrical Room 6'x10'60160 Total Support Spaces 9 Support Spaces SF Total 2326 SF TOTAL WITH CIRCULATION (35%)3140 LEARNING CENTER SPACE TOTAL 3140 Standard SpacesTotal WRRF Project Building Program 6/9/2015 Page 9 of 72 SPACE IDENTIFICATION ROOM NAME: Facility Manager SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space Meeting space 8 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Other manager offices and reception FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: SCADA ACCESS GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 10 of 72 WRRF Project Building Program 6/9/2015 Page 11 of 72 SPACE IDENTIFICATION ROOM NAME: Operations Manager SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space Meeting space 8 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Other manager offices and reception FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: SCADA access GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 12 of 72 WRRF Project Building Program 6/9/2015 Page 13 of 72 SPACE IDENTIFICATION ROOM NAME: Lab Manager SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space Meeting space 8 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Other manager offices, reception and lab FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE No window into lab desired SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: SCADA access GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 14 of 72 WRRF Project Building Program 6/9/2015 Page 15 of 72 SPACE IDENTIFICATION ROOM NAME: Maintenance Manager SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space Meeting space 8 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Other manager offices and reception FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 16 of 72 WRRF Project Building Program 6/9/2015 Page 17 of 72 SPACE IDENTIFICATION ROOM NAME: Lobby SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Reception, waiting 8 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Reception FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE Located at public entrance to building SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: Drinking fountain to be nearby if not in the lobby GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 18 of 72 WRRF Project Building Program 6/9/2015 Page 19 of 72 SPACE IDENTIFICATION ROOM NAME: Lab SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space Teaching space 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Adjacent to lab work areas, lab receiving, lab manager FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE Views into from interpretive center desired SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED METAL UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT 36” FULL LITE WARDROBE DEPTH 24” HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: Special chemical resistant countertops MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: Fume hoods, furnace hood, power for incubators and equipment (110v ands 240v), video monitor for teaching, autoclave, special dishwasher, eye wash GENERAL COMMENTS/REMARKS: Mud room adjacent to lab entry. WRRF Project Building Program 6/9/2015 Page 20 of 72 WRRF Project Building Program 6/9/2015 Page 21 of 72 SPACE IDENTIFICATION ROOM NAME: Lab Equipment Storage SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Storage 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Lab FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: Storage area to be provided with power, data, and daylight to allow for flexible use in the future. GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 22 of 72 WRRF Project Building Program 6/9/2015 Page 23 of 72 SPACE IDENTIFICATION ROOM NAME: Lab File Storage SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Storage 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Lab FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: Room to be equipped with power/data/daylight to allow for flexible use in the future. GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 24 of 72 WRRF Project Building Program 6/9/2015 Page 25 of 72 SPACE IDENTIFICATION ROOM NAME: Control Room SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Lab workstations FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: Whiteboards MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: SCADA display GENERAL COMMENTS/REMARKS: Room to open up to corridor for tours through facility WRRF Project Building Program 6/9/2015 Page 26 of 72 WRRF Project Building Program 6/9/2015 Page 27 of 72 SPACE IDENTIFICATION ROOM NAME: Operations Workstation SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Control Room FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: SCADA connectivity GENERAL COMMENTS/REMARKS: Used by staff and interns WRRF Project Building Program 6/9/2015 Page 28 of 72 WRRF Project Building Program 6/9/2015 Page 29 of 72 SPACE IDENTIFICATION ROOM NAME: Library Alcove SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Storage Study Space 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Operations work areas, conference rooms FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 30 of 72 WRRF Project Building Program 6/9/2015 Page 31 of 72 SPACE IDENTIFICATION ROOM NAME: Field SCADA Station SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space Lab testing 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Located central to the station FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE COLOR CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED METAL UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: Special equipment needs will vary depending on station MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: SCADA display GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 32 of 72 WRRF Project Building Program 6/9/2015 Page 33 of 72 SPACE IDENTIFICATION ROOM NAME: Kitchen Break Room SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Break Area Meeting space 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE Would like to be accessible to outdoor patio SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE COLOR CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: Flooring to be coved to facilitate cleaning, selected cabinets to have locks MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: Filter system for drinking water GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 34 of 72 WRRF Project Building Program 6/9/2015 Page 35 of 72 SPACE IDENTIFICATION ROOM NAME: Work Room SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space 8 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Manager offices and reception FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 36 of 72 WRRF Project Building Program 6/9/2015 Page 37 of 72 SPACE IDENTIFICATION ROOM NAME: File Room SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Storage 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Lab FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: GENERAL COMMENTS/REMARKS: Room to be equipped with power and data for potential alternate use. WRRF Project Building Program 6/9/2015 Page 38 of 72 WRRF Project Building Program 6/9/2015 Page 39 of 72 SPACE IDENTIFICATION ROOM NAME: Conference Room Large SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Meeting Space Instructional Space 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE Potential use as second tier EOC, Public meeting room SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Interpretive Center, Kitchen Break Room FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: SCADA data, Large wall monitor, whiteboards GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 40 of 72 WRRF Project Building Program 6/9/2015 Page 41 of 72 SPACE IDENTIFICATION ROOM NAME: Small Conference Room SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space Meeting space 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Managers, Operations FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: Whiteboard, murphy bed, large format monitor, SCADA data GENERAL COMMENTS/REMARKS: Murphy bed for operator use in storm event WRRF Project Building Program 6/9/2015 Page 42 of 72 WRRF Project Building Program 6/9/2015 Page 43 of 72 SPACE IDENTIFICATION ROOM NAME: Storage Room SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Storage 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Lab FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 44 of 72 WRRF Project Building Program 6/9/2015 Page 45 of 72 SPACE IDENTIFICATION ROOM NAME: Restrooms and Locker Rooms SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Toilet, Shower 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Near staff entry FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE Custodial space nearby SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE COLOR CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: Hanging space for uniforms, dirty uniform and towel bins, full length mirrors MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: Showers, exhaust air inlets near towels and laundry bins, GFI outlets at lavatories for blow dryers. GENERAL COMMENTS/REMARKS: Removable door panel can be relocated in adjacent frames to adjust balance of men’s and women’s showers based on staffing WRRF Project Building Program 6/9/2015 Page 46 of 72 WRRF Project Building Program 6/9/2015 Page 47 of 72 SPACE IDENTIFICATION ROOM NAME: Bike Storage SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Storage Maintenance 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION May be a separate out building FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE COLOR CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: Work bench for minor repairs, storage system for bicycles MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: Compressed air GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 48 of 72 WRRF Project Building Program 6/9/2015 Page 49 of 72 SPACE IDENTIFICATION ROOM NAME: Interactive Visitor Space SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Education Public outreach 8 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Lab and SCADA Control views desirable FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: Deionized water, sewer cleanouts in walls for potential water features, water supply in wall boxes with doors. GENERAL COMMENTS/REMARKS: This room to be the public face of the facility with features or connections to the plant and the operators. WRRF Project Building Program 6/9/2015 Page 50 of 72 WRRF Project Building Program 6/9/2015 Page 51 of 72 SPACE IDENTIFICATION ROOM NAME: Public Restroom SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Toilet 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Interactive Visitor Space, Large Conference Room FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE COLOR CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: Changing tables MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 52 of 72 WRRF Project Building Program 6/9/2015 Page 53 of 72 WRRF Project Building Program 6/9/2015 Page 54 of 72 WRRF Project Building Program 6/9/2015 Page 55 of 72 SPACE IDENTIFICATION ROOM NAME: Mud Room SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Entry to Lab / Lab Receiving/ Operations FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE COLOR CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: Passive air flow ideal to dry boots and gear, telephone shower for washing down boots and waders GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 56 of 72 WRRF Project Building Program 6/9/2015 Page 57 of 72 SPACE IDENTIFICATION ROOM NAME: Maintenance Manager SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space Meeting space 8 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Other manager offices and reception FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 58 of 72 WRRF Project Building Program 6/9/2015 Page 59 of 72 . SPACE IDENTIFICATION ROOM NAME: Maintenance Workstation SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Maintenance Shop, Library alcoves FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 60 of 72 WRRF Project Building Program 6/9/2015 Page 61 of 72 SPACE IDENTIFICATION ROOM NAME: Library Alcove SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Storage 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Maintenance work areas FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 62 of 72 WRRF Project Building Program 6/9/2015 Page 63 of 72 SPACE IDENTIFICATION ROOM NAME: Machine Shop SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space Storage 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Maintenance work areas, Welding shop, toilet, shower FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE COLOR CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: Equipment layout to be further developed by staff includes drill press, press, lathe, tool storage, parts washing, bead blast MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: Eyewash station at trough sink, gantry crane runs from wash down area into space GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 64 of 72 WRRF Project Building Program 6/9/2015 Page 65 of 72 SPACE IDENTIFICATION ROOM NAME: Welding Shop SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space Storage 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Maintenance work areas, Machine shop FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE COLOR CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: Equipment layout to be further developed by staff includes portable welding and cutting equipment, tables, tool storage MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: Gantry crane into space shared with machine shop GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 66 of 72 WRRF Project Building Program 6/9/2015 Page 67 of 72 SPACE IDENTIFICATION ROOM NAME: Parts Warehouse SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Storage 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Machine shop, Welding shop FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE COLOR CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: Storage layout to provide mix of small parts storage and large part storage on pallets MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 68 of 72 WRRF Project Building Program 6/9/2015 Page 69 of 72 SPACE IDENTIFICATION ROOM NAME: Shop Toilet Facilities SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space Safety 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Maintenance machine shop FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE COLOR CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 70 of 72 WRRF Project Building Program 6/9/2015 Page 71 of 72 SPACE IDENTIFICATION ROOM NAME: Electronics Workroom SPACE USE PRIMARY ACTIVITIES: SECONDARY ACTIVITIES: UTILIZATION ACCESS SECURITY Work space 10 HRS / DAY PUBLIC NO LOCK KEYPAD 24 HRS / DAY STAFF KEY LOCK CARD KEY SPECIAL REQUIREMENTS: OTHER SECURE SPACE RELATIONSHIPS ADJACENCIES: FLOOR LEVEL LOCATION ISOLATION Maintenance work areas FIRST SOUND: YES NO SECOND VISUAL: YES NO SPECIAL REQUIREMENTS: NO PREFERENCE SPACE CHARACTERISTICS FLOOR FINISH WALL FINISH CEILING FINISH CEILING HEIGHT INTERIOR GLAZING/COVER SOUND/ACOUSTIC TREATMENT SEALED CONCRETE PAINT ACOUSTIC TILE 9’‐0’ STANDARD NONE POLISHED CONCRETE TACKABLE SURFACE DRY WALL 12’‐14’ TINTED WALL INSULATION CARPET CERAMIC TILE EXPOSED OTHER BLINDS CEILING INSULATION CARPET TILE WALLCOVERING SKYLIGHT NO WINDOW INSULATED DOOR RESILIENT WAINSCOT OTHER OTHER: OTHER CERAMIC TILE ONE‐WAY GLASS RUBBER DOOR DOOR FINISH CASEWORK FINISH CASEWORK TYPE COUNTERTOPS WOOD PAINT PLASTIC LAMINATE BASE CABINET PLASTIC LAMINATE METAL STAINED PAINTED WOOD UPPER CABINET SOLID PHENOLIC METAL FRAME LAMINATE STAINED WOOD FULL HEIGHT CABINET SOLID SURFACE POLYMER DOUBLE SOLID PHENOLIC PANTRY HEIGHT FULL LITE WARDROBE DEPTH HALF LITE EXPOSED SHELVING SIDE LIGHT LOCK OTHER BUILT‐IN SYSTEM FURNISHING SPECIAL REQUIREMENTS: MECHANICAL AND ELECTRICAL REQUIREMENTS LIGHTING HVAC PLUMBING ELECTRICAL POWER COMMUNICATION NATURAL LIGHT EXHAUST FAN COMPRESSED AIR 120V DEDICATED OUTLET PHONE/DATA TASK THERMOSTAT GAS EMERGENCY POWER VIDEO/CABLE DIMMER OTHER HOSE BIBB OTHER AUDIO SYSTEM OTHER SINK CCTV DRINKING FOUNTAIN OTHER: OTHER SPECIAL REQUIREMENTS: GENERAL COMMENTS/REMARKS: WRRF Project Building Program 6/9/2015 Page 72 of 72 Appendix U Community Workshop Summary San Luis Obispo 3765 S. Higuera St., Ste. 102 San Luis Obispo, CA 93401 P: (805) 543‐1794 | F: (805) 543‐4609 Santa Maria 1862 S. Broadway, Ste. 101 Santa Maria, CA 93454 P: (805) 349‐7788 | F: (805) 354‐7050 Santa Barbara 10 E. Figueroa St., Ste. 1 Santa Barbara, CA 93101 P: (805) 963‐8283 | F: (805) 963‐8184 San Clemente 232 Avenida Fabricante, Ste. 232 San Clemente, CA 92672 P: (949) 361‐7950 | F: (949) 361‐7955 www.rrmdesign.com ARCHITECTS | ENGINEERS | LANDSCAPE ARCHITECTS | PLANNERS | SURVEYORS A California Corporation | Victor Montgomery, Architect #C11090 | Jerry Michael, PE #36895, LS #6276 | Jeff Ferber, LA #2844 City of San Luis Obispo Water Resource Recovery Facility (WRRF) June 4, 2014 – Community Workshop The City of San Luis Obispo’s Utility department held a Community Workshop on Wednesday, June 4th, from 6:30 p.m. to 9:00 p.m., at the Ludwick Community Center. Approximately 40 community members, plus a number of WRRF employees, attended the workshop. The workshop focused on identifying and prioritizing issues and ideas, understanding architectural character preferences, as well as educating the community on the WRRF and the WRRF Project. The workshop engaged participants in a fun and interactive way through a brainstorming exercise, prioritization exercise, and a visual preference survey. The workshop began with an overview of what our WRRF does for our community, the WRRF Project process, and a photo tour of the site. The second part of the workshop, the public was asked to participate in a brainstorming exercise to voice their issues, ideas, and concerns regarding six (6) categories: Bike and Pedestrian Circulation, Prado Road, Public Amenities, Learning and Interpretive Features, Environment/Sustainability, and Issues/Concerns. The community was very engaging and expressed many ideas and issues that they would like to see considered in this process. It was really fun to see how one good idea from one community member would spur another good idea from a different community member. The creative ideas were really flowing. Their comments were recorded on large posters with the six (6) categories/headings. Upon completion of the brainstorming exercise, each participant was given 15 small green sticker dots and three (3) red sticker dots. The green dots were used to show high priority items and the red dots represented low priority items. The top priority items include ideas about incorporating interpretive and educational features on the site, along the bike path, and within an interpretive building. Other ideas include designing the facility to minimize energy consumption (net zero building), utilize sustainable building and landscape practices, and to consider a wetland/marsh treatment component. Creating opportunities to educate visitors on the city and state water cycle and on the natural habitat around the site. One of the many popular creative suggestions was to have a bike tour route through the plant “Tour de Sewer”. Participants also ranked safety on the adjacent Bob Jones bike path and homeless encampments in the creek a top concern, along with bike trail maintenance, odor, and sensitivity to neighborhood impacts. The final part of the workshop was a Visual Preference Survey which allowed participants to express their preferences on different architectural styles and elements that could be incorporated into the site’s buildings, as well as community‐focused elements to be considered as part of the site planning. Each participant was given a remote control device to vote on projected architectural character images and site features that would be appropriate or not appropriate for the San Luis Obispo WRRF. Participants voted on each image and the results appeared instantaneously. In summary, the participants preferred architectural character that was more contemporary in nature, that blended with City of San Luis Obispo Water Resource Recovery Facility June 4, 2014 – Community Workshop Page 2 of 2 the natural surroundings, and that integrated sustainable design elements. More traditional craftsman, agrarian, or industrial looking architecture was not preferred for the WRRF at this location in San Luis Obispo. Participants gravitated toward interpretive and educational design elements that were interactive and that would be fun for younger school children during field trips. They liked the images of the wetlands, native plantings, meeting rooms and outdoor spaces open for public use, water features incorporated into visitor experiences, creating a pleasing entrance from Prado Road and enhancing the view from 101 with landscaping, and attractive buildings or architectural features. A complete dot exercise tally and a summary of the Visual Preference Survey exercise will be located on the project website: www.slowater.org Ideas Concerns X Creek (danger zone, heavily wooded, homeless encampments in creek) X Bridge across to bike path from Zaca Lane X Clean out creek (shrubs, encampments) X Maybe lights on bike path X Eyes on bike path to make safer for pedestrians on bike path (homeless make it feel unsafe) X Safe (make it safe) X Cars, bikes, and campers from homeless creek campers on Zaca Lane X Bike storage became homeless storage X Don't use bike path because of safety with homeless X Not sure we want to encourage use of trail. Don't want to set people up for conflict with homeless X Old building (3565 S. Higuera): smell was a problem; hot days there is strong odor X Once in a while, can smell at Zaca Lane Stakeholder suggestions- active homeless issue: Tom Maino, Rob Olson; Mission Bank, Music Motive, Bill Thoma WRRF has grown into site with varioius uses over the years. X Prado Day Center site may become available X Other community public uses would be good - keep in public use X Nice entry to City - Green - on 101 On other side of 101 -Further uses will expand there, Community currently wants it O.S. X Prado Interchange - Plan for this X Los Osos Valley Road future road expansion - plan for this X Continued access and control of creek and maintain water flow Was flooded in 1973 storm X Have not heard much about homeless in this area but, know they are in the creek with encampments X Used to remove brush and trees and encampments prior to every rainy season Reclaimed water - tried to get approval to run pipeline to Laguna Lake but there were environmental issues and concerns City's Master Plan - interchange at 101 and Prado as an arterial street - will have to enlarge bridge over creek on Prado Road. X Prado Road and Los Osos Valley Road plan for future expansion X Community Use - Ok as long as not too expensive Gary Henderson and John Mass - Utilities department retired - possible stakeholders or resource X Restrooms (but don’t create a homeless attraction) X SLO City Farm - Bob Jones will connect to it, Central Coast Grown - Jenna Smith - food security & Policy X Target - nice neighborhood park behind Target X Arcata - good example of treatment SLO Water Resource Recovery Facility Stakeholder Interviews May, 2014 X Poway - east of San Diego, integrating ponding - good example of treatment plant X Interpretive Signage - could be integrated to complement the exhibits on the Bob Jones Trail X Public Relations - Should use Facebook page to outreach for things like water shut off. Poor messaging about higher unit costs Election Year When we conserve it costs more X "We have been putting money aside" - Good message X Don't need dog park Howard - Employee driven plan to improve the WRRF X Send info to Aron @ Chamber to post on website and facebook X Chamber committees - could make presentations: Economic Development committee, Sustainability committee, Issues committee Have a great crew at the plant, people have a lot of respect for them, they will be important ambassadors for this project. X Had a number of employees using trail but have stopped due to panhandlers X The more low covering greenery and shrubs create homes for panhandlers X More lighting would help X More safety precautions - Now use electric gates for safety, Don't allow female staff alone at night X Parking - people use JB Dewers lot to park for trail X Prado Road - City's designated truck route; Busy street M-F , ie. UPS trucks / at 5pm during weekdays congested to leave SLO X Prado and Higuera - impacted intersection X Odor - yes, very noticeable at times. See more flys than we used to. X See a lot of families on bikes with young children, need areas for bike racks X Space for employees to eat lunch - benefit park environment X Maximum recycling of water & minimal disposal X Least amount put in creek X Odors - major issue for neighborhood X Watsonville - good example - built recycling plant recently X Cal Poly collaboration encouraged X View - first thing on 101 you see, like landscaping Has not taken bike trail X Maximizing trail X Protect lower rates for rate payer Process wise - recently upgraded to remove nitrates X Plugged flow types of reactor (some best results from: S. Santa Clara county, CMC - discharges to Chorro Creek) X Education: LID - Bio swales, pervious pavement - demonstrate, interpretive signs, household chemicals, prescriptions, storm water, SLO Green Build X Bob Jones trail: incorporate interpretive signage, low impact dev. principals - showcase, i.e. Octagon Barn (consistency with effort at Octagon Barn), X Access- how to allow access to beautiful site but protect X Used meeting rooms X Access road along creek could be used as a bike trail X Par course stations along trail, mini-park along trail, restrooms or drinking fountains X As trail becomes more used the less the homeless will want to be there X Keep visibility of picnic area close to where other people are seen X Play structure for kids X Locate public amenities in areas without odor X Locate admin building to look out onto trail for safety of trail and for beautiful views of creek X Mtg room - across from bldg to trail X Educating public - on natural resources X Bike racks - near interpretive panels & at benches and at main community center/interpretive center X Decomposed granite shoulders on bike path are good for runners - Bike Coalition are receiving feedback from running community X May want to talk to Runner usergroup, Get off the couch potato - Samantha Pruit x Community/interpretive center should be located near bike path X Love width of trail X Coordinate with Octagon Barn Interpretive Center/exhibits X Bob Jones trail study X Drinking fountains would be great X Talk to City Natural Resources Management X Think about new residential that will be built in Margarita area. There will be more people using the path X Keep tot lot far enough away from path to avoid conflicts X Transient population will go away when path becomes busier X Need to have a meeting place for class visits X Typically bring 2 classes at a time - 50-70 students plus chaperones and teachers X Split them up for tour X Need place for Power Point/movie show capability X Cold Canyon facility - good example X Flyer for school teachers X Good interpretive exhibits throughout facility - cross sections "what does it look like inside" filters, bio filter; text light, graphic heavy X Observation towers X Tilman Recreation Facility - Japanese Gardens (beautiful with tea, education tower) X Hyperian - new education center X Need to educate people about: amount of electricity water use takes, greenhouse gasses X Need good videos that can also send to website X Need benches in grounds to tie shoe or sit down during tours X Water fountains X Educational facility location: If it by appointment only (can be back in site), if it open to public (Prado Rd) X Would like to take kids to outfall but often too far X Greenhouse gasses - will need to look at how to reduce these through design, city being a leader should lead by example X Any sensitive receptors should be separated from emissions X Consider possible future expansion of residential uses on other side of 101 X Since 1998 there have been 81 complaints X Resolving/enhancements regulatory control requirements X Asking for a comprehensive document - odor control X Don't have: plant process flow diagram, view diagram X Most issues: headworks, clarifier, design & operation of waste gas, emergency & planned maintenance X Buffer - important for neighborhoods X If we modernize plant it's a win/win: energy efficient, green, lower emission X SF Exploratorium - good example X Connecting to neighborhoods would be good X Water conservation measures, energy it takes to clean water, purple pipes X Water conservation: evaporates X Does it help if the clarifiers/ponds are covered? (both for odor and evaporation) X Good to show discharge point and how it is clean X 200 AC Arcada Marsh: magnet for birders, saved a ton of money X Viewing opportunities - Arkansas Pass - birding towers X i.e. Towers, could be towers off the trail X Marsh costs are so much cheaper; great water quality X Emergent contaminants, best removals: RO, Ozanation treatment, wetlands X Cal Poly could use for studies X Water reuse is critical X Give tours - 15-20 kids, 40 kids X Storm water retention - intercept it and reroute to Tank Farm, 2015 2 million plus stormwater could be converted X Minimize hardscape and improve filtration X Micro turbines sized too small - has to replace filters every 2 months X Gearheart, Bob - professor at Humboldt State (Arcada) X Interview Neil Havlick about creek trees - may be a problem to extend path near trees X Signage - need directional signage, interpretive signage X Meeting room was good for bike meeting X Advertise tours of plan on side of path X More signs, more bike racks X Monterey County landfill - have tours X Fix sloped sides of trail X Staging area/car parking for trail X Stakeholders- others, Los Verdes, Neil Havlick, Freddy Otte, Bob Hill Day center and ML 9.8AC, 4.6AC+3.1AC+_____AC public use Elks Lane will be rerouted, access on and off 101 will extend down Prado Rd 35 employees No real shopping center nearby X Would like a bridge X Storm water retention is always needed, could we put our storm water on WRRF? X Keep industrial part of plant (north/west of site) from residential X Keep trees along creek - they provide wind break X Be nice to create controls to inhibit the migration of homeless up and down creek X Love the idea of bridge but concerns about bringing homeless in to neighborhood -also concerned about impacting native vegetation X incorporate tot lot, ie slide X Not easily accessible X Would be nice to have a local park but would be hard to police X Planning on Solar? X Moorpark Water reclamation facility - REC Solar incorporated a large steel viewing platform for schools - looked over solar system elevated viewing ponds, series of platforms X Have solar field Sent flyer to neighbors Odor issues: not too much, maybe one day per year. Notice it north on Higuera X Don’t create more smells X Homeless issue X 1/2 neighborhood want bridge to bike path, 1/2 afraid of homeless X Active bird watching opportunity X Active challenge course that you could do, could do bike challenge course Not ampitheater due to noise Location of Interpretive Center: visibility from freeway not as important, ability for tours is good Solar or alternative energy demonstration area Providing technical information to Airport Commission X Homeless encampments (enter from Creekside and Silver City) X Bridge across to bike path would be good but not from our neighborhood X Architecture: mid-century modern type with wood, glass looks modern but blends in the environment X Will email me photo X Atrium with trees X connecting the trail to Avila will help X play area for kids with benches X Silver City Community Room used for baby showers, birthdays and is always booked. Another Community Room and/or BBQ area would be a benefit Silver City is 50%-70% seniors, 20% families, 5% college: 700-1000 people' 200 spaces CATEGORY GREEN DOTSRED DOTS Environment/Sustainability Marsh/wetland treatment 191 Net zero (minimize energy)150 Use Tank Farm wetlands 70 Internship program 70 Address chemicals/pharmaceuticals 60 Sustainable buildings (LEED)61 Permiable hardscape 50 Recharge ground water 40 Sustainability analysis 30 Solar energy/lighting 30 Treatment wetlands 32 Coordinate water with City Farm 20 Alternative collection system 20 Work force development 20 Composting toilets 10 Decentralize treatment 10 Reduce transport 10 Reclaimed water to Laguna Lake 11 Oxidation ponds 11 TOTAL:896 Ci t y o f S L O W a t e r Re s o u r c e R e c o v e r y CATEGORY GREEN DOTSRED DOTS Learning and Interpretive Features City water cycle 80 Water system diagram 60 Educational signs throughout the city 60 Viewing platform/overlook 40 Career education 40 Interpretive/environmental center 40 Environmental community center 40 Habitat education 40 What not to throw in the toilet 30 Map of a California water distribution 30 Interactive water component 30 Low‐impact development 30 Sitewide education/interpretive walk 30 Interpretive signs 20 Water uses pie chart 20 Educational classroom 20 Local flora/fauna guides 20 Biosolids education 20 Senior‐led programs (docents)20 Educational art 10 What and why is it in the water?10 Water conservation tips 10 Energy efficiency demonstration 10 Education on drought 10 Geo cache 11 Recycled water distribution and use 00 Education on sustainability 00 Education on flood 00 Electronic content/self‐guided tour 00 Educational games 00 Fire prevention/safety 03 Free WI‐FI 08 TOTAL:7312 Ci t y o f S L O W a t e r Re s o u r c e R e c o v e r y CATEGORY GREEN DOTSRED DOTS Issues/Concerns Homeless 70 Bike trail maintenance 60 Safety 50 Enforcement/patrol 50 Odor 50 Be realistic/market research 50 Improving visibility of site 40 Neighborhood impacts 41 Bike path safety 30 Emergency call phones 30 Cleanliness 20 Security 20 Soil/geology 10 TOTAL:521 Ci t y o f S L O W a t e r R e s o u r c e Re c o v e r y F a c i l i t y CATEGORY GREEN DOTSRED DOTS Bike and Pedestrian Circulation Tour de sewer 70 Bike/Pedstrian Separation 40 Parking at trailhead (for Bob Jones Trail)30 Class II bike connection 30 Benches 30 Unintrusive lighting 20 Class I standard bikeway (having shoulders)10 Fragrant landscape 10 trash/recycle cans (inlcuding dog pick‐up bags)10 Picnic area 10 Bicycle parking 00 Connect to Broad Street 01 Mid‐path bridge across creek 01 Access to creek 02 Separate play areas from bike path 02 TOTAL:266 Ci t y o f S L O W a t e r R e s o u r c e Re c o v e r y F a c i l i t y CATEGORY GREEN DOTSRED DOTS Public Amenities Wetland 40 Bus stop 30 Meeting room 30 Safe outdoor lighting 30 Public health education 30 Biosolids composting onsite 34 Drinking fountain ‐ (including dog fountain) 20 Pilot test area 20 Viewing portals 20 Restrooms with potty parity 21 Bike fix‐it station 10 Outdoor gathering space 10 Interpretive models ‐ sitewide 10 Demonstration gardens (xeroscape)11 Bird viewing sites 12 Free compost/biosolid 13 Childs urinal in women's restroom 14 Picnic area 00 Public safety 00 World view education 01 Bike park 02 Biosolid demo garden 03 Museum 03 Water play area 04 TOTAL:3428 Ci t y o f S L O W a t e r R e s o u r c e Re c o v e r y F a c i l i t y CATEGORY GREEN DOTSRED DOTS Prado Road Class II bike lane 30 Landscaping 21 Sidewalks 10 Welcoming signage 10 Information center 11 Widen Prado 02 No two‐way center lane 02 No parking 02 TOTAL:88 Ci t y o f S L O W a t e r Re s o u r c e R e c o v e r y Response Reports Session:WRF Workshop Class:Default Class Page 1 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) What is the average amount of wastewater treated at the SLO WRRF daily?1 A 250,000 gallons0% B 1.25 million gallons25% C 3.5 million gallons65% D 50 million gallons10% What is the average daily amount of recycled water consumed in 2013?2 A 50,000 gallons per day21% B 160,000 gallons per day47% C 1 million gallons per day26% D 5 million gallons per day5% Is this architectural character appropriate?3 A Appropriate17% B Neutral39% C Not Appropriate44% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 2 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Is this architectural character appropriate?4 A Appropriate60% B Neutral25% C Not Appropriate15% Is this architectural character appropriate?5 A Appropriate32% B Neutral26% C Not Appropriate42% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 3 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Is this architectural character appropriate?6 A Appropriate50% B Neutral25% C Not Appropriate25% Is this architectural character appropriate?7 A Appropriate70% B Neutral25% C Not Appropriate5% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 4 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Is this architectural character appropriate?8 A Appropriate45% B Neutral35% C Not Appropriate20% Is this architectural character appropriate?9 A Appropriate10% B Neutral5% C Not Appropriate85% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 5 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Through direct discharge to the creek, the SLO WRRF's treated wastewater improves the water quality of San Luis Obispo Creek. 10 A True79% B False21% Is this architectural character appropriate?11 A Appropriate53% B Neutral32% C Not Appropriate16% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 6 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Is this architectural character appropriate?12 A Appropriate26% B Neutral5% C Not Appropriate68% Is this architectural character appropriate?13 A Appropriate35% B Neutral50% C Not Appropriate15% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 7 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Is this character of architecture appropriate?14 A Appropriate68% B Neutral11% C Not Appropriate21% Is this character of architecture appropriate?15 A Appropriate15% B Neutral15% C Not Appropriate70% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 8 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Is this architectural character appropriate?16 A Appropriate63% B Neutral11% C Not Appropriate26% The facility removes 99.1% of solids in wastewater prior to discharge.17 A True79% B False21% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 9 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Is this architectural character appropriate?18 A Appropriate40% B Neutral15% C Not Appropriate45% Is this architectural character appropriate?19 A Appropriate16% B Neutral5% C Not Appropriate79% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 10 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Is it important to have interpretive exhibits and learning stations?20 A Important85% B Neutral5% C Not Important10% Is it important to have indoor space for public use?21 A Important65% B Neutral20% C Not Important15% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 11 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Is it important to have outdoor spaces for public use?22 A Important68% B Neutral21% C Not Important11% Is it important to have viewing platforms?23 A Important25% B Neutral40% C Not Important35% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 12 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Is it important to have water features incorporated into the visitor experience?24 A Important79% B Neutral16% C Not important5% Is this architectural character appropriate?25 A Appropriate21% B Neutral26% C Not Appropriate53% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 13 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Which of the following animal species relies on the treated wastewater flow into the San Luis Obispo Creek to survive? 26 A Red-legged frog11% B Merganser Duck0% C Heron0% D Steelhead Trout11% E All of the above78% Is this architectural character appropriate?27 A Appropriate32% B Neutral32% C Not Appropriate37% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 14 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Is this architectural character appropriate?28 A Appropriate15% B Neutral30% C Not Appropriate55% Is this architectural character appropriate?29 A Appropriate21% B Neutral16% C Not Appropriate63% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 15 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Is this architectural character appropriate?30 A Appropriate26% B Neutral37% C Not Appropriate37% Are green building practices important to you?31 A Important95% B Neutral0% C Not Important5% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 16 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) How many pounds of biosolids were converted into compost in 2013?32 A 500 pounds0% B 1,100 pounds5% C 2,200 pounds32% D 4,400 pounds63% Is it important to interface with the Bob Jones Bike Path?33 A Important65% B Neutral20% C Not Important15% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 17 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Is it important to have a visually pleasing entrance to the facility from Prado Road?34 A Important89% B Neutral5% C Not Important5% 6/4/2014 8:55:19 PM Response Reports Session:WRF Workshop Class:Default Class Page 18 Class Points Avg:60.54 out of 100.00 (60.54%) (Includes only students who took assessment) Would you prefer landscaping or attractive buildings and architectural treatment along the 101 view shed? 35 A Landscaping40% B Architecture0% C Both60% How many people tour the facility on average every year?36 A 100 people15% B 500 people20% C 1000 people55% D 1 million people10% 6/4/2014 8:55:19 PM Appendix V Cost Estimates City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost City of San Luis Obispo Public Works Water Resource Recovery Facility (WRRF) Project Facilities Plan Draft Final Plan Costs 1Flow Equalization $1,501,000 2Headworks Odor Control $788,000 3Primary Clarifiers $2,879,000 4Aeration Basins $14,121,000 5Final Clarifiers $4,272,000 6 Tertiary Filtration and Cooling $6,163,000 7UV Disinfection $7,485,000 8Solids (Digestion, Thickening, Dewatering)$6,759,000 9Sidestream $3,642,000 10Renewable Energy Generation $1,066,000 11General Site $11,090,000 12Water Resource Center & Learning Center $6,305,000 13Maintenance Building $1,953,000 14Flood Protection $1,500,000 $69,524,000 Allowance for Design, Environmental, Permitting, and CM (25 percent)$20,857,200 Total Project Cost in Current Dollars$90,381,200 $104,777,000 Notes for Cost Table: (1) Construction costs in 2014 dollars and include 30% contingency. (2) Allowance for Design, Environmental, Permitting, and CM is 30%. Total Construction Costs in Current Dollars Total Project Costs in 2019 Dollars (escalated to midpoint of construction) No. Description Summary Table Summary - Page 1 of 1 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Flow Equalization - Page 1 of 3 City of San Luis Obispo Public Works Water Resource Recovery Facility (WRRF) Project Facilities Plan Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Flow Equalization CG/MR Task:Opinion of Probable Construction Cost CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Flow Equalization Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COST DIVISION 1 - GENERAL REQUIREMENTS Mobilization/Demobilization 1 LS 3.00%$31,000 Bonds and Insurance 1 LS 1.00%$10,300 Construction Facilities/Fencing/Offices 1 LS 2.00%$20,700 General Conditions 1 LS 2.00%$20,700 Shop Drawings and O&M Manuals 1 LS 1.50%$15,500 Facilities Start-up & Testing 1 LS 2.50%$25,900 Construction Sequencing & Constraints 1 LS 3.00%$31,000 SUBTOTAL $155,100 DIVISION 2 - SITE WORK Demolition of Secondary Clarifier (mechanism, piping, e 1 LS $30,000 $30,000 EQ Pond Structural Excavation 197 CY $24 $4,700 Aggregate Bedding 197 CY $46 $9,100 Backfilling (Engineered Fill, Compaction Included)3,500 CY $10 $35,000 Dirt Hauling 197 CY $7 $1,400 AC Paving 14,100 SF $6 $84,600 EQ Return Water Pump Station Structural Excavation 200 CY $24 $4,800 Shoring 1,000 SF $45 $45,000 Aggregate Bedding 10 CY $46 $500 Backfilling (Engineered Fill, Compaction Included)100 CY $10 $1,000 Dirt Hauling 40 CY $7 $300 SUBTOTAL $216,400 DIVISION 3 - CONCRETE EQ Pond Concrete Walls 0 CY $1,000 $0 Concrete Floor 0 CY $900 $0 EQ Return Water Pump Station Slab on Grade 14 CY $900 $12,600 Thick Wall 13 CY $1,200 $15,600 SUBTOTAL $28,200 DESCRIPTION Prepared By: Reviewed By: City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Flow Equalization - Page 2 of 3 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Flow Equalization CG/MR Task:Opinion of Probable Construction Cost CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Flow Equalization Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COSTDESCRIPTION Prepared By: Reviewed By: DIVISION 4 - MASONRY Not Used 0 EA $0 $0 SUBTOTAL $0 DIVISION 5 - MISCELLANEOUS METALS Misc. Metals 1 LS $50,000 $50,000 SUBTOTAL $50,000 DIVISION 6 - WOOD AND PLASTIC HDPE Pond Liner 118,000 SF $2 $236,000 SUBTOTAL $236,000 DIVISION 7 - THERMAL AND MOISTURE PROTECTION Moisture Seal 1 LS $30,000 $30,000 SUBTOTAL $30,000 DIVISION 8 - DOORS AND WINDOWS Not Used 0 EA $0 $0 SUBTOTAL $0 DIVISION 9 - FINISHES Paintings and Protective Coatings (Piping and Equipment)1 LS $20,000 $20,000 SUBTOTAL $20,000 DIVISION 10 - SPECIALTIES Signs, Identification, Stenciling and Tagging System 1 LS $10,000 $10,000 SUBTOTAL $10,000 DIVISION 11 - EQUIPMENT EQ Pond New Return Pumps 2 EA $40,000 $80,000 Allowance - Water Cannons 1 LS $50,000 $50,000 Venturi Air Injector 1 EA $75,000 $75,000 SUBTOTAL $205,000 DIVISION 13 - INSTRUMENTATION I&C Allowance (10% of Div 11 and 15)10%LS $355,000 $35,500 SUBTOTAL $35,500 DIVISION 14 - CONVEYANCE Not Used 0 EA $0 $0 SUBTOTAL $0 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Flow Equalization - Page 3 of 3 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Flow Equalization CG/MR Task:Opinion of Probable Construction Cost CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Flow Equalization Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COSTDESCRIPTION Prepared By: Reviewed By: DIVISION 15 - MECHANICAL EQ Pond Misc Pipe and Fittings 1 LS $150,000 $150,000 SUBTOTAL $150,000 DIVISION 16 - ELECTRICAL Electrical Allowance (15% of Div 11 and 15)15%LS $355,000 $53,250 SUBTOTAL $53,250 $1,034,350 $156,000 $310,305 $1,501,000TOTAL, Rounded SUBTOTAL (WITHOUT DIVISION 1), Rounded HDR DIVISION 1, Rounded CONSTRUCTION CONTINGENCY (30%) City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Public Works Water Resource Recovery Facility (WRRF) Project Facilities Plan Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Preliminary Treatment CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Headworks Date:6/10/2015 QUANTITYUNITSUNIT COSTTOTAL COST DIVISION 1 - GENERAL REQUIREMENTS Mobilization/Demobilization1LS3.00%$16,300 Bonds and Insurance 1LS1.00%$5,500 Construction Facilities/Fencing/Offices1LS2.00%$10,900 General Conditions 1LS2.00%$10,900 Shop Drawings and O&M Manuals1LS1.50%$8,200 Facilities Start-up & Testing1LS2.50%$13,600 Construction Sequencing & Constraints1LS3.00%$16,300 SUBTOTAL$81,700 DIVISION 2 - SITE WORK Headworks - Site Work Site Clearing (curb, trees and fence removal, and AC paving demolition)0LS$10,000$0 Shoring 0SF$45$0 Structural Excavation 0SF$24$0 Aggregate Bedding 0CY$46$0 Backfilling (Engineered Fill, Compaction Included)0 CY$10$0 Dirt Hauling 0CY$7$0 Odor Control Excavation 1,400CY$24$33,000 Aggregate Bedding 450CY$46$20,600 SUBTOTAL $53,600 DIVISION 3 - CONCRETE Headworks Slab on Grade 0CY$900$0 Thick Wall 0CY$1,200$0 Elevated Slab 0CY$1,300$0 Misc. Concrete (Lean)0CY$400$0 Grit Removal Facility Slab on Grade 0CY$900$0 Thick Wall 0CY$1,200$0 Elevated Slab 0CY$1,300$0 Misc. Concrete (Lean)0CY$400$0 SUBTOTAL $0 DESCRIPTION City of San Luis Obispo Reviewed By: Prepared By: Grit Removal - Page 1 of 3 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Preliminary Treatment CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Headworks Date:6/10/2015 QUANTITYUNITSUNIT COSTTOTAL COSTDESCRIPTION Reviewed By: Prepared By: DIVISION 4 - MASONRY Not Used 0EA$0$0 SUBTOTAL$0 DIVISION 5 - MISCELLANEOUS METALS Not Used 0EA$0$0 SUBTOTAL$0 DIVISION 6 - WOOD AND PLASTIC FRP Duct Work Allowance1LS$40,000$40,000 SUBTOTAL$40,000 DIVISION 7 - THERMAL AND MOISTURE PROTECTION Moisture Protection 1LS$15,000$15,000 SUBTOTAL$15,000 DIVISION 8 - DOORS AND WINDOWS Not Used 0EA$0$0 SUBTOTAL$0 DIVISION 9 - FINISHES Paintings and Protective Coatings (Piping and Equipment)1LS$20,000$20,000 SUBTOTAL$20,000 DIVISION 10 - SPECIALTIES Signs, Identification, Stenciling and Tagging System 1LS$10,000$10,000 SUBTOTAL$10,000 DIVISION 11 - EQUIPMENT Mechanical Bar Screen0EA$170,000$0 Influent Pumps 0EA$60,000$0 Odor Control (biofilter system)12,000SF$14$168,000 Odor Control Fans 3EA$5,000$15,000 SUBTOTAL$183,000 DIVISION 13 - INSTRUMENTATION I&C Allowance (10% of Div 11 and 15)10%LS$275,500$27,550 Influent Magmeters on Influent Pumps4EA$15,000$60,000 SUBTOTAL$87,550 DIVISION 14 - CONVEYANCE Screenings Conveyor 0EA$40,000$0 Not Used $0 SUBTOTAL$0 Grit Removal - Page 2 of 3 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Preliminary Treatment CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Headworks Date:6/10/2015 QUANTITYUNITSUNIT COSTTOTAL COSTDESCRIPTION Reviewed By: Prepared By: DIVISION 15 - MECHANICAL Misc. Utility Water Pipes0.5LS$10,000$5,000 Misc. Piping and Fittings0.5LS$75,000$37,500 Misc. Valves and Isolation Gates0.5LS$75,000$37,500 Misc. Air Ductwork 0.5LS$25,000$12,500 SUBTOTAL$92,500 DIVISION 16 - ELECTRICAL Electrical Allowance (15% of Div 11 and 15)15%LS$275,500$41,325 SUBTOTAL$41,325 $542,975 $82,000 $163,000 $787,975TOTAL, Rounded CONSTRUCTION CONTINGENCY (30%) HDR DIVISION 1, Rounded SUBTOTAL (WITHOUT DIVISION 1), Rounded Grit Removal - Page 3 of 3 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost City of San Luis Obispo Public Works Water Resource Recovery Facility (WRRF) Project Facilities Plan Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Primary Clarifiers CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Primary Clarifiers Date:6/10/2015 QUANTITYUNITSUNIT COSTTOTAL COST DIVISION 1 - GENERAL REQUIREMENTS Mobilization/Demobilization 1 LS 3.00%$59,600 Bonds and Insurance 1 LS 1.00%$19,900 Construction Facilities/Fencing/Offices 1 LS 2.00%$39,700 General Conditions 1 LS 2.00%$39,700 Shop Drawings and O&M Manuals 1 LS 1.50%$29,800 Facilities Start-up & Testing 1 LS 2.50%$49,700 Construction Sequencing & Constraints 1 LS 3.00%$59,600 SUBTOTAL$298,000 DIVISION 2 - SITE WORK Primary Sludge Pump Structure Site Prep 1LS$10,000$10,000 Excavation 300CY$24$7,100 Aggregate Bedding 100CY$46$4,600 Backfilling (Engineered Fill, Compaction Included)100CY$10$1,000 Primary Effluent Distribution Box (PEDB) Site Prep 1LS$5,000$5,000 Excavation 200CY$24$4,800 Aggregate Bedding 100CY$46$4,600 Backfilling (Engineered Fill, Compaction Included)100CY$10$1,000 Odor Control Structural Excavation 0CY$24$0 Aggregate Bedding 0CY$46$0 Backfilling (Engineered Fill, Compaction Included)0 CY$10$0 Dirt Hauling 0CY$7$0 SUBTOTAL$38,100 DIVISION 3 - CONCRETE Existing Primary Clarifier No. 1 Misc. Concrete Work, Rehab 1 LS $50,000 $50,000 Existing Primary Clarifier No. 2 Misc. Concrete Work, Rehab 1 LS $50,000 $50,000 Prepared By: Reviewed By: DESCRIPTION Primary Clarifiers - Page 1 of 3 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Primary Clarifiers CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Primary Clarifiers Date:6/10/2015 QUANTITYUNITSUNIT COSTTOTAL COST Prepared By: Reviewed By: DESCRIPTION Primary Sludge Pump Structure Slab 119 CY $900 $107,000 Walls 41 CY $1,200 $50,000 Misc Allowance 1 LS $15,000 $15,000 Primary Effluent Diversion Box Slab 30 CY $900 $27,000 Walls 21 CY $1,200 $25,000 Misc Allowance 1 LS $15,000 $15,000 Odor Control Slab on Grade 0 CY $900 $0 Thick Wall 0 CY $1,200 $0 SUBTOTAL$339,000 DIVISION 4 - MASONRY Not Used 0 EA $0 $0 SUBTOTAL$0 DIVISION 5 - MISCELLANEOUS METALS Misc. Allowance 1 LS $25,000 $25,000 SUBTOTAL$25,000 DIVISION 6 - WOOD AND PLASTIC Allowance for Weir Replacement 500 LF $120 $60,000 Allowance for PEDB Weirs 1 LS $12,000 $12,000 FRP Odor Control Covers for PCs 10,100 SF $50 $505,000 SUBTOTAL$577,000 DIVISION 7 - THERMAL AND MOISTURE PROTECTION Moisture Seal 1 LS $20,000 $20,000 SUBTOTAL$20,000 DIVISION 8 - DOORS AND WINDOWS Not Used 0 EA $0 $0 SUBTOTAL$0 DIVISION 9 - FINISHES Paintings and Protective Coatings (Piping and Equipment)1LS$10,000$10,000 SUBTOTAL$10,000 DIVISION 10 - SPECIALTIES Signs, Identification, Stenciling and Tagging System 1LS$7,000$7,000 SUBTOTAL$7,000 Primary Clarifiers - Page 2 of 3 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Primary Clarifiers CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Primary Clarifiers Date:6/10/2015 QUANTITYUNITSUNIT COSTTOTAL COST Prepared By: Reviewed By: DESCRIPTION DIVISION 11 - EQUIPMENT Primary Clarifier 2 EA $50,000 $100,000 2 EA $25,000 $50,000 Replace Existing Clarifier Mechanisms 2 LS $200,000 $400,000 Odor Control Biofilter Media and Support System0SF$14$0 Fans 0EA$5,000$0 Misc Duct Work 0LS$50,000$0 SUBTOTAL$550,000 DIVISION 13 - INSTRUMENTATION I&C Allowance (10% of Div 11 and 15)10%LS $775,000 $77,500 SUBTOTAL$77,500 DIVISION 14 - CONVEYANCE Not Used 0 -$0 $0 SUBTOTAL$0 DIVISION 15 - MECHANICAL 1 LS $100,000 $100,000 Allowance for Valves 1 LS $50,000 $50,000 Allowance for Slide Gates/Weir Gates (PEDB)1 LS $30,000 $30,000 Allowance for Utility Piping, Plant Drain Connections 1 LS $25,000 $25,000 Misc. Allowance for Fittings, etc 1 LS $20,000 $20,000 SUBTOTAL$225,000 DIVISION 16 - ELECTRICAL Electrical Allowance (15% of Div 11 and 15)15%LS $775,000 $116,250 SUBTOTAL$116,250 $1,984,850 $298,000 $595,455 $2,879,000TOTAL, Rounded SUBTOTAL (WITHOUT DIVISION 1), Rounded HDR DIVISION 1, Rounded CONSTRUCTION CONTINGENCY (30%) Replace Existing Sludge Pumps Replace Existing Scum Pumps Allowance for PS Piping and Fittings Primary Clarifiers - Page 3 of 3 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Aeration Basins - Page 1 of 3 City of San Luis Obispo Public Works Water Resource Recovery Facility (WRRF) Project Facilities Plan Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Aeration Basins CG/MR Task:Opinion of Probable Construction Cost CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Aeration Basins Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COST DIVISION 1 - GENERAL REQUIREMENTS Mobilization/Demobilization 1 LS 3.00%$292,200 Bonds and Insurance 1 LS 1.00%$97,400 Construction Facilities/Fencing/Offices 1 LS 2.00%$194,800 General Conditions 1 LS 2.00%$194,800 Shop Drawings and O&M Manuals 1 LS 1.50%$146,100 Facilities Start-up & Testing 1 LS 2.50%$243,500 Construction Sequencing & Constraints 1 LS 3.00%$292,200 SUBTOTAL $1,461,000 DIVISION 2 - SITE WORK Demolition - Existing Aeration Basins Allowance for Piping, valving, etc.1 LS $10,000 $10,000 Aeration Basin Extension Shoring 9,792 SF $45 $440,600 Structural Excavation 18,700 CY $24 $440,600 Aggregate Bedding 1,000 CY $46 $45,800 Backfilling (Engineered Fill, Compaction Included)4,600 CY $10 $46,000 Dirt Hauling 14,200 CY $7 $99,400 Chemical Storage Structural Excavation 0 CY $24 $0 Aggregate Bedding 0 CY $46 $0 Backfilling (Engineered Fill, Compaction Included)0 CY $10 $0 Dirt Hauling 0 CY $7 $0 SUBTOTAL $1,082,400 DIVISION 3 - CONCRETE Existing Aeration Basins Interior Walls 290 CY $1,200 $348,000 Aeration Basin Extension Slab on Grade 1,800 CY $900 $1,620,000 Thick Wall 1,470 CY $1,200 $1,764,000 Influent/ Effluent Channels Slab on Grade 160 CY $900 $144,000 Thick Wall 370 CY $1,200 $444,000 Prepared By: Reviewed By: DESCRIPTION City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Aeration Basins - Page 2 of 3 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Aeration Basins CG/MR Task:Opinion of Probable Construction Cost CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Aeration Basins Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COST Prepared By: Reviewed By: DESCRIPTION Blower Building Slab on Grade 150 CY $900 $135,000 Chemical Storage Slab on Grade 0 CY $900 $0 Thick Wall 0 CY $1,200 $0 SUBTOTAL $4,455,000 DIVISION 4 - MASONRY Blower Building - CMU Walls 0 SF $50 $0 SUBTOTAL $0 DIVISION 5 - MISCELLANEOUS METALS Aeration Basin Extension Guard Rail 1,280 LF $80 $102,400 Access Stairs 1 LS $10,000 $10,000 Misc. Metals 1 LS $15,000 $15,000 Blower Building Metal Roof Deck 2,000 SF $10 $20,000 SUBTOTAL $147,400 DIVISION 6 - WOOD AND PLASTIC Influent Weirs to Aeration Basins 1 LS $12,000 $12,000 Allowance for Parshall Flumes 2 EA $30,000 $60,000 SUBTOTAL $72,000 DIVISION 7 - THERMAL AND MOISTURE PROTECTION Moisture Seal Allowance 11,154 SF $10 $111,540 SUBTOTAL $111,540 DIVISION 8 - DOORS AND WINDOWS Allowance for Doors and Windows (Blower Building)1 LS $11,000 $11,000 SUBTOTAL $11,000 DIVISION 9 - FINISHES Paintings and Protective Coatings 1 LS $25,000 $25,000 SUBTOTAL $25,000 DIVISION 10 - SPECIALTIES Signs, Identification, Stenciling and Tagging System 1 LS $20,000 $20,000 SUBTOTAL $20,000 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Aeration Basins - Page 3 of 3 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Aeration Basins CG/MR Task:Opinion of Probable Construction Cost CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Aeration Basins Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COST Prepared By: Reviewed By: DESCRIPTION DIVISION 11 - EQUIPMENT Aeration Basins ML Recirc. Pump (with installation)6 EA $40,000 $240,000 ML Recirc. Pump (shelf spare)1 EA $30,000 $30,000 Anoxic Zone Mixer 12 EA $30,000 $360,000 Aeration Zone Diffusers 28,000 SF $13 $364,000 Aeration Blowers (350 HP, each)3 EA $500,000 $1,500,000 Chemical Storage Chemical Metering Pump Skid 0 LS $25,000 $0 SUBTOTAL $2,494,000 DIVISION 13 - SPECIAL CONSTRUCTION I&C Allowance (10% of Div 11 and 15)10%LS $2,979,000 $297,900 Storage Tanks 4 EA $15,000 $60,000 SUBTOTAL $357,900 DIVISION 14 - CONVEYANCE Davit Crane 6 EA $5,000 $30,000 SUBTOTAL $30,000 DIVISION 15 - MECHANICAL Blower Building Building Ventilation 0 LS $10,000 $0 Aeration Basins Aeration Piping and Supports 1 LS $170,000 $170,000 Air Control Valves and Actuators 10 EA $7,500 $75,000 Misc. Piping and Fittings 1 LS $50,000 $50,000 ML Pipe 640 LF $16 $10,000 Chemical Feed Piping Double Containment Piping & Valves 0 LS $75,000 $0 Modifications to SE Distribution Box (allowance)1 LS $50,000 $50,000 Misc. Fittings, Valves and Supports 1 LS $130,000 $130,000 SUBTOTAL $485,000 DIVISION 16 - ELECTRICAL Electrical Allowance (15% of Div 11 and 15)15%LS $2,979,000 $446,850 SUBTOTAL $446,850 $9,738,090 $1,461,000 $2,921,427 $14,121,000TOTAL, Rounded SUBTOTAL (WITHOUT DIVISION 1), Rounded HDR DIVISION 1, Rounded CONSTRUCTION CONTINGENCY (30%) City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Final Clarifiers - Page 1 of 3 City of San Luis Obispo Public Works Water Resource Recovery Facility (WRRF) Project Facilities Plan Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Final Clarifiers CG/MR Task:Opinion of Probable Construction Cost CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Final Clarifiers Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COST DIVISION 1 - GENERAL REQUIREMENTS Mobilization/Demobilization 1 LS 3.00%$88,400 Bonds and Insurance 1 LS 1.00%$29,500 Construction Facilities/Fencing/Offices 1 LS 2.00%$58,900 General Conditions 1 LS 2.00%$58,900 Shop Drawings and O&M Manuals 1 LS 1.50%$44,200 Facilities Start-up & Testing 1 LS 2.50%$73,700 Construction Sequencing & Constraints 1 LS 3.00%$88,400 SUBTOTAL $442,000 DIVISION 2 - SITE WORK New Final Clarifier No. 7 and 8 Site Clearing (curb and AC paving demolition)1 LS $2,000 $2,000 Shoring 500 SF $45 $22,500 Structural Excavation 4,700 CY $24 $110,732 Aggregate Bedding 300 CY $46 $13,725 Backfilling (Engineered Fill, Compaction Included)4,100 CY $10 $41,000 Dirt Hauling 700 CY $7 $4,900 Yard Piping Allowance of Relocation of Existing Utilities 1 LS $100,000 $100,000 SUBTOTAL $294,857 DIVISION 3 - CONCRETE New Final Clarifier No. 7 and 8 Slab on Grade 900 CY $900 $810,000 Thick Wall 300 CY $1,200 $360,000 SUBTOTAL $1,170,000 DIVISION 4 - MASONRY Not Used 0 EA $0 $0 SUBTOTAL $0 DESCRIPTION Prepared By: Reviewed By: City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Final Clarifiers - Page 2 of 3 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Final Clarifiers CG/MR Task:Opinion of Probable Construction Cost CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Final Clarifiers Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COSTDESCRIPTION Prepared By: Reviewed By: DIVISION 5 - MISCELLANEOUS METALS New Final Clarifier No. 7 and 8 Metal Stairs and Landing 1 LS $15,000 $15,000 Guard Rail 510 LF $80 $40,800 Misc Metals 1 LS $15,000 $15,000 SUBTOTAL $70,800 DIVISION 6 - WOOD AND PLASTIC FRP Weir Plate 510 LF $120 $61,200 Scum Baffle and Supports 510 LF $100 $51,000 SUBTOTAL $112,200 DIVISION 7 - THERMAL AND MOISTURE PROTECTION Moisture Seal 1 LS $30,000 $30,000 SUBTOTAL $30,000 DIVISION 8 - DOORS AND WINDOWS Not Used 0 EA $0 $0 SUBTOTAL $0 DIVISION 9 - FINISHES Paintings and Protective Coatings (Piping and Equipment)1 LS $20,000 $20,000 SUBTOTAL $20,000 DIVISION 10 - SPECIALTIES Signs, Identification, Stenciling and Tagging System 1 LS $10,000 $10,000 SUBTOTAL $10,000 DIVISION 11 - EQUIPMENT New Final Clarifier No. 7 and 8 Sludge Scraper, Center Column, Feed Well, Motor Drive, Scum Box and Scum Skimmer 2 EA $320,000 $640,000 RAS Pump 4 EA $30,000 $120,000 Scum Pump 2 EA $15,000 $30,000 WAS Pump 2 EA $25,000 $50,000 SUBTOTAL $840,000 DIVISION 13 - INSTRUMENTATION I&C Allowance (10% of Div 11 and 15)10%LS $990,000 $99,000 SUBTOTAL $99,000 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Final Clarifiers - Page 3 of 3 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Final Clarifiers CG/MR Task:Opinion of Probable Construction Cost CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Final Clarifiers Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COSTDESCRIPTION Prepared By: Reviewed By: DIVISION 14 - CONVEYANCE Not Used 0 EA $0 $0 SUBTOTAL $0 DIVISION 15 - MECHANICAL New Final Clarifier No. 7 and 8 Misc Pipe 1 LS $100,000 $100,000 Misc Fittings/ Valves 1 LS $50,000 $50,000 SUBTOTAL $150,000 DIVISION 16 - ELECTRICAL Electrical Allowance (15% of Div 11 and 15)15%LS $990,000 $148,500 SUBTOTAL $148,500 $2,946,000 $442,000 $883,800 $4,272,000TOTAL, Rounded SUBTOTAL (WITHOUT DIVISION 1), Rounded HDR DIVISION 1, Rounded CONSTRUCTION CONTINGENCY (30%) City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Tertiary Filtration and Cooling - Page 1 of 4 City of San Luis Obispo Public Works Water Resource Recovery Facility (WRRF) Project Facilities Plan Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Tertiary Filtration and Cooling CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Tertiary Filtration and Coolin Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COST DIVISION 1 - GENERAL REQUIREMENTS Mobilization/Demobilization 1 LS 3.00%$127,500 Bonds and Insurance 1 LS 1.00%$42,500 Construction Facilities/Fencing/Offices 1 LS 2.00%$85,000 General Conditions 1 LS 2.00%$85,000 Shop Drawings and O&M Manuals 1 LS 1.50%$63,700 Facilities Start-up & Testing 1 LS 2.50%$106,200 Construction Sequencing & Constraints 1 LS 3.00%$127,500 SUBTOTAL $637,400 DIVISION 2 - SITE WORK New Tertiary Filters 5,6 Site Clearing (curb and AC paving demolition)1 LS $10,000 $10,000 Shoring 230 SF $45 $10,350 Structural Excavation 400 CY $24 $9,424 Aggregate Bedding 100 CY $46 $4,575 Backfilling (Engineered Fill, Compaction Included)300 CY $10 $3,000 Dirt Hauling 0 CY $7 $0 Cooling Tower Structural Excavation 300 CY $24 $7,068 Aggregate Bedding 200 CY $46 $9,150 Backfilling (Engineered Fill, Compaction Included)200 CY $10 $2,000 Dirt Hauling 200 CY $7 $1,400 Chiller Structural Excavation 10 CY $24 $236 SUBTOTAL $56,967 DIVISION 3 - CONCRETE New Tertiary Filters 5,6 Slab on Grade 500 CY $900 $450,000 Thick Wall 300 CY $1,200 $360,000 Elevated Slab 100 CY $1,300 $130,000 Cooling Tower Slab on Grade 200 CY $900 $180,000 Wet well 90 CY $1,200 $108,000 SUBTOTAL $1,228,000 DESCRIPTION Prepared By: Reviewed By: City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Tertiary Filtration and Cooling - Page 2 of 4 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Tertiary Filtration and Cooling CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Tertiary Filtration and Coolin Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COSTDESCRIPTION Prepared By: Reviewed By: DIVISION 4 - MASONRY Not Used 0 EA $0 $0 SUBTOTAL $0 DIVISION 5 - MISCELLANEOUS METALS New Tertiary Filters 5,6 Walkway and rails 1 LS $15,000 $15,000 Metal Stairs and Landing - 2'-6" High 1 LS $5,000 $5,000 Guard Rail 700 LF $80 $56,000 Gates for isolation 4 EA $15,000 $60,000 Filter Canopy 200 SF $150 $30,000 Chiller Chiller Canopy 200 SF $150 $30,000 SUBTOTAL $196,000 DIVISION 6 - WOOD AND PLASTIC FRP Weir Plate 300 LF $120 $36,000 Scum Baffle and Supports 300 LF $100 $30,000 SUBTOTAL $66,000 DIVISION 7 - THERMAL AND MOISTURE PROTECTION Moisture Seal 1 LS $30,000 $30,000 SUBTOTAL $30,000 DIVISION 8 - DOORS AND WINDOWS Not Used 0 EA $0 $0 SUBTOTAL $0 DIVISION 9 - FINISHES Paintings and Protective Coatings (Piping and Equipment)1 LS $20,000 $20,000 SUBTOTAL $20,000 DIVISION 10 - SPECIALTIES Signs, Identification, Stenciling and Tagging System 1 LS $10,000 $10,000 SUBTOTAL $10,000 DIVISION 11 - EQUIPMENT New Tertiary Filters 5,6 Underdrain/ filter media/ troughs 2 EA $241,000 $482,000 Backwash pumps 1 EA $50,000 $50,000 Blowers 1 EA $50,000 $50,000 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Tertiary Filtration and Cooling - Page 3 of 4 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Tertiary Filtration and Cooling CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Tertiary Filtration and Coolin Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COSTDESCRIPTION Prepared By: Reviewed By: Cooling Tower Cooling towers and fans 2 EA $130,000 $260,000 Feed pumps 5 EA $25,000 $125,000 Recirc pumps 5 EA $15,000 $75,000 Chiller Cooling towers and fans 1 EA $130,000 $130,000 Feed pumps 2 EA $25,000 $50,000 Recirc pumps 2 EA $15,000 $30,000 SUBTOTAL $1,042,000 DIVISION 13 - INSTRUMENTATION I&C Allowance (10% of Div 11 and 15)10%LS $1,511,000 $151,100 SUBTOTAL $151,100 DIVISION 14 - CONVEYANCE Not Used 0 EA $0 $0 SUBTOTAL $0 DIVISION 15 - MECHANICAL Existing Filters Replace Actuators 1 LS $120,000 $120,000 New Tertiary Filters 5,6 Underdrain piping, air scour, and backwash piping 0.5 LS $100,000 $50,000 Air piping - 8"0.5 LS $50,000 $25,000 New Actuated Butterfly Valves 6 EA $10,000 $60,000 New Plug Valves 4 EA $6,000 $24,000 Misc Valves and Piping 0.5 LS $80,000 $40,000 New 3W Pumps 3 EA $30,000 $90,000 Cooling Tower Cooling tower recirc piping and valves 1 LS $60,000 $60,000 Chiller Chiller 1 LS $435,000 $435,000 Heat Exchanger 1 LS $100,000 $100,000 SUBTOTAL $469,000 DIVISION 16 - ELECTRICAL Electrical Allowance (15% of Div 11 and 15)15%LS $1,511,000 $226,650 SUBTOTAL $226,650 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Tertiary Filtration and Cooling - Page 4 of 4 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Tertiary Filtration and Cooling CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Tertiary Filtration and Coolin Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COSTDESCRIPTION Prepared By: Reviewed By: $4,249,459 $638,000 $1,274,838 $6,163,000TOTAL, Rounded SUBTOTAL (WITHOUT DIVISION 1), Rounded HDR DIVISION 1, Rounded CONSTRUCTION CONTINGENCY (30%) San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost UV Disinfection - Page 1 of 3 City of San Luis Obispo Public Works Water Resource Recovery Facility (WRRF) Project Facilities Plan Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Disinfection CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]UV Disinfection Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COST DIVISION 1 - GENERAL REQUIREMENTS Mobilization/Demobilization 1 LS 3.00%$154,800 Bonds and Insurance 1 LS 1.00%$51,600 Construction Facilities/Fencing/Offices 1 LS 2.00%$103,200 General Conditions 1 LS 2.00%$103,200 Shop Drawings and O&M Manuals 1 LS 1.50%$77,400 Facilities Start-up & Testing 1 LS 2.50%$129,000 Construction Sequencing & Constraints 1 LS 3.00%$154,800 SUBTOTAL $774,000 DIVISION 2 - SITE WORK Drain and Stormwater 300 LF $200 $60,000 Clearing and Grubbing 0.3 AC $15,000 $4,500 Excavation for UV Structure (Includes Shoring)3,000 CY $30 $90,000 Structural Backfill 2,750 CY $8 $22,000 Structural Bedding 95 CY $55 $5,200 Material Disposal 1,500 CY $8 $12,000 Concrete Pavement 700 SF $75 $52,500 Final Grading & Seeding 0.3 AC $8,000 $2,400 Demolition 1 LS $250,000 $250,000 Connection 1 LS $50,000 $50,000 Conduit Fittings 1 LS $50,000 $50,000 Influent Conduit/Piping 70 LF $1,500 $105,000 SUBTOTAL $703,600 DIVISION 3 - CONCRETE Influent Channel 50 CY $700 $35,000 Effluent Channel 50 CY $700 $35,000 UV Channel and Deck 450 CY $700 $315,000 Access Walkway Slabs & Stairs 5 CY $800 $4,000 SUBTOTAL $389,000 DIVISION 4 - MASONRY Not Used 0 EA $0 $0 SUBTOTAL $0 DESCRIPTION Prepared By: Reviewed By: San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost UV Disinfection - Page 2 of 3 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Disinfection CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]UV Disinfection Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COSTDESCRIPTION Prepared By: Reviewed By: DIVISION 5 - MISCELLANEOUS METALS Ladders and Stairs 25 VLF $75 $1,900 Miscellaneous Structural Steel 1 LS $1,300 $1,300 Bollards 4 EA $1,000 $4,000 Grating 1,800 SF $30 $54,000 Fixed Weir 200 LF $120 $24,000 Stilling Plates 2 EA $5,000 $10,000 SUBTOTAL $95,200 DIVISION 6 - WOOD AND PLASTIC FRP Handrail 100 LF $35 $3,500 Aluminum Guardrail 100 LF $110 $11,000 SUBTOTAL $14,500 DIVISION 7 - THERMAL AND MOISTURE PROTECTION Sealant 1 LS $10,000 $10,000 SUBTOTAL $10,000 DIVISION 8 - DOORS AND WINDOWS Not Used 0 -$0 $0 SUBTOTAL $0 DIVISION 9 - FINISHES Paintings and Protective Coatings (Piping and Equipment)1 LS $5,000 $5,000 SUBTOTAL $5,000 DIVISION 10 - SPECIALTIES Equipment Tagging 1 LS $5,000 $5,000 Signage 1 LS $1,500 $1,500 Fire Extinguishers 3 EA $1,000 $3,000 SUBTOTAL $9,500 DIVISION 11 - EQUIPMENT UV Equipment (including installation)1 EA $2,278,150 $2,278,200 Influent Isolation Gates 2 EA $20,000 $40,000 Influent Weir 2 EA $15,000 $30,000 Effluent Isolation Gates 2 EA $20,000 $40,000 Effluent Stop Logs 3 EA $2,000 $6,000 Sump Pump 1 EA $15,000 $15,000 SUBTOTAL $2,409,200 San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost UV Disinfection - Page 3 of 3 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Disinfection CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]UV Disinfection Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COSTDESCRIPTION Prepared By: Reviewed By: DIVISION 13 - INSTRUMENTATION Instrumentation and Controls 1 LS $50,000 $50,000 Canopy 4500 SF $40 $180,000 Siding 3500 SF $20 $70,000 Open Channel Flow Meter 3 EA $50,000 $150,000 SUBTOTAL $450,000 DIVISION 14 - CONVEYANCE Not Used $0 SUBTOTAL $0 DIVISION 15 - MECHANICAL Valves, Miscellaneous 1 LS $50,000 $50,000 Channel Liners 1 LS $100,000 $100,000 Plumbing 1 LS $50,000 $50,000 Potable Water Lines 500 LF $40 $20,000 SUBTOTAL $220,000 DIVISION 16 - ELECTRICAL UV System 1 LS $775,080 $775,100 Transfer Switch 1 LS $80,000 $80,000 SUBTOTAL $855,100 $5,161,100 $774,000 $1,549,000 $7,484,100TOTAL, Rounded SUBTOTAL (WITHOUT DIVISION 1), Rounded HDR DIVISION 1, Rounded CONSTRUCTION CONTINGENCY (30%) City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost City of San Luis Obispo Public Works Water Resource Recovery Facility (WRRF) Project Facilities Plan Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Solids CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Solids Handling Date:6/10/2015 QUANTITYUNITSUNIT COSTTOTAL COST DIVISION 1 - GENERAL REQUIREMENTS Mobilization/Demobilization 1 LS 3.00%$139,900 Bonds and Insurance 1 LS 1.00%$46,700 Construction Facilities/Fencing/Offices 1 LS 2.00%$93,300 General Conditions 1 LS 2.00%$93,300 Shop Drawings and O&M Manuals 1 LS 1.50%$70,000 Facilities Start-up & Testing 1 LS 2.50%$116,600 Construction Sequencing & Constraints 1 LS 3.00%$139,900 SUBTOTAL$699,700 DIVISION 2 - SITE WORK Demolition - Existing Solids Handling Facility Demolish DAF Equipment 1 LS $25,000 $25,000 Demolish BFP 0 LS $10,000 $0 1LS$25,000$25,000 Electrical Demolition 1 LS $8,000 $8,000 Solids Thickening Site Clearing 1 LS $5,000 $5,000 Structural Excavation 119 CY $24 $2,800 Aggregate Bedding 59 CY $46 $2,800 Anaerobic Digester Excavation 2,800 CY $24 $66,000 Backfilling (Engineered Fill, Compaction Included)2,800 CY $10 $28,000 Shoring 3,100 SF $45 $139,500 SUBTOTAL $302,100 DIVISION 3 - CONCRETE Solids Thickening Allowance for DAF Tank Rehab 1 LS $30,000 $30,000 Slab on Grade 119 CY $900 $107,000 Anaerobic Digester Slab on Grade 330 CY $900 $297,000 Thick Wall 220 CY $1,200 $264,000 Elevated Slab 220 CY $1,300 $286,000 DESCRIPTION Demolish Digester 2 and 3 Equipment Prepared By: Reviewed By: Solids Handling - Page 1 of 4 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Solids CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Solids Handling Date:6/10/2015 QUANTITYUNITSUNIT COSTTOTAL COSTDESCRIPTION Prepared By: Reviewed By: Misc. Concrete and Materials Allowance 1 LS $20,000 $20,000 SUBTOTAL$1,004,000 DIVISION 4 - MASONRY Not Used $0 SUBTOTAL$0 DIVISION 5 - MISCELLANEOUS METALS Solids Thickening Aluminum Grating 500 SF $50 $25,000 Stairs 1 LS $5,000 $5,000 Canopy 1,800 SF $120 $216,000 Guardrails 165 LS $90 $14,850 Misc. Metals 1 LS $20,000 $20,000 Anaerobic Digester Guardrails 300 LF $90 $27,000 Metal Stairs and Landing 1 LS $15,000 $15,000 Misc. Metals 1 LS $20,000 $20,000 Screw Press Aluminum Grating 300 SF $50 $15,000 Stairs 1 LS $5,000 $5,000 Guardrails 100 LF $90 $9,000 Misc. Metals 1 LS $15,000 $15,000 SUBTOTAL$386,850 DIVISION 6 - WOOD AND PLASTIC Not Used $0 SUBTOTAL$0 DIVISION 7 - THERMAL AND MOISTURE PROTECTION Coatings/ Moisture Protection 1 LS $20,000 $20,000 SUBTOTAL$20,000 DIVISION 8 - DOORS AND WINDOWS Not Used 0 -$0 $0 SUBTOTAL$0 DIVISION 9 - FINISHES Paintings and Protective Coatings (Piping and Equipment)1LS$60,000$60,000 SUBTOTAL$60,000 Solids Handling - Page 2 of 4 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Solids CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Solids Handling Date:6/10/2015 QUANTITYUNITSUNIT COSTTOTAL COSTDESCRIPTION Prepared By: Reviewed By: DIVISION 10 - SPECIALTIES Signs, Identification, Stenciling and Tagging System 1LS$15,000$15,000 SUBTOTAL$15,000 DIVISION 11 - EQUIPMENT Solids Thickening Rotary Drum Thickener and Floc Tank 2 EA $304,000 $608,000 Feed Pumps 3EA$20,000$60,000 Thickened Sludge Pumps 2 EA $30,000 $60,000 NPW Pressure Booster Pump - 5 HP 2 EA $2,500 $5,000 Air Control Fan 1 EA $5,000 $5,000 Air Control System 1 LS $60,000 $60,000 Anaerobic Digester Draft Tube Mixing/Pump Mixing System 2 LS $200,000 $400,000 Digester Heating, Recirculation Eqpmt 1 LS $200,000 $200,000 Screw Press Screw Press 1 LS $300,000 $300,000 Screw Conveyor 1 EA $25,000 $25,000 Feed Pump 1 EA $20,000 $20,000 SUBTOTAL$1,743,000 DIVISION 13 - INSTRUMENTATION I&C Allowance (10% of Div 11 and 15)10%LS $2,298,000 $229,800 SUBTOTAL$229,800 DIVISION 14 - CONVEYANCE Not Used $0 SUBTOTAL$0 DIVISION 15 - MECHANICAL Thickening 350 LF $100 $35,000 Polymer feed piping and valving1LS$10,000$10,000 Thickened Sludge -6-in. glass lined200LF$100$20,000 Miscellaneous Fittings and Pipe1LS$25,000$25,000 Foul Air Ductwork 1LS$30,000$30,000 Anaerobic Digester Recirc Piping and Fittings 1 LS$125,000$125,000 Hot Water Piping, Digester Overflow, Gas Piping, Etc 1 LS$150,000$150,000 Misc. Fittings, and Valves 1 LS$100,000$100,000 Blended Sludge - 6-in. glass lined Solids Handling - Page 3 of 4 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Solids CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Solids Handling Date:6/10/2015 QUANTITYUNITSUNIT COSTTOTAL COSTDESCRIPTION Prepared By: Reviewed By: Screw Press Feed and filtrate piping 1 LS$25,000$25,000 Chemical Piping and Fittings 1 LS$25,000$25,000 Misc. Piping 1 LS$10,000$10,000 SUBTOTAL$555,000 DIVISION 16 - ELECTRICAL Electrical Allowance (15% of Div 11 and 15)15%LS $2,298,000 $344,700 SUBTOTAL$344,700 $4,660,450 $700,000 $1,398,135 $6,759,000TOTAL, Rounded SUBTOTAL (WITHOUT DIVISION 1), Rounded HDR DIVISION 1, Rounded CONSTRUCTION CONTINGENCY (30%) Solids Handling - Page 4 of 4 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Sidestream Treatment - Page 1 of 3 City of San Luis Obispo Public Works Water Resource Recovery Facility (WRRF) Project Facilities Plan Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Sidestream Treatment CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Sidestream Treatment Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COST DIVISION 1 - GENERAL REQUIREMENTS Mobilization/Demobilization 1 LS 3.00%$75,000 Bonds and Insurance 1 LS 1.00%$25,000 Construction Facilities/Fencing/Offices 1 LS 2.00%$50,000 General Conditions 1 LS 2.00%$50,000 Shop Drawings and O&M Manuals 1 LS 1.50%$38,000 Facilities Start-up & Testing 1 LS 2.50%$63,000 Construction Sequencing & Constraints 1 LS 3.00%$75,000 SUBTOTAL $376,000 DIVISION 2 - SITE WORK Demolition Mechanical Demolition - D2 and D3 1 LS $25,000 $25,000 Site Prep D3 1 LS $15,000 $15,000 Yard Piping Demolition 1 LS $10,000 $10,000 New Digester 3 (EQ for SST) Structural Excavation 70 CY $24 $1,680 Aggregate Bedding 40 CY $46 $1,830 SUBTOTAL $53,510 DIVISION 3 - CONCRETE New Digester 3 (EQ for SST) Slab on Grade 40 CY $900 $36,000 Digester 2 Allowance for Concrete Rehab 1 LS $50,000 $50,000 Misc. Concrete for Converstion to Reactor 1 LS $30,000 $30,000 SUBTOTAL $116,000 DIVISION 4 - MASONRY Not Used SUBTOTAL $0 DESCRIPTION Prepared By: Reviewed By: City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Sidestream Treatment - Page 2 of 3 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Sidestream Treatment CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Sidestream Treatment Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COSTDESCRIPTION Prepared By: Reviewed By: DIVISION 5 - MISCELLANEOUS METALS New Digester 3 (EQ for SST) Steel Glass Lined Tank 500,000 gallons $2 $1,000,000 Misc Metals Allowance 1 LS $50,000 $50,000 SUBTOTAL $1,050,000 DIVISION 6 - WOOD AND PLASTIC Not Used $0 SUBTOTAL $0 DIVISION 7 - THERMAL AND MOISTURE PROTECTION Allowance 1 LS $15,000 $15,000 SUBTOTAL $15,000 DIVISION 8 - DOORS AND WINDOWS Not Used $0 SUBTOTAL $0 DIVISION 9 - FINISHES Paintings and Protective Coatings (Piping and Equipment)1 LS $20,000 $20,000 SUBTOTAL $20,000 DIVISION 10 - SPECIALTIES Signs, Identification, Stenciling and Tagging System 1 LS $10,000 $10,000 SUBTOTAL $10,000 DIVISION 11 - EQUIPMENT New Digester 3 (EQ for SST) Feed Pumps to Reactor 2 EA $25,000 $50,000 Odor Control System 1 LS $60,000 $60,000 Odor Contol Fans 1 LS $7,500 $7,500 Digester 2 (SST Reactor) Aeration Blowers 3 EA $202,500 $607,500 Diffused Air System 1 LS $120,000 $120,000 Alkalinity Feed Pumps 1 LS $30,000 $30,000 SUBTOTAL $875,000 DIVISION 13 - INSTRUMENTATION I&C Allowance (10% of Div 11 and 15)10%LS $998,000 $99,800 SUBTOTAL $99,800 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost Sidestream Treatment - Page 3 of 3 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:Sidestream Treatment CG Task:Opinion of Probable Construction Cost MR/CO/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]Sidestream Treatment Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COSTDESCRIPTION Prepared By: Reviewed By: DIVISION 14 - CONVEYANCE Not Used $0 SUBTOTAL $0 DIVISION 15 - MECHANICAL 200 LF $100 $20,000 Feed Piping 200 LF $60 $12,000 Effluent to Plant Drain 300 LF $60 $18,000 Connection to EQ Tank 100 LF $80 $8,000 Foul Air Duct Work 1 LS $50,000 $50,000 Chemical Piping 150 LF $100 $15,000 SUBTOTAL $123,000 DIVISION 16 - ELECTRICAL Electrical Allowance (15% of Div 11 and 15)15%LS $998,000 $149,700 SUBTOTAL $149,700 $2,512,010 $376,000 $753,603 $3,642,000TOTAL, Rounded Aeration Piping SUBTOTAL (WITHOUT DIVISION 1), Rounded HDR DIVISION 1, Rounded CONSTRUCTION CONTINGENCY (30%) City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost General Site - Page 1 of 4 City of San Luis Obispo Public Works Water Resource Recovery Facility (WRRF) Project Facilities Plan Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:General Site Work CG Task:MR/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]General Site Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COST DIVISION 1 - GENERAL REQUIREMENTS Mobilization/Demobilization 1 LS 3.00%$229,000 Bonds and Insurance 1 LS 1.00%$76,000 Construction Facilities/Fencing/Offices 1 LS 2.00%$153,000 General Conditions 1 LS 2.00%$153,000 Shop Drawings and O&M Manuals 1 LS 1.50%$114,700 Facilities Start-up & Testing 1 LS 2.50%$191,200 Construction Sequencing & Constraints 1 LS 3.00%$229,500 SUBTOTAL $1,146,400 DIVISION 2 - SITE WORK Demolition of Existing WRRF Structures Supernatant Pond 1 LS $30,000 $30,000 1 LS $30,000 $30,000 Sludge Drying Beds - North of Dewatering (3)1 LS $20,000 $20,000 Ex. Control Building 1 LS $50,000 $50,000 Primary Clarifier Pump Station 1 LS $20,000 $20,000 Biofilters 1, 2 and 3 3 LS $80,000 $240,000 Recirculation Pump Station 1 LS $10,000 $10,000 Digester 3 1 LS $70,000 $70,000 MgOH Storage 1 LS $10,000 $10,000 Cal Poly Research Center 1 LS $50,000 $50,000 Existing Blower Canopy Structure 1 LS $10,000 $10,000 Chlorine Contact Basins 1 LS $80,000 $80,000 Misc Equipment and Piping Demolition 1 LS $50,000 $50,000 Electrical Demolition 1 LS $50,000 $50,000 Yard Piping Demolition 1 LS $30,000 $30,000 Structural Excavation 0 CY $24 $0 Backfilling (Engineered Fill, Compaction Included)0 CY $10 $0 Shoring 0 SF $45 $0 RV Dump Station 0 LS $75,000 $0 Material Drainage Beds 2 LS $75,000 $150,000 Demolition of Prado Day Center Buildings at the Day Center Lot 1 LS $100,000 $100,000 Site Clearing 79,200 SF $5 $396,000 DESCRIPTION Sludge Drying Beds - North of EQ Basin Prepared By: Reviewed By: City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost General Site - Page 2 of 4 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:General Site Work CG Task:MR/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]General Site Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COSTDESCRIPTION Prepared By: Reviewed By: Fencing and Security Perimeter Fencing - Omega 1000 LF $50 $50,000 Allowance Perimeter Fencing - Chain Link 1700 LF $27 $45,900 Security Camera 17 EA $10,000 $170,000 Automated Gates 5 EA $12,000 $60,000 Card Readers 5 EA $5,000 $25,000 Infrared Illuminator 12 pair $4,000 $48,000 Building Access Equipment 3 EA $7,500 $22,500 Interior Sensitive Equipment 5 EA $2,600 $13,000 Security System Integration 1 LS $40,000 $40,000 Construction Dewatering 1 LS $75,000 $75,000 Potholing 1 LS $15,000 $15,000 Paving Grading 167,300 SF $2 $308,018 Backfill for Chlorine Contact Basin 6,200 CY $20 $124,000 Aggregate Bedding 0 CY $20 $0 AC Paving 167,300 SF $6 $1,003,800 Curb and Gutter Allowance 11,760 LF $31 $364,560 Paving for Corp Yard Road Grading 25,600 SF $2 $47,132 Aggregate Bedding 0 CY $20 $0 AC Paving 25,600 SF $6.00 $153,600 Curb and Gutter Allowance 1 LS $30,000 $30,000 Path for Access to Outfall Grading 17,600 SF $2 $32,404 Aggregate Bedding 326 CY $20 $6,519 Drainage Culverts 2 EA $5,000 $10,000 Landscaping Allowance 1 EA $25,000 $25,000 Landscaping 1 LS $25,000 $25,000 Stormwater Management LID/Management 1 LS $50,000 $100,000 Chlorine Contact Basin - South End of Plant Demolition of Structures (5 ft below grade)1 LS $70,000 $70,000 Backfill of Structures 2,100 CY $10 $21,000 Grading 20,000 SF $6 $120,000 Landscaping 1 LS $20,000 $20,000 SUBTOTAL $4,391,432 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost General Site - Page 3 of 4 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:General Site Work CG Task:MR/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]General Site Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COSTDESCRIPTION Prepared By: Reviewed By: DIVISION 3 - CONCRETE Not Used $0 SUBTOTAL $0 DIVISION 4 - MASONRY Not Used $0 SUBTOTAL $0 DIVISION 5 - MISCELLANEOUS METALS Not Used $0 SUBTOTAL #REF! DIVISION 6 - WOOD AND PLASTIC Not Used $0 SUBTOTAL $0 DIVISION 7 - THERMAL AND MOISTURE PROTECTION Not Used $0 SUBTOTAL $0 DIVISION 8 - DOORS AND WINDOWS Not Used $0 SUBTOTAL $0 DIVISION 9 - FINISHES Not Used $0 SUBTOTAL $0 DIVISION 10 - SPECIALTIES Not Used $0 SUBTOTAL $0 DIVISION 11 - EQUIPMENT Not Used $0 SUBTOTAL $0 DIVISION 13 - INSTRUMENTATION Not Used $0 SUBTOTAL $0 DIVISION 14 - CONVEYANCE Not Used $0 SUBTOTAL $0 City of San Luis Obispo Water Resource Recovery Facility Project Facilities Plan Opinion of Probable Construction Cost General Site - Page 4 of 4 Job No. Calc. No. Computation Project: SLO WRRF Facilities Plan Subject:General Site Work CG Task:MR/MC File Name:c:\pwworking\sac\d0633132\[SLO Cost Estimate - Facilities Plan-150601.xlsx]General Site Date:6/10/2015 QUANTITY UNITS UNIT COST TOTAL COSTDESCRIPTION Prepared By: Reviewed By: DIVISION 15 - MECHANICAL Allowance for Stormwater Conveyance 1 LS $150,000 $150,000 48-inch Raw WW to Headworks 100 LF $480 $48,000 30-inch Primary Influent 200 LF $300 $60,000 30-inch PEDB to Recirc PS 250 LF $300 $75,000 42-inch Recirc PS to SEDB 200 LF $420 $84,000 30-inch filter influent pipe 200 LF $300 $60,000 36-inch to 3W PS 100 LF $360 $36,000 30-inch ML to Final Clarifiers 480 LF $300 $144,000 30-inch NE Pipe from Filter Feed EQ to Filters 200 LF $300 $60,000 Allowance for Plant Drain Relocation 1 LS $150,000 $150,000 Allowance for Misc Piping Relocations 1 LS $150,000 $150,000 Allowance for fittings and valves 1 LS $80,000 $80,000 Allowance for PS, WAS and scum piping and TS 1 LS $130,000 $130,000 SUBTOTAL $1,227,000 DIVISION 16 - ELECTRICAL Standby Generator 2 EA $1,000,000 $2,000,000 SUBTOTAL $2,000,000 $7,648,432 $1,147,000 $2,294,530 $11,090,000TOTAL, Rounded SUBTOTAL (WITHOUT DIVISION 1), Rounded HDR DIVISION 1, Rounded CONSTRUCTION CONTINGENCY (30%) Appendix W Value Engineering Comments and Responses 6/11/2015 1 of 4 Global Comment No. Reviewer Reviewer Comment No. Reference / Subject Comment Response 1 Pam Oullette 1 Figure 1-2 Final clarifiers numbering: there already is a clarifier 1 & 2, the new Finals should be numbered 6 & 7, not Final 1 & 2.Updated 2 Pam Oullette 2 Figure 1-2 Filters: We haven’t decided to go with 4 new monomedia filters. We want to look at compressible media filter systems by Schreiber (Fuzzy filter pink) and WWETCO flexfilter (orange balls). The idea is that they would be used for wet weather; they have a very small footprint and can handle a lot more water. We refined the updated facility plan by reducing the number of necessary GMF filters from 4 to 2 additional cells (240 sf/cell). We maintained the recommendation of GMF. However, we also evaluated other competing technologies and provided a roadmap regarding filtration. 3 Pam Oullette 3 Table 1-3 Filters: The cost savings of using prefabricated, (almost) plug and play units could be significant vs. formed concrete structures. The cost for GMF versus other prefabricated filter units was considered in our analysis. We worked closely with the vendors while forming the cost estimates. 4 Pam Oullette 4 Table 3-1 Influent pumps: add to comments: both 5 mgd pumps will be replaced as CIP It was communicated at several workshops that those 5 mgd pumps will be replaced over the next few years as a near-term project and not part of this upgrade. 5 Pam Oullette 5 Table 3-1 Grit Separators/Dewaterers: add to comments: Will be replaced under the WRRF Energy Efficiency Project Updated 6 Pam Oullette 6 Table 3-4 Sludge/scum pumps: There are only two pumps for secondary clarifier # 3: Sludge pump 600 (1200 gpm) and scum pump 500 (75 gpm). There are three pumps listed. Also: The value section for these pumps do not line up with the description.Updated 7 Pam Oullette 7 Table 3-5 Blowers: In the comment section: there is only one turbo blower, not two. Both Lamsons are (will be next week) operational and are being used until the installation of two Neuros blowers under CIP.Updated 8 Pam Oullette 8 Table 3-6 Cooling Towers: add to comments: CT cooling media was replaced in July 2014 Updated 9 Pam Oullette 9 Table 3-7 Backwash Water Tank: change description to: stores filtered nitrified effluent via two feed gates from backwash water diversion box to BW tank.Updated 10 Pam Oullette 10 Table 3-11 Digester Mixing: Digester # 1 has two sparge lines with one gas mixer/compressor. Digester # 2 only has one.Updated 11 Pam Oullette 11 Table 3-11 Digester Heating: Digester # 1 has four hot water exchangers. Digester # 2 has two.Updated 12 Pam Oullette 12 3.2.1 Wet Weather Operation First bullet is partly incorrect: peak wet weather flows from the PEDB either go to biofilter #3 (via recirc pumps) or will peak shave in that box on excessive flow to the EQ basin or, if the two way valve is open at the SEDB (connecting the two boxes together), it will flow to SEDB, where the blend flow weir gate is dropped, allowing excess flow to be diverted to the NEFF box, etc. Updated 13 Pam Oullette 13 Table 3.2.3: Operations and Maintenance Anaerobic digesters are cleaned every 5-7 years. The DAFT 2x/yr, all other tanks, clarifiers, grit bays, etc. are annual.Updated 14 Pam Oullette 14 Table 3.2.4: Laboratory Should it be mentioned that composite samplers are also flow proportional? The VE people asked about it. We have conflicting verbal communications with the WRRF on this. Our understanding is the raw influent and effleunt are flow proportional but all other composite samplers are time based. The updated facility plan reflects our understanding. 15 Pam Oullette 15 Page 3-28 Filter complex The automated system keeps having breakdown issues so it is often manually run. One of the SST projects includes replacement of the filter controls with a new system that will allow automated and manual backwashes (as before)Updated 16 Pam Oullette 16 Table 3-19 Supernatant Lagoon: remove ‘not replacement’ in second bullet (editing issue)Updated 17 Pam Oullette 17 NPDES Tables throughout document how a number (1) or a (2) next to ammonia limit but the footnotes at the bottom has a letter (a). The (a) footnote is not found anywhere in the table and neither (1) nor (2) in the table are found in the footnotes.Updated 18 Pam Oullette 18 4.2.8 Air Emissions Second line has grammatical errors Updated 19 Pam Oullette 19 7.1.2 Equalization Pond Probably moot at this point, but actually we were looking at partitioning with concrete walls and gates connecting the sections rather than overflow. Overflow means each successive tank will hold less than the prior tank. If the EQ basin were excavated and made into three distinct concrete sections of equal depth and height, it would also increase capacity. Utilizing gates to connect tanks is desired if we do this. The wet weather equalization pond concept was refined since the draft facility plan. The updated version does not have compartmentalization, but it is concrete lined and it has spray down water cannons. The decision to remove compartmentalization was based on the cost associated with infrequent usage. SLO Program Management WRF Upgrade Project Comments on the Draft Facilities Plan submitted December 18, 2014 and Responses Comments Received: 01/27/2015 - Revision Date: 06/07/2015 6/11/2015 2 of 4 Global Comment No. Reviewer Reviewer Comment No. Reference / Subject Comment Response 20 Pam Oullette 20 7.1.3 Filter Equalization Tanks Installing one more tank allows us the flexibility to install flex filters directly adjacent to the EQ tanks for wet weather filtration. We would like to see a pilot on these types of filters very soon. We are not recommending an additional filter equalization tank due to little or not storage benefits. We believe you can do this same thing using the existing filter equalization tanks. 21 Pam Oullette 21 7.2.1 Grit Removal System After discussion on this system, WRRF staff and WW Div. Mgr. Dave Hix have discussed generating a CIP project to demolish the upper headworks dewatering section after the new headworks and vortex grit systems from the SST are in place and operational. Once the upper section is removed, the grit bay can be filled in and the new vortex equipment can be relocated in that space. This would result in a huge cost savings regarding this process in the upgrade. After further evaluation, replacing the aerated grit with forced vortex was not recommended. The existing aerated grit are fully functional so priority should go to expansion equipment that is essential to operating the WRRF. 22 Pam Oullette 22 7.3 Primary Clarifiers and Sludge Pumping Primary clarifier mechanisms are over 50 years old. The last inspection showed wear on some metal structures so we need to look at the possibility of replacing the internal works. The weirs look fine. The primaries may be tilted by design to get the water to flow toward the effluent box. Updated with a recommendation to replace the primary clarifier mechanisms. 23 Pam Oullette 23 7.5.2 Evaluation of Filtration Alternatives Schreiber CMF is 26% of the footprint of the existing GMF. It is Title 22 compliant and can deliver 30gpm/ft₂ set forth as the maximum allowed for title 22. Disc filters are 67% of GMF footprint. I think we are jumping the gun to go with recommending the addition of more monomedia filter towers. Unless and until we do more research on the alternatives above for wet weather service only, I think this portion recommending what we already have be deleted or changed to reflect that we will visit facilities, look at data and pilot these other technologies before we recommend anything. The location of added filtration could be next to the new EQ tank (see comment 7.1.3 above). We re-visited the filter evaluation. The recommendation has been maintained but it only requires two additional filter cells, not four. Additionally, we added language to support consideration of other filter technologies. We also compiled a listing of facilities and their respective contact info. 24 Pam Oullette 24 7.6 Cooling We should look at enhancements to performance on the existing equipment. An option on the BAC units is something called Velocity Recovery (VR) stacks. From their Product and Application handbook: ‘A VR stack is a conical fan cowl extension that reduces the discharge pressure the fan has to work against, allowing the fan to move more air for the same energy input. By moving more air through the same unit, the cooling capacity is increased without increasing horsepower or footprint. Effectively, the amount of energy required for each ton of cooling capacity is reduced. VR stacks are CTI certified and can be configured during initial unit purchase to reduce energy requirements or through the aftermarket to increase capacity.’ Also, looking at the cooling towers, there is a bypass pipe that send chilled water back to the top of the unit. Can this be used to recycle the water to increase cooling? This should be investigated during design. 25 Pam Oullette 25 7.9 Anaerobic Digesters My stronger preference is to replace digester No. 3 with a new digester equal in capacity to Digester No. 1 and use Digester No. 2 as the feed storage tank for the dewatering system. It makes more sense to have the feed tank between the two digesters. There is a storage building next to Digester No 3 that could be demolished to increase footprint needed for a new digester A smaller sidestream management tank could be erected where the new Digester was going to be built. Given the larger volume of Digester 2 compared to Digester 3, replacing Digester 2 was included over Digester 3 in the updated facility plan. Having access to a larger volume should result in the ability to have both sidestream treatment and solids storage in the repurposed Digester 2. 26 Pam Oullette 26 General The DAFT should be considered for FOG. Operating the DAFT to blend the flow is an affordable use of this tank with minor modifications. If the City decides to move forward with FOG this might be a good use of this tankage. Before that decision is made, it makes sense to use this tankage to blend thickener feeds. 27 Howard 1 General This document is excellent, a very detailed for the entire scope of the project at this time phase of the project. After reading all of Dave's and Pam's comments along with listening and reviewing the Value Engineering Report as well as attending the meeting that the Core Management Team had on 1/21/15 I concur with all of this information and know it will be reviewed and included in the revision of this draft. Thank you 28 Dave Hix 1 Introduction The WRF was upgraded in 1942, 1962, 1980 and 1994. In 2006 the City added the Water Reuse Project.Updated 29 Dave Hix 2 Chapter 3 We’re wastewater folk, can we use MG instead of 1000 cf?Updated 30 Dave Hix 3 3.2.3 We have operators on two different schedules 4/10 (4, 10 hour days per week) and 9/80 (9, days that equal 80 hours within two weeks, this schedule usually has every other Friday off). The chief operator and the “rover” are on 9/80 schedules. We updated the table to reflect this. We also added additional language regarding the Wed work week when the WRRF staff has overlap. 31 Dave Hix 4 Table 3-19 Summary of conditions assessment. The influent wet well has limited access and hasn't been inspected and hasn't had a condition evaluation since 1993. This should be added and/or addressed.Added this language to the table 32 Dave Hix 5 4.1.1 The ammonia limit hasn’t changed, just the method used to determine compliance. This paragraph needs to be clearer. This does need to be considered in the design.Language updated to reflect this 33 Dave Hix 6 Table 4-1 Nitrate should read Nitrate (as N) in all related tables.Updated 6/11/2015 3 of 4 Global Comment No. Reviewer Reviewer Comment No. Reference / Subject Comment Response 34 Dave Hix 7 4.2.8 While I agree that it takes more energy to comply with lower nutrient limits; I can’t see the nexus between NOX generation and lower nutrient limits. I believe that NOX generation is a product of excess O2 combing with NO and creating NOX. I believe this is an operational strategy issues rather than a treatment level issues given that we wouldn’t be able to discharge excessive levels of NOX regardless. The text was removed to reflect this. As a point of reference, NOx formation is a by- product of incomplete nitrificatin/denitrification. The incomplete biological pathway is directly related to DO levels that are in between anoxic and oxic conditions. For example, denitrification in non-anoxic conditions (e.g., DO=0.75 mg/L) will result in NOx formation. 35 Dave Hix 8 Chapter 5 I recently submitted some documents regarding this. Specifically Call Poly’s .470 MGD capacity share and information regarding the ADWF during Sept, Oct and Nov. Let me know if I need to resend. We revisited the flows and have since had a webinar to finalize this in May 2015. The flows and loads facility plan chapter and TM have been updated to reflect this. 36 Dave Hix 9 Chapter 7 I think the figure 7-1 and the EQ basin idea is completely over designed.Updated based on discussions with the WRRF since the draft facility plan was issued. 37 Dave Hix 10 Chapter 8 Please include the hydraulic profile of the recycled water tank in this figure. It looks like there is a 10 foot diff between the tank and UV system which would result in an increase in storage (and production flexibility) for very little $$$. Updated. 38 Dave Hix 11 Chapter 9 Can we decrease tankage with contact stabilization and/or utilize the secondary clarifier’s 0.9 MG capacity for wet weather operations? The design feature of contact stabilization is included. The tankage was decreased as a result of reduced loadings and contact stabilization (marginal savings). 39 Carrie Mattingly 1 Figures - Generally The graphics are useful tools. Check the graphics throughout for some level of presentation consistency. Some are easier to read than others (example: Figure 7-4, page 7-6 and Figure 6-3, page 6-6). Certainly only my personal perspective.Those in chapter 7 were updated accordingly for consistency. 40 Carrie Mattingly 2 Page 7-26 "Manage the existing supernatant lagoon facilitites" Previously discussed during CMT phone call - please amend this section's wording. Do not know what the sentence starting with "However, the WRRF..." is meant to convey. The language was updated accordingly. The term "manage" referred to the lagoon pumping schedule for returning high strength nitrogen loads. 41 Carrie Mattingly 3 7.13.1 Package A Upgrades (and throughout) Also discussed during CMT phone call - consider alternate name to Package A and B. Perhaps Phase A and B.Removed reference to Packages, Phases, etc. 42 Carrie Mattingly 4 7.13.2 Package B Upgrades (and throughout) I encourage HDR to make stronger statements for its recommendations. The first sentence in this sections says "The Package B upgrades, while not required to meet discharge permit requirements, may be needed (underline added) to address capacity, redundancy, condition, O&M...." HDR is our expert and carries significant weight with its recommendations. Written in this passive voice it gives the reader a "nice to have" feel which is not the case - these upgrades are all needed. This type of wording is sprinkled throughout the entire facilities plan document. I would prefer words like "are needed" "should be seriously considered" "strongly recommended" "may be pushed to future phase but requires upgrade in the near future". Using this language from a highly respected engineering consultant will help us with funding and community acceptance of this project. Updated. 43 Carrie Mattingly 5 10.3 WRRF Controls This is a good example of where how we say it matters. The first sentence says "The plant control is mostly manual with very little automation. Plant staff would like additional plant functions to be monitored and automated as follows:" This type of wording is sprinkled throughout the document. It would be of benefit to project acceptance to word it in a recommendation type way. For example it could be written like: "...very little automation. Automation, among other benefits, aids in rapid response to emergency situations and provides remote monitoring and control capabilities. After discussions with plant staff the following plant functions should be monitored and automated as follows:" Updated 44 Carrie Mattingly 6 General No doubt I was a proof-reader in some prior life so I've got some minor suggested edits/inserts in my binder that I'll hand off to Leanne at the next CMT - not worth putting in here.Incorporated. 45 Verbal Add language into the front end of the plan referencing the minimum flow requirements to SLO Creek and other key information from the VE presentation (it was nicely summarized), including steelhead in SLO Creek and the MUN designation Added language to the introduction and the regulatory sections 46 Verbal Add discussion to plan regarding the potential future move of the bus yard and discuss the location of the plan with respect to Prado Road Frontrage as future major road, and the overpass.Added language to address this issue 47 Verbal Add discussion regarding uncertainty of future flow projections due to decreasing demands/water use associated w new development. Comment on need to revisit phasing of capacity-driven recommendations. Future flow projections and the assumed per capita generation rates language added to the TM and chapter. Phasing of capacity-driven recommendations would impact filters/UV the most. Given that the peak flows govern these facilities we do not recommend postponing the phasing. The peak flows are tied closer to the weather and conveyance, not population. 48 Verbal Add replacement of all mechanical features at the primaries, including the sweeps, arm, etc.Updated with new mechanisms 6/11/2015 4 of 4 Global Comment No. Reviewer Reviewer Comment No. Reference / Subject Comment Response 49 Verbal Consider alternate option for filter expansion w lower capital cost since it won't be used most of the year Several options were considered. Refer to Chapter 7 and the filtration appendix. 50 Verbal Did we include re-routing of the return stream from the DAFT to Aeration Basins to DAFT to Primaries? If it drains to the plant drain, need to upsize drain line. No, we did not include this for two reasons: i) the drain line would need to be up-sized and ii) there is little or no process benefit. The aeration basins operate based on loads, not flows. 51 Verbal Did we include mixing system upgrade for Digester 1?Yes 52 Verbal Did we include $ for second screw press?Yes; redundancy needed 53 Verbal Is Diurnal EQ necessary? Without it, how would the downtream processes be impacted in capacity and operation? No; language was added to chapter 7 to address this. 54 Verbal Don't partition the EQ Pond Agree. It was removed. 55 Verbal Would HR A/ B have more odor than MLE? No. It should have less odors as the A-stage would be aerated compared to the existing primaries. The B-stage is essentially a smaller MLE that has a smaller footprint due to reduced loads. 56 Verbal Need to add location for a vactor to dump and other trucked in wastes (e.g., Street Sweepers) from Public Works. It should be called "Material Drainage". Probably need 2 drying beds, ideally located near the new Maintenance Facility. Added. 57 Verbal Need to add location / facility costs for an RV dump station. Check w Pismo re: associated flow and load assumptions.This has been resolved. Has not been included. 58 Verbal Will there be algae growth in the UV channels on the concrete? If yes, how to avoid? Filter EQ tanks get growth now and they dose 50-100 gpd when they have BacT issues.. Should the tanks be covered? Could PAA or some other disinfectant be used to clean the filter/cooling towers? If so, can the existing Hypo facilities be repurposed to avoid new equipment? Need to cover filter eq tanks? 1) The UV channels will require occasional cleaning to remove any algae that proliferates; 2) the filter EQ tanks could be covered; 3) an alternative to hypochlorite requires further investigation and should be considered during design. 59 Verbal Spent filter backwash is pumped back to the Headworks, but the pipe is only 6-inch. It probably needs to be upsized (Unit 4 Plant Drain needs to be upsized). Although there will be more filter cells, the backwash flowrate at any given time should not change. The filter backwash cycles will be staggered so having more cells does not necessarily require a larger pipe. 60 Verbal Add a recommendation to collect more Temp data to optimize the cooling tower design criteria Agree; this is added at the appropriate locations in the report 61 Verbal DAFT is 20 years old, so timing of replacement is a bit critical. Don’t push out too far.Agree; it is during stage 3. 62 Verbal Belt filter press is at end of useful life, may not start up if taken offline. Thus, no redundancy for the new screw press Agree; this is added at the appropriate locations in the report. A redundant screw is included. 63 Verbal Anoxic zone of the new MLE could generate a lot of odor per Bud Benges. Need to add a recommendation to do a future Odor Control Master Plan after upgrades to ID hot spots and prioritize odor control projects. Agree; an odor control master plan is recommended following the WRRF upgrade to confirm the need for additional odor control. 64 Verbal Take out grit removal upgrade, but need to retain an upgrade of the existing Parshall Flume. Updated with a recommendation to add mag meters to each discharge pump at the influent pumping station 65 E-mail 6/11/2015 1 of 3 Comment No.Comment Response 1 Flood control issues may raise FEMA issues with nearby new developments and/or construction at the WERF. Need to address these issues. May violate standard provisions of NPDES permit if not addressed. Also consider effect of potential flood control channel through WERF site. These issues were resolved in the Spring 2015 and included with the updated docs 2 Design loads used in MLE analysis do not seem to match loads in text – Appendix C, mass balance, Appendix N, TM 12, table 1-2 text. The values in the report and appendices were based on the originally accepted flows and loads. These flows and loads were refined multiple times since. The updated facility plan will include the refined mass balance output results that reflect the final flows and loads. 3 Table 1-2, increase in ammonia as flow increases from 6.1 mgd to 17.3 mgd is from 2100 lbs/day to 9100 lbs/day. Check, this increase in ammonia load appears high and does not appear consistent with TM12. The ammonia and TKN load/concentration values for Max Week and Max Day values are typos The appropriate values will be updated in the updated facility plan. The sizing of equipment and costs were based on the correct ammonia and TKN loads/concentrations. 4 Consider potential future need for P removal and plan WERF layout for future anaerobic basin for bio P removal or perhaps include anaerobic basin in initial construction as the anaerobic basin would be a small portion of aeration basin structure and it would be much less costly to build the anaerobic basin now rather than retrofitting it to the site in the future. Space will be provided and the layout should have the flexibility to incorporate this feature in the future. The rationale behind delaying P removal implementation has to do with operational complexity coupled with carbon management. The organisms that perform P removal consume carbon in the first zone (anaerobic), which would exacerbate the concerns over requiring an external carbon source (e.g., methanol) in the downstream denitrifying anoxic zone. Given this potential carbon shortage, it does not make sense to perform P removal unless required. If the City is interested in furthering this option, we would not recommend conventional Bio-P removal; rather, something like Return Activated Sludge Bio-P is more attractive to address carbon management issues. 5 Check cost of methanol feed system. Cost looks low when considering all code requirements. We used data from installations and publications to develop our cost (1 tank at 4,000 gal). For example, Hampton Roads Sanitation District installed 2 separate methanol facilities ($1.5 M for a 1-14,000 gal tank ($110/gal); $2.5 M for 2-12,000 gal tanks ($100/gal)). If you assume $120/gal then the WRRF Facility would be about $470k. In order to accomodate code requirements, we added an additional $300k which we feel is conservative rather than aggressive. SLO Program Management WRF Upgrade Project Value Engineering Notes to the Desgner and Responses Comments Received: 01/05/2015 Response Date: 05/02/15 6/11/2015 2 of 3 Comment No.Comment Response 6 Are there any perceived issues with mist from cooling towers on adjacent bike trail that need to be addressed? The language in Title 22 was reviewed for cooling towers where there are two sections, Section 1 and 2. Section 1: "Recycled water used for industrial or commercial cooling or air conditioning that involves the use of a cooling tower, evaporative condenser, spraying or any mechanism that creates a mist shall be a disinfected tertiary recycled water" and Section 2: "Whenever a cooling system, using recycled water in conjunction with an air conditioning facility, utilizes a cooling tower or otherwise creates a mist that could come into contact with employees or members of the public, the cooling system shall comply with the following: (1) A drift eliminator shall be used whenever the cooling system is in operation. (2) A chlorine, or other, biocide shall be used to treat the cooling system recirculating water to minimize the growth of Legionella and other microorganisms." The WRRF does not currently satisfy Section 1 requirements as the water is not tertiary treated recycled water. The proposed WRRF process flow diagram will have the cooling towers located downstream of the filters which will satisfy the Section 1 filtration requirements. However, this still does not satisfy the disinfection requirements under Section 1. The WRRF currently and will continue to satisfy the Section 2 requirements as the cooling tower specs include the Title 22 drift eliminator requirement. Additionally, the WRRF currently chlorinates the water in the filter feed channel that is diverted to the cooling towers. The ability to chlorinate the filter feed channel will most likley not be possible with the TSO THM limits. Thus, the WRRF will need to consider possible disinfectants for the cooling towers and any other locations within the WRRF that routinely use chlorine to maintain operation. 7 Consider feasibility of option to decrease effluent pH during low flow periods to reduce amount of unionized ammonia. We agree that this is a nice feature to provide redundancy in the case the un-ionized ammonia levels encroach upon the discharge limit. However, meeting the un-ionized ammonia limits are not a concern during the low flow periods as stated in the recommendation. The concern is meeting the un-ionized ammonia limits during the colder peak flows. We think this can be a safety and redundancy feature to implement if the WRRF is approaching the discharge limit, but should not be counted on as part of the design. 8 The reported primary clarifier performance is 63% BOD removal, 83% TSS removal and 16% ammonia removal. All of the values are very high compared to other municipal treatment plants. We suspected the pressate recycle stream may influence the data, but we have been assured the samples are flow composited and not time composited (the Draft Facilities Plan says “time composites”). We agree that the values are higher than typical industry values. Following the initial data compilation we requested additional sampling to address such issues. The additional sampling results are in-line with the historical data. As for the composite samplers, we have since spoken with City Staff and they confirmed the composite samplers are flow-paced for the influent and time-paced for the primary clarifiers effluent. In order to verify the results, the additional testing has continued through May 2015 and testing has been proposed in Phase 2. 9 61% BOD removal in primary clarifiers is used in modeling of bio process. This removal is much higher than typically achieved. The 61% is consistent with currently reported data but as noted in Note 8, the current 63% is much higher than typical values. See response 8 above 10 Fully automate plant operation. This appears to be the intent of the plan and the VE team concurs that replacing the current manual operation is highly desirable. The intent is to automate as many things as possible, while being cost effective. Additional refine is recommended for design. 11 Consider providing low level aeration in anoxic zone to enhance nitrogen removal. Biological nitrogen removal via denitrification occurs under anoxic conditions whereby nitrogen removal is inversely related to oxygen levels. Providing low level aeration (i.e., 0.5<X<1.0 mg/L) will inhibit nitrogen removal. The MLE layout assumes anoxic conditions (DO<0.5 mg/L) in the anoxic zone to provide maximum nitrogen removal. 12 Consider Ostara process to recover phosphorus, nitrogen and magnesium. WRRF may be smaller than optimum size for this process but the process would provide emphasis to the City’s commitment to sustainability. The technology should be called chemical precipitation for P recovery. Ostara is a vendor but there are several other vendors (Multi-Form, AirPrex, etc.). The technology recovers nutrients in the sidestream, with P recovery as the focus. Given that the project focused on N removal, we did not consider this technology as it only recovers a small fraction of the sidestream N load (0.4 lb N recovered per lb P recovered). Additionally, a business case is hard to make for plants that treat flows less than 40 mgd. If the WRRF is interested, such a technology can be constructed at a later date. 6/11/2015 3 of 3 Comment No.Comment Response 13 Add odor control for anoxic portions of aeration basins. Odor evaluations at other plants show that the anoxic zones can be a significant source of odor. Rather than commit funds to an uncertain odor issue, this would be addressed under a future odor master plan study. 14 Provide odor control for control structures ahead of aeration basins.See response above 15 Install all new electrical equipment above 100 year flood plain.Agree. 16 Replace MCCs with smart MCCs. Advantages of smart MCCs: • Eliminates the need for hard wired controls between programmable logic controllers (PLC) and individual motor starters. Control and monitoring is done with single Ethernet cable. • Reduces the amount of PLC input and output modules. • Can specify so MCC buckets have desired indicating lights (run, fault, overload) and local control (start/stop, hand/auto, reset) pushbuttons. • Allows for more data and control to reside at SCADA Agree. 17 Push controls down to package systems. Specify vendor supplied control panels to be complete with programmable logic controllers that are consistent with City desired make and model, Allen Bradley ControlLogix. This is as recommended in Draft WRRF Facilities Plan (Page 10-12, Paragraph 10.4). This keeps the programming responsibility on the supplier, as well as testing and startup. Coordinate with supplier for need of plant SCADA to both monitor and control aspects of packaged systems as desired so that is included in PLC programming. This wil be addressed by the designer. 18 Put work stations throughout site, no operator terminals. Include SCADA work stations around site instead of operation interface terminals. Recommend inexpensive work stations and monitors that are “clients” to SCADA Data and Graphic servers; i.e. the workstations are dump terminals. By using workstations, graphic screens only need to be updated at the server level, not at each operator interface terminal. This wil be addressed by the designer. 19 Consider using CCTV for process monitoring.This wil be addressed by the designer. 20 Consider raising elevation of new aeration basins to improve hydraulic profile. Our understanding on the comment assumes the recirculation pump will be used; otherwise, one cannot increase the aeration basin elevation. The Facility Plan recommendation will not use the recirculation pump so this is a moot comment. 21 Cost in general site work cost estimate for chlorine contact demolition grading appears excessive ($2,280,000).The original estimate iinadvertantly ncluded final grading of the triangular effluent ponds that are adjacent to the old chlorine contact basin. 22 Consider the 15% allowance used for General Provisions in the cost estimate. Typically these costs are about 8%.A conservative 15% allowance was used as this is a Facility Plan, not a design where values are closer to 8%. 6/11/2015 1 of 4 Response Capital O&M/Yr Present Worth G4 Phase construction to closely match growth No Reject G6 Reuse all flow, bring in water for creek from City raw water reservoirs -5,130 1,647 15,396 Yes Accept the comment based on recent work by WSC/HDR in evaluating this option. This will be addressed in a separate RW Facilities Plan Study, pursued on a parallel track, to ensure that the WRRF upgrade continues on schedule to meet the TSO. G7 Water quality trading to meet temperature standards (Fresh Water Trust ) - Alt 1 -1,540 84 -490 Yes Accept the comment but continue down the current path; consider including this as an add-on to improve the creek and ability to reliably meet permit. G7 Water quality trading to meet temperature standards (Fresh Water Trust ) - Alt 2 -5,860 221 -3110 Yes Same response as above G12 Use Acti-Flo for primary treatment, modify overall treatment process, blend effluent at high flow 16,012 -31 15616 Yes Reject; we discourage blending as the Regional Board will not support this and the inability to meet discharge limits. The VE evaluation assumed a very low raw influent ammonia concentration of 18 mg N/L which is significantly less than wet weather ammonia levels at the WRRF (30+ mg N/L). Using the actual ammonia levels in the VE evaluation would result in an ammonia discharge violation. Additionally, the THM limits are so low that any exposure to free chlorine would result in a violation. G13 Trickling Filter/Activated Sludge denitrification with supplemental carbon with or without recirculated activated sludge to trickling filter -13,000 -810 -23000 No Reject HW1 Use existing aerated grit basin 3,500 -30 3127 Yes Accept; the updated Facility Plan language will reflect this. HW6 Use mag or Venturi meters for flow measurement -143 -143 Yes Accept the comment for futher consideration during detailed design; we put in allowances for addressing the flow meter issues. EQ1 Increase equalization volume to reduce size of secondary treatment, filtration, cooling and UV -4,670 -4670 No Reject; this was evaluated in detail since the VE and it resulted in little or no value. The additional storage volume is 3+ MG to see any downstream savings so it was deemed not cost effective. EQ2 Eliminate diurnal flow equalization 902 14 1076 Yes Accept and modify cost accordingly. If desired in the future, this could be added in at a later date. EQ3 Modify Laguna pumping station to reduce peak flows sent to plant and control odors at pumping station -54 -54 Yes Accept; this may represent an opportunity to attenuate the peaks, but with PWWF equalization, it is not likely to result in process downsizing. EQ4 Eliminate filter equalization basin 1,165 1165 Yes Accept; analysis since the VE has shown that adding a third filter equalization basin provides no additional benefit as the peak flows are sustained for multiple days. EQ8 Use hypochlorite to disinfect peak flows from primaries, bypass secondary, reduce flow equalization, downsize UV, send chlorinated peak flow to reuse storage 9,919 61 10679 No Reject; this is a major risk in violating THM limits. The THM levels are at such low levels that any exposure to free chlorine would most likely lead to a discharge limit. EQ9 Divide EQ basin into one smaller covered cell and one larger cell segment with larger cell used only for high peaks 1,680 1680 Yes Modify; do not partition but re-line the EQ Pond. PC3 Thicken sludge in primaries with new pumping system at lower elevation and reduce size of rotary drum thickness 190 63 978 Yes Accept it for further evaluation in design. The analysis needs to confirm the ability to thicken in the primaries without compromising primary performance and do a cost benefit analysis compared to the status quo. VE Team Comment SLO Program Management WRF Upgrade Project Value Engineering Summary and Responses Comments Received: 01/05/2015 Updated Response Date: 06/07/2015 Estimated Cost Savings ($1000) 2014 Dollars Recommended for Consideration Accept, Reject, Modify and ResponseDescription Comment No. 6/11/2015 2 of 4 ResponseVE Team Comment AB2 Build larger, fewer aeration basins 1,570 1570 Yes Accept; Building larger, fewer aeration basins can reduce construction costs and ease of operation. Since the VE, the overall volume requirements have been reduced which will reduce overall construction costs. The updated size/number of basins is considering the balance between ease of operation and construction cost. AB6 Use MicroC instead of methanol 501 -46 -72 Yes Accept for further evaluation in detailed design. Methanol was assumed for the Facility Plan as it is conservative for planning purposes. AB8a Use crude glycerin from biodiesel plants instead of methanol 464 103 1740 Yes See response above (for MicroC) AB8b Use refined glycerin from biodiesel plants instead of methanol 464 44 1020 Yes See response above (for MicroC) AB11 Use step feed to reduce size of aeration basins 672 672 Yes Reject; the updated aeration basins found little if any benefit in basin sizing with step feed versus the draft facility plan. Additionally, using step feed can result in occasional ammonia bleed through. Given the stringent ammonia limits this concept is not recommended. AB12 Use circular aeration basins to reduce construction cost 400 400 Yes Accept for further evaluation in detailed design; two circular aeration basins could be accomodated at the site. The benefit is reduced concrete ($200 to 400k savings) and the number of equipment . The circular basin fits in the available area adjacent to the existing basins. One aeration basin would likely need to be located where Secondary Clarifier 3 is located. The existing aeration basins would also likely need to be demolished. Any updated layout would need to consider conflicts with nearby facilities (e.g. the primary clarifiers) and re-routing of roads to provide ample space around the basins. The disadvantage to circular basins is that it would limit the ability for incremental expansion of the secondary treatment system due to space constraints. AB13 Use baffled aeration basin with low DO in initial zone to increase oxygen transfer -113 40 385 Yes Reject; the initial zone is anoxic (DO<0.5 mg/L). As a result, oxygen transfer efficiency is a moot point. In fact, this strategy might result in elevated oxygen levels. This concept could be considered in the first aeration zone during the preliminary design. The benefits of such a concept would be marginal at best as the oxygen demand is the greatest in this zone so any aeration provided is consumed rapidly by the biology. AB17 Use odorous air as intake air to aeration basin blowers 327 9 435 Yes Accept for further evaluation in design. The analysis needs to consider the additional air piping to convey air to the aeration basins. In addition, we have concerns regarding the potential for corrosion associated with using odorous air. Our mechanical engineer does not recommend this. AB18 Eliminate NH3, NO3 and pH probes 261 261 Yes Reject; the O&M benefits were not considered in the VE analysis which is the basis for the recommendation. The use of probes can lower DO (improves O2 transfer), ability to monitor performance and reliably meet permit, and modulate blowers (save funds). SC3 Modify secondary clarifier design to increase allowable overflow rate to reduce clarifier size and/or modify existing secondary clarifies to increase capacity 1,012 0 1012 Yes Accept; the analysis required is more robust than simply loading rates. HDR performed state point analysis on various wet weather conditions. The state point results suggest that adding a 3rd clarifier (100' diameter) has merits and would reduce overall costs. We think this decision should be passed on to the designer. C1/C2 Water chiller for peak cooling instead of 2 new towers Modify. Both cooling towers and chillers were included. "Alt 1-Refrigerator cooling downstream of expanded towers -1,261 -15 -1452 Yes Accept chillers downstream of air tower (Alt 1) to provide additional cooling to meet regulatory requirements under worst-case scenario conditions; the sizing of chillers is to be determined in preliminary design. In the interim, continue to collect stream temperature data and evaluate effectiveness of new cooling tower media. This additional data will help determine the design criteria (temperature requirement) to be used for sizing chiller equipment. "Alt 2-Cool only required discharge cooling towers+refrig cooling 530 162 2,550 Yes Pending further evaluation on the ability to cool and meet other discharge requirements "Alt 3-All effluent cooled with refrigerator cooling -2,420 -1,821 -25,113 No Reject "Alt 4-Cool only required with only refrigerator cooling 682 -172 -1460 No Reject C6 Do not automate cooling tower operation 90 18 -34 Yes Modify; include some automation to facilitate ease of operation and energy efficiency. Further analysis is required during detailed design once the method of cooling is confirmed. 6/11/2015 3 of 4 ResponseVE Team Comment F3 Increase filter equalization, reduce filter size -3,820 -3820 No Reject; the updated hydrograph found that any additional filter equalization will provide no benefit on filter footprint as the hydrograph has a sustained attenuated flow. F4 Use chlorine contact basin for filter flow equalization 5,360 5360 Yes Reject; additional filter flow equalization is not necessary. D2 UV for base flow, hypochlorite for peak flow 4,750 4750 Yes Reject. The analysis found that the THM limits are such that there is a high risk of discharge violation if chlorine is used to disinfect under any flow scenario. The proposed UV facilities are sized with minimal redundancy during peak wet weather events. The updated Facility Plan has supporting language regarding redundancy. Otherwise, the facilities will be over designed for the peak wet weather event. S4 Run digesters in parallel, use existing digesters, don't build new digester 2,311 2311 Yes Modify; run in parallel but we do not agree with not building a new digester (digester 3 does not have heating or mixing; that would result in no storage; and digester 2 is not big enough while digester 1 is out of service for maintenance) S9 Digest FOG or food waste to generate revenue and/or increase power generated -500 137 1207 Yes Accept; pending City comments. If desired, it can be phased in later. The plant should be laid out to accommodate this. S10 Add natural gas padding instead of gas storage -1 -1 Yes Accept for further refinement in design. S15 Run screw press up to 24 hrs/day, eliminate or phase second screw press 866 -17 654 Yes Reject. Tthe existing BFP is an antique and may not serve well as a backup to only 1 screw press. S17 Construct acid phase digester instead of planned digester 2,200 2200 Yes Reject; acid phase digesters require considerable more operator attention than mesophilic anaerobic digesters. They are sensitive to process upset as well. S19 Phase new digester to coordinate with increased solids see G4 No Reject. Digester 2 will be repurposed for sidestream treatment, so a second digester is required. SS2 Store screw press filtrate and return at low flow periods, avoid side stream treatment and eliminate supernatant pond 3,154 79 4140 Yes Modify; HDR performed further analysis and found managing pressate return flows results in chemical difficiencies that would require additional alkalinity and carbon (if necessary). The benefits of sidestream treatment on either liquid stream alkalinity and carbon management outweigh managing the return flows. The updated facility plan has language supporting this. OC7 Use trickling filter #3 structure for odor biofilter 727 727 Yes Reject; the trickling filter #3 structure will be demo'ed as a new building facility will be placed here. OC8 Use trickling filter #1 structure for odor biofilter 876 876 Yes TBD; pending City comments. Should be considered for further evaluation in design. E1 Eliminate PGE service at recycle building, tie into main switchgear 193 192.5 Yes Reject. As we understand, the idea is to abandon the 1,200 Amp PG&E service at SWBD-R, subfeed SWBD-R from the main plant switchboard, SWBD-MSG; and increase the size of the standby generation at the main plant electrical service. The PG&E service at switchboard R is in service, is relatively new and is in satisfactory operating condition. Other than any potential cost savings to the city in combining the services there is no other reason to consider abandoning this service. Once this service is abandoned it is unlikely that PG&E would restore a second service to the plant as their normal policy is to only provide one service to a facility. The total projected demand load (concurrent load) for this expansion project is 3,200 kVA including a diversity factor of 70% for SWBD-SWG. If this load were to be served at a single 480 volt service point at least a 4,000 Amp service would be required along with 2,500 kW of standby generation. The cost of a new main electrical service was not included in the VE cost estimate for this idea. By making full use of the capacity of the PG&E 1,200 Amp service at switchboard R the cost of anew main service can be deferred until the next major improvement project. E2 Intertie recycle building and main switchgear See E1 See above. 6/11/2015 4 of 4 ResponseVE Team Comment E3 Keep generator and install new diesel generator in parallel, size new generator in phases to match trends in loads 113 112.5 Yes Reject. Our understanding of this idea is to keep the existing 560 kW propane standby generator in service and add a new 1,500 kW diesel standby generator in parallel. We agree that the existing generator is functional and has very low operating hours. We have designed and commissioned a number of recent diesel generation systems with generators operating in parallel. Some of these have paralleled older technology generators with new generators, but all have been diesel and the paralleled units the same size. Caterpillar has indicated to us that it is possible to parallel an older gas (propane) fueled generator with a new diesel generator, but our past experience in paralleling older and new diesel generators makes us look at this case with caution especially considering the generators would also be different capacity. The VE team states a disadvantage to this alternative as “Requires new generator to match characteristics of existing generator.” Matching the alternators is easily achieved, but the larger issue is the difference in the two types of engines which cannot be “matched”. A diesel engine is highly responsive to load changes while a carbureted and even a fuel injected gas engine is much less responsive to load changes and much slower in recovery. We do not believe the relatively small cost saving between a 1,500 and a 2,000 kW generator set is worth the added risk of difficulties with system operation. A standby generation system needs to be simple and highly reliable or it will not serve its purpose. Our experience in paralleling even relatively new generators with new generators is that the older unit requires significant control upgrades for this service and it can still be a difficult, trying and expensive startup/commissioning process. . E4 Replace existing main plant switchgear -500 -500 Yes Reject. If we understand this VE idea correctly it is a maintenance item and not a VE idea. This is an O&M decision the City would need to make, but we see no compelling reason to abandon this equipment at this time. The main switchboard appears to be in excellent condition and has been indoors all or a major part of its service life. The breakers are draw out power type and are designed so they can be repaired and maintained for a long service life with many operations. It is unlikely that these breakers operate more than a few times a year and that most of the operations are not under any significant load. We are not sure what limits this switchboard to a 25 year life. We believe this switchboard has the potential for a much longer service life. E7 Run single feeder to MCC building, intertie MCCs at building 24 24 Yes Modify. We agree with the VE team concept to run single, not multiple feeders to MCC’s. We seldom design multiple feeder systems unless required by the Owner. We cover this subject in our report and plan single feeders for any new MCC’s. We see no real advantage to abandoning dual feeds where they now exist in the plant. SG4 Incorporate existing buildings into design 1,765 1765 Yes Accept. The existing admin building will be repurposed. SG5 Convert existing admin building into lab 1,124 1124 Yes Modify. The existing admin building will be repurposed for a learning center. SG8 Replace blower building with canopy 300 300 Yes Reject; our experience is that placing blowers under a canopy can lead to corrosion (strong possibility here with proximity to sea), the building louvers can serve as a first barrier to dust and insects that clog the filters, and direct sunlight can cause potential overheating issues with the PLC and VFD’s.