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R-10783 - Resolution approving the 2017 Recycled Water Master Plan and a Negative Declaration of Environmental Impact
Utilities Department, Water Division 2017 Recycled Water Master Plan THIS PAGE LEFT INTENTIONALLY BLANK City of San Luis Obispo 2017 Recycled Water Master Plan i Table of Contents Terminology ......................................................................................................................... iv Abbreviations & Acronyms .......................................................................................................... v Executive Summary ............................................................................................................... 1 Chapter 1. Introduction ......................................................................................................... 3 Master Plan Scope ....................................................................................................................... 3 Chapter 2. Policy Framework and Program History ................................................................ 5 Statewide Policy Framework ....................................................................................................... 5 Statewide Goals for Expanded Recycled Water Use ............................................................... 5 Conservation, a California Way of Life .................................................................................... 5 Potable Reuse Options ............................................................................................................ 5 Local Plans and Policies ............................................................................................................... 6 Municipal Code ........................................................................................................................ 6 General Plan Goals and Policies .............................................................................................. 7 2015 Urban Water Management Plan .................................................................................... 8 2012 Climate Action Plan ........................................................................................................ 8 Master Reclamation Permit ..................................................................................................... 9 2005 Biological Opinion ........................................................................................................... 9 Water Resource Recovery Facility Project............................................................................. 10 2004 Master Plan ................................................................................................................... 11 Chapter 3. Existing Recycled Water Distribution System and Demand .................................. 13 Construction Water Demand .................................................................................................... 17 Chapter 4. Strategic and Beneficial Use of Recycled Water ................................................... 23 Factors Influencing Availability and Demand of Recycled Water ............................................. 23 Recycled Water Supply Assumptions .................................................................................... 23 Recycled Water Demand Assumptions ................................................................................. 24 Deliveries to Irrigation Customers ............................................................................................ 24 Irrigation Demand in 2015 ..................................................................................................... 24 Irrigation Demand at Buildout ............................................................................................... 25 Alternative Uses of Recycled Water .......................................................................................... 26 Recycled Water Use Outside of the City ............................................................................... 27 City of San Luis Obispo 2017 Recycled Water Master Plan ii Indirect Potable Reuse (IPR) .................................................................................................. 28 Direct Potable Reuse ............................................................................................................. 29 Laguna Lake ............................................................................................................................... 30 Dual Plumbing ........................................................................................................................... 30 Chapter 5. Future Recycled Water Use for Landscape Irrigation............................................ 31 Pending Projects/Approved Accounts ...................................................................................... 31 Use of Recycled Water in Specific Plan Areas ........................................................................... 32 High-Priority Retrofit Projects ................................................................................................... 32 Medium-Priority Irrigation System Retrofit Projects ................................................................ 37 Low Priority Irrigation System Retrofit Projects ....................................................................... 41 Chapter 6. Recycled Water Storage ...................................................................................... 43 Chapter 7. Capital Improvement Plan .................................................................................. 45 Past Capital Investment ............................................................................................................ 45 Future Capital Investment ......................................................................................................... 45 Recycled Water Distribution System Projects ....................................................................... 46 Irrigation System Retrofit Project Cost Estimates ................................................................. 46 Documents Referenced ....................................................................................................... 48 Appendix A. Recycled Water Facilities Planning Study ......................................................... A-1 Appendix B. Recycled Water to Augment Lake Level at Laguna Lake ................................... B-1 Appendix C. Storage Analysis .............................................................................................. C-1 Appendix D. High Priority Irrigation System Retrofit Projects .............................................. D-1 Appendix E. Medium Priority Projects ................................................................................. E-1 City of San Luis Obispo 2017 Recycled Water Master Plan iii List of Tables Table 1. Metered Recycled Water Irrigation Account Expansion, 2006 to 2016 ......................... 16 Table 2. Construction Use of Recycled Water, 2014 to 2016 ....................................................... 17 Table 3. Recycled Water Demand and Availability, Calendar Year 2015 ..................................... 24 Table 4. Future (Buildout) Monthly Recycled Water Demand with High and Medium Projects . 25 Table 5. Estimated Short-term Recycled Water Surplus by Month ............................................. 26 Table 6. Estimated Long-term Recycled Water Surplus by Month .............................................. 27 Table 7. Estimated Recycled Water Demand from Pending Projects .......................................... 30 Table 8. Recycled Water Demand Estimate for Specific Plan Areas ............................................ 31 Table 9. High-Priority Irrigation System Retrofit Projects ............................................................ 33 Table 10. Medium-Priority Irrigation System Retrofit Projects .................................................... 37 Table 11. Low-Priority Irrigation System Retrofit Projects ........................................................... 40 Table 12: Recycled Water Capital Plan ......................................................................................... 47 List of Figures Figure 1. One Water Approach ..................................................................................................... 11 Figure 2. Recycled Water Service Area ......................................................................................... 14 Figure 3. Existing (2016) Recycled Water Customers ................................................................... 18 Figure 4. Recycled Water System Expansion (2006-2015) ........................................................... 20 Figure 5. High-Priority Irrigation System Retrofit Projects ........................................................... 34 Figure 6. Medium-Priority Irrigation System Retrofit Projects..................................................... 38 City of San Luis Obispo 2017 Recycled Water Master Plan iv Terminology Acre-foot: The volume of one acre of surface area to a depth of one foot. Since the acre is defined as a chain by a furlong (66 ft × 660 ft) the acre-foot is exactly 43,560 cubic feet. In San Luis Obispo in 2016, one acre-foot is the water usage of approximately six single-family households, annually. Creek Discharge: As a condition of approval of the Water Reuse Project in 2005, the City was required by National Oceanic and Atmospheric Administration, National Marine Fisheries Service to maintain a minimum average daily release, year-round, of treated effluent to San Luis Obispo Creek at a rate of 2.5 cubic feet per second (cfs), or 1.6129 million gallons per day (mgd) to provide satisfactory habitat and flow volume for anadromous fish species (steelhead trout) within the San Luis Obispo Creek environment. Direct Potable Reuse (DPR): The planned introduction of advanced purified water either directly into a public water system, as defined in Section 116275 of the Health and Safety Code, or into a raw water supply immediately upstream of a water treatment plant. Indirect Potable Reuse (IPR): Indirect potable reuse is the planned use of advanced purified water for replenishment of a groundwater basin or an aquifer that has been designated as a source of water supply for a public water system. One-Water: The One-Water approach considers the urban water cycle as a single integrated system, in which all urban water flows are recognized as potential resources, and the interconnectedness of water supply, groundwater, stormwater and wastewater is optimized, and their combined impact on flooding, water quality, wetlands, watercourses, estuaries and coastal waters is recognized. Potable or Drinking Water: Potable water is water that meets the Environmental Protection Agency (EPA) Safe Water Drinking Act and California Water Code requirements. Residents and businesses receive potable water at their water meter connection, and its use is unrestricted. Recycled Water: Recycled water means water which, as a result of treatment of waste, is suitable for a direct beneficial use or a controlled use that would not otherwise occur and is therefore considered a valuable resource. (Water Code § 13050(n)). Surplus Recycled Water: The quantity of recycled water available beyond the City’s required creek discharge and the quantity of recycled water delivered for landscape irrigation is described as the “Seasonal Surplus” as it is available outside of the irrigation season. Title 22: Wastewater recycling is regulated under Title 22, Division 4 of the California Code of Regulations. These regulations establish the treatment and water quality requirements for recycled water to varying levels, as well as establish types of uses that are allowed for each level. The State Water Resources Control Board (SWRCB) has jurisdiction over recycled water use and enforcement of Title 22 regulations. Wastewater: Wastewater comes from homes or businesses and has been polluted to the point of requiring special management and treatment. In the City, wastewater is collected and treated at the Water Resource Recovery Facility. Some of the City’s wastewater is recovered as recycled water. Wastewater does not include stormwater in San Luis Obispo. Stormwater is collected in a separate system of pipes and typically not treated before discharge. Water Resource Recovery: Water resource recovery is a broad term used to describe the process of converting wastewater to a valuable water resource through treatment processes. Water resource recovery includes non-potable recycled water development and either direct potable reuse or indirect potable reuse involving integration with drinking water supplies. City of San Luis Obispo 2017 Recycled Water Master Plan v Abbreviations & Acronyms AF - Acre-Foot or Acre-Feet AFY (of afy) - Acre-Feet per Year AWWA - American Water Works Association CDPH - California Department of Public Health CIMIS - California Irrigation Management Information System CUWCC - California Urban Water Conservation Council CWC - California Water Code DDW - State Water Resources Control Board, Division of Drinking Water DOF - Department of Finance DPR - Direct Potable Reuse DWR - California Department of Water Resources EPA - U.S. Environmental Protection Agency ETo - Reference Evapotranspiration GIS - Geographic Information System GPCD (or gpcd) - Gallons per Capita per Day IPR - Indirect Potable Reuse IRWM - Integrated Regional Water Management LAFCO - Local Agency Formation Commission MGD (or mgd) - Million Gallons per Day NOAA NMFS - National Oceanic and Atmospheric Administration , National Marine Fisheries Service NPDES - National Pollutant Discharge Elimination System PRV - Pressure Reducing Valve RWMP - Recycled Water Master Plan RWQCB - Regional Water Quality Control Board SB X7-7 - Senate Bill Seven of the Senate’s Seventh Extraordinary Session of 2009 SDWA - Safe Drinking Water Act SGMA - Sustainable Groundwater Management Act SWRCB - State Water Resources Control Board UWMP - Urban Water Management Plan WDR - Waste Discharge Requirement WRRF - Water Resource Recovery Facility. The WRRF is the City’s wastewater treatment facility. THIS PAGE LEFT INTENTIONALLY BLANK City of San Luis Obispo 2017 Recycled Water Master Plan 1 Executive Summary The City of San Luis Obispo has been utilizing recycled water as a component of its multi-source water supply since 2006. The City’s goal is to use this water source to the highest and most beneficial use and is committed to sound and progressive planning for its recycled water infrastructure. The main purpose of the City’s Master Plan in 2004, originally called the Water Reuse Master Plan, was to offset potable water use by reducing the need to use potable water for non-potable uses. While the City continues to deliver recycled water for landscape irrigation , technology and regulations have evolved and other opportunities for utilization of recycled water have emerged. The 2017 Recycled Water Master Plan describes future opportunities for the City to consider potable reuse consistent with a One-Water approach, presents a plan to serve recycled water to developing areas of the community for use as landscape irrigation, prioritizes opportunities to retrofit existing sites to offset potable water use, and explores use of recycled water outside the City limits during periods where much of the City’s recycled water supply goes underutilized. The Master Plan includes an updated storage analysis and a capital plan through 2035. The 2017 Master Plan is organized into the following seven chapters: Chapter 1 provides an introduction to the 2017 Recycled Water Master Plan. Chapter 2 provides a summary of State regulations and local recycled water policy framework and describes changed conditions since adoption of the 2004 Master Plan. Chapter 3 describes the existing recycled water distribution system and demand. Chapter 4 summarizes alternatives considered to maximize use of the City’s available recycled water supply. Chapter 5 provides a plan for the continued logical expansion of the City’s recycled water distribution system. Chapter 6 describes existing recycled water storage and future storage needs Chapter 7 includes the capital plan for the expanded use of recycled water. Five appendices to the 2017 Master Plan are provided with detailed analysis that supports the City’s water management goals. City of San Luis Obispo 2017 Recycled Water Master Plan 2 City of San Luis Obispo 2017 Recycled Water Master Plan 3 Chapter 1. Introduction Population growth and climate change are leading cities to further consider methods of sustainable development and management. Recycling treated wastewater is a strategy being utilized around the world to meet and manage urban water demands. Recycling water involves altering the traditional municipal pathway from the wastewater treatment facility to the discharge point, and treating it sufficiently to reuse for either non-potable or potable applications. As opposed to treating and discharging, recycling treated wastewater is a more sustainable practice. By recycling water through potable reuse, cities could extend or create an additional municipal supply, also reducing demand on the City’s potable water resources. By recycling water for landscape irrigation, policy makers ensure reduced consumption of potable water, thereby conserving availability of freshwater sources. In accordance with the City’s General Plan, the City intends to use recycled water to the highest and most beneficial use today and into the future. To effectively manage this resource, the City must have a solid understanding of evolving State water regulations, production capability, cost, and existing and future water demands and demand patterns. This Master Plan presents a plan to serve recycled water to developing areas of the community for use as landscape irrigation , presents opportunities to retrofit existing sites to offset potable water use, explores use of recycled water outside the City limits during periods where much of the City’s recycled water supply is underutilized, and describes future opportunities for the City to consider potable reuse consistent with a One-Water approach. Master Plan Scope The 2017 Recycled Water Master Plan is part of a comprehensive strategy to efficiently manage the City’s water resources. The scope of the Master Plan work effort is as follows: 1. Plan for the strategic and beneficial use of recycled water, including the potential for future potable reuse. 2. Analyze recycled water production capability in the short- and long-term, ensuring the Master Plan reflects current wastewater generation rates. 3. Understand the City’s expected growth patterns and recycled water demand. 4. Develop a hydraulic model for the recycled water distribution system that can be utilized for future infrastructure analysis. 5. Analyze the available recycled water supply, including surplus supply. 6. Confirm the long-term extent of the Master Plan area. 7. Provide a plan for incremental expansion of the recycled water distribution system. 8. Prioritize future retrofit opportunities based on defined criteria. 9. Identify future storage needs based on future peak day demand. 10. Evaluate infrastructure improvements needed to reach new customers and a prioritized Capital Improvement Project (CIP). The Master Plan covers the planning period to the year 2035 consistent with development projections in the City’s General Plan. City of San Luis Obispo 2017 Recycled Water Master Plan 4 Recycled water means water which, as a result of treatment of waste, is suitable for a direct beneficial use or a controlled use that would not otherwise occur and is therefore considered a valuable resource. Water Code § 13050(n) City of San Luis Obispo 2017 Recycled Water Master Plan 5 Chapter 2. Policy Framework and Program History This chapter summarizes State and local recycled water policy framework, discusses the history of the City’s recycled water program, and describes changed conditions since adoption of the 2004 Master Plan. Statewide Policy Framework Since the City adopted its 2004 Master Plan and began delivering recycled water for landscape irrigation in 2006, State water regulations related to recycled water use have continued to evolve in a number of areas. These regulations involve expanding recycled water use, new water use efficiency requirements, and the treatment of wastewater to drinking water standards. Statewide Goals for Expanded Recycled Water Use On February 3, 2009, the State Water Resources Control Board adopted a Recycled Water Policy for California and statewide goals for expanded use of this valuable resource. The policy identifies the goals and mandates to recycled water by 2010, 2015 and 2030. Section 13577 of the California Water Code establishes water recycling goals of 700,000 acre feet of water per year by the year 2000 and 1,000,000 acre-feet of water per year by the year 2010. Conservation, a California Way of Life On May 9, 2016 the Governor released Executive Order (B-37-16) which established a new water use efficiency framework for California by aiming to “Make Conservation a California Way of Life.” The 2016 Executive Order bolsters the state’s drought resilience and preparedness by establishing long-term water conservation measures that include: Permanent monthly water use reporting, New urban water use targets based on strengthened standards, Reducing system water loss, Eliminating clearly wasteful practices, and Strengthening urban drought contingency plans. These updated measures aim to not only reduce water use in the short-term but to establish a long-term change in the way Californians think about water. The drought across the State of California, and specifically in the Central Coast region, has contributed to a heightened interest in the City’s recycled water supply. Potable Reuse Options In 2010, then-Governor Arnold Schwarzenegger signed a bill that in part required the California Department of Public Health (CDPH) to investigate the feasibility of developing uniform water recycling criteria for direct potable reuse. Direct potable reuse, or DPR, is the planned introduction of recycled water either directly into a public water system, as defined in Section 116275 of the Health and Safety Code, or into a raw water supply immediately upstream of a water treatment plant. Direct potable reuse is a practice which is not currently occurring in California; however, the feasibility of implementing direct potable reuse is be ing drafted. City of San Luis Obispo 2017 Recycled Water Master Plan 6 Indirect potable reuse, or IPR, is a practice that occurs when tertiary or advanced treated wastewater augments drinking water resources. The two types of indirect potable reuse are: • Indirect potable reuse for groundwater recharge where recycled water recharges a groundwater basin and groundwater is later extracted from the basin. • Surface water augmentation where recycled water is added into a surface water reservoir used as a source of domestic drinking water supply. Indirect potable reuse does not actually occur until the water is subsequently pumped from the ground or withdrawn from the reservoir, treated, and added to the drin king water distribution system. Indirect potable reuse through groundwater recharge has occurred in California since 1962. Title 22, Division 4, Chapter 3, Article 5.1 (CCR §60320 et seq), effective June 18, 2014, describes the permitting and monitoring process required to obtain a R egional Water Quality Control Board (RWQCB) permit for groundwater recharge. Indirect potable reuse through surface water augmentation is not currently permitted in California, but regulations are being drafted. Like groundwater recharge with recycled water, surface water augmentation will only occ ur with a permit and monitoring requirements from a RWQCB. Local Plans and Policies Water recycling has been part of the overall water supply strategy in the City since the 1980s. In 1994 the City completed a major capital improvement project at its Water Resource Recovery Facility (WRRF) that included addition of tertiary treatment and other unit processes required to meet stringent effluent quality limits intended to protect and enhance the receiving waters of San Luis Obispo Creek. The City received regulatory approvals for diversion of treated effluent for off-site landscape irrigation and other approved uses in 2002. In 2004, the City’s Water Reuse Master Plan analyzed alternative distribution system routes, identified areas of the City to be served with recycled water, and anticipated future recycled water demand. Municipal Code The City adopted a mandatory use ordinance for recycled water in 2004. The policy, codified in the Municipal Code as Chapter 13.24, allows the City to require the use of recycled water on parcels when considered feasible. The code language is as follows: 13.24.010 Statement of Policy When in the judgment of the city, reclaimed water service can be feasibly provided to a particular parcel for particular uses, the utilities director shall require the use of reclaimed water in lieu of potable water for those uses. As used herein, the term “feasible” means reclaimed water is available for delivery to the property in compliance with all applicable federal, state, and local laws, ordinances and regulations and such reclaimed water can be delivered to the property at an overall City of San Luis Obispo 2017 Recycled Water Master Plan 7 cost to the user which does not exceed the overall cost of potable water service (Ord. 1403 § 1,2001). The mandatory use ordinance is an important component of the City’s recycled water program as small volume users are ultimately expected to make up a significant portion of the City’s overall recycled water demand for irrigation use. General Plan Goals and Policies The City’s Water and Wastewater Management Element of the General Plan, or WWME, has been the guiding policy document for the provision of water and wastewater services to the community since 1987. The Element translates the Land Use Element's capacity for development into potential demand for water supply and wastewater service. The WWME Element identifies multiple water sources to meet projected short and long-term water demand. Having several sources of water avoids dependence on any one source that may not be available during a drought or other water supply reduction or emergency. There is usually greater reliability and flexibility if sources are of different types (such as surface water and groundwater) and if the sources of one type are in different locations (such as reservoirs in different watersheds). Consistent with the multi-source concept, the City obtains water from five sources: Salinas Reservoir (Santa Margarita Lake), Whale Rock Reservoir, Nacimiento Reservoir, recycled water from the City’s Water Resource Recovery Facility, and groundwater. When the 2004 Master Plan was adopted, the City’s General Plan had established a buildout population of 56,000 with a potable water demand of nearly 9,100 acre feet per year. The City had a water supply deficit of approximately 1,800 acre-feet per year at projected buildout. The City was considering several water supply projects to meet the projected demand including a recycled water program and participation in the Nacimiento Water Project. When recycled water deliveries began in 2006, it was the first new water supply project developed by the City in 40 years. The 2004 Master Plan saw the use of recycled water as a method to offset potable water use and extend the City’s potable water supply to serve General Plan buildout. The City adopted an updated WWME in June 2016. With that update, the City’s goal (7.1.1) for the utilization for its recycled water supply was broadened to read as follows: Maximize recycled water use for all approved purposes. The 2017 Master Plan presents opportunities to maximize recycled water use and future potable reuse opportunities. It describes the existing recycled water distribution system and expansions through 2035, and identifies potential long-term recycled water distribution system expansion concepts. Deliveries of recycled water outside the City limits is addressed in two areas of the General Plan. The 2014 General Plan Land Use Element update included a new policy and specific findings related to potential recycled water deliveries outside the City limits. Related to Annexation and Services, Policy 1.13.2 states the following: City of San Luis Obispo 2017 Recycled Water Master Plan 8 Provision of recycled water outside of City limits may only be considered in Compliance with Water and Wastewater Element Policy A 7.3.4 and the following finding: A. Non-potable/recycled water is necessary to support continued agricultural operations. B. Provision of non-potable/recycled water will not be used to increase development potential of property being served. C. Non-potable/recycled water will not be further treated to make it potable. D. Prior to provision of non-potable/recycled water, the property to be served will record a conservation, open space, Williamson Act, or other easement instrument to maintain the area being served in agriculture and open space while recycled water is being provided. The WWME includes Program A 7.3.4, which states that the City should: Consider the potential to deliver available recycled water supplies to customers outside the city limits, including analysis of policy issues, technical concerns, and cost recovery, provided it is found to be consistent with the General Plan. The 2017 Master Plan addresses deliveries outside the city limits in more detail in Chapter 3. 2015 Urban Water Management Plan Chapter 5 of the City’s 2015 Urban Water Management Plan was prepared to fulfill the requirements of Section 10633 (a-g) of California Water Code Division 6, Article 2, Part 2.6 regarding the City’s recycled water supply. In this document the City made conservative estimates that future recycled water use for landscape irrigation and construction water would reach 350 acre feet per year by 2035. 2012 Climate Action Plan The goal identified in the City’s 2012 Climate Action Plan (CAP) related to water is to reuse water consumed by the community. The CAP includes implementation measure WTR 1.3 to “encourage the use of recycled water, greywater or rainwater- harvesting systems” and notes that: The use of recycled water for non-potable needs directly reduces drinking water demand and conserves water resources. The City will continue to implement the [Recycled Water] Master Plan to utilize the capacity of recycled water when available. Recycled Water Uses Landscape Irrigation Mandatory Use Ordinance adopted in 2004 Deliveries began in 2006 Construction Water Permit program began in 2009 Sale of Seasonal Surplus Under Study Potable Reuse Under Study Pending New Statewide Regulations City of San Luis Obispo 2017 Recycled Water Master Plan 9 Continued implementation of the Recycled Water Master Plan will help the City meet its Climate Action Plan goals. Master Reclamation Permit Production and distribution of tertiary treated recycled water is regulated under the City’s existing Waste Discharge Requirements/Master Reclamation Permit (Order No. R3 -2003-081). The Permit outlines prohibitions, requirements for construction and irrigation use, and a monitoring program for use of recycled water. In accordance with this Permit, the City complies with the following: 1. Meter the total quantity of reclaimed water distributed daily, 2. Monitor and record chlorine residual concentration at a point after the final chlorine contact basin, 3. Provide guidance to recycled water users including a user manual and other guidance as needed, 4. Provide instruction to all City field staff to report incidents of unauthorized daytime irrigation activity or runoff, 5. Cooperate with County Environmental Department of Health Services to ensure backflow devices are present, tested and repaired or replaced if found defective, 6. Inspect the operation of reuse sites, 7. Perform cross connection testing, 8. Conduct site supervisor training and quarterly interviews to verify system operation, and 9. Quarterly review of monthly meter readings with follow-up on change in patterns of use. The entirety of the recycled water treated at the WRRF is compliant with Title 22 requirements, but only a portion is currently used. The remainder is discharged to San Luis Obispo Creek. The available seasonal surplus of recycled water is described further in Chapter 3. 2005 Biological Opinion In addition to complying with the permit requirements described above, t he City is required to comply with minimum daily average discharge requirements from the WRRF to San Luis Obispo Creek for protection of downstream biological resources as required by National Oceanic Atmospheric Association, National Marine Fisheries Service (NOAA NMFS). The City’s 2004 Master Plan noted that the City must discharge a minimum of 1.7 cubic feet per second (cfs), equivalent to 1.1 MGD, to San Luis Obispo Creek at all times to provide satisfactory habitat and flow volume for anadromous fish species within the creek environment. However, in 2005 the NOAA NMFS amended the Biological Opinion for the City’s Water Reuse Project to a minimum daily average year-round discharge of 1.6129 MGD (or 2.5 CFS). This change reduced the City’s total available recycled water supply by over 500,000 gallons a day. Operationally, this City of San Luis Obispo 2017 Recycled Water Master Plan 10 requirement may lead to other challenges during period s where the Water Resource Recovery Facility receives low flows. The City may work to reduce the mandatory discharge requirement to balance competing needs for recycled water in the future consistent woth the One-Water approach. Water Resource Recovery Facility Project The design phase for the upgrade of the City’s WRRF began in 2016 and will allow the City to accommodate General Plan buildout and maximize recycled water production. The proposed project will meet more stringent standards of the City’s 2014 NPDES permit (Order No. R3-2014-0033) which will improve the quality of recycled water that would be distributed to customers. The WRRF upgrade will also enable the City to consider potable reuse, part of a One- Water approach (See Figure 1), in the future. Completion of the upgrade is anticipated to occur in 2021. The Environmental Impact Report for the Water Resource Recovery Facility Project states: The proposed project would upgrade the WRRF facility to meet performance standards and be in compliance with the State Water Resources Control Board discharge requirements. The project would include increasing the facility’s capacity to produce recycled water, as well as upgrading and replacing aging infrastructure. The proposed project would increase the amount of recycled water available for use within the City of San Luis Obispo, which is one of the GHG reduction strategies outlined in the CAP. Also, the use of recycled water in place of imported, offset, at least partially, the energy requirements to deliver the same amount potable water supplies would of water from outside sources. WRRF Community Open House at the San Luis Obispo Farmer’s Market on March 19, 2015 City of San Luis Obispo 2017 Recycled Water Master Plan 11 FIGURE 1: One-Water Approach 2004 Master Plan The City adopted the 2004 Master Plan on September 21, 2004. In the 2004 Master Plan, the City estimated that demand existed for over 1,000 acre-feet of recycled water annually. The 2004 Master Plan was a plan to deliver recycled water for landscape irrigation to the Orcutt, Margarita, and Airport Specific Plan areas, as well as retrofits of existing irrigation systems using potable water to use recycled water. The One-Water approach considers the urban water cycle as a single integrated system, in which all urban water flows are recognized as potential resources, and the interconnectedness of water supply, groundwater, stormwater and wastewater is optimized, and their combined impact on flooding, water quality, wetlands, watercourses, estuaries and coastal waters is recognized. SOURCE: US Water Alliance. City of San Luis Obispo 2017 Recycled Water Master Plan 12 The 2004 Master Plan included a groundwater exchange program concept whereby the City’s recycled water supply would be exchanged for a potable ground water supply that was used to irrigate agricultural land outside the City limits. This included both the Dalidio Groundwater Exchange and the South Higuera Groundwater Exchange. Since that time, the City elected not to pursue a groundwater exchange program. A number of other factors have changed since the adoption of the 2004 Master Plan related to water demand and wastewater generation. Per capita water demand is down from 126 gallons per capita per day (gpcd) in 2004 to 92 gpcd in 2015. Correspondingly, the average daily and monthly influent flows to the WRRF have also decreased since the 2004 Master Plan reported the average flow as 4.5 mgd (a 2003 figure) to 2.74 mgd in 2015. This average daily flow is further lowered during the summer months while the student population associated with Cal Poly is away (mid-June to mid-September), thus reducing the available recycled water supply during the peak irrigation season. The available recycled water supply and demand trends are descr ibed in more detail in Chapter 3 and in Appendix C related to recycled water storage. City of San Luis Obispo Multi-Source Water Supply City of San Luis Obispo 2017 Recycled Water Master Plan 13 Chapter 3. Existing Recycled Water Distribution System and Demand The City completed construction of the Water Reuse Project in 2006 which included eight miles of the recycled water distribution system with two main branches (see Figure 2). West Branch: The west branch extends west from the Water Resource Recovery Facility under Highway 101, then along Calle Joaquin to Los Osos Valley Road to near the westerly City limits. There is a secondary branch which extends from Los Osos Valley Road along Madonna Road to Laguna Lake Park. East Branch: The east branch begins at the Water Resource Recovery Facility and follows Prado Road east to the City limits, then along existing easements to Broad Street, south along Broad to Tank Farm Road, then east to the terminus at Islay Hills Park. The Water Reuse Project also included improvements within the Water Resource Recovery Facility. These are: A diversion structure and modulating control valve to split the effluent flow between the recycled water tank and San Luis Obispo Creek. A new 220,000-gallon chlorine contact tank to meet recycled water disinfection requirements which differ from those for discharge to San Luis Obispo Creek. A 600,000 gallon buried concrete recycled water storage tank to provide the storage necessary for operation of the distribution system. A pump station to deliver recycled water into the distribution system. It included two 40- horsepower and three 120-horsepower variable speed pumps and was designed to accommodate two additional 120 horsepower pumps for a future capacity expansion. Recycled water delivery began in October, 2006 to a large City park, the Damon Garcia Sports Complex. In 2016, the City delivered over 193 acre-feet of recycled water with over 40 metered connections to the system. To date, the Damon Garcia remains as the City’s largest user of recycled water. Additional sites continue to be connected to the recycled water distribution system through retrofits of existing irrigation systems as well as the irrigation systems associated with new development in the master plan area. Recycled water is used for the irrigation of parks, streetscape and median landscaping, common area (homeowner’s association) landscaping, and landscaping in commercial centers, industrial areas, and business parks. There are currently 39 metered connections to the recycled water system that supply recycled water for irrigation use. The recycled water service area is shown on Figure 2 and locations of the existing connections and approved future connections can be found on Figure 3. City of San Luis Obispo 2017 Recycled Water Master Plan 14 City of San Luis Obispo 2017 Recycled Water Master Plan 15 Since the City’s original eight miles of recycled water main were installed for the water reuse project, an additional 3.2 miles of main line have been installed to expand the system. Both the east and west branch of the recycled water system have been expanded since 2004, leading to an increased demand in recycled water for ten consecutive years. As the recycled water system has expanded, existing customers currently served by potable water have converted existing irrigation systems to recycled water. As shown in Figure 2, segments of “dry” recycled water main have been installed in areas not yet served by recycled water. The installation of “dry” pipe has been done in order to place the City in a position to connect additional customers to recycled water as the system expands through capital projects and expansion into several specific plan areas. City of San Luis Obispo 2017 Recycled Water Master Plan 16 Table 1: Metered Recycled Water Irrigation Account Expansion 2006 to 2016 East/West Branch Irrigation Accounts Year Connected New Construction (N) or Retrofit (R)? West Los Osos Valley Road Medians 2006 R West Courtyard by Marriott 2006 N East Damon Garcia Park 2006 N West Laguna Middle School 2007 R West Laguna Village Shopping Center 2007 R West Costco 2007 N West Irish Hills Plaza West 2007 N West Calle Joaquin Parkways 2007 N West Laguna Lake Golf Course 2008 R West Laguna Hills Park 2009 R West Laguna Lake Park 2009 R West Mission Community Bank 2009 N West De Tolosa Ranch 2010 R West DeVaul Ranch Park 2010 R West Los Verdes I Home Owners Association 2010 R East Meathead Movers 2010 N East Margarita Medians 2010 R East French Park 2010 R East Islay Hills Park 2010 R West Olive Garden 2011 N West Irish Hills Plaza East 2011 N West Hampton Inn 2012 N West American Tire 2013 N West Madonna Road Apartments 2014 R East SESLOC Credit Union 2014 N West Cal Trans 2009/2015 R East Wathen Castano Homes 2015 N Note: Properties may be supplied by multiple recycled water meters/connections. Source: City of San Luis Obispo, Utilities Department, Cityworks database, 2017. City of San Luis Obispo 2017 Recycled Water Master Plan 17 Construction Water Demand A portion of the City’s increase in recycled water use since 2014 has come from the use of recycled water for construction activities. Since 1989, in accordance with the City’s Municipal Code section 13.07.070 C 3: Potable city water shall not be used for major construction activities, such as grading and dust control, and shall not be used to wash down sidewalks, driveways, or parking areas except to alleviate immediate fire or sanitation hazards. The presence of recycled water filling stations at various locations in the City has reduced the demand on the Prado Road well and other non-potable resources that were traditionally used to supply water for dust control, grading and compaction related to large construction projects. While the municipal code does not require the use of recycled water for construction- related activities, the City’s only publicly accessible non-potable well is no longer permitted as a source of water for construction use. While construction water demand varies from year-to- year, based on construction activity, weather, and a variety of other factors, there is not a large future increase expected in construction water use. Annual construction water demand from 2014 to 2016 is provided in Table 2. Table 2: Construction Use of Recycled Water 2014 to 2016 Source: City of San Luis Obispo, Utilities Department, Springbrook database, 2017. As shown on Figure 2, in 2017 the City has six existing recycled water filling stations, and three temporary locations in the Margarita and Orcutt specific plan areas. Additional filling stations are planned in the future proximate to developing areas of the City. Locating recycled water filling stations within the recycled water distribution system can reduce a significant number of truck trips through the City. Year Acre-Feet 2014 9.20 2015 17.56 2016 16.94 Wharf head-style hydrants are provided at existing recycled water filling stations. City of San Luis Obispo 2017 Recycled Water Master Plan 18 City of San Luis Obispo 2017 Recycled Water Master Plan 19 City of San Luis Obispo 2017 Recycled Water Master Plan 20 Page Intentionally Left Blank City of San Luis Obispo 2017 Recycled Water Master Plan 21 City of San Luis Obispo 2017 Recycled Water Master Plan 22 Page Intentionally Left Blank City of San Luis Obispo 2017 Recycled Water Master Plan 23 Chapter 4. Strategic and Beneficial Use of Recycled Water The City’s goal is to use its available recycled water supply to the highest and most beneficial use today and into the future, which requires an understanding of recycled water demand patterns. This chapter examines factors that influence the supply of and demand for recycled water, and summarizes assumptions regarding increased demand for recycled water over time for landscape irrigation use. Also provided in this chapter is a detailed examination of potable reuse opportunities, and short- and long-term use of surplus water outside of the City. Factors Influencing Availability and Demand of Recycled Water A variety of factors influence future recycled water supply and demand. The supply and demand assumptions explained below forecast a conservative baseline for wastewater generation and recycled water irrigation demand. The City will update this analysis as new information becomes available to help forecast the supply and demand of recycled water in the future. Recycled Water Supply Assumptions As the drought in California has highlighted the need for expansion and diversification of water supplies across the state, it has also led to a reduction in indoor water use which has reduced wastewater flows to the WRRF. Along with this reduction, the State is drafting legislation (Executive Order B-37-16) which could further reduce wastewater generation rates by increasing water efficiency standards for water-using fixtures and appliances. Improved water efficiency standards, along with an increased awareness in water conservation, may lead to a continued decrease in the water demand of new homes and businesses. Applying what the City learned during the early 1990s when plumbing and appliance water efficiency standards were last significantly lowered, the City may also see decreased water use within the existing customer base. The amount of reduction will be dependent on the level of water efficiency required by new standards and if state or local ordinances are enacted to require replacement of existing fixtures with more efficient fixtures. The City also made assumptions to develop the 2017 Master Plan related to construction schedules and the future of potable reuse. Future recycled water supply projections are based on the quantity of available recycled water during 2015, which represents a conservative baseline year as wastewater flows were at a historic low. The City should make adjustments over time to these supply assumptions as new information is available about water efficiency standards, Irrigation Use Outside City Delivery Direct Potable Reuse Indirect Potable Reuse City of San Luis Obispo 2017 Recycled Water Master Plan 24 construction schedules, etc. These adjustments will ensure the City does not over allocate the available recycled water supply. Recycled Water Demand Assumptions As most of the existing demand for recycled water is for landscape irrigation, weather influences recycled water demand in the City. When the City enters wet or dry periods, demand for recycled water may decrease or increase. In this study, the baseline period used to predict future recycled water demand was calendar year 2015. This year was used as it is a conservative representation of what demand may look like during periods of extended drought. As described in Chapter 2, another factor that may influence future demand of recycled water is City and State policy related to water conservation. In 2017, recycled water is not regulated by water efficiency ordinances and state-mandated reduction requirements (such as SBx 7-7 and the State’s emergency drought declaration). If the City elects to further pursue potable reuse options, it may make sense to conserve all water resources. For the purposes of this study, recycled water demand was examined as it is today, exempt from most conservation mandates and requirements. Deliveries to Irrigation Customers Over the past ten years, the City has analyzed daily, monthly, and yearly irrigation trends, noting that approximately 75 percent of recycled water demand occurs between May and October. During the same time frame, recycled water production decreases due to reduced wastewater generation related to the City’s reduced population during Cal Poly’s summer break. Irrigation Demand in 2015 Table 3 shows calendar year 2015 monthly wastewater generation, required environmental discharges, recycled water demand, surplus recycled water, and the percent of the available supply utilized each month for irrigation and construction use. As shown, supply and demand occur on an inverse schedule throughout the year, resulting in several months where there is limited demand for recycled water but production is at its highest. In 2015, there were five months where the City used less than ten percent of available recycled water due to limited demand for landscape irrigation during these months. Total Wastewater Generated Environmental Discharges Irrigation & Construction Demand Surplus Recycled Water City of San Luis Obispo 2017 Recycled Water Master Plan 25 Table 3: Recycled Water Demand and Availability Calendar Year 2015 Month Total Wastewater Generated (AF) Environmental Discharges (AF) 2015 Demand (AF)* Surplus Recycled Water (AF) % of available RW used ** January 323.49 155.22 5.64 165.63 3% February 327.62 137.49 5.05 185.08 3% March 305.90 152.22 10.61 143.07 7% April 307.73 147.31 16.89 143.53 11% May 307.73 152.22 23.46 132.05 15% June 289.12 147.31 26.11 115.70 18% July 255.93 152.22 25.76 77.95 25% August 262.15 152.22 28.64 81.29 26% September 261.92 147.31 28.16 86.45 25% October 317.79 152.22 22.25 143.32 13% November 301.44 147.31 9.78 144.36 6% December 263.23 152.22 5.04 106.03 5% Total 3,524.09 1,792.23 207.39 1,524.47 11% * Current demand includes water loss; this figure does not represent billed/metered water. ** 2015 Demand / (Total Wastewater Generated - Environmental Discharges) Note: “Surplus Recycled Water” is an estimate of recycled water available for future u se over the course of a month this does not account for storage constraints or treatment plant limitations. SOURCE: City of San Luis Obispo Utilities Department, 2017. Irrigation Demand at Buildout Table 4 projects the total monthly recycled demand and surplus recycled water at General Plan buildout with high and medium priority projects completed. Although the buildout timeline is uncertain, if wastewater flow does not increase above 2015 levels, the City will have a sufficient supply to provide recycled water to irrigation customers through the year. In July, August, and September the City may experience peak day shortages in recycled water availability. Under this scenario the City may supplement recycled water supplies temporarily or consider scheduled recycled water deliveries. Future storage constraints limiting the delivery of the available supply are described in Chapter 6. High and medium priority project details are provided in Chapter 5. While the City plans to use recycled water to its highest and most beneficial use, expanding the recycled water system for landscape irrigation will offset the demand for potable water both during drought and non-drought periods. Table 4 also shows that should the City choose to continue expansion of the recycled water distribution system; it will continue to have seasonal surplus water for available for alternative uses such as potable reuse or delivery outside of City limits. However, there may be limitations on availability of surplus water during peak demand periods such as July, August, and September. City of San Luis Obispo 2017 Recycled Water Master Plan 26 Table 4: Future (Buildout) Monthly Recycled Water Demand With High and Medium Projects Month Recycled Water Demand Surplus Recycled Water 2015 Demand Pending Projects High Priority Projects Medium Priority Projects New Development January 5.64 0.74 1.72 2.42 11.01 149.74 February 5.05 0.66 1.54 2.17 9.85 170.87 March 10.61 1.39 3.23 4.55 20.69 113.21 April 16.89 2.21 5.15 7.25 32.95 95.98 May 23.46 3.07 7.15 10.06 45.76 66.01 June 26.11 3.42 7.95 11.20 50.94 42.18 July 25.76 3.37 7.85 11.05 50.26 5.42 August 28.64 3.75 8.73 12.29 55.88 0.65 September 28.16 3.69 8.58 12.08 54.93 7.17 October 22.25 2.92 6.78 9.55 43.41 80.67 November 9.78 1.28 2.98 4.19 19.07 116.83 December 5.04 0.66 1.54 2.16 9.84 91.83 Total 207.39 27.17 63.18 88.97 404.59 NOTE: Assumes use of recycled water for landscape irrigation; demand for approved projects is as of June 2016. SOURCE: City of San Luis Obispo Utilities Department, 2017. Alternative Uses of Recycled Water With the assistance of Water Systems Consulting (WSC), the City was awarded state grant funding to develop a Recycled Water Facilities Planning Study (RWFPS). The study examined several options in addition to in-City landscape irrigation for maximizing the long-term beneficial use of recycled water within the City’s sphere of influence. These are: 1: Deliver tertiary-treated recycled water to agricultural interests outside of the City; 2: Deliver tertiary-treated recycled water to California Polytechnic State University, San Luis Obispo (Cal Poly); 3: Provide groundwater recharge (GWR) within the San Luis Obispo Valley Basin for indirect potable reuse (IPR); 4: Provide direct potable reuse (DPR); and 5: Construct a new satellite water resource recovery facility to serve Cal Poly and the surrounding areas. Using a “triple bottom line” approach to examine the social, economic, and environmental benefit of the five options, the City and other stakeholders narrowed the list of the top three. The top three options were: 1: Deliver tertiary-treated recycled water to agricultural interests outside of the City; City of San Luis Obispo 2017 Recycled Water Master Plan 27 3: Provide groundwater recharge (GWR) within the San Luis Obispo Valley Basin for indirect potable reuse (IPR); 4: Provide direct potable reuse (DPR); For more information on the methodology and criteria used to identify these options, along with associated cost estimates for each option, please see Appendix A. Recycled Water Use Outside of the City As discussed in the RWFPS, the City’s current recycled water demand is less than its production capability. The City refers to this unallocated recycled water supply as “surplus.” Short- and long- term outside City delivery scenarios may provide short-term beneficial use of the City’s recycled water supply through the entire year and long-term beneficial use during off-peak demand. Details on future WRRF infrastructure upgrades, outside City delivery scenarios, and a timeline for implementation are provided in Appendix A. Short-Term Use of Surplus Water Based on 2015 recycled water demand data, the City has approximately 75 acre- feet of surplus recycled water available per month during the peak demand period (July, August, and September). During the remainder of the year (off-peak period) the City has over 100 acre-feet per month of surplus recycled water. As demand increases within the City, the volume of surplus recycled water would reduce; however, monthly deliveries of surplus recycled water could continue for several years before significant impacts to available surplus are seen from irrigation system expansion or potable reuse. A potable reuse program cannot be implemented until after completion of the WRRF Project, in the short-term, as the timeline for IPR is estimated at greater than five years and the timeline for DPR is unknown in 2017. Table 5: Estimated Short-term Recycled Water Surplus by Month Month Available Recycled Water Surplus (AF)* January 165.63 February 185.08 March 143.07 April 143.53 May 132.05 June 115.70 July 77.95 August 81.29 September 86.45 October 143.32 November 144.36 December 106.03 Total 1,524.47 *Recycled water quantities identified above are preliminary estimates based on 2015 WRRF influent and 2015 recycled water demand. The City’s production capability may vary. SOURCE: City of San Luis Obispo Utilities Department, 2017. City of San Luis Obispo 2017 Recycled Water Master Plan 28 Long-Term Use of Surplus Water Based on the estimated surplus water available at buildout, the City has minimal surplus recycled water available per month during the peak demand period (July, August, and September) for outside City delivery. During the remainder of the year (off-peak period) the City has a significant supply of surplus recycled water. With the upgrade of the WRRF, the City will explore potable reuse in the future. Until the City conducts additional research on the groundwater basin, the quantity of recycled water that could be used for indirect potable reuse is unknown. Just as deliveries to outside City interests could be reduced as recycled water is needed for future development and irrigation system expansion, the same could occur when water is needed for potable reuse. Indirect Potable Reuse (IPR) As described in the RWFPS, an alternative use of recycled water is IPR through groundwater recharge. Using recycled water as a means for recharging the basin allows the City to increase groundwater availability by injecting or percolating recycled water into the aquifer during months when the basin is not naturally recharging through rainfall. IPR can be completed through percolation or direct injection which are each discussed in further detail below. Groundwater Recharge via Percolation Groundwater recharge via percolation can be completed in two ways: streambed percolation or dedicated infiltration basins. Groundwater recharge via streambed percolation was examined in the RWFPS. According to the RWFPS, streambed percolation could only occur during periods when San Luis Obispo Creek is dry which would limit the overall yield due to the limited quantity of recycled water available during the summer months. The RWFPS concluded that the basin may recharge up to 840 acre-feet during dry weather periods. This number could be affected by a variety of factors including yearly variance in rainfall and weather, the rate at which the basin could percolate the recycled water, future supply constraints related to changing indoor water use, or future demand increases related to in-City irrigation use and outside City deliveries. The potential recharge amount identified in the RWFPS was not based on hydrogeological data and would require additional studies to determine the actual yield that the City could realize. Advantages and disadvantages of streambed percolation, along with cost estimates and regulatory considerations are provided in Appendix A. Table 6: Estimated Monthly Long-term Recycled Water Surplus Month Long-term Recycled Water Surplus (AF)* January 149.74 February 170.87 March 113.21 April 95.98 May 66.01 June 42.18 July 5.42 August 0.65 September 7.17 October 80.67 November 116.83 December 91.83 *The long-term recycled water surplus identified here represents an estimate of the available recycled water supply each month once buildout has been reached and all high- and low-priority projects have been implemented. SOURCE: City of San Luis Obispo Utilities Department, 2017. City of San Luis Obispo 2017 Recycled Water Master Plan 29 Groundwater recharge via percolation can also be achieved through dedicated infiltration basins. The RWFPS did not examine the ability to recharge through dedicated infiltration basins and additional studies would be required to determine the feasibility, cost, and the yield that could be achieved through the use of dedicated infiltration basins. Dedicated infiltration basins are commonly used to reduce stormwater pollution by diverting stormwater into dedicated basins where the water is filtered naturally into the groundwater basin. As with streambed percolation, the City could experience difficulties recharging the basin during wet weather months. Groundwater Recharge via Injection Although not studied in the RWFPS, groundwater recharge can also be achieved using injection wells. Additional treatment may be required using this technique as the earth’s natural treatment abilities that are provided through percolation would be bypassed. The injection/recharge rate, costs, and a variety of other matters would require further study. Direct Potable Reuse Direct Potable Reuse (DPR) is the introduction of advanced purified water directly into a public water system, or into a raw water supply immediately upstream of a water treatment plant. Based on the information available in 2016, WSC provided a high level overview of the feasibility of use of direct potable reuse in the RWFPS. Unlike IPR, direct potable reuse would not experience seasonal limitations and could be used during times of low demand and high supply when irrigation use and groundwater recharge are not feasible. While the City may have existing obligations to irrigation customers, potable reuse could supply the remainder of the water to the community as a drinking water source. While DPR is not approved in California as of 2017, regulations are being developed and should provide the City with the information necessary to further examine the cost effectiveness and feasibility. While DPR may provide the highest and best use of recycled water by providing it as a potable source, costs, regulatory requirements, and public acceptance are still yet to be fully vetted and identified. Pending regulatory approval, an implementation timeline for DPR is unknown but has been estimated to take close to ten years. This leaves the City with adequate time to further consider the potential use of DPR. Additional information on cost estimates, regulatory concerns and advantages and disadvantages of DPR are provided in Appendix A. City of San Luis Obispo 2017 Recycled Water Master Plan 30 Laguna Lake Another potential customer for recycled water within the City is Laguna Lake. Laguna Lake Park is a 375-acre City park, with the main entrance located at the corner of Madonna Road and Dalidio Drive. The park includes group barbecue and picnic areas, fitness and recreational facilities, hiking trails, and provides habitat for waterfowl and other wildlife . Recycled water is used for landscape irrigation within the park. The Laguna Lake Management Program (1982), as well as the updated Laguna Lake Natural Reserve Conservation Plan in 2014, recognized use of recycled water as one option to enhance Lake levels. It is estimated that up to 450 AFY of water could be utilized to augment the lake level. This demand would vary from year to year with the amount of runoff from the corresponding drainage basins. Additional analysis related to Laguna Lake is provided in Appendix B. Dual Plumbing The use of disinfected tertiary recycled water for toilet and urinal flushing in nonresidential buildings is allowed in Section 60307(a) of Title 22 of the California Code of Regulations (Title 22). Recycled water has been used for toilet and urinal flushing in buildings in California since 1991. The Irvine Ranch Water District (IRWD) in Orange County has over 40 dual plumbed commercial buildings using recycled water within its service area. Marin Municipal Water Distr ict, the City of San Diego, and several other agencies have also constructed dual plumbed buildings within their service areas. One concern with dual plumbing is the potential for the cross connection of potable and non- potable water supplies. A cross connection occurs when a potable water supply and a non- potable supply are connected, creating an environment where non-potable water may be unknowingly consumed. Proper design and diligent agency oversight of dual plumbed facilities is necessary to prevent any cross-connections and minimize risk to public health. Recycled water has not been used for dual plumbing in the City, however, the City may consider taking the necessary steps in the future to be permitted to deliver recycled water for dual plumbed systems. The City would need to obtain the required permits and approvals prior to allowing customers to use recycled water for dual plumbed systems including: Regulatory permitting from the RWQCB, and Responsibilities of the City’s Chief Building Official to ensure compliance with specific Plumbing Code requirements, and Modifications to the City’s Procedures for Recycled Water Use ensuring that the City’s rules and regulations properly address dual plumbed uses. City of San Luis Obispo 2017 Recycled Water Master Plan 31 Chapter 5. Future Recycled Water Use for Landscape Irrigation In order to understand future recycled water demand for landscape irrigation, t his chapter discusses demand from pending projects, use of recycled water in specific plan areas, and high, medium and low priority retrofit opportunit ies and projects. Pending Projects/Approved Accounts The City and the Regional Water Quality Control Board have approved the use of recycled water at eleven locations. These projects are at various stages of construction or are existing properties that have submitted plans to retrofit irrigation systems to use recycled water. Table 7: Estimated Recycled Water Demand from Pending Projects Account/Property Address Projected Recycled Water Demand (Acre-Feet) Community Garden 11175 Los Osos Valley Road 0.5 Irish Hills Hamlet 11321-11359 Los Osos Valley Road 7 Calle Joaquin Park and Ride Calle Joaquin 1 Long Bonetti Ranch Public Market 3987 South Higuera / Tank Farm 5 Toscano Homes (4 meters) 3000 Calle Malva (meter locations on San Vicente and Arrezo) 10 Ironworks 3682-3684 Broad Street 5 Coast BMW 1251 Calle Joaquin 2.5 Homeless Services Center 40 Prado Road 2.5 Town Place Suites 1301 Calle Joaquin 2.5 Perry Ford 12200 Los Osos Valley Road 1 36-unit Affordable Housing Project 3175 Violet Street 2.5 Total: 39.5* Note: Projected recycled water demand is an estimate based on projected use, irrigated area, and previous use by similar properties. *Additional properties have been approved for recycled water use since the projection of 27.17 AF/year was made in Table 4. City of San Luis Obispo 2017 Recycled Water Master Plan 32 Use of Recycled Water in Specific Plan Areas The route of the City’s initial eight miles of recycled water pipe from the Water Reuse Project was selected to serve the developing portions of the City including the Margarita Area, the Orcutt Area, and the Airport Area (including Avila Ranch). The San Luis Ranch and Froom Ranch specific plan areas are also located proximate to the City’s existing recycled water distribution system. New development in these areas will be designed to use recycled water for irrigation rather than potable water. Although development in these areas may not occur for many years, the backbone distribution system has been planned to deliver recycled water to future development areas as the need develops. High-Priority Retrofit Projects As shown in Table 1, many existing recycled water customers were brought online by retrofitting existing irrigation systems for recycled water use. The City has provided funding for irrigation system retrofits in the past, however, due to completing priorities in the Water Fund, this funding was eliminated. The City requires existing potable water customers to retrofit their irrigation system to utilize recycled water when seeking a discretionary approval. The City has continued to see property owners seeking to retrofit their properties to use recycled water without reimbursement by the City. Customers may retrofit their properties for a variety of reasons including: Recycled water is not subject to most water conservation and drought regulations. Reduced rates for recycled water may provide a cost-benefit to transitioning from potable to recycled water for irrigation use. Social and environmental stewardship involved with reducing the demand for potable water. The identified high-priority projects would be considered with other projects for funding during the City’s Financial Plan process. The City’s 2017-19 Capital Improvement Plan proposes funding for a study related to additional recycled water storage. Retrofitted properties must follow the same procedures for recycled water use as newly constructed properties. Expansion of the recycled water system through retrofits remains a priority to the City as a method for expanding the beneficial use of recycled water. Appendix D describes 12 potential recycled water service/irrigation system retrofits. These projects are identified as “high priority” (or “high feasibility”) as they meet the following criteria: TABLE 8: Recycled Water Demand Estimate for Specific Plan Areas Specific Plan Area Projected Recycled Water Demand (Acre-Feet) Margarita Area 35 Orcutt Area 98 Airport Area* 139 San Luis Ranch 73 Froom Ranch 60 TOTAL: 405 Note: Projected recycled water demand is an estimate based on projected use, irrigated area, and previous use by similar properties. * Recycled water demand for the Avila Ranch project and the Chevron, Fiero Lane, and East Airport annexations areas are included in the Airport Area Specific Plan total. City of San Luis Obispo 2017 Recycled Water Master Plan 33 All locations have existing irrigation meters or could easily have a new meter installed. No new recycled water mains extensions or installations are required. Service locations are proximate to existing mains or could feasibly be relocated. Minor irrigation system modifications and signage installations would be necessary. The identified projects are highly desirable due to the amount of potable water offset that could be achieved, varying from approximately one-acre foot per year to over eight acre feet per year. The total potable water offset from the completion of these projects is over 63 acre-feet per year. A summary table and cost estimates is provided in Table 9 and project locations are shown on Figure 5. The average per acre foot cost for these high-priority retrofit projects is $3,764 per acre foot. Detailed maps and descriptions of projects can be found in Appendix D. City of San Luis Obispo 2017 Recycled Water Master Plan 34 Table 9: High-Priority Irrigation System Retrofit Projects Project # Address Customer/Common Name AF/Y Total AF/Y Cost/AF* 1.1 1490 Descanso Laguna Linda Homeowners 0.92 2.50 $12,480 1492 Prefumo Canyon Prefumo Canyon Estates 0.50 1496 Prefumo Canyon Prefumo Canyon Estates 0.28 1445 Prefumo Canyon Laguna Green Home Assoc 0.80 1.2 1106 Oceanaire Windermere Homeowners 1.15 2.53 $6,166 11295 Los Osos Valley Cedarwood Inc. / HOA 1.38 1.3 1704 Tonini (1) De Tolosa Ranch 1.84 3.67 $3,433 1704 Tonini (2) De Tolosa Ranch 1.84 1.4 1778 Tonini Rancho Obispo Properties 3.44 4.59 $3,399 2000 Devaul Ranch Rancho Obispo HOA 1.15 1.5 1433 Calle Joaquin Motel 6 1.15 1.15 $6,261 1.6 1585 Calle Joaquin Rose Garden Inn 2.30 4.59 $3,573 1625 Calle Joaquin Motel 6 2.30 1.7 210 Margarita SLO Non Profit Housing 0.69 8.95 $2,011 200 Via San Blas Margarita Villa Association 2.75 210 Via San Blas Margarita Villa Association 2.07 280 Via La Paz Margarita Villa Association 2.07 285 Via La Paz Margarita Villa Association 1.38 1.8 711 Tank Farm Tank Farm Properties 1.38 3.44 $5,930 715 Tank Farm Tank Farm Properties 0.46 735 Tank Farm Edna Valley Office BLDG 1.61 1.9 899 Columbine REG/Santa Lucia Hills 3.10 8.41 $3,424 945 Tank Farm L-B City of San Luis Obispo 1.15 946 Tank Farm L-A Willowbrook II HOA 2.98 944 Felicia Willowbrook II HOA 1.18 1.10 1096 Sunrose REG/Willowcreek HOA 2.07 8.38 $3,437 1024 Tank Farm SLO Parks 0.11 949 Bluebell Summerhills HOA 4.13 1055 Bluebell Summerhills HOA 2.07 1.11 1102 Ironbark Islay Hills Associates 1.19 6.47 $3,617 1223 Manzanita Islay Pointe HOA 1.72 1280 Chaparral Islay Pointe HOA 3.56 1.12 3590 Broad Broad St Owners Assoc 1.73 8.49 $2,332 3588 Broad Broad St Community Assoc 5.05 3586 Broad Sacramento Owners Assn 1.71 Total High Priority Retrofit AF: 63.18 $3,764 NOTE: Cost information is summarized in Table 12 and detailed in Appendix D. The Project #s included in the table are for identification purposed only and are not intended to suggest project prioritization. SOURCE: City of San Luis Obispo, Utilities Department, 2017. City of San Luis Obispo 2017 Recycled Water Master Plan 35 City of San Luis Obispo 2017 Recycled Water Master Plan 36 Page Intentionally Left Blank City of San Luis Obispo 2017 Recycled Water Master Plan 37 Medium-Priority Irrigation System Retrofit Projects This section describes nine potential retrofit projects to expand recycled water use for landscape irrigation. These projects are identified as “medium priority,” or “medium feasibility,” as they meet the following criteria: All locations have existing irrigation meters or could have an irrigation meter installed New recycled water main extensions are required Service locations are proximate to existing recycled water mains or the service location could be relocated Irrigation system modifications and signage installations would be necessary. The identified projects are desirable due to the amount of potable water offset that could be achieved, varying from approximately 2.66 acre-feet per year to over 36 acre-feet per year. The total offset from existing potable water usage for these projects is estimated at 89 acre-feet per year. A summary table and cost estimates can be viewed in Table 11, all locations are shown on Figure 4. Detailed maps and descriptions of these medium-priority projects are provided in Appendix E. City of San Luis Obispo 2017 Recycled Water Master Plan 38 Table 10: Medium Priority Irrigation System Retrofit Projects Project # Address Customer/Common Name AF/Y Total AF/Y Cost/AF* 2.1 11491 Los Osos Valley Pathpoint/Old SESLOC 0.55 2.85 $5,474 1351 Royal The Pines HOA 2.30 2.2 1375 Balboa CL Smith Elementary School 10.32 10.34 $25,706 2.3 90 Encanto Los Verdes II 1.15 6.26 $29,808 20 Perla Los Verdes II 1.61 50 El Mirador Los Verdes II 1.55 51 El Mirador Los Verdes II 1.95 2.4* 4021 Broad Ottano Shell Station 1.26 2.66 $115,940 651 Tank Farm Mindbody 1.4 2.5* 892 Aerovista Aerovista LLC 1.03 5.62 $166,612 895 Aerovista Aeroloop LLC 4.59 2.6 1211 Ironbark Islay Hill Owners 2.47 8.62 $57,285 1341 Purple Sage L-B Rodriguez Adobe Park 3.49 4600 Spanish Oaks Islay Hill Owners 2.66 2.7* 3510 Broad IOMG Inheritence LLC 0.40 5.73 $24,817 3550 Broad Broad & Capitolio LLC 2.00 775 Capitolio Level 3 Communications 3.33 2.8* 803 Basil Avivo HOA 3.44 10.79 $41,928 805 Bay Leaf Tumbling Waters INC 2.75 3280 Sacramento Four Creeks 4.59 2.9* 1102 Laurel Andre Morris & Buttery 0.95 36.12 $17,488 1150 Laurel ESCORP 3.44 904 Southwood (Field) Sinsheimer Baseball Fields 8.03 2550 Blvd Del Campo Sinsheimer Park Bike Path 0.73 904 Southwood (Park) Sinsheimer Park 6.89 2800 Augusta Johnson Park 4.82 1045 Southwood Parkwood Village HOA 4.59 1198 Bedford Laurelwood HOA 1.38 2755 Augusta Sinsheimer Elementary 5.28 Total Medium Priority Retrofit AF: 88.98 NOTE: Cost information is summarized in Table 12 and detailed in Appendix E. The Project #s included in the table are for identification purposed only and are not intended to suggest project prioritization. * Portions of identified projects may be constructed with orderly development and may require prior completion of other projects to be feasible. SOURCE: City of San Luis Obispo, Utilities Department, 2017. City of San Luis Obispo 2017 Recycled Water Master Plan 39 City of San Luis Obispo 2017 Recycled Water Master Plan 40 Page Intentionally Left Blank City of San Luis Obispo 2017 Recycled Water Master Plan 41 Low Priority Irrigation System Retrofit Projects Through the examination of potential recycled water customers within the city limits, staff identified 50 existing accounts that were deemed “low-priority” or “low-feasibility” for connecting to the recycled water system. Many of these properties encountered one or a combination of the following factors which influenced their placement as low priority/feasibility projects. Low projected recycled water demand Lack of existing irrigation meter separate from domestic meter Requirement of significant capital to finance extensive main line installations Needed additional research/information to inform placement While these properties are currently low-priority/feasibility, the continued extension of recycled water lines may increase feasibility of certain projects over time. Staff will reevaluate the feasibility and likelihood of connecting future accounts as the recycled water system is expanded. Table 11: Low-Priority Irrigation System Retrofit Projects Project # Address Customer/Common Name AF/Y Total AF/Y 3.1 1451 Diablo - A Clearview HOA 1.15 2.30 1451 Diablo - B Clearview HOA 1.15 3.2 1750 Prefumo Canyon La Canada Village 4.59 5.02 1098 Isabella Prefumo Creek HOA 0.42 3.3 1274 Laguna Laguna Shores 0.69 3.16 1330 Vista Lago Laguna Shores 0.57 1269 Vista Lago City of San Luis Obispo 0.57 1267 Vista Lago Laguna Shores 0.17 1220 Vista Lago Laguna Shores 1.15 3.4 1551 Froom Ranch Home Depot 0.80 0.80 3.5 4280 Higuera S Housing Authority 0.92 0.92 3.6 3765 Higuera S Hind Properties 0.00 0.05 3650 Higuera S Eagles 0.05 3.7 3595 Higuera S Wayne's tires 0.01 0.76 3566 Higuera S Coastal Peaks Coffee 0.23 3536 Higuera S Fiduciary Properties 0.11 3583 Higuera S Gary Heon 0.02 3577 Higuera S Big Brand Tire 0.04 3547 Higuera S Tract 1399 Homeowners 0.34 3.8 145 Prado Easy Ad 0.11 0.11 3433 Higuera S County of San Luis Obispo 0.00 183 Prado Wightons 0.00 3.9 2885 Higuera S Cal Trans 1.55 1.55 City of San Luis Obispo 2017 Recycled Water Master Plan 42 Project # Address Customer/Common Name AF/Y Total AF/Y 3.10 1800 El Mercado Madonna Plaza SRT LP 4.82 5.97 201 Madonna Madonna Plaza SRT LP 1.15 3.11 2275 King Meadow Park 11.94 25.02 2331 Meadow Meadow Park 12.63 2333 Meadow Meadow Park Garden 0.46 3.12 4111 Broad Alan Mcvay 0.06 0.20 4115 Broad Alan Mcvay 0.14 4119 Broad Alan Mcvay 0.00 3.13 4420 Broad Pepper tree business park 0.26 1.64 943 Ambrosia Willows at Islay Hill 0.46 986 Fuller HOA of Stonecreek DEV 0.92 3.14 4005 Poinsettia Willowbrook I HOA 0.57 1.49 4035 Poinsettia Edna-Islay Housing Corp 0.92 3.15 1170 Poppy Santa Lucia Hills HOA 0.69 3.27 1074 Yarrow Santa Lucia Hills HOA 2.30 4662 Poinsettina -A City of San Luis Obispo 0.29 3.16 3362 Rockview Quaglino Properties 1.03 2.76 3340 Rockview Ridgepoint H/O Assoc 1.15 3240 Broad Dan Lemburg (Subway Complex) 0.24 3230 Broad Dan Lemburg (Thai Boat Complex) 0.34 3.17 3212 Broad Village Marketplace (Lemos) 0.63 6.23 3180 Broad Chevron Sta - Site 81341 0.23 3165 Broad Michael Hook 0.09 3050 Broad Chevron USA INC 1.10 781 Mutsuhito Rosa Homeowners Assn 4.18 3.18 3003 Rockview Jack Foster 0.14 0.98 2975 Rockview Rockview Heights 0.84 Total Low Priority 62.22 NOTE: The Project #s included in the table are for identification purposed only and are not intended to suggest project prioritization. SOURCE: City of San Luis Obispo, Utilities Department, 2017. City of San Luis Obispo 2017 Recycled Water Master Plan 43 Chapter 6. Recycled Water Storage Future recycled water demand for landscape irrigation is approximately 800 acre-feet per year. This chapter discusses storage necessary to meet anticipated daily recycled water deliveries and summarizes the Recycled Water Storage Analysis prepared by Wallace Group. The complete memorandum is provided in Appendix C. Incremental expansion of the City’s recycled water storage will be necessary to supply this level of recycled water demand. To minimize operation and maintenance costs, the City’s recycled water distribution system is designed with one pressure zone. As part of the City’s Water Reuse Project completed in 2006, a 600,000-gallon underground storage tank was constructed at the WRRF to provide storage for the recycled water distribution system. The usable storage volume is approximately 500,000 gallons. The 2004 Master Plan concluded that this existing storage volume could supply approximately 320 acre feet per year. As part of the storage evaluation, Wallace Group reviewed the 2004 RWMP to confirm assumptions and hydraulic parameters compared to current data. It is evident that several 2004 assumptions have changed over the past 12 years; findings include: Actual irrigation demands are 30 to 35 percent less than projected in 2004. Overall demand, including average-day demand and peak-day demand, are somewhat lower than anticipated in 2004. Peak hour demand for recycled water is at or near the 2004 RWMP projections. Historically, the City generally operated the distribution system at 133 psi at the pumping station, which corresponds to a hydraulic grade line of 432 feet above mean sea level. More recently, the operating pressure set point was reduced to 125 psi (410 feet) to help control hydraulics and pressure fluctuations in the delivery system. The Storage Analysis recognizes key factors related to WRRF operations and the upcoming WRRF project. As part of their work on the RWFPS, WSC prepared a recycled water production analysis which concluded that currently the WRRF was limited in recycled water production by availability of secondary effluent, estimated to be 1.5 mgd to 1.9 mgd. However, the reliability of delivering such effluent during summer demand was seen to diminish below 90 pe rcent when demands ranged from 1.0 mgd to 1.4 mgd. When the WRRF improvements are completed in Year 2021, all effluent, minus the 1.6 mgd creek discharge required by NOAA NMFS, will be available for recycled water production. This flow will not be available at a constant flow rate. The WRRF project was designed to treat 5.4 mgd to serve General Plan buildout. As part of the storage evaluation, Wallace Group evaluated recent supply and demand information. This includes the City's population and flow data planned as part of the City's WRRF Project, slated for completion in Year 2021. The storage analysis is based on the following: City of San Luis Obispo 2017 Recycled Water Master Plan 44 • Recycled water demand will occur within an irrigation window between 11 pm and 6 am. Incidental demands for construction water will occur during the day. • Future daily recycled water demand uses the same trend curve as existing daily recycled water demand through the daily irrigation period. • WRRF Production rates will be assumed to follow a typical municipal diurnal curve. The analysis evaluated both storage volume and demand to identify when the City would need additional recycled water storage. Four scenarios were analyzed to simulate maximum daily demand through the irrigation period for 2016, 2018, 2019 and 2036. The chart below illustrates estimated recycled water production at the WRRF, recycled water supplied for irrigation, and recycled water storage volume for a 24-hour period in the year 2018. The Wallace Group recommends additional storage be constructed when annual recycled water demand reaches 300 acre-feet, and notes that by providing additional 1.36 million gallons of storage for a total of 1.96 million gallons of storage, the City can meet summer peak day demands under buildout conditions. Additional storage will be included in the Capital Improvement Plan provided in Chapter 7. The City’s desire is that future storage continue to be integrated into the existing recycled water distribution system to minimize necessary maintenance. The Wallace Group analyzed the following sites for additional recycled water storage including repurposing existing facilities within the WRRF (approximately 1.36 million gallons), repurposing the existing potable water Islay Tank (a 400,000 gallon tank south of Tank Farm Road), construction of a “sister” tank next to the existing recycled water storage tank, locating an elevated storage tank adjacent to the Froom Ranch project, and locating an elevated storage tank off of Higuera Street east of the cemetery. A study phase of a recycled water storage project is proposed as part of the 2017-19 Capital Improvement Plan to provide further analysis of storage tank options. A review of the existing pump station may be conducted while considering the future recycled water storage options. Recycled Water Storage Analysis Memorandum, Figure 8, 2018 Production, Outflow and Cumulative Storage Volume. City of San Luis Obispo 2017 Recycled Water Master Plan 45 Chapter 7. Capital Improvement Plan Past Capital Investment When recycled water deliveries began in 2006, it was the City’s first new water supply since deliveries from Whale Rock Reservoir began in the 1960s. In the City’s 2003-05, 2005-07, 2007-09 and 2009-11 Financial Plans, annual funding of $250,000/year was identified from the Water Fund Capital Improvement Plan (CIP) for expansion of the recycled water distribution system and to reimburse customers who re trofitted irrigation systems to use recycled water. This funding was utilized for the retrofit of five City parks irrigation systems, user site improvements at Laguna Middle School, Los Verdes I and De Tolosa Homes, and the extension of the recycled water distribution system on Broad Street, South Higuera Street and Margarita Street. In the 2011-13 Financial Plan, with limited available revenue, the Water Fund CIP focused on debt repayment and replacement of aged potable water infrastructure and facilities. This was the City’s continued focus in the 2013-15 Financial Plan. In the past, the Utilities Department has applied for grant funding through the Integrated Regional Water Management (IRWM) funds and will pursue additional grant opportunities in the futu re as available. Future Capital Investment This chapter presents a capital improvement plan for future expansion of the City’s recycled water distribution system. The capital plan summarizes improvements, cost estimates, and establishes phasing of projects through the 2035 planning horizon. The purpose of this capital plan is to provide the City with a guideline for the planning and budgeting of future improvements to the recycled water distribution system. This capital plan is based on the evaluation of the projects described in Chapter 6 and Appendices C and D. These include: Recycled water storage Recycled water distribution system and retrofit projects All project costs are in 2016 dollars. Treatment improvements required for maximum recycled water production are identified in the City’s Water Resource Recovery Facility Facilities Plan from June of 2015. Capital investment is required to expand the City’s recycled water distribution system to establish a reliable recycled water supply for existing and new recycled water customers through year 2035. Figures 5 and 6 show distribution system expansions, with corresponding identification number (IDs) shown in Table 9 and 10. As presented in Table 12, the improvements total approximately $5.25 million dollars. The City is planning to expand its recycled water distribution system , where appropriate, to continue offsetting potable water demands and improve the City’s overall water supply resiliency. To define and prioritize the capital improvement projects needed to achieve this goal, City of San Luis Obispo 2017 Recycled Water Master Plan 46 the City worked with the Wallace Group on modelling the future recycled water distribution system and to identify potential locations for future recycled water storage tanks. Planning level project costs were developed and include estimated costs of engineering design, construction, construction management and inspection, and contingencies. Recycled Water Distribution System Projects Construction costs for extending the recycled water distribution system includ e pipe material, excavation, installation, bedding material, backfill material, transport, and paving where applicable. Valves and appurtenances are included in the cost estimate. The costs of acquiring easements for pipeline construction are not included in this estimate, although most distribution pipeline routings are within existing City street right-of-way. Cost estimates for pipeline construction were based on unit costs from the Wallace Group for the water pipelines within the City. Pipeline capital costs for 8-inch and smaller pipelines was estimated to be $200 per linear foot (LF), 10-inch to 18-inch pipelines to be $300/LF. Irrigation System Retrofit Project Cost Estimates New service connections are required for serving recycled water from the di stribution pipelines to customer properties. Items included in the connection cost are: abandonment of existing potable services, tapping the recycled water distribution mains and installing service laterals, meters, pressure reducing valves (PRVs), and a backflow prevention device on the property’s potable water system. It is assumed that the average size for laterals, meters, and PRVs will be two-inch. Service connection costs are estimated to be $4,000 each. Irrigation system retrofit costs are associated with separating the customer’s existing water system from a new recycled water system. An example would be a park where restroom and drinking fountain water supply pipes would need to be isolated from an existing irrigation system. Additional costs include posting signs that identify recycled water is being used. Customer retrofits are one-time costs and are a function of existing irrigation systems at each individual site. Retrofits for most customers were estimated to range from $1,500 to $2,500 based on the extent of necessary irrigation modifications. If the site has existing separate landscape irrigation service, then the retrofit cost is assumed to be on the low-end of that range. City of San Luis Obispo 2017 Recycled Water Master Plan 47 Table 12: Recycled Water Capital Plan Project # Project Estimated Cost Phasing Recycled Water Storage Project S-1 Recycled Water Storage – Study Phase $50,000 2017-19 S-2 Recycled Water Storage – Design Phase $250,000 2019-21 S-3 Recycled Water Storage – Construction Phase $1,250,000 2021-23 Recycled Water Storage Project Total $1,550,000 High Priority Irrigation System Retrofit Projects 1.1 Los Osos Valley Road / Descanso $31,200 2017-25 1.2 Los Osos Valley Road / Oceanaire $15,600 1.3 Los Osos Valley Road / Madonna $12,600 1.4 Los Osos Valley Road / DeVaul Ranch $15,600 1.5 Calle Joaquin (1400 Block) $ 7,200 1.6 Calle Joaquin (1500-1600 Block) $16,400 1.7 Margarita (200 Block) $18,000 1.8 Tank Farm / Broad $20,400 1.9 Tank Farm / Columbine / Felecia $28,800 1.10 Tank Farm / Sunrose / Bluebell $28,800 1.11 Tank Farm / Chaparral $23,400 1.12 Broad (3500 Block) $19,800 High Priority Irrigation System Retrofit Projects Total $237,800 Medium Priority Irrigation System Retrofit Projects 2.1 Los Osos Valley Road / Royal $15,600 2025-35 2.2 Main Extension to CL Smith $265,800 2.3 Los Osos Valley Road / South Higuera $186,600 2.4* Tank Farm west of Broad Street $308,400 2.5* Broad Street south of Tank Farm Road $936,360 2.6 Brookpine/Purple Sage $493,800 2.7* Capitolio Extension $142,200 2.8* Capitolio/Sacramento $452,400 2.9* Sinsheimer Extension $667,500 Medium Priority Irrigation System Retrofit Projects Total $3,468,660 NOTE: * Portions of identified projects may be constructed with orderly development and may require prior completion of other projects to be feasible. SOURCE: City of San Luis Obispo, Utilities Department, 2017. City of San Luis Obispo 2017 Recycled Water Master Plan 48 Documents Referenced City of San Luis Obispo a. Municipal Code http://www.codepublishing.com/CA/SanLuisObispo/#!/SanLuisObispo13/SanLuisObispo 1324.html b. General Plan Land Use Element, 2014. http://www.slocity.org/home/showdocument?id=6635w Water and Wastewater Management Element, 2016. c. Climate Action Plan, August 2012 http://www.slocity.org/home/showdocument?id=4086 d. Urban Water Management Plan, 2015 http://www.slocity.org/home/showdocument?id=13618 e. Water Resource Recovery Facility Project, Final Environmental Impact Report (SCH2015101044), July 2016. http://www.slocity.org/Home/ShowDocument?id=10532 f. Water Reuse Master Plan, Dudek and Associates, 2004. City of San Luis Obispo 2017 Recycled Water Master Plan A-1 Appendix A. Recycled Water Facilities Planning Study City of San Luis Obispo 2017 Recycled Water Master Plan A-2 DRAFT Final Draft Recycled Water Facilities Planning Study Prepared for the City of San Luis Obispo Prepared Under the Responsible Charge of: Jeffery Szytel, P.E. 1/19/2017 June 30, 2018 DRAFTCity of San Luis Obispo 0. Acknowledgements Recycled Water Facilities Planning Study - Final Draft i 1/19/2017 ACKNOWLEDGEMENTS The Recycled Water Facilities Planning Study for the City of San Luis Obispo was [action taken TBD] by the San Luis Obispo City Council on [date TBD]. Heidi Harmon, Mayor Dan Rivoire, Vice Mayor Carlyn Christianson, Council Member Aaron Gomez, Council Member Andy Pease, Council Member Jan Marx, Former Mayor Dan Carpenter, Former Vice Mayor John Ashbaugh, Former Council Member The Study was prepared by Water Systems Consulting, Inc., and its subconsultants, HDR, Inc. and Cleath- Harris Geologists. The primary authors are listed below. Water Systems Consulting, Inc. HDR, Inc. Emily Iskin, EIT Mike Falk, PE, PhD Jeffery Szytel, PE, MS, MBA Holly Kennedy, PE Lianne Westberg, PE, MS, CEM Ron Munds Cleath-Harris Geologists, Inc. Joshua Reynolds, PE Timothy Cleath, PG, CHG, CEG Laine Carlson, PE Jasmine Diaz, Grade V WWTP Operator, EIT Water Systems Consulting, Inc. would like to acknowledge the significant contributions of the following City of San Luis Obispo staff: Carrie Mattingly Howard Brewen, Grade V Operator (Wastewater) Dave Hix Dean Furukawa, Grade V Operator (Water) Aaron Floyd Chris Lehman, Grade V Operator (Wastewater) Jennifer Metz David Yun Mychal Boerman Miguel Barcenas, PE Funding for this project has been provided in full or in part through an agreement with the State Water Resources Control Board. The contents of this document does not necessarily reflect the views and policies of the State Water Resources Control Board, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. DRAFTCity of San Luis Obispo 0. Table of Contents Recycled Water Facilities Planning Study - Final Draft ii 1/19/2017 TABLE OF CONTENTS Acknowledgements ........................................................................................................................................ i Table of Contents .......................................................................................................................................... ii List of Tables ................................................................................................................................................. v List of Figures ............................................................................................................................................... vi List of Terms, Acronyms, and Abbreviations .............................................................................................. vii 1 Executive Summary ............................................................................................................................... 1 Recycled Water Alternatives ......................................................................................................... 1 Alternatives Analysis ..................................................................................................................... 2 Results and Recommendations ..................................................................................................... 3 Implementation Plan .................................................................................................................... 4 Edna Valley Irrigation Area Project ....................................................................................... 4 Potable Reuse Project ........................................................................................................... 5 2 Introduction .......................................................................................................................................... 7 Study Area ..................................................................................................................................... 7 Related Recycled Water Initiatives ............................................................................................. 10 Goals and Objectives of This Study ............................................................................................. 13 3 Water Supply and Characteristics ....................................................................................................... 14 Water Supply ............................................................................................................................... 16 Water Demand ............................................................................................................................ 19 Water Pricing .............................................................................................................................. 20 4 Wastewater Characteristics and Facilities .......................................................................................... 21 Existing Facilities ......................................................................................................................... 21 Waste Discharge Requirements .......................................................................................... 24 Future Facilities ........................................................................................................................... 25 5 Treatment Requirements .................................................................................................................... 27 Treatment Requirements for IPR and DPR Projects ................................................................... 30 6 Recycled Water Market and Opportunities ........................................................................................ 32 Market Analysis Update .............................................................................................................. 32 Stakeholder Outreach ................................................................................................................. 36 7 Project Alternatives Analysis ............................................................................................................... 37 Alternative 1: Deliver Recycled Water to Agricultural Customers in the Edna Valley Irrigation Area 38 Background ......................................................................................................................... 38 DRAFTCity of San Luis Obispo 0. Table of Contents Recycled Water Facilities Planning Study - Final Draft iii 1/19/2017 Description and Analysis ..................................................................................................... 38 Preliminary Cost Estimate ................................................................................................... 42 Advantages and Disadvantages .......................................................................................... 43 Alternative 2: Deliver Recycled Water to Cal Poly ...................................................................... 45 Background ......................................................................................................................... 45 Description and Analysis ..................................................................................................... 45 Preliminary Cost Estimate ................................................................................................... 47 Advantages and Disadvantages .......................................................................................... 48 Alternative 3: Groundwater Recharge in the San Luis Obispo Valley Groundwater Basin for Indirect Potable Reuse ............................................................................................................................ 49 Background ......................................................................................................................... 49 Preliminary Hydrogeological Assessment of Groundwater Recharge with Recycled Water 50 Description and Analysis ..................................................................................................... 52 Preliminary Cost Estimate ................................................................................................... 54 Advantages and Disadvantages .......................................................................................... 56 Alternative 4: Provide Direct Potable Reuse (DPR) ..................................................................... 57 Background ......................................................................................................................... 57 Description and Analysis ..................................................................................................... 57 Preliminary Cost Estimate ................................................................................................... 59 Advantages and Disadvantages .......................................................................................... 61 Alternative 5: Construct a New Satellite WRRF to Serve Cal Poly and the Surrounding Areas .. 62 Background ......................................................................................................................... 62 Description and Analysis ..................................................................................................... 64 Preliminary Cost Estimate ................................................................................................... 67 Advantages and Disadvantages .......................................................................................... 67 No Project Alternative ................................................................................................................. 68 Alternative Summary .................................................................................................................. 68 Alternative Assessment Process ................................................................................................. 68 Alternatives Screening and Evaluation Results ........................................................................... 69 8 Recommended Facilities Project Plan ................................................................................................. 73 Deliver Recycled Water to the Edna Valley Irrigation area ......................................................... 73 Potable Reuse: Indirect and Direct Reuse ................................................................................... 74 9 Implementation Plan .......................................................................................................................... 75 Edna Valley Irrigation Area Project ............................................................................................. 75 DRAFTCity of San Luis Obispo 0. Table of Contents Recycled Water Facilities Planning Study - Final Draft iv 1/19/2017 Implementation Schedule ................................................................................................... 75 Estimated Project Cost ........................................................................................................ 75 Permitting Requirements .................................................................................................... 76 Environmental Documentation ........................................................................................... 76 Coordination and Governance ............................................................................................ 76 Potable Reuse Project ................................................................................................................. 76 Implementation Schedule ................................................................................................... 76 Estimated Project Cost ........................................................................................................ 78 IPR Hydrogeological Analysis .............................................................................................. 78 Permitting Requirements .................................................................................................... 78 Environmental Documentation ........................................................................................... 79 Coordination and Governance ............................................................................................ 79 10 Financing Plan ..................................................................................................................................... 80 Funding Opportunities ................................................................................................................ 80 Grant and Loan Programs ............................................................................................... 80 Partnerships .................................................................................................................... 80 11 References .......................................................................................................................................... 82 Appendix A. Recycled Water Production Analysis ........................................................................................ A Appendix B. WRRF NPDES Permit and TSO ................................................................................................... B Appendix C. Recycled Water Treatment Requirements ............................................................................... C Appendix D. Water Reuse Permit ................................................................................................................. D Appendix E. Cost Estimating Assumptions and Methodology ...................................................................... E Appendix F. Alternatives Screening Criteria ................................................................................................. F Appendix G. The Edna Valley Irrigation Area Growers White Paper ........................................................... G Appendix H. Preliminary Cost Estimates and Implementation Timeline Technical Memorandum .............H Appendix I. Cleath-Harris Geologists Technical Memorandum ..................................................................... I DRAFTCity of San Luis Obispo 0. List of Tables Recycled Water Facilities Planning Study - Final Draft v 1/19/2017 LIST OF TABLES Table 1. Alternatives Summary Table ........................................................................................................... 4 Table 2. Edna Valley Irrigation Area Project Implementation Schedule ....................................................... 5 Table 3. Indirect Potable Reuse Implementation Schedule .......................................................................... 6 Table 4. Previous City Recycled Water Reports .......................................................................................... 12 Table 5. 2015 Actual Water Supplies (3 pp. 4-7) ........................................................................................ 16 Table 6. Projected Water Supplies (3 pp. 4-7) ............................................................................................ 16 Table 7. Water Supply Reliability ................................................................................................................ 17 Table 8. Supply and Demand Comparison for a Normal Year (3 pp. 6-4) ................................................... 19 Table 9. 2011-2015 Recycled Water Usage (3 pp. 5-2) ............................................................................... 19 Table 10. Current Water and Sewer Rates in San Luis Obispo ................................................................... 20 Table 11. Peaking Factors for Historical Flows............................................................................................ 21 Table 12. Effluent Limitations for Discharge Point 001 .............................................................................. 24 Table 13. Basin Plan Water Quality Objectives ........................................................................................... 28 Table 14. City of San Luis Obispo Recycled Water Customers .................................................................... 32 Table 15. 2015 Recycled Water Users ........................................................................................................ 33 Table 16. Potential Total Future Recycled Water Use (3 pp. 5-5) .............................................................. 34 Table 17. Background and Peak Recycled Water Delivery to Edna Based on Historical Data .................... 40 Table 18. Maximum Recycled Water Delivery to Edna Based on Distribution System Capacity Limits ..... 41 Table 19. Alternative 1: Preliminary Cost Estimate .................................................................................... 43 Table 20. Alternative 2: Layout 3 Preliminary Cost Estimate ..................................................................... 48 Table 21. Alternative 3: Preliminary Cost Estimate .................................................................................... 55 Table 22. Alternative 4: Preliminary Cost Estimate .................................................................................... 60 Table 23. Alternative 5: Preliminary Cost Estimate .................................................................................... 67 Table 24. Alternatives Summary Table ....................................................................................................... 68 Table 25. Alternatives Screening Results .................................................................................................... 70 Table 26. The Edna Valley Irrigation Area Project Implementation Schedule ............................................ 75 Table 27. Edna Valley Irrigation Area Project Implementation Cost Estimate, including escalation to mid- point of construction .................................................................................................................................. 76 Table 28. Indirect Potable Reuse Implementation Schedule ...................................................................... 77 Table 29. Potable Reuse Project Implementation Cost Estimate, including escalation to the mid-point of construction ................................................................................................................................................ 78 Table 30. Eligible Funding Programs ........................................................................................................... 81 DRAFTCity of San Luis Obispo 0. List of Figures Recycled Water Facilities Planning Study - Final Draft vi 1/19/2017 LIST OF FIGURES Figure 1. Recycled Water Facilities Planning Study Areas ............................................................................ 8 Figure 2. Recycled Water Area and Distribution (5 pp. 8-25) ....................................................................... 9 Figure 3. City of San Luis Obispo Water Supply (3 pp. 2-5) ......................................................................... 15 Figure 4. 2015 Recycled Water Supply and Demand, 2015 (7)................................................................... 18 Figure 5. WRRF Process Flow Schematic (1) ............................................................................................... 23 Figure 6. WRRF Project Draft Civil Site Plan ................................................................................................ 26 Figure 7. Recycled Water Treatment Requirements .................................................................................. 29 Figure 8. Seasonal Recycled Water Demand Pattern ................................................................................. 35 Figure 9. Pipeline Extension to City Limits .................................................................................................. 39 Figure 10. Maximum Recycled Water Delivery to The Edna Valley irrigation area Growers ..................... 41 Figure 11. Alternative 2 Pipeline Alignment ............................................................................................... 46 Figure 12. Map of San Luis Obispo Valley Groundwater Basin (14) ........................................................... 51 Figure 13. Aerial Schematic of the Indirect Potable Reuse Groundwater Recharge Location ................... 51 Figure 14. Process Flow Schematic Considered for Indirect Potable Reuse ............................................... 53 Figure 15. Pathogen Log Reduction Credits Potential with the Process Flow Schematic Considered for Indirect Potable Reuse (Target is 12/10/10 for Virus/Crypto/and Giardia, respectively) (Adapted from (15)) .................................................................................................................................................................... 53 Figure 16. Process Flow Schematic Considered for Direct Potable Reuse .................................................. 58 Figure 17. Pathogen Log Reduction Credits Potential with the Process Flow Schematic Considered for Direct Potable Reuse (Target is 12/10/10 for Virus/Crypto/and Giardia, respectively) (Adapted from (15)) .................................................................................................................................................................... 58 Figure 18. Potential Satellite WRRF Siting Location at Cal Poly .................................................................. 62 Figure 19. Engineered Hydroponic System Technology Schematic for a Satellite WRRF ........................... 63 Figure 20. MBR Technology Schematic for a Satellite WRRF ...................................................................... 64 Figure 21. Process Flow Schematic for a Satellite WRRF Membrane Bioreactor ....................................... 64 Figure 22. Alternatives Screening Criteria and Results Table ..................................................................... 71 DRAFTCity of San Luis Obispo 0. List of Terms, Acronyms, and Abbreviations Recycled Water Facilities Planning Study - Final Draft vii 1/19/2017 LIST OF TERMS, ACRONYMS, AND ABBREVIATIONS Below is the list of abbreviations found in this report and their definitions, in alphabetical order. Abbreviation Definition (X pp. Y-W) Reference X, page Y-W ACOE Army Corps of Engineers AFY Acre feet per year AOP Advanced oxidation processes ATC Authority to Construct AWWA American Water Works Association BAC Biologically active carbon filtration B Boron Basin Plan Water Quality Control Plan for the Central Coast Basin Cal Poly California Polytechnic State University, San Luis Obispo CDFW California Department of Fish and Wildlife CEC California Energy Commission CEQA California Environmental Quality Act cfs Cubic feet per second CHG Cleath-Harris Geologists City City of San Luis Obispo Cl Chlorine DAC Disadvantaged community DAFT Dissolved air floatation thickener DBPs Disinfection byproducts DDW State Water Resources Control Board, Division of Drinking Water DPR Direct potable reuse DWR California Department of Water Resources EA Environmental Assessment EHS Engineered hydroponic system EIR Environmental Impact Report EIS Environmental Impact Statement EPA Environmental Protection Agency FAT Full advanced treatment Gpcd Gallons per capita per day GSA Groundwater Sustainability Agency GSP Groundwater Sustainability Plan gpm Gallons per minute IPR Indirect potable reuse IRWM Integrated Regional Water Management IS Initial Study DRAFTCity of San Luis Obispo 0. List of Terms, Acronyms, and Abbreviations Recycled Water Facilities Planning Study - Final Draft viii 1/19/2017 IWA International Water Association MBR Membrane bioreactor MF Microfiltration MGD Million gallons per day MHI Median household income Na Sodium NDMA N-Nitrosodimethylamine NEPA National Environmental Policy Act NOAA NMFS National Oceanic Atmospheric Association, National Marine Fisheries Service NPDES National Pollutant Discharge Elimination System O&M Operation and maintenance PCE Tetrachloroethylene Production Analysis Recycled Water Production Analysis psi Pounds per square inch PTO Permit to Operate RO Reverse osmosis RDT Rotary drum thickener RW Master Plan 2004 Water Reuse Master Plan RWC Recycled Water Concentration RWQCB Regional Water Quality Control Board SCADA Supervisory Control and Data Acquisition SGMA Sustainable Groundwater Management Act SNMP Salt and Nutrient Management Plan SO4 Sulfate Study Recycled Water Facilities Planning Study SWRCB State Water Resources Control Board TDS Total Dissolved Solids THMs Trihalomethanes TSO Time Schedule Order UF Ultrafiltration USBR United States Bureau of Reclamation USDA United States Department of Agriculture USFWS United States Fish and Wildlife Service UV Ultraviolet UWMP Urban Water Management Plan WDR Water Discharge Requirement WRR Water Reclamation Requirement WRRF Water Resource Recovery Facility WSC Water Systems Consulting, Inc. WWME Water and Wastewater Management Element DRAFTCity of San Luis Obispo 1. Executive Summary Recycled Water Facilities Planning Study - Final Draft 1 1/19/2017 1 EXECUTIVE SUMMARY The City of San Luis Obispo (City) hired Water Systems Consulting, Inc. (WSC) to conduct this Recycled Water Facilities Planning Study (Study) to investigate alternatives for maximizing the long-term beneficial use of the City’s recycled water supply. The City owns and operates a Water Resource Recovery Facility (WRRF) that treats municipal wastewater flow from the City, California Polytechnic State University, San Luis Obispo (Cal Poly), and the San Luis Obispo County Airport. Tertiary treated and disinfected effluent is either distributed for landscape irrigation and construction uses, or dechlorinated and discharged to San Luis Obispo Creek. Between 2009 and 2014, the City’s WRRF treated approximately 3.9 million gallons of wastewater per day (MGD) of average annual flow including contributions from Cal Poly (1). This equates to approximately 4,400 acre-feet per year (AFY). The WRRF is required to maintain a minimum daily average year-round discharge of 2.5 cubic feet per second (cfs) of treated effluent to San Luis Obispo Creek, which equals approximately 1.6 MGD or 1,800 AFY, for protection of downstream biological resources as required by the National Oceanic Atmospheric Association, National Marine Fisheries Service (NOAA NMFS) (2) (3 pp. 5-1). Over the last several years, average influent flows to the WRRF have been decreasing due to extended drought conditions and enhanced conservation measures. In the spring of 2016, the City conducted a Recycled Water Production Analysis (Production Analysis) (included as Appendix A) to determine the WRRF tertiary treatment system’s infrastructure capacity to produce recycled water and to analyze secondary effluent supply to the tertiary treatment system to estimate how much recycled water the WRRF could produce. This study determined that the WRRF’s infrastructure is capable of producing and delivering up to 3.5 MGD of recycled water at any given time, while the average daily secondary effluent supply available for recycled water ranges between 1.5 and 1.9 MGD, excluding the 1.6 MGD of required discharge to San Luis Obispo Creek (based on 2015 data) (4). This range equals approximately 1,700 to 2,100 AFY of secondary effluent available for recycling. For the purpose of this Study, the recycled water available for additional beneficial use is estimated to be between 1,500 and 1,900 AFY, based on the results from the Production Analysis described above, and deducting 200 AFY of recycled water use by existing customers (3). This available supply estimate is conservative in that it does not include any growth, and it assumes continued drought conditions and conservation. This Study outlines the recycled water alternatives vetted by the Study team which included representatives from the City, WSC and its two subconsultants, HDR, Inc., and Cleath-Harris Geologists, Inc. (CHG). This Study evaluates the alternatives while maintaining consistency with local policies and using a “triple bottom line” framework, which considers social, economic and environmental value. The Study also provides recommendations and implementation considerations for the preferred alternatives. RECYCLED WATER ALTERNATIVES As part of the grant application process, the Study team identified five recycled water use alternatives to analyze in this Study: DRAFTCity of San Luis Obispo 1. Executive Summary Recycled Water Facilities Planning Study - Final Draft 2 1/19/2017 • Alternative 1: Deliver tertiary-treated recycled water from the WRRF to agricultural customers in the Edna Valley irrigation area; • Alternative 2: Deliver tertiary-treated recycled water from the WRRF to Cal Poly; • Alternative 3: Provide groundwater recharge within the San Luis Obispo Valley Groundwater Basin for indirect potable reuse (IPR); • Alternative 4: Provide direct potable reuse (DPR); and • Alternative 5: Construct a new satellite WRRF to serve Cal Poly and the surrounding areas. The City recognizes that there may be other potential uses for its recycled water, but the scope of this Study was focused on those alternatives that were considered to be most viable at the time the Study was initiated. This Study is not intended to rule out other potential uses of the City’s recycled water, but to help inform decision-making as the City moves forward with its recycled water planning and implementation efforts. ALTERNATIVES ANALYSIS Alternative 1 evaluated delivering recycled water to the growers in the agricultural area southeast of the City (the Edna Valley irrigation area) for agricultural irrigation. The City recognizes that there are additional outside-City interests that have the potential to receive recycled water from the City. This alternative is not meant to rule other interests out, rather to evaluate a specific alternative that had been identified by the Study team. The Edna Valley irrigation area partially overlaps with the San Luis Obispo Valley Groundwater Basin. The Edna Valley irrigation area growers have requested 1,000 AFY of recycled water from the City. This alternative requires an extension of the City’s current recycled water distribution system along Orcutt Road to the City limits, and turnout infrastructure at the end of the extension. This alternative has the potential to provide a scalable and flexible beneficial use of the City’s recycled water. It may also support the continuation of agricultural operations surrounding the City, which is consistent with the City’s Land Use Element (5). Since delivery of recycled water for irrigation within the Edna Valley irrigation area would likely offset some groundwater pumping from the San Luis Obispo Valley Groundwater Basin, consideration should be given to the potential implications under the Sustainable Groundwater Management Act (SGMA), which will be led by the Groundwater Sustainability Agency (GSA) that has yet to be formed. Alternative 2 evaluated delivering recycled water from the WRRF to the Cal Poly campus for irrigation. Cal Poly’s irrigation demand is approximately 82 AFY (estimated with monthly average irrigation data from 2012 to 2015 (without agricultural use)). This would require a pipeline through the City from the WRRF to the campus. For the purposes of this analysis, a pipeline extending the existing recycled water delivery system along Broad Street was used as a basis for developing representative cost estimates. This alternative would strengthen the relationship between the City and Cal Poly, but has a relatively high unit cost due to the significant infrastructure that would be required to deliver a relatively small quantity of recycled water. Additionally, Cal Poly’s seasonal demand pattern mimics the City’s existing recycled water demands that correspond to the lowest flows at the WRRF. Alternative 3 evaluated IPR through groundwater recharge in the San Luis Obispo Valley Groundwater Basin. Groundwater recharge could be achieved by either surface percolation or direct injection, and would require advanced treatment to be in compliance with current groundwater replenishment regulations if insufficient blend water is available. The expected average annual yield for this alternative varies from 800 to 1,900 AFY depending upon the method of recharge that is used and the capacity of the aquifer to accept the recharge. For the purposes of this analysis, streambed percolation in San Luis Obispo DRAFTCity of San Luis Obispo 1. Executive Summary Recycled Water Facilities Planning Study - Final Draft 3 1/19/2017 Creek was selected for analysis. This represents the most conservative approach for groundwater recharge as it assumes that recharge through percolation is only possible during the summer, and therefore it serves to bracket the low end of yield for potable reuse projects. Additional study of the groundwater basin is needed to optimize the replenishment strategy and refine the estimated yield and cost. This alternative would provide a supplemental potable water source to the City, expanding its water supply portfolio. Alternative 4 evaluated DPR to produce drinking water through advanced treatment and subsequent drinking water treatment. This alternative would provide multi-barrier advanced treatment at the WRRF to deliver purified water directly to the City’s water distribution system, or would transport advanced treated water from the WRRF to the City’s existing Water Treatment Plant for blending with other raw water sources upstream of conventional drinking water treatment. It was assumed for this analysis that approximately 1,800 AFY of drinking water could be produced for DPR, based on calendar year 2015 flows. Regulations are not yet in place for DPR, and it is uncertain what the specific treatment and/or operational requirements might be if DPR regulations are developed. Despite the regulatory uncertainty of this alternative, it could allow the City to maximize beneficial use of its recycled water, and has the potential to increase the reliability and resiliency of the City’s water supply portfolio. Alternative 5 evaluated the installation of a satellite WRRF at Cal Poly, in the form of either an engineered hydroponic system (EHS) or a membrane bioreactor (MBR). This alternative would produce a yield of approximately 270 AFY, based on average monthly sewer flows at Cal Poly (data from 2005-2013). This alternative would reduce average flows to the WRRF, which may negatively affect the City’s wastewater collection system. Additionally, assuming the satellite WRRF was not designed to be a complete stand- alone facility with full redundancy, peak capacity and residuals handling systems, the City’s WRRF would still need to be sized to handle the peak hydraulic flows from Cal Poly, as well as the residuals stream from the satellite WRRF. RESULTS AND RECOMMENDATIONS The five recycled water alternatives were presented and scored using a triple bottom line framework during the Alternatives Screening Workshop. The top three alternatives that emerged were Alternatives 1 (Edna Valley irrigation area), 3 (IPR), and 4 (DPR). Table 1 summarizes the yield, associated costs, and weighted scores from the Alternative Screening Workshop for each alternative. It should be noted that costs shown in this study only reflect infrastructure costs within the City limits, and do not reflect costs for infrastructure required to distribute and/or deliver recycled water outside of the City limits (e.g. within Cal Poly and the Edna Valley Irrigation Area). DRAFTCity of San Luis Obispo 1. Executive Summary Recycled Water Facilities Planning Study - Final Draft 4 1/19/2017 Table 1. Alternatives Summary Table Value Alternative 1: Edna Valley Irrigation Area Alternative 2: Cal Poly Recycled Water Alternative 3: Indirect Potable Reuse Alternative 4: Direct Potable Reuse Alternative 5: Satellite WRRF Potential Recycled Water Demand (AFY) 1,000 82 900 1,800 270 Total Capital Cost $991,000 $7,996,000 $9,454,000 $31,796,000 - $35,739,000 $4,425,000 - $18,675,000 One Year of O&M $79,000 $91,000 $134,000 $577,000 - $689,000 $234,000 - $384,000 Net Present Value $2,830,000 $10,120,000 $12,586,000 $45,276,000 - $51,844,000 $9,896,000 - $27,652,000 Unit Cost ($/AF) $140 $7,450 $830 $1,470 - $1,670 $1,930 - $5,920 Weighted Score 86 74 80 76 40 Note: These costs are 2016 costs, and do not include escalation corresponding to implementation schedules shown in Section 9. Following the Screening Workshop, an Alternatives Evaluation Workshop was conducted to review and refine analyses and cost estimates for Alternatives 1, 3, and 4. Through this workshop, it was recommended that all three of the top alternatives be carried forward in the development of an implementation plan. IMPLEMENTATION PLAN It is expected that delivery of recycled water to the Edna Valley irrigation area or other outside-City interests would take 2 to 3 years to negotiate, design, permit and construct. It would likely take 5 to 7 years to implement an IPR by groundwater replenishment project. The implementation of a DPR project is dependent on adoption of regulations. It is recommended that the Edna Valley irrigation area project be pursued in the short term (2 to 3 years), while potable reuse is being further studied for potential implementation in the longer term (5 to 10 years). The implementation plan is based on the fact that regulations and markets exist today to support delivery of recycled water to the Edna Valley irrigation area, while a potable reuse project would require more time to develop. Edna Valley Irrigation Area Project City Council authorization is required before negotiations with outside-City interests can commence, and the length of recycled water delivery commitment to interests outside of the City should be considered carefully relative to the City's own short- and long-term water supply needs. It is assumed that the City will continue to take the lead on moving this project forward, including coordinating and collaborating with the Edna Valley irrigation area growers on an agreement and contract terms and working through developing a cost model for recycled water pricing if directed by City Council. Additionally, consideration should be given to the potential implications under SGMA and the development of a Groundwater Sustainability Plan (GSP) for the Basin. DRAFTCity of San Luis Obispo 1. Executive Summary Recycled Water Facilities Planning Study - Final Draft 5 1/19/2017 Project implementation is expected to take 2 to 3 years. A preliminary implementation schedule is provided in Table 2. Table 2. Edna Valley Irrigation Area Project Implementation Schedule Potable Reuse Project Since groundwater replenishment regulations are in-place, an IPR project is estimated to take 5 to 7 years to implement, considering the need to demonstrate an alternative, non-reverse osmosis (RO) based advanced treatment train. Table 3 shows an estimated implementation schedule for an IPR project. Considering final regulations for DPR have not yet been developed, a detailed schedule for DPR implementation is not included. As part of the preliminary design for an IPR project, it is recommended that a groundwater model for the San Luis Obispo Valley Groundwater Basin be developed to estimate yield and seasonal recharge periods, evaluate operational scenarios for developing planning level design recommendations, and assist with developing a Salt and Nutrient Management Plan (SNMP). An IPR project that includes groundwater replenishment with streambed percolation would require an additional discharge location from the WRRF to San Luis Obispo Creek. This would require a Petition of Change to be filed with the SWRCB. Both an IPR and DPR project would initiate a permit re-opener and renewal process for the City’s National Pollutant Discharge Elimination System (NPDES) permit, and would require California Environmental Quality Act (CEQA) documentation. For a complete list of regulatory considerations, please see the Project Alternatives Analysis and the Implementation Plan for Alternatives 3 and 4. Implementation Schedule Outside Interests Project Tasks and Milestones Develop and execute a contract with outside City interests Implement Recycled Water Improvements at the WRRF Design, CEQA, and permitting Construction of pipeline and turnout Deliver water to outside City interests ♦ YEAR Year 1 Year 2 DRAFTCity of San Luis Obispo 1. Executive Summary Recycled Water Facilities Planning Study - Final Draft 6 1/19/2017 Table 3. Indirect Potable Reuse Implementation Schedule Indirect Potable Reuse Project Tasks and Milestones Public outreach Groundwater modeling, including assimilative capacity study if necessary Treatment technology studies and piloting Pathogen log reduction credits for MBR* Preliminary engineering Environmental documentation (CEQA) Permitting Pursue funding Design Construction Delivery ♦ *Anticipated in the next few years. This is imperative for meeting the pathogen log reduction credit requirement and must be completed prior to permitting. Year 6 Year 7 Implementation Schedule Year 1 Year 2 Year 3 YEAR Year 4 Year 5 DRAFTCity of San Luis Obispo 2. Introduction Recycled Water Facilities Planning Study - Final Draft 7 1/19/2017 2 INTRODUCTION The City engaged WSC to develop this Recycled Water Facilities Planning Study (Study) to evaluate five recycled water use alternatives to define a preferred strategy for maximizing the beneficial use of recycled water from the WRRF. Maximizing the beneficial use of recycled water is consistent with several of the City’s water management goals, as defined in the City’s General Plan (5), including: 1. Ensure a long-term, reliable water supply to meet both current and future water demand associated with development envisioned by the General Plan; 2. Manage the City’s water resources to meet the current and future water demand requirements associated with development envisioned by the General Plan; 3. Identify and meet the City’s multi- source water supply needs; 4. Use the City’s water resources efficiently to protect both short- and long-term water supply reliability; 5. Utilize recycled water for non-potable purposes, thereby offsetting the use of potable water; 6. Maximize the use of the City’s available recycled water supply for approved uses; 7. Provide wastewater treatment that meets or exceeds regulatory requirements and ensures the protection of public health and the environment; and 8. Produce a high-quality, dependable recycled water supply that meets an increasing portion of the City’s non-potable demand. The Study is funded in part by a Water Recycling Funding Program Planning Grant from the SWRCB Water Recycling Funding Program. STUDY AREA The City is located on the Central Coast of California, about half way between Los Angeles and San Francisco, and has a total area of 10.8 square miles. The City has a Mediterranean climate that typically includes dry summers and mild winters because it is in a coastal valley about 10 miles inland from the Pacific Ocean. Summers are generally warm and sunny, often with morning fog from the Pacific coast. Winters are generally mild, though below freezing lows may be expected during the winter. Temperatures do, however, vary widely at any time of the year, when 80°F readings in January and February are not uncommon. On average, the City has 50 days with measurable rain per year, mostly during the winter months, and an annual average precipitation of approximately 23 inches (3 pp. 2-1). The Study Area includes the area within the City limits plus Cal Poly north of the City and the agricultural area southeast of the City that partially overlaps with the San Luis Obispo Valley Groundwater Basin (the Edna Valley irrigation area). Both Cal Poly and the Edna Valley irrigation area are outside of the City limits, but parts of Cal Poly are within the City’s sphere of influence and the Edna Valley irrigation area is nearby, as shown in Figure 1. Cal Poly has agricultural operations on campus, and agriculture is the primary industry in the Edna Valley irrigation area. Cal Poly and the Edna Valley irrigation area are described in more detail in Section 7 Project Alternatives Analysis. Figure 1 shows the City limits, the San Luis Obispo Valley Groundwater Basin, Cal Poly, the Edna Valley irrigation area and San Luis Obispo Creek. Figure 2 shows the City’s existing recycled water distribution system from the City’s General Plan. The purple-shaded Water Reuse Master Plan Area in Figure 2 outlines where the City can deliver recycled water based on the design of the distribution system. DRAFTCity of San Luis Obispo 2. Introduction Recycled Water Facilities Planning Study - Final Draft 8 1/19/2017 Figure 1. Recycled Water Facilities Planning Study Areas DRAFTCity of San Luis Obispo 2. Introduction Recycled Water Facilities Planning Study - Final Draft 9 1/19/2017 Figure 2. Recycled Water Area and Distribution (5 pp. 8-25) DRAFTCity of San Luis Obispo 2. Introduction Recycled Water Facilities Planning Study - Final Draft 10 1/19/2017 RELATED RECYCLED WATER INITIATIVES The City has been producing and delivering recycled water to customers for landscape irrigation since 2006, and there have been several other recycled water studies prior to this Study. The City’s previously completed recycled water studies include those summarized in Table 4, in chronological order, starting with the most recent. This Study builds on the recycled water analyses previously completed for the City. To elaborate on the first entry in Table 4 and according to the City’s 2015 Urban Water Management Plan (UWMP), the City is in the process of updating its 2004 Water Reuse Master Plan (RW Master Plan) to address changing conditions experienced since 2004, including decreased water demand and influent flows to the WRRF and the absence of a groundwater exchange program that was originally envisioned in 2004. The update to the RW Master Plan will provide the City the opportunity to model the expansion of the recycled water distribution system, update potential and anticipated recycled water users, and incorporate planned expansion of the system. The 2004 RW Master Plan included the following goals (3 pp. 5-4): 1. Increase the City’s safe annual yield by utilizing recycled water for non-potable purposes, thereby offsetting the use of potable water. 2. Develop a dependable water supply to meet a portion of the City’s non-potable demand. 3. Efficiently manage the City’s water resources. 4. Provide non-potable water to meet future non-potable demand. The RW Master Plan includes a high-level discussion of IPR and DPR. There is a direct relationship between the expansion of the recycled water distribution system and the future availability of recycled water for the projects proposed in this Study. It is important to acknowledge that the expansion of the recycled water distribution system could have an impact on the quantity of water available for IPR, DPR, and deliveries to outside-City interests. To elaborate on the fourth entry in Table 4, the City’s Water and Wastewater Management Element of the General Plan has been the guiding policy document for the provision of water and wastewater services to the community since 1987. The Element translates the Land Use Element's capacity for development into potential demand for water supply and wastewater service. Deliveries of recycled water outside the city limits is addressed in two areas of the General Plan. The 2014 General Plan Land Use Element update included a new policy and specific findings related to potential recycled water deliveries outside the City limits. Related to Annexation and Services, Policy 1.13.2 states the following (5): Provision of recycled water outside of City limits may only be considered in Compliance with Water and Wastewater Element Policy A 7.3.4 and the following finding: A. Non-potable/recycled water is necessary to support continued agricultural operations. B. Provision of non-potable/recycled water will not be used to increase development potential of property being served. C. Non-potable/recycled water will not be further treated to make it potable. D. Prior to provision of non-potable/recycled water, the property to be served will record a conservation, open space, Williamson Act, or other easement instrument DRAFTCity of San Luis Obispo 2. Introduction Recycled Water Facilities Planning Study - Final Draft 11 1/19/2017 to maintain the area being served in agriculture and open space while recycled water is being provided. The Water and Wastewater Element includes Program A 7.3.4, which states that the City should (5): Consider the potential to deliver available recycled water supplies to customers outside the city limits, including analysis of policy issues, technical concerns, and cost recovery, provided it is found to be consistent with the General Plan. DRAFTCity of San Luis Obispo 2. Introduction Recycled Water Facilities Planning Study - Final Draft 12 1/19/2017 Table 4. Previous City Recycled Water Reports Report Title, Year Author Stated Purpose Stated Findings/Recommendations as Related to Recycled Water Recycled Water Master Plan Update, 2016 City of San Luis Obispo, Utilities Department Preparation of the Plan will assist the City in shaping the future for recycled water use within the City service area and beyond, prioritizing both current and future recycled water system needs and set forth a mechanism for addressing those needs. At the time of writing of this report, the Master Plan Update is in draft form. Recycled Water Production Analysis (Production Analysis), 2016 WSC The purpose of this Recycled Water Production Analysis is to conduct a production capacity evaluation of the existing recycled water production system at the City’s WRRF. This evaluation determines current infrastructure production capabilities, and evaluates secondary effluent supply and recycled water demand. WSC estimates that the WRRF’s infrastructure is capable of producing and delivering up to 3.5 MGD at any given time, while the average daily secondary effluent supply available for recycled water ranges between 1.5 and 1.9 MGD (based on 2015 data). A daily average recycled water supply of 1.5 to 1.9 MGD equals approximately 1,700 AFY to 2,100 AFY of recycled water available per year. WSC has provided recommendations for the City to consider in order to maximize the production of recycled water at the WRRF in the near-term, before the WRRF Project is complete. These recommendations include operational changes, automation improvements, and delivery schedule alternatives. Urban Water Management Plan (UWMP), 2016 City of San Luis Obispo, Utilities Department Comply with the Urban Water Management Act Goal: Maximize the use of the City’s available recycled water supply for approved uses. The City will also consider potable reuse in the future. Water and Wastewater Management Element, City of San Luis Obispo General Plan, 2016 City of San Luis Obispo The Water Wastewater Management section of the General Plan includes goals, policies, and programs related to water supply, demand, and other emerging issues; and establishes goals, policies, and programs to ensure provision of adequate sanitary sewer infrastructure and wastewater treatment capacity to accommodate existing and future development in order to protect public health, human safety, and the environment. Policies Recycled Water Supply: The City will make available recycled water to substitute for existing potable water uses as allowed by law and to supply new non-potable uses. Accounting for Recycled Water: The City will add total recycled water usage from the prior year to the City’s water resource availability on an annual basis. Recycled Water Production: The City will produce high-quality, dependable recycled water, suitable for a wide range of uses. Beneficial Use: The City will pursue treatment and disposal methods which provide for further beneficial use of wastewater and bisosolids. Water Reuse Master Plan, 2004 Dudek and Associates The City of San Luis Obispo has previously undertaken several recycled water planning efforts that are the basis for the treatment, storage and backbone distribution facilities currently being constructed. The intent of this master planning effort is to develop a strategic and comprehensive plan for expansion of the City’s recycled water system. The recycled water distribution system expansion alternatives presented in the previous chapter were developed to supply the total system reuse objective of 1,233 AFY. The alternatives were reviewed and evaluated by City Staff, and the consensus was to proceed with Alternative A, which expands the Phase I distribution system in a single pressure zone and does not supply Cal Poly. Alternatives A-1 and A-2 supply the same users, but Alternative A-1 provides future storage capacity at an additional [WRRF] clearwell and Alternative A-2 constructs a new reservoir in the distribution system. A revised alternative was developed with the input of City Staff which locates clearwell storage at the [WRRF], but incorporates the distribution system pipelines of Alternative A-2. Final Project Report Wastewater Treatment Plant Upgrade and Sewer Line Replacements, 1990 Brown and Caldwell Consultants The City's wastewater system includes facilities for the collection, treatment, and disposal of wastewater. The management of these facilities requires a periodic evaluation of their condition and determination of future needs. The purpose of this project report is to summarize previous evaluations of the current condition of the wastewater system, identify problems, analyze alternatives, and propose solutions. In addition, the · report identifies management policies and implementation strategies. The foundation of the project report is the Wastewater Management Plan, dated October 1987. The project report also draws information from the following studies : Supplement to Wastewater Management Plan, December 1988; Wastewater Reclamation and Beneficial Use Investigations, August 1988; Lateral Investigation and Rehabilitation Report, September 1988; Final Preliminary Design Report Improvements to Wastewater Collection System, January 1989; Basis-of-Design Report Wastewater Treatment Plant Facility Upgrading Project, September 1988; Cash Flow Forecast and Revenue Program, May 1989; Revised Draft Environmental Impact Report (EIR) Wastewater Treatment Plant Upgrade and Sewer Line Replacements, December 1989; and Wastewater Pilot Study Report, January 1990. Pursuant to a total resource management philosophy, the City directed Brown and Caldwell to further investigate wastewater reclamation and beneficial use options first outlined in the WMP. Four such options were examined in detail in a report submitted in August 1988 and are discussed in Chapter 7 of this report. These were (1) stream enhancement, (2) agricultural irrigation, (3) landscape irrigation, and (4) indirect discharge to Laguna Lake. Two projects were recommended. One involved landscape irrigation of future development (industrial parks and a golf course) near the airport area. The other was a stream enhancement program on the Pereira property just south of the discharge point. The project would consist of (1) reestablishment of riparian vegetation along the creek corridor, (2) temporary fencing of the corridor to keep cattle out until the vegetation becomes established, (3) construction of instream structures to improve steelhead habitat, (4) irrigation of the riparian vegetation for 2 to 3 years until it becomes established, and (5) providing terracing or shaving of the bank slope to increase the channel cross section and therefore its flow capacity. Discussions were held with the landowner, Mr. David Pereira, who expressed interest in such a project. DRAFTCity of San Luis Obispo 2.Introduction Recycled Water Facilities Planning Study - Final Draft 13 1/19/2017 GOALS AND OBJECTIVES OF THIS STUDY Water is a vital resource, and recycled water is a critical component of San Luis Obispo’s water supply portfolio. The City has the capacity to produce more recycled water for beneficial use, but at this time, does not have adequate demand and must discharge excess flows to San Luis Obispo Creek. This Recycled Water Facilities Planning Study aims to answer the question: what is the highest and best use of the City’s excess available recycled water? The goal of this Study is to analyze and evaluate additional beneficial uses of the City’s recycled water. The ultimate objective is to identify preferred use(s) so that the City can begin implementation of the identified beneficial use project(s). The evaluation of recycled water alternatives was conducted using a triple bottom line framework that takes into account social, environmental, and economic costs and benefits. It should be noted that this Study is based on current knowledge and understanding of the recycled water system, market, regulations, and available technologies. As additional information is developed, technologies improve, and regulatory policies evolve, the recommendations from this study can and should be adapted. Timing of this study is pertinent because the City is currently in the design phase of a major upgrade to the WRRF located on Prado Road (WRRF Project). The WRRF Project will improve effluent water quality through complete nitrogen removal and reduction of disinfection byproducts. Recycled water is a key resource recovered at the WRRF and the City’s goal is to maximize the production of recycled water at the facility today and into the foreseeable future. As mentioned in the previous section, the City is also preparing an update to its RW Master Plan. This Study will inform the RW Master Plan by providing analysis of additional beneficial uses of recycled water beyond the current non-potable use and service area. DRAFTCity of San Luis Obispo 3.Water Supply and Characteristics Recycled Water Facilities Planning Study - Final Draft 14 1/19/2017 3 WATER SUPPLY AND CHARACTERISTICS The City has adopted a multi-source water supply strategy and obtains its water from five sources: surface water from Salinas Reservoir (also known as Santa Margarita Lake), Whale Rock Reservoir, and Nacimiento Reservoir, along with groundwater and recycled water. Salinas Reservoir, near the community of Santa Margarita, has provided water to the City since 1944. Whale Rock Reservoir, managed by the Whale Rock Commission, which includes the City, Cal Poly, and California Men’s Colony, has been a water source for the City since 1961. With the addition of the Nacimiento Reservoir water supply in 2011, the City has a very reliable water supply portfolio and is able to meet its potable water supply needs even during drought years (6 pp. 2-1) (7 pp. 5-1). All surface water supplies are considered to be of high quality, and are blended and then treated at the City’s Water Treatment Plant near Stenner Creek in San Luis Obispo. Figure 3 from the 2015 UWMP shows the three surface water reservoirs and the conveyance pipeline to the Water Treatment Plant. The City does not currently rely on local groundwater to serve long-term water supply needs; however, it has relied heavily on groundwater during past droughts (such as 1986 to 1990) and could use this source in the future during water shortage emergencies (3 pp. 2-3). The City also augments supply for its non- potable water demands through its recycled water program, delivering recycled water to various customers throughout the City for landscape irrigation and construction water (7 pp. 5-1). DRAFTCity of San Luis Obispo 3.Water Supply and Characteristics Recycled Water Facilities Planning Study - Final Draft 15 1/19/2017 Figure 3. City of San Luis Obispo Water Supply (3 pp. 2-5) DRAFTCity of San Luis Obispo 3.Water Supply and Characteristics Recycled Water Facilities Planning Study - Final Draft 16 1/19/2017 WATER SUPPLY The City is the sole purveyor of water within the City limits. This allows the City to maintain uniformity of water service and distribution standards, and to be consistent in developing and implementing water policy. As the sole water purveyor, the City maintains control over water quality, distribution, and service to users of the potable and recycled water systems, as well as ensuring consistency with the City's General Plan policies and goals (5 pp. 8-7). The Water and Wastewater Management Element of the General Plan, first adopted in 1987 and most recently updated in 2016, identifies multiple water projects to meet projected short- and long-term water demand. Having several sources of water avoids dependence on any one source that may not be available during a drought or other water supply reduction or emergency. In November of 1990, the City Council affirmed the multi-source water supply concept (5 pp. 8-7). Consistent with the multi-source water supply concept and as previously discussed, the City has five sources of water: Salinas Reservoir, Whale Rock Reservoir, Nacimiento Reservoir, groundwater, and recycled water (5 pp. 8-7). In recent years the City has not been using groundwater for potable use, but is working to reestablish and enhance its groundwater program. Table 5, Table 6, and Table 7 summarize the City’s water supplies in 2015, projected water supplies through 2035, and water supply reliability, respectively. The majority of the data presented is from the City’s 2015 UWMP, unless otherwise noted. Table 5. 2015 Actual Water Supplies (3 pp. 4-7) Source of Water Water Supplies in 2015 (AFY) Nacimiento Reservoir 2,677 Supplier-produced groundwater (potable) 43 Salinas and Whale Rock Reservoirs 2,000 Recycled Water 187 Total 4,908 Notes: 1. Water volumes are rounded to the nearest AF Table 6. Projected Water Supplies (3 pp. 4-7) Source of Water Projected Water Supplies (AFY) 2020 2025 2030 2035 Nacimiento Reservoir 5,482 5,482 5,482 5,482 Supplier-produced groundwater 0 0 0 0 Salinas and Whale Rock Reservoirs 626 939 1,265 1,611 Recycled Water 250 300 350 400 Total 6,358 6,721 7,097 7,493 Projected Population 48,826 51,317 53,934 56,686 Notes: 1. Water volumes are projected using population projections from Table 2 from the City’s 2015 UWMP DRAFTCity of San Luis Obispo 3.Water Supply and Characteristics Recycled Water Facilities Planning Study - Final Draft 17 1/19/2017 Table 7. Water Supply Reliability Water Resource Supplies (AFY) Description Nacimiento Reservoir1 5,482 Dependable yield Salinas and Whale Rock Reservoirs1 6,940 Safe Annual yield Recycled Water2 1,700-2,100 Estimated recycled water supply available under current conditions Siltation from 2010 to 20603 (500) City’s General Plan, Water and Wastewater Management Element Policy A 4.2.2 Total 13,600-14,000 2015 annual availability Notes: 1 Source: City’s 2015 UWMP 2 Source: Recycled Water Production Analysis, WSC, 2016. Note: Reflects the range of water available to the recycled water system based on 2015 daily average. 3 Source: City’s 2015 Water Resources Status Report. Note: Reservoir siltation is a natural occurrence that reduces storage capacity over long periods, resulting in the reduction of safe annual yield. Figure 4 compares the daily average filter influent flow to the daily average total plant effluent flow at the WRRF. It shows that there was a daily average of between 3.1 and 3.5 million gallons per day (MGD) (3,500-3,900 AFY) in the WRRF tertiary treatment system in 2015, based on differences between the filter influent flow and total plant effluent data (4). The WRRF is required to maintain a minimum daily average year-round discharge of 2.5 cubic feet per second (cfs) of treated effluent on a daily average to San Luis Obispo Creek, which equals approximately 1.6 MGD (1,800 AFY), for protection of downstream biological resources as required by the NOAA NMFS (2) (3 pp. 5-1). Given the creek discharge requirement and secondary effluent supply from the Production Analysis, there was approximately 1.5 to 1.9 MGD of effluent available for recycled water production, on average in 2015. This corresponds to a recycled water supply of 1,700 to 2,100 AFY as presented in Table 7. Assuming in- City recycled water demands of 200 AFY, the recycled water available for additional beneficial use is set at 1,500 to 1,900 AFY for the purpose of this Study. This available supply estimate is conservative in that it does not include any growth, and it assumes continued drought conditions and conservation. DRAFTCity of San Luis Obispo 3.Water Supply and Characteristics Recycled Water Facilities Planning Study - Final Draft 18 1/19/2017 Figure 4. 2015 Recycled Water Supply and Demand, 2015 (7) DRAFTCity of San Luis Obispo 3.Water Supply and Characteristics Recycled Water Facilities Planning Study - Final Draft 19 1/19/2017 WATER DEMAND According to the City’s 2015 UWMP, per capita water demand dropped 34 gallons per capita per day (gpcd) from 126 gpcd in 2004 to 92 gpcd in 2015. In the 2015 UWMP, the City uses a potable water use rate of 117 gpcd to estimate future demand, summarized in Table 8 (3). Table 8. Supply and Demand Comparison for a Normal Year (3 pp. 6-4) Projected Water Demand (AFY) 2020 2025 2030 2035 Supply Totals 1 12,622 12,672 12,722 12,772 Demand Totals 6,599 6,975 7,369 7,779 Difference 6,023 5,697 5,353 4,993 Notes: 1 Supply total includes the City’s contractual supply from Nacimiento Reservoir, Safe Annual Yield from Salinas and Whale Rock Reservoirs, and recycled water use that will increase over time. Recycled water usage from the last five years is tabulated in Table 9 (3). The data show that recycled water demand has increased each year from 2011 to 2015. Future recycled water demand projections will be discussed in Section 6. Table 9. 2011-2015 Recycled Water Usage (3 pp. 5-2) Year Usage (AF) 2011 77.17 2012 89.95 2013 138.07 2014 152.63 2015 187.4 Based on data from the WRRF’s Supervisory Control and Data Acquisition (SCADA), and as represented in Figure 4, approximately 202.7 AF of recycled water was pumped into the recycled water distribution system in 2015. There is a discrepancy of about 15 AF (or roughly 8%) between the total metered recycled water usage (Table 9) and total recycled water supplied in 2015 (Figure 4). This difference represents non-revenue water, and is made up of unmetered deliveries, apparent losses (e.g. unauthorized usage, metering inaccuracies, systematic data handling errors) and real losses (e.g. leakage in the recycled water distribution system). The International Water Association (IWA)/American Water Works Association (AWWA) water audit method can be used to further evaluate the primary contributing factors to the non- revenue water within the City’s recycled water system. DRAFTCity of San Luis Obispo 3.Water Supply and Characteristics Recycled Water Facilities Planning Study - Final Draft 20 1/19/2017 WATER PRICING The City has a two-tiered inclining block rate structure for both potable and recycled water. Recycled water is charged at 90% of the potable rate. The rates adopted as part of the 2015-17 Financial Plan include a potable water drought surcharge for potable water on both the base fee and the volume charge (not applied to recycled water). The purpose of the surcharge is to generate revenue to balance water system operating costs due to decreased water demand during periods of drought. Water rates can change at the start of the fiscal year (July 1). Table 10 below shows the rates in the City as of July 1, 2016, sourced from the City’s Utilities website. Table 10. Current Water and Sewer Rates in San Luis Obispo Rate Description Cost 1 Water Base Fee 2 $9.98 per month Base Fee Drought Surcharge $0.74 per month Water Usage Tier 1 (1-8 Units) $6.92 per Unit Drought Surcharge Tier 1 $1.10 per Unit Water Usage Tier 2 (9+ Units) $8.65 per Unit Drought Surcharge Tier 2 $1.37 per Unit Sewer Treatment Base Fee $8.57 per month Sewer Treatment 3 $9.44 per Unit Notes: 1 Recycled water is charged at 90% of the potable base rate. No drought surcharge is applied to recycled water. 2 A 5% Utility Users Tax is applied to the entire Water portion of the bill, including the base fee and all surcharges. 3 Sewer usage is not billed by tier. The per-unit rate applies to all usage. Source: City’s Utilities Department website: http://www.slocity.org/government/department- directory/utilities-department/utility-billing/water-and-sewer-rates DRAFTCity of San Luis Obispo 4.Wastewater Characteristics and Facilities Recycled Water Facilities Planning Study - Final Draft 21 1/19/2017 4 WASTEWATER CHARACTERISTICS AND FACILITIES EXISTING FACILITIES The WRRF, located at 35 Prado Road in San Luis Obispo, treats municipal wastewater flow from the City, Cal Poly, and the San Luis Obispo County Airport. As stated previously, the WRRF is required maintain a minimum daily average year-round discharge of 2.5 cfs of treated effluent on a daily average to San Luis Obispo Creek, which equals approximately 1.6 MGD (1,800 AFY), for protection of downstream biological resources as required by the NOAA NMFS (2) (3 pp. 5-1). Treated effluent is also distributed as Title 22 tertiary recycled water for irrigation and construction uses in the City. Effluent water quality reliably meets or exceeds discharge permit limits (1 pp. 30, Appendix A). Excess treated effluent that is not delivered to recycled water customers is discharged to San Luis Obispo creek. See Section 5 of the Production Analysis (Appendix A. Recycled Water Production Analysis) for more details on the existing flow splitting configuration of the WRRF, and the respective treatment requirements. The creek discharge complies with NPDES permit No. R3-2014-0036, and the recycled water complies with Title 22 disinfection requirements. The 2015 WRRF Facilities Plan includes an analysis of flows at the WRRF. The WRRF has a rated capacity of 5.1 MGD for average dry weather conditions (1 pp. 1-1). The Facilities Plan states that the average annual flow at the WRRF is 3.9 MGD, based on historical flow data from January 2009 to January 2014 (1 pp. 5-1). This equates to approximately 4,400 acre-feet per year (AFY). Historical flows and corresponding peaking factors from the WRRF Facilities Plan are provided in Table 11 (1). Design flows from the Draft Predesign Report for the WRRF Project are also given in Table 11 (8). Additional information on the methodology for calculating peaking factors can be found in Chapter 5 of the WRRF Facilities Plan. Table 11. Peaking Factors for Historical Flows Averaging Period Historical Flow (MGD) 1 Design Criteria (MGD) 2 Peaking Factor with respect to Average Annual 1 Average Dry Weather Flow with Cal Poly Contributions 3.5 5.4 0.9 Average Annual Flow 3.9 6.1 1.0 Maximum Month Flow 5.4 8.4 1.4 Maximum Week Flow 7.4 11.4 1.9 Maximum Day Flow 11.1 17.3 2.9 Peak Hour Flow 3 32.0 - 8.2 Notes: 1 Source: WRRF Facilities Plan, page 5-2 2 Source: WRRF Draft Predesign Report, page 1-2 3 Staff have indicated that peak hour flows exceed the capacity of the flow meter. The value indicated in the table corresponds to the capacity of preliminary treatment. To treat the described flows, the WRRF currently has the following liquid and solids processes (1 p. 3 of Appendix G), and Figure 5 shows the current process schematic of the WRRF. DRAFTCity of San Luis Obispo 4.Wastewater Characteristics and Facilities Recycled Water Facilities Planning Study - Final Draft 22 1/19/2017 Liquid Treatment 1. Screening and grit removal; 2. Primary treatment – clarifiers; 3. Diurnal flow equalization; 4. Secondary treatment – trickling biofilter, activated sludge process, clarifiers; 5. Filtration – monomedia gravity filter; 6. Cooling – cooling towers; 7. Disinfection – chlorine contact channels, and dechlorination for the flow discharged to the creek. 8. Sidestream equalization – dewatering process filtrate Solids Treatment 1. Thickening – dissolved air flotation thickener (DAFT); 2. Digestion – anaerobic digestion; 3. Dewatering – screw press, belt press, or sludge drying beds. The City has been producing and delivering recycled water since 2006 with the completion of the Water Reuse Project. This project included (5 pp. 8-24): • A diversion structure and modulating control valve to split the effluent flow between the recycled water tank and San Luis Obispo Creek; • A 220,000-gallon chlorine contact tank to meet recycled water disinfection requirements, which differ from those for discharge to San Luis Obispo Creek; • A 600,000 gallon buried concrete recycled water storage tank to provide the storage necessary for operation of the distribution system; • A pump station to deliver recycled water into the distribution system, including two 40- horsepower and three 120-horsepower variable speed pumps, with room to accommodate two additional 120 horsepower pumps for a future capacity expansion; and • The initial eight miles of the recycled water distribution system with two main branches. DRAFTCity of San Luis Obispo 4.Wastewater Characteristics and Facilities Recycled Water Facilities Planning Study - Final Draft 23 1/19/2017 Figure 5. WRRF Process Flow Schematic (1) *Note that the WRRF currently uses a Screw Press, implemented as part of the WRRF Energy Efficiency Project, that is now operating in place of the Belt Filter Press DRAFTCity of San Luis Obispo 4.Wastewater Characteristics and Facilities Recycled Water Facilities Planning Study - Final Draft 24 1/19/2017 Waste Discharge Requirements The City’s NPDES discharge permit (Order No. R3-2014-0033; NPDES No. CA0049224) was renewed on September 25, 2014, and became effective on December 1, 2014. This permit supersedes the previous NPDES discharge permit (Order No. R3-2002-0043; NPDES No. CA0049224). The key changes in the renewed permit are more stringent discharge limits for nitrogen species and trihalomethanes (THMs). 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 (1 pp. 3, Appendix G). A link to the renewed permit and TSO is included for reference in Appendix B. WRRF NPDES Permit and TSO. A summary of the effluent limitations for the San Luis Obispo Creek discharge location from the NPDES permit is provided in Table 12. Table 12. Effluent Limitations for Discharge Point 001 DRAFTCity of San Luis Obispo 4.Wastewater Characteristics and Facilities Recycled Water Facilities Planning Study - Final Draft 25 1/19/2017 FUTURE FACILITIES The City is in the process of upgrading its WRRF in order to meet the discharge requirements mandated in the TSO. The WRRF Project, currently in the design phase, include such upgrades as new treatment processes, replacement of aging infrastructure, and an increase in capacity and process redundancy. A summary of the major upgrades planned for the WRRF is listed below (9): 1. Two new aeration basins in addition to the two existing basins, including new blowers, diffusers, pumps, and mixers; 2. A MBR to replace the existing secondary clarifiers and monomedia filter towers; 3. An ultraviolet disinfection (UV) system to replace the existing chlorine contact channels; a. This will play a substantial role in reducing the amount of THMs in the WRRF effluent 4. New odor control for major processes that produce malodors; a. This will play a pivotal role in addressing community concerns 5. A new anaerobic digester and screw press in place of the DAFT, for solids processing; a. The DAFT will be repurposed for sludge blending prior to thickening 6. Thickening upgrades with rotary drum thickeners (RDTs); 7. A new Water Resource Center that will house WRRF Operations, WRRF Maintenance, Wastewater Collections, Water Distribution, Water Resource Laboratory, and Environmental Compliance; 8. A new public Interpretive Center and demonstration wetlands that will serve to engage and educate the local community and visitors; and 9. Process control strategies to maximize recycled water production. The draft civil site plan is included as Figure 6 on the following page. For more information on the upgrades being implemented as part of the WRRF Project, please visit the project website at slowrrf.org and/or see the WRRF Project Draft Predesign Report. The preliminary design for the WRRF Project was being prepared concurrently with this Study, and results from this Study have been incorporated into the decisions made and designs prepared for the WRRF Project to-date. DRAFTCity of San Luis Obispo 4.Wastewater Characteristics and Facilities Recycled Water Facilities Planning Study - Final Draft 26 1/19/2017 Figure 6. WRRF Project Draft Civil Site Plan DRAFTCity of San Luis Obispo 5.Treatment Requirements Recycled Water Facilities Planning Study - Final Draft 27 1/19/2017 5 TREATMENT REQUIREMENTS There are several regulatory requirements and policies currently governing the development of recycled water projects. The SWRCB Department of Drinking Water (DDW) is charged with protection of public health and drinking water supplies and with the development of uniform water recycling criteria appropriate to particular uses of water. The SWRCB also exercises general oversight over recycled water projects, including review of Regional Water Quality Control Board (RWQCB) permitting practices. Boundaries for the Regional Boards are based on regional watersheds and each RWQCB has local jurisdiction over water quality requirements. The RWQCB is charged with protection of surface and groundwater resources and with the issuance of permits that implement DDW recommendations. The following are existing regulations and policies that pertain to recycled water uses: • SWRCB Policies: Recycled Water Policy and Antidegradation Policy, including the SNMP • DDW Regulations: Title 22, Division 4, Chapter 3, Section 60301 et seq., California Code of Regulations (Title 22) • Central Coast RWQCB: Water Quality Control Plan for the Central Coast Basin (Basin Plan) • Sustainable Groundwater Management Act (SGMA) • City of San Luis Obispo: Procedures for Recycled Water Use, NOAA NMFS Biological Opinion, 2016 Water and Wastewater Management Element (WWME), and Waste Discharge/Master Reclamation Requirements Figure 7 provides an overview of the required treatment levels, beneficial uses and regulatory status for each recycled water use type. Regulations currently exist for non-potable reuse and IPR by surface spreading and groundwater recharge. IPR by surface water augmentation and DPR regulations are not yet in effect. In this evaluation, surface water augmentation is not included as one of the alternatives because the distance to any of the existing reservoirs is not practical and is cost prohibitive when compared to groundwater recharge and DPR. This Study will evaluate both non-potable and potable reuse recycled water alternatives. Appendix C. Recycled Water Treatment Requirements provides additional information on the current recycled water regulations, and Section 5.1 includes a general overview of RO treatment and associated costs. Table 13 includes a copy of the water quality objectives for Total Dissolved Solids (TDS), chlorine (Cl), sulfate (SO4), boron (B), and sodium (Na) for San Luis Obispo Creek and San Luis Obispo Valley Groundwater Basin. These objectives will be important if an IPR by groundwater replenishment project is selected (10). DRAFTCity of San Luis Obispo 5.Treatment Requirements Recycled Water Facilities Planning Study - Final Draft 28 1/19/2017 Table 13. Basin Plan Water Quality Objectives Sub-Basin/Sub-Area TDS (mg/l) Cl (mg/l) SO4 (mg/l) B (mg/l) Na (mg/l) Surface Water Quality Objectives Estero Bay: San Luis Obispo Creek (10 pp. III-13) 1 650 100 100 0.2 50 Median Ground Water Objectives Estero Bay: San Luis Obispo (10 pp. III-16) 2 900 200 100 0.2 50 Notes: 1 Objectives shown are annual mean values. Objectives are based on preservation of existing quality or water quality enhancement believed attainable following control of point sources. 2 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. DRAFTCity of San Luis Obispo 5.Treatment Requirements Recycled Water Facilities Planning Study - Final Draft 29 1/19/2017 Figure 7. Recycled Water Treatment Requirements DRAFTCity of San Luis Obispo 5.Treatment Requirements Recycled Water Facilities Planning Study - Final Draft 30 1/19/2017 TREATMENT REQUIREMENTS FOR IPR AND DPR PROJECTS For groundwater recharge projects, the primary factors influencing level of treatment and selected treatment process are: (1) availability of high quality dilution water in the vicinity of the recharge area; and (2) whether additional treatment is required to meet the Basin Plan Objectives for TDS for the proposed beneficial use location. Either factor can be the driver for the required treatment level and treatment process, depending on the specifics of a particular project. The groundwater replenishment regulations in Title 22 require that the initial concentration of filtered and disinfected tertiary recycled water (Recycled Water Concentration or RWC) not exceed 20% of the total recharge water, which requires 80% of the total recharge water to come from other high quality water sources for blending. Dilution water can be a combination of imported surface water, captured stormwater, or natural underflow. If sufficient dilution water is not available from these sources, advanced purified recycled water can serve as a dilution source. Due to the lack of suitable dilution water sources near the WRRF, this report assumes that groundwater recharge will require 100% advanced purified water. Current groundwater recharge regulations define the full advanced treatment process as RO with advanced oxidation. The regulations also include a provision that allows the use of alternative treatment processes if the process is demonstrated to assure at least the same level of protection to public health. The approval process requires the project proponent to perform pilot testing of the proposed alternative treatment process and engage an independent scientific advisory panel to review the testing plan, process, and results. Final acceptance of the alternative treatment process is subject to approval by DDW and the RWQCB. There are currently no regulations in California for DPR. In December 2016, the SWRCB submitted a Report to the Legislature titled Investigation on the Feasibility of Developing Uniform Water Recycling Criteria for DPR. The Report to Legislature was based on the SWRCB’s analysis of recommendations provided by two independent groups: an Expert Panel of scientists and engineers, and an Advisory Group of stakeholders. The Report to Legislature concluded that it is feasible to develop uniform water recycling criteria for DPR, but that there are key knowledge gaps and key research recommendations that must be addressed before DPR regulations can be adopted. Key research topics identified by the SWRCB in the Report to Legislature include the evaluation of various treatment technologies now in use for IPR and DPR to determine the optimal coupling of these technologies, as well as development of validation programs to determine performance of established and alternative treatment trains. With respect to the use of RO in DPR projects, the Expert Panel report stated that, although it is prudent to include RO in the first set of DPR projects due to the water quality benefits and performance reliability that RO provides, proposals for DPR projects that do not employ RO could be considered and ultimately approved by the State Water Board. The SWRCB identified the need to develop specific reliability criteria and metrics for alternatives as critical to assure the high reliability necessary for DPR. Most DPR projects currently under consideration in California include RO as one of the treatment steps so it is anticipated that the initial DPR projects will include RO in their respective treatment trains. It is anticipated that a provision for consideration of non-RO based treatment trains could be incorporated into the future DPR regulations, subject to additional research aimed at identification of appropriate reliability criteria and metrics for alternative treatment processes. DRAFTCity of San Luis Obispo 5.Treatment Requirements Recycled Water Facilities Planning Study - Final Draft 31 1/19/2017 The primary concern with RO for the City is the cost of brine reject disposal as there is no available brine line to discharge to the Pacific Ocean and the City is several miles inland. Without an available brine line, the cost of the reject disposal system can be as costly as the RO treatment system itself. RO system treatment and disposal costs are highly variable, depending on the feed water quality, and would require additional analysis to provide representative capital and operation and maintenance (O&M) costs specific to the WRRF. To provide a range of potential costs for an RO system, costs for several brackish water RO systems were evaluated and revealed a treatment cost in the range of approximately $820/AF to $1,600/AF. Without an available brine line, brine reject disposal significantly increases the capital and operations cost and may fatally flaw IPR and DPR for the City. As part of the WRRF Project, a memo was prepared to evaluate treatment requirements for potable reuse from the WRRF (11). This work provided a preliminary evaluation of alternative treatment trains for IPR and DPR that do not rely on RO and suggested that the City might be able to implement potable reuse without RO, subject to approval by DDW and the SWRCB. As a result, RO was not included in the IPR and DPR treatment trains for this report. DRAFTCity of San Luis Obispo 6.Recycled Water Market and Opportunities Recycled Water Facilities Planning Study - Final Draft 32 1/19/2017 6 RECYCLED WATER MARKET AND OPPORTUNITIES The five alternatives for beneficial use of recycled water that will be described and evaluated in Section 7 will serve new recycled water customers. The following sections describe the market analysis for various uses of tertiary-treated recycled water produced at the WRRF. MARKET ANALYSIS UPDATE Potential new recycled water markets for the City include users outside the City (agricultural interests and Cal Poly campus), additional housing developments inside the City (for more info see the City’s General Plan Land Use Element), and potable reuse customers (IPR and DPR). This market expansion is in addition to the current non-potable recycled water customers in the City. Table 14 shows the number of metered connections for landscape irrigation and construction water sources from 2007 to 2016 (note that some sites have more than one meter, so this value is not number of customers). All of the recycled water users from 2015 are summarized in Table 15. Table 14. City of San Luis Obispo Recycled Water Customers Year Metered Connections for Landscape Irrigation Construction Water Sources 2007 10 0 2008 11 1 2009 17 5 2010 25 5 2011 30 6 2012 32 6 2013 36 6 2014 38 6 2015 39 6 2016 40 8 DRAFTCity of San Luis Obispo 6.Recycled Water Market and Opportunities Recycled Water Facilities Planning Study - Final Draft 33 1/19/2017 Table 15. 2015 Recycled Water Users (City Utilities Department, Springbrook Utilities Billing System, calendar year 2015) # Reclaimed Water Use Sites Site Address Yearly Total (gal) Yearly Total (AF) 1 Damon Garcia Sports Field 680 Industrial Way 10,200,000 31.2 2 Los Osos Valley Rd. Medians 10990 Los Osos Valley Road 108,000 0.333 3 Los Osos Valley Rd. Medians 11000 Los Osos Valley Road 47,900 0.147 4 Calle Joaquin Parkways 1500 Calle Joaquin 12,700 0.039 5 Courtyard by Marriott (2) 1605 Calle Joaquin 886,000 2.72 6 Irish Hills Plaza (2) 11951 and 11981 Los Osos Valley Road 1,640,000 5.03 7 Costco 1540 Froom Ranch Way 2,090,000 6.40 8 Laguna Village Shopping Center 11550 Los Osos Valley Road 690,000 2.12 9 Laguna Lake Golf Course 11175 Los Osos Valley Road 5,520,000 16.9 10 Laguna Middle School - SLCUSD 11050 Los Osos Valley Road 7,910,000 24.3 11 Laguna Hills Park 925 San Adriano 1,410,000 4.33 12 Laguna Lake Park 504 Madonna Road 2,790,000 8.57 13 French Park 4165 Morning Glory 5,850,000 18.0 14 Islay Park 1511 Tank Farm Road 2,050,000 6.30 15 City Hydrants and Construction Water Program (Corp Yard-000, WRRF-001, Industrial Way-006, Tank Farm Rd-005, Prado Rd- 004, and Calle Joaquin-003, Prado Rd- 007 (removed Oct.), Cherry-008) 4,840,000 14.8 16 Cal Trans 31 Prado (located @ WRRF) serves Hwy 101 irrig.; also wash rack @ 66 Madonna, and filling station and irrig. of 50 Higuera 3,360,000 10.3 17 DeVaul Park - City 1593 Madonna Road 691,000 2.12 18 Los Osos Valley Rd. Medians 1401 Madonna Road 153,000 0.468 19 DeTolosa Homes (2) 1501 and 1601 Madonna Road 717,000 2.20 20 Los Verdes Park I (2) 92 and 93 Los Verdes Drive 1,970,000 6.03 21 Meathead Movers 3600 Higuera S. 133,000 0.409 22 Heritage Oaks Bank 3380 Higuera S. 87,500 0.269 23 Margarita Medians (3) 211, 301, 385 Margarita 548,000 1.68 24 Prefumo Creek Commons (2) 11980 A&B Los Osos Valley Rd. 1,790,000 5.51 25 Olive Garden 11966 Los Osos Valley Road 89,000 0.273 26 Hampton Inn 1530 Calle Joaquin 236,000 0.725 27 America's Tire 1443 Calle Joaquin 567,000 1.74 28 Wathen Castanos Homes (4)/Maganos Homes (3) 300 and 392 Prado; 3420 Serra Meadows; 3239 Cherry 3,140,000 9.64 29 Madonna Road Apartments 1550 Madonna Road 939,000 2.88 30 SESLOC 3813 Broad Street (or 3807) 853,000 2.62 TOTAL: 61 MG 188 AFY 1 Note: 1 Difference of 1 AFY between this total and value in Table 9 is most likely due to rounding error. DRAFTCity of San Luis Obispo 6.Recycled Water Market and Opportunities Recycled Water Facilities Planning Study - Final Draft 34 1/19/2017 Table 16 presents the City’s projections for future recycled water use, up to 2035. These projections show increasing irrigation and commercial demand for recycled water in the next 20 years. These projections also show a decrease in golf course irrigation and a flattening of construction water demand. Table 16. Potential Total Future Recycled Water Use (3 pp. 5-5) Beneficial Use Type General Description of 2015 Uses Level of Treatment 2015 (AFY) 2020 (AFY) 2025 (AFY) 2030 (AFY) 2035 (AFY) Landscape Irrigation (excludes golf courses) Irrigation at parks, school, medians, etc. Tertiary 128 135 175 200 235 Golf Course Irrigation Laguna Lake Golf Course Tertiary 17 15 15 15 15 Commercial Use Irrigation at commercial sites Tertiary 27 30 35 60 75 Other: Construction Water Construction Water Permit program Tertiary 15 20 25 25 25 Total: 187 200 250 300 350 Notes: Projected recycled water usage for 2020 to 2035 is based on the City’s knowledge of planned projects identified in the City’s General Plan Land Use Element to be served with recycled water (including the Margarita Area, Orcutt Area, Airport Area, Avila Ranch Area, San Luis Ranch Area, and Madonna on Los Osos Valley Road). Figure 8 shows five years of recycled water demand data (provided by the City Utilities Department). The values are presented as the total recycled water demand at all meters. It should be noted that until 2015, meter reading was not completed by a contractor, and the days in the month when the meters were read were not consistent month to month. The figure does, however, show the general pattern of recycled water demand: highest in the summer and fall months (June, July August, September, and October), and lowest in the winter months (December, January, February, and March). DRAFTCity of San Luis Obispo 6.Recycled Water Market and Opportunities Recycled Water Facilities Planning Study - Final Draft 35 1/19/2017 Figure 8. Seasonal Recycled Water Demand Pattern DRAFTCity of San Luis Obispo 6.Recycled Water Market and Opportunities Recycled Water Facilities Planning Study - Final Draft 36 1/19/2017 Overall, the presented data show: 1. Recycled demand and the number of customers have increased each year (Table 14); 2. Recycled water demand is projected to continue to increase in the future (Table 16); 3. Theoretically, there is recycled water available to meet current and future demands (Figure 4); and 4. There is prominent seasonal variation in demand patterns, when high demand corresponds to low flows at the WRRF (Figure 8). There is a sufficient market for recycled water in the Study Area. The key challenge will be aligning seasonal demand and deliveries with available recycled water. STAKEHOLDER OUTREACH Throughout the preparation of this Study, the City has been reaching out to key stakeholders to participate in the discussion and evaluation of the recycled water alternatives. The City and WSC have conducted several meetings with the Edna Valley irrigation area stakeholders and with Cal Poly. These meetings introduced the Study team to the stakeholders, and reviewed the study purpose, alternatives, and the potential recycled water concepts for each group. The City should consider continued coordination with Cal Poly and the Edna Valley irrigation area growers to enhance the partnerships and move the selected projects forward. WSC and representatives from the Edna Valley irrigation area met with the RWQCB to discuss the Edna Valley irrigation area alternative and to summarize the Edna Valley irrigation area growers’ white paper from February 2016 entitled, “The Sustainability of Agriculture in the City of San Luis Obispo’s Edna Valley Greenbelt”, with three technical attachments. For the purposes of this Study, the white paper and attachments will be referred to as the White Paper. The White Paper is included as Appendix G. The RWQCB staff indicated that they did not have any issue with the approach for agricultural irrigation as presented in the White Paper. Public outreach meetings in 2015 included three City Council meetings in 2015 and the City-led Community Water Forum in 2016. The first City Council meeting on February 3, 2015 included a request for authorization to submit the grant application for the Study. The meeting on March 3, 2015 included a triple bottom line evaluation for the WRRF Project, and the City Council expressed their desire to “do more” with recycled water. The meeting on July 7, 2015 included a presentation on the five recycled water alternatives. The Community Water Forum was held on April 21, 2016 at the Ludwick Community Center. The Utilities Department presented the five recycled water alternatives being analyzed as part of this Study. Future outreach to stakeholders and the public will continue as part of the WRRF Project. As the City’s strategy for potable reuse develops, the City will engage in heavy outreach with regards to public acceptance of potable reuse. DRAFTCity of San Luis Obispo 7.Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 37 1/19/2017 7 PROJECT ALTERNATIVES ANALYSIS Five recycled water alternatives were developed by the Study team as part of the grant application process to evaluate opportunities for beneficial use of the City’s recycled water. These alternatives are: • Alternative 1: Deliver tertiary-treated recycled water from the WRRF to agricultural customers in the Edna Valley irrigation area; • Alternative 2: Deliver tertiary-treated recycled water from the WRRF to Cal Poly; • Alternative 3: Provide groundwater recharge within the San Luis Obispo Valley Groundwater Basin for IPR; • Alternative 4: Provide DPR; and • Alternative 5: Construct a new satellite WRRF to serve irrigation demands within Cal Poly and the surrounding areas. Through the Study process, these alternatives were narrowed down from five to three preferred alternatives. A high-level analysis was performed on all five alternatives, and a more detailed analysis was performed on the top three alternatives. The following sections present the alternative analysis. Results and recommendations are provided in Section 8. The City recognizes that there may be other potential uses for its recycled water, but the scope of this Study was focused on those alternatives that were considered to be most viable at the time the Study was initiated. This Study is not intended to rule out other potential uses of the City’s recycled water, but to help inform decision-making as the City moves forward with its recycled water planning and implementation efforts. DRAFTCity of San Luis Obispo 7.Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 38 1/19/2017 ALTERNATIVE 1: DELIVER RECYCLED WATER TO AGRICULTURAL CUSTOMERS IN THE EDNA VALLEY IRRIGATION AREA Background The Edna Valley irrigation area, located south of the City of San Luis Obispo, is home to many vineyards, orchards, and farms. Current water sources used for irrigation in the Edna Valley irrigation area are surface water and groundwater (12). The current drought has highlighted the vulnerability to reduced rainfall of the region’s water supply, and the growers in the Edna Valley irrigation area have approached the City about the potential to receive recycled water. The City recognizes that there are additional outside-City interests that have the potential to receive recycled water from the City. This alternative is not meant to rule other interests out, rather to evaluate a specific alternative that had been identified by the Study team. The White Paper summarizes the goals and objectives of the growers and their interest in purchasing recycled water from the City of San Luis Obispo through a new turnout at the eastern City limits on Orcutt Road. This White Paper states that the growers in the Edna Valley irrigation area use approximately 2,908 AFY of water for about 3,697 acres of irrigated crops, including citrus, row crops, wine grapes, and cattle pasture, and that they are seeking 1,000 AFY of recycled water from the City to offset some of that water demand (12). Description and Analysis Alternative 1 includes 2,600 feet of 10” recycled water pipeline along Orcutt Road, from the northernmost terminus of the City’s existing recycled water system to the City limit boundary. It includes an 8” water meter and SCADA to connect to the City’s system. This is consistent with the recommendations in the White Paper. Figure 9 shows the approximate location of the pipeline extension along Orcutt Road, the City’s existing recycled water distribution system, City limits and sphere of influence, and the Edna Valley irrigation area. All infrastructure is assumed to be constructed by the Edna Valley irrigation area growers, and infrastructure outside City limits is not included in this analysis. DRAFTCity of San Luis Obispo 7.Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 39 1/19/2017 Figure 9. Pipeline Extension to City Limits DRAFTCity of San Luis Obispo 7.Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 40 1/19/2017 7.1.2.1 Use Volume, Seasonal Variations and Delivery Capacity The Edna Valley irrigation area growers are requesting delivery of 1,000 AFY of recycled water (12). It is the City’s understanding that the Edna Valley irrigation area growers want to maximize delivery since the Edna Valley irrigation area’s total demands exceed the available recycled water supply. WSC evaluated the distribution system in order to determine how much recycled water could be delivered to City limits. The analysis began by assessing the historic in-City recycled water delivery patterns. Figure 4 shows the seasonal variation in existing demand, with the lowest demands in the winter and the highest demands in late summer and early fall. This variation was split into four demand “seasons” as shown by the months listed in Table 17 column 2. The data also showed that there is typically a minimum background demand in all seasons, estimated at 150 gallons per minute (gpm) (column 4). This happens to be the maximum demand in the winter months (there is little to no nighttime irrigation in January and December). For the remaining irrigation seasons, the data shows peak sustained flows for several hours each day. The peak flow and duration for each season were estimated using the detailed 2015 data and are shown in Table 17 column 6. A hydraulic model of the City’s distribution system was then developed to determine what could be delivered to the Edna Valley irrigation area during each demand season, as shown in Table 18. 800 gpm was used as Edna’s maximum delivery flow rate for periods during the day when existing customers were receiving their minimum of 150 gpm (column 4). During peak in-City customer demand hours (columns 5 and 6 in Table 17) the available recycled water flow was estimated using the hydraulic model. The results of the hydraulic simulation are shown in column 6 of Table 18. Figure 10 shows the estimated available recycled water (black and grey), the amount of water requested by the Edna Valley irrigation area (purple) and the estimated possible deliveries to Edna (yellow line). The results from this capacity evaluation show that the existing recycled water delivery system could deliver the 1,000 AFY requested by the Enda Valley growers with the delivery schedule shown in and Figure 10. Table 17. Background and Peak Recycled Water Delivery to Edna Based on Historical Data Column 1 Column 2 Column 3 and 4 Column 5 and 6 Seasonal Demand Scenario Months Condition 1: Minimal RW Demand on System by City’s Existing Recycled Water Users Condition 2: Peak RW Demand on System from City’s Existing Recycled Water Users Duration (hrs/day) Estimated Recycled Water Background Demand (gpm) Duration (hrs/day) Estimated Recycled Water Peak System Demand (gpm) 1 Dec, Jan 24 150 See Note 1 See Note 1 2 Feb, Mar, Nov 20 150 4 450 3 Apr, May, Jun 16 150 8 800 4 Jul, Aug, Sep, Oct 12 150 12 1700 Note: 1 The peak demand from existing recycled water customers does not exceed 150 gpm in December and January. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 41 1/19/2017 Table 18. Maximum Recycled Water Delivery to Edna Based on Distribution System Capacity Limits Column 1 Column 2 Column 3 and 4 Column 5 and 6 Column 7 Column 8 Seasonal Demand Scenario Months Condition 1: Minimal RW Demand on System by City’s Existing Recycled Water Users Condition 2: Peak RW Demand on System from City’s Existing Recycled Water Users Maximum Recycled Water Delivery to Edna (MGD) Total for the Scenario (AF) Duration (hrs/day) Estimated Recycled Water Flowrate to Edna (gpm) Duration (hrs/day) Estimated Recycled Water Flowrate to Edna (gpm) 1 Dec, Jan 24 800 See Note 1 See Note 1 1.15 219 2 Feb, Mar, Nov 20 800 4 625 1.11 303 3 Apr, May, Jun 16 800 8 525 1.02 285 4 Jul, Aug, Sep, Oct 12 800 12 300 0.79 299 Total AFY: 1106 ,,,,, ,,,,,,,,,, Note: 1 800 gpm could be delivered to The Edna Valley irrigation area 24 hrs/day in December and January. Figure 10. Maximum Recycled Water Delivery to The Edna Valley irrigation area Growers DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 42 1/19/2017 7.1.2.2 Potential Upgrades and Regulatory Considerations In order to maximize production of recycled water at the WRRF, automation and operation improvements would be required, as described in the Production Analysis. It is assumed that these improvements would be made prior to delivery of recycled water to the Edna Valley irrigation area. The recommendations, preliminary cost estimates, and conceptual implementation plan for this alternative are included in the Preliminary Cost Estimates and Implementation Technical Memorandum in Appendix H. The Edna Valley irrigation area growers’ preliminary discussions with the Central Coast RWQCB indicated that this alternative would not be considered a groundwater recharge project, as long as annual recycled water application is limited to the amount needed by the crops. This alternative would need to comply with Title 22 requirements for irrigation, including development of a Use Site report, which provides a detailed description of the intended use site for approval by RWQCB to ensure Title 22 compliance. The site and those designated as responsible for the site would be required to maintain proper signage, training, cross-connection control, and other relevant measures. Considerations regarding SGMA still need to be evaluated and any potential permit modifications need to be confirmed with the RWQCB. The City already has an NPDES and a water reuse permit from the RWQCB. It is not anticipated that the City would need any more permits from the RWQCB to implement this project. It unclear if a Petition for Change would be required to be filed with the SWRCB. This Study did not analyze impacts and/or benefits from this alternative to salt and nutrient management within the San Luis Obispo Valley Groundwater Basin, nor did it evaluate the potential implications under SGMA since the GSA is still being formed and the GSP for the San Luis Obispo Valley groundwater basin has not yet been developed. Preliminary Cost Estimate The preliminary cost estimate for Alternative 1 is shown in Table 19, however the City would not bear the cost of delivery of recycled water to outside-City interests such as to the Edna Valley irrigation area growers. This preliminary cost estimate is not intended to reflect a potential pricing structure for a water delivery agreement with the Edna Valley growers, nor is it a comprehensive representation of the actual costs related to implementation of this alternative. It is strictly intended to identify the costs of new infrastructure within the City limits that is required for this alternative. Additionally, costs to extend the pipeline to the points of use are not included, and this estimate does not include additional maintenance costs at the WRRF for increased recycled water production. Finally, this estimate does not include any “buy-in” costs to the existing infrastructure. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 43 1/19/2017 Table 19. Alternative 1: Preliminary Cost Estimate Capital Cost Items Capital Cost Recycled Water Main $520,000 Water Meter $7,000 Turnout Infrastructure $58,000 SCADA Controls $25,000 Subtotal $610,000 30% Construction Contingency $183,000 25% Implementation Costs $198,000 Total Capital Cost $991,000 Operation and Maintenance Costs Items 1 Annual O&M Cost Recycled Water Main and Turnout $6,000 Total Energy Cost Attributed to Edna deliveries $73,000 Total Annual O&M Cost $79,000 Payment Cost Annual Capital Payment 5% interest for a 30 year term $64,000 Year 1 O&M $79,000 Total Annual Payment $143,000 Net Present Value $2,830,000 Unit Cost based on 1,000 AFY $140 Notes: 1 O&M considered energy and materials and maintenance. Staffing was excluded from the analysis. It is anticipated that the 0.05 to 0.10 full time employees (FTEs) would be required over a calendar year for this alternative. Advantages and Disadvantages The main advantages of Alternative 1 include ease and speed of implementation, and flexibility of demand to match recycled water availability and delivery capacity from the WRRF. Most of the infrastructure to deliver the water to the Edna Valley irrigation area is in place. Alternative 1 has the potential to grow, and increases the beneficial use of recycled water because the growers are willing to take water when it is available, allowing the City to meet its obligations to current customers while still adding additional users such as the Edna Valley irrigation area. It could also potentially provide an in-lieu water supply benefit to the City if credits were granted to the City for offsetting groundwater pumping in the Edna Valley irrigation area with recycled water delivery, however the feasibility of this concept needs to be further explored through the process of GSA formation and GSP development for the San Luis Obispo Valley groundwater basin. This alternative is consistent with the City’s Land Use Element, and supports continued viability of agriculture operations in the Edna Valley irrigation area. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 44 1/19/2017 The primary disadvantage of Alternative 1 is that as long as water is being delivered to the Edna Valley, it cannot be utilized for potable reuse. That said, a near term delivery agreement could preserve the City’s longer term options for potable reuse (IPR or DPR). Additionally, if a framework for receiving in-lieu water supply credits from the groundwater basin (as described above) cannot be established, the City’s water portfolio does not benefit from these deliveries. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 45 1/19/2017 ALTERNATIVE 2: DELIVER RECYCLED WATER TO CAL POLY Background Cal Poly has two primary sources of water: water from Whale Rock Reservoir delivered to campus by the City and groundwater from Cal Poly’s agricultural wells (13). Cal Poly has a longstanding water resources partnership with the City. As Cal Poly plans for the future and develops its campus master plan, future water supply availability has become a concern. Cal Poly expressed interest in collaborating with the City on future water supply needs, including the potential to receive tertiary-treated recycled water from the City. Cal Poly is also looking into other water sources, such as Nacimiento Reservoir, Salinas Reservoir, etc., in addition to recycled water. This alternative explores what would be required to deliver treated recycled water from the WRRF to Cal Poly campus for irrigation reuse at the University. Potential yearly recycled water demand on campus amounts to approximately 82 AFY (estimated with monthly average irrigation data from 2012 to 2015 (without agricultural use)). Description and Analysis Alternative 2 includes approximately 5 miles of 8” pipe to extend the existing distribution system to Cal Poly to deliver recycled water. It also includes the cost of a booster station, with a discharge pressure at Cal Poly of 40 pounds per square inch (psi). Any connection and distribution infrastructure required on campus to utilize the recycled water is assumed to be the responsibility of Cal Poly and is not analyzed in this Study. Figure 11 shows three pipeline alignments in the City that were considered as part of this Study. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 46 1/19/2017 Figure 11. Alternative 2 Pipeline Alignment DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 47 1/19/2017 Alignment 1 would require 4.5 miles of pipe and follows the US 101 shoulder. This option would require approval from the California Department of Transportation (CalTrans). This option could also face potentially significant construction challenges along the freeway. Alignment 2 would require 5.4 miles of pipe, and would extend the existing recycled water delivery system down Los Osos Valley Road and Foothill Boulevard. This option would partially be within the County of San Luis Obispo’s right-of-way. There could be potential future users of recycled water along this alignment. Alignment 3 would require 4.6 miles of pipe, and would extend the existing recycled water delivery system on Broad Street. This option could also potentially deliver recycled water to Sinsheimer Park, schools, and other locations along Broad Street. For the purposes of this Study, Alignment 3 was used as a basis for developing representative cost estimates. 7.2.2.1 Use Volume and Seasonal Variations As previously stated, Cal Poly’s estimated irrigation demand for recycled water is 82 AFY. This value was estimated by summing monthly average irrigation use on campus from 2012 to 2015 (without agriculture use). This irrigation demand is seasonal, similar to the City’s existing recycled water demand. Based on 2015 conditions, there theoretically is enough potential recycled water available to meet Cal Poly’s demand during the summer. 7.2.2.2 Potential Upgrades and Regulatory Considerations See Section 7.1.2.2 for recommended upgrades to the WRRF and regulatory considerations. Preliminary Cost Estimate The following preliminary cost estimate for Alternative 2 in Table 20 includes the pipeline up to Cal Poly and a booster station. Costs that would be incurred by Cal Poly are not included. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 48 1/19/2017 Table 20. Alternative 2: Layout 3 Preliminary Cost Estimate Capital Cost Items Capital Cost Recycled Water Main $4,493,000 Pump Station $428,000 Subtotal $4,921,000 30% Construction Contingency $1,476,000 25% Implementation Costs $1,599,000 Total Capital Cost $7,996,000 Operation and Maintenance Costs Items 1 Annual O&M Cost Recycled Water Main $45,000 Pump Station Maintenance $21,000 Power $25,000 Total Annual O&M Cost $91,000 Payment Cost Annual Capital Payment 5% interest for a 30 year term $520,000 Year 1 O&M $91,000 Total Annual Payment $611,000 Net Present Value $10,120,000 Unit Cost based on 82 AFY $7,450 Notes: 1 O&M considered energy and materials and maintenance. Staffing was excluded from the analysis. It is anticipated that the 0.15 to 0.30 full time employees (FTEs) would be required over a calendar year for this alternative for pumping and conveyance. Advantages and Disadvantages Advantages of Alternative 2 include maintaining and enhancing the positive relationship between the City and Cal Poly. Delivering recycled water to Cal Poly would help Cal Poly diversify its water supply portfolio and increase reliability. Alignment 3 could also potentially deliver recycled water to additional customers, such as Sinsheimer Park, San Luis Obispo High School, and others. This alternative includes high capital costs for extension of the recycled water distribution system up to campus and the yield is limited. Therefore, the unit cost of water for this alternative is very high. Additionally, Cal Poly’s seasonal demand pattern mimics the City’s existing recycled water demands and corresponds to the lowest flows at the WRRF thereby exacerbating the problem of supply/demand balance. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 49 1/19/2017 ALTERNATIVE 3: GROUNDWATER RECHARGE IN THE SAN LUIS OBISPO VALLEY GROUNDWATER BASIN FOR INDIRECT POTABLE REUSE This section discusses the IPR alternative for groundwater recharge in the San Luis Obispo Creek subarea of the San Luis Obispo Valley Groundwater Basin. Background The strain on water supply induced by the on-going drought has caused the City of San Luis Obispo to investigate and develop options for increasing water resiliency. One such option is groundwater recharge coupled with expanded groundwater production. Groundwater recharge can be accomplished by percolation or direct Injection, as described below: 1. Percolation: Groundwater replenishment through percolation can be accomplished by percolation in a streambed or percolation in dedicated infiltration basins. Percolation into the San Luis Obispo Creek streambed would require a new point of discharge from the WRRF on the creek where highly permeable sediments are close to the surface. Recharge is most likely only possible during periods when the creek bed is dry, which would limit the overall yield of this approach due to limited availability of recycled water during the dry season and the inability to recharge recycled water that is available during the wet season. This Study did not evaluate potential locations and/or criteria for dedicated infiltration basins. If the City is interested in pursuing dedicated off-stream surface percolation, a separate siting analysis, subsurface investigation(s), and criteria development should be performed. 2. Direct Injection: Direct injection includes dedicated injection wells for introducing highly-treated water directly into productive zone(s) of the groundwater aquifer. The preliminary hydrogeological evaluation could not confirm nor reject the feasibility of direct injection. If the City is interested, however, in evaluating this alternative further in order to maximize the yield of a groundwater recharge program, additional hydrogeological modeling and/or investigations would be required. The expected average annual yield for IPR by groundwater replenishment varies depending upon the method of recharge that is used and the capacity of the aquifer to accept the recharge. If it were possible to recharge the aquifer year-round and recover 100% of injected flows, the yield would be 1,500 to 1,900 AFY. Based on 2015 data, the average availability of recycled water at the WRRF during the six-month period from June through November, which generally corresponds with the lowest natural flows in San Luis Obispo Creek 1, is between 800 and 1,000 AF. Therefore, the yield for streambed percolation is estimated to be 900 AFY for this analysis. 1 Flows in San Luis Obispo Creek vary annually. Annual creek flow data can be obtained from the County of San Luis Obispo’s website. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 50 1/19/2017 Preliminary Hydrogeological Assessment of Groundwater Recharge with Recycled Water CHG prepared a technical memorandum entitled, “Overview of Groundwater Recharge of Recycled Water San Luis Obispo Groundwater Basin”, included as Appendix I, reviewing the characteristics of the San Luis Obispo Valley Groundwater Basin and the potential for groundwater recharge. Major conclusions from the memo include the following (14): 1. The storage capacity of the aquifers near San Luis Obispo Creek is limited. 2. Groundwater levels in this area fluctuate between 20 and 40 feet over a year. 3. “While there have been periods of groundwater level declines in the past, the groundwater level trend is stable, reflecting lower groundwater extractions due to the conversion of agricultural lands to urban uses and reduced pumpage by the City of San Luis Obispo.” 4. Moving the discharge from the WRRF to between Prado Lane and Madonna Road when groundwater storage is available could enhance groundwater recharge. 5. “Impacts resulting from artificial groundwater recharge would include: a. Reduce[d] groundwater level depth b. Stabilized water level fluctuations c. Reduced subsidence d. Reduced stream flow losses [to percolation as the aquifer levels will increase over time] e. A blending of recharge water quality with existing water quality (positive or negative impact, depending on quality of recharge waters) f. Increase [in] the [amount] groundwater [that is] available for [sustained] use” 6. Depending on recharge location and time of year, groundwater recharge could benefit users and land owners, potentially the City, water purveyors, Cal Poly, rural property owners, agriculture landowners, and flora and fauna. A map of San Luis Valley that highlights the San Luis Obispo Valley Groundwater Basin (dashed outline) is provided in Figure 12. An aerial schematic of the potential recharge location within the San Luis Obispo Valley Groundwater Basin is provided in Figure 13. The location is approximately 0.5 miles from the WRRF. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 51 1/19/2017 Figure 12. Map of San Luis Obispo Valley Groundwater Basin (14) Figure 13. Aerial Schematic of the Indirect Potable Reuse Groundwater Recharge Location (about 0.5 miles from the WRRF)(Adapted from (14)) WRRF located ~0.5 mile from Recharge DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 52 1/19/2017 Description and Analysis For the purposes of this Study, streambed percolation in San Luis Obispo Creek was selected for analysis. This represents the most conservative approach for groundwater recharge as it assumes that recharge through percolation is only possible during the summer, and therefore it serves to bracket the low end of yield for potable reuse projects. For this alternative, water from the WRRF would be treated to potable reuse standards (advanced treatment) prior to recharge via streambed percolation in the San Luis Obispo Valley Groundwater Basin. The recharged water could be subsequently extracted for drinking water through new or existing production wells following residence time and natural treatment in the aquifer. As previously stated in Section 5 and detailed in Appendix C. Recycled Water Treatment Requirements, the regulations are already in place for groundwater recharge. Alternative 3 includes advanced treatment of the recycled water at the WRRF (described in Section 7.3.3.2) and a 0.5 mile pipeline and pump to deliver the water upstream of the WRRF. RO is not included in this analysis. Wellhead treatment, if required after groundwater recharge and extraction, is not included in these cost estimates. 7.3.3.1 Use Volume and Seasonal Variations As previously stated, the assumed yield for groundwater recharge by stream percolation is 900 AFY. This yield is not based on hydrogeological data but is instead based on average 2015 tertiary flows from June through November. An additional study would need to be performed in order to determine the actual yield from the San Luis Obispo Valley Groundwater Basin that the City could realize. 7.3.3.2 Potential Upgrades and Regulatory Considerations As previously described, the WRRF is in the process of upgrading and expanding the plant with an MBR. This analysis assumes MBR is implemented at the WRRF prior to development of the groundwater recharge project. The process flow schematic considered and the corresponding potential values for pathogen log reduction credits are presented in Figure 14 and Figure 15, respectively. The MBR product water would be further treated with ozone to breakdown complex organics (e.g., pharmaceuticals and personal care products), followed by a biological active carbon (BAC) filter to remove the broken down organics, disinfection and advanced oxidation (UV/AOP) to remove pathogens, and streambed percolation. Wellhead treatment is not shown in the process flow schematic as the treatment requirements are still unclear. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 53 1/19/2017 Figure 14. Process Flow Schematic Considered for Indirect Potable Reuse Figure 15. Pathogen Log Reduction Credits Potential with the Process Flow Schematic Considered for Indirect Potable Reuse (Target is 12/10/10 for Virus/Crypto/and Giardia, respectively) (Adapted from (15)) The regulations are already in place for groundwater recharge. Considerations specific to Alternative 3 include the following: 1. Advanced treatment would be required to comply with the groundwater replenishment regulations. The extent of advanced treatment is discussed further below; 2. The groundwater recharge location would be considered a new point of discharge to San Luis Obispo Creek, and therefore a new or modified NPDES permit would be required from the RWQCB; 3. Submission of a Report of Waste Discharge to the RWQCB and an Engineering Report to the RWQCB and DDW; 4. A Petition for Change would be required to be filed with the SWRCB; 5. Studies would have to be conducted to measure water residence time from when it enters the basin until it is extracted; 6. Groundwater modeling is needed to estimate yield and evaluate operational scenarios; 7. New infrastructure within the bed and banks of the creek would trigger Army Corps of Engineers (ACOE) 404 permit and RWQCB 401 Water Quality Certification, as well as a Streambed Alteration Agreement from the California Department of Fish and Wildlife (CDFW); 8. Habitat considerations and impacts to sensitive species would require consultation from the resources agencies (United States Fish and Wildlife Service (USFWS) and NOAA NMFS); DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 54 1/19/2017 9. Groundwater quality objectives, specifically TDS, would need to be evaluated to meet the intent of the RWQCB’s anti-degradation policy; 10. A SNMP would be required to comply with the SWRCB Recycled Water Policy; and 11. Existing groundwater quality issues may require wellhead treatment. Basic concerns include Chromium VI, Tetrachloroethylene (PCE), nitrate, corrosion control, and disinfection byproducts (DBPs). DDW would require demonstration and approval of the level of advanced treatment to ensure an appropriate level of public health protection. As described in Appendix C. Recycled Water Treatment Requirements, there are currently no pathogen log reduction credits in place for an MBR. The lack of credits is attributed to the inability to perform proper membrane integrity testing on the MBR membrane that is commonly performed on tertiary microfiltration (MF) or ultrafiltration (UF) membranes. It is anticipated that some level of pathogen log reduction credits will be in place for MBRs in the near future. In the case that the proposed process flow schematic (Figure 14) for this alternative is deemed insufficient, more advanced treatment unit processes would be required (e.g., tertiary MF or UF and/or RO). Additional unit processes would result in more capital and O&M expenses. The capital and O&M costs would increase significantly if RO were required. Additionally, the MF and RO processes result in a waste stream that reduces the amount of treated effluent available for beneficial use, so the unit cost would be further increased as a result of the reduced yield. Prior to the operation of the IPR by groundwater replenishment project, the City will also be required to develop and implement an Operation Optimization Plan which identifies and describes the operations, maintenance, analytical methods and monitoring necessary for the project to meet the requirements of the Groundwater Recharge Regulations. Preliminary Cost Estimate The preliminary cost estimate in Table 21 for Alternative 3 includes the advanced treatment facilities that follow the MBR implemented with the WRRF Project. It is important to note that the unit process flow schematic (Figure 14) assumes that neither membrane pre-treatment for RO nor RO treatment is required. The preliminary cost estimate would increase significantly if either were required for groundwater recharge by streambed percolation. Costs for wellhead treatment are not included. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 55 1/19/2017 Table 21. Alternative 3: Preliminary Cost Estimate Capital Cost Items 1, 2, 4 Capital Cost Conveyance and Pumping $971,000 Ozone $2,826,000 BAC $453,000 Advanced Oxidation and Disinfection 3 $1,014,000 Chemicals $554,000 Subtotal $5,818,000 30% Construction Contingency $1,745,000 25% Implementation Costs $1,891,000 Total Capital Cost $9,454,000 Operation and Maintenance Costs Items 5,6 Annual O&M Cost Conveyance and Pumping $13,000 Ozone $70,000 BAC $7,000 Advanced Oxidation and Disinfection $24,000 Chemicals $20,000 Total Annual O&M Cost $134,000 Payment Cost Annual Capital Payment 5% interest for a 30 year term $615,000 Year 1 O&M $134,000 Total Annual Payment $749,000 Net Present Value $12,586,000 Unit Cost based on 900 AFY $830 Notes: 1 MF/UF membranes were not considered in this analysis. There is a chance that such technology would be required if demonstration testing does not meet treatment requirements. 2 RO or NF treatment was not considered in this analysis. There is a chance that such a technology would be required if demonstration testing does not meet treatment requirements. 3 It is anticipated that the potable reuse UV/AOP will be independent of the UV/AOP having a UV dose of more than a magnitude greater than the WRRF Project UV disinfection system. 4 Wellhead treatment was not considered as it is unclear what that treatment would entail. 5 The analysis conservatively assumed the Full Advanced Treatment (FAT) train would operate 6-months per year (see CHG report). There is the potential for year round recharge. 6 O&M considered energy, chemicals, and materials and maintenance. Staffing was excluded from the analysis. It is anticipated that the 0.5 to 1.0 full time employees (FTEs) would be required over a calendar year for this alternative. For example, this alternative conservatively assumes that the FAT train would operate 6-months per year which translates to 1.0 to 2.0 FTEs while in operation. This translates to 0.5 to 1.0 FTEs over a full 12-month calendar year. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 56 1/19/2017 Advantages and Disadvantages Advantages of Alternative 3 include an increase in and diversification of the City’s water supply reliability, and ease of social acceptance when compared to DPR. Some disadvantages of Alternative 3 are the requirement of an additional point of discharge at the percolation location in San Luis Obispo Creek and that groundwater recharge is limited to the months of year when the creek has the capacity to accept percolation. This is anticipated to last approximately 6 months per year during the dry season. Additionally, the level of treatment is unclear. This alternative may require RO pre-treatment membranes and/or RO treatment (preliminary cost estimates do not reflect this), and this alternative will most likely require the second-highest level of advanced treatment of the five alternatives evaluated. Alternative 3 requires pumping to the additional point of discharge, followed by pumping to extract the water, and studies would have to be conducted to measure water residence time from when it enters the basin until it is extracted. Wellhead treatment at the extraction location may also be required (preliminary cost estimates do not include this), but the City does have existing wells that have the potential to be used for extraction. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 57 1/19/2017 ALTERNATIVE 4: PROVIDE DIRECT POTABLE REUSE (DPR) This section discusses the DPR alternative that would augment the City’s existing potable water supply. Background The City could augment its potable water supply through DPR – production of potable water at the WRRF. This type of potable reuse provides fully advanced-treated water that meets potable reuse standards, has spent time in an engineered buffer (clearwell), and has gone through surface drinking water treatment processes before delivery to the City’s potable water distribution system. DPR could also be achieved by transporting advanced treated water from the WRRF to the City’s Water Treatment Plant. For this reason, cost estimates for both methods of DPR are included in this alternative. For the purpose of this analysis, a yield of 1,800 AFY is used. As stated in Section 5 and in Appendix C. Recycled Water Treatment Requirements, there are no regulations yet for DPR. The feasibility evaluation of DPR regulations are targeted to be in place at the end of 2016, but formal regulations will more likely be issued in 2017. Description and Analysis Alternative 4 includes DPR via water treatment at a satellite water treatment plant at the WRRF and delivery to the potable water distribution system. This includes advanced treatment of the water at the WRRF (including an additional MF/UF membrane) and a clearwell (tank) that is expected to be required for DPR. This alternative also includes cost estimates for pumping and conveyance of the advanced treated water to the City’s Water Treatment Plant as both are viable options for DPR. This includes a 6 mile pipe from the WRRF to the Water Treatment Plant. RO is not included in this analysis. 7.4.2.1 Use Volume and Seasonal Variations DPR is an opportunity to diversify and increase water supply on a daily basis. This alternative is unique in that potable water demand is more consistent year-round than non-potable use and does not encounter limitations based on seasonal demand patterns. As discussed in Section 3, recycled water available for DPR is 1,500-1,900 AFY. For this analysis, a value of 1,800 AFY, based on 2015 flows, was used to prepare the cost estimate. 7.4.2.2 Potential Upgrades and Regulatory Considerations As previously described, the City is in the process of upgrading and expanding the WRRF with an MBR. This analysis is based on the implementation of an MBR at the WRRF. Similar to IPR, ozone, BAC, and UV/AOP would follow MBR treatment, with an additional membrane step (MF/UF), and a clearwell environmental buffer, followed by drinking water treatment prior to distribution. The process flow schematic considered and the corresponding pathogen log reduction credits potential are presented in Figure 16 and Figure 17, respectively. If the advanced treated water were transported to the City’s Water Treatment Plant, the treatment train at the WRRF would only include the “Full Advanced Treatment (FAT) Treatment Train Portion” in the following figures. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 58 1/19/2017 Figure 16. Process Flow Schematic Considered for Direct Potable Reuse Figure 17. Pathogen Log Reduction Credits Potential with the Process Flow Schematic Considered for Direct Potable Reuse (Target is 12/10/10 for Virus/Crypto/and Giardia, respectively) (Adapted from (15)) The pathogen log reduction credits are the same for IPR and DPR. The additional regulatory measures anticipated with DPR include, but are not limited to, additional barriers of treatment and sufficient response time to divert flows in the case of compromised process performance. The former is addressed by adding the MF membrane to the DPR treatment train. The latter is addressed by increasing the number of process controls and the addition of a clearwell. The clearwell provides 24-hours storage prior to drinking water treatment and distribution, which should to allow sufficient response time in the case of compromised process performance. This is not certain because regulations are not yet in place for DPR. Based on the Draft Report to Legislature on Feasibility of Developing Uniform Water Recycling Criteria for Direct Potable Reuse (September 2016), it is anticipated that key issues that will inform development of DPR regulations will include, at a minimum: 1) Specialized operator training and certification 2) Log Reduction Values for treatment trains 3) Variations in source water contaminants 4) Constituents of Emerging Concern 5) Process monitoring to ensure public safety 6) Engineered storage buffer 7) Treatment redundancy DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 59 1/19/2017 Without DPR regulations in place, there are some suggested microbial and chemical criteria for treatment based on previous studies and DPR practices. The suggested microbial criteria are similar to the log reduction requirements for IPR with an additional 9-log removal of total coliform bacteria due to its abundant presence in wastewater. The FAT processes with MBR, ozone, BAC, MF, and the combination of UV/AOP can achieve the accumulated log removal from raw wastewater. DPR regulations will likely include stringent chemical criteria including disinfection byproducts (e.g. N- Nitrosodimethylamine (NDMA)) and unregulated chemicals that have adverse impact on public health, such as 1,4-dioxane. UV/AOP is an essential treatment process for removal of these chemicals. Particular UV/AOP system design criteria for reduction of NDMA and/or 1,4-dioxane have been established in a number of potable reuse cases in Southern California. Considerations specific to Alternative 4 include the following: 1. FAT would be required with AOP as an essential treatment process to satisfy chemical criteria; 2. More stringent microbial and chemical criteria are anticipated for DPR; 3. RO may be required for stringent pathogen and total organic carbon requirements; 4. Studies would have to be conducted on the existing treated water quality in the distribution system; and 5. A model would need to be developed to evaluate blending and operational scenarios. Extended treatment demonstration is expected to be required. As with IPR, DDW would require demonstration and approval of the level of advanced treatment, and it is anticipated that some level of pathogen log reduction credits will be in place for MBRs in the near future. For more information, refer back to Section 7.3.3.2. In the case that the proposed process flow schematic (Figure 16) for this alternative maybe deemed insufficient, more advanced treatment unit processes would be required (e.g., RO, free chlorine, etc.). Additional unit processes would result in more capital and O&M expenses. As with IPR, the capital and O&M costs would increase exponentially if RO were required and may fatally flaw this alternative. Additionally, the RO processes result in a waste stream that reduces the amount of treated effluent available for beneficial use, so the unit cost would be further increased as a result of the reduced yield. DPR project may initiate a permit re-opener and renewal process for the City’s National Pollutant Discharge Elimination System (NPDES) permit, and would require CEQA documentation Preliminary Cost Estimate The preliminary cost estimate in Table 22 for Alternative 4 includes the advanced treatment facilities that follow the WRRF Project MBR. As with IPR, it is important to note that the unit process flow schematic (Figure 16) assumes that neither membrane pre-treatment for RO nor RO treatment is required. The preliminary cost estimate would increase significantly if either were required for DPR. The estimate includes costs for both a satellite water treatment plant at the WRRF and transportation of the advanced- treated water to the City’s Water Treatment Plant. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 60 1/19/2017 Table 22. Alternative 4: Preliminary Cost Estimate Capital Cost Items 1,2 Capital Cost DPR to City Water Treatment Plant 3 DPR Direct to City Water Distribution 4 Conveyance and Pumping $7,287,000 $380,000 Ozone $2,729,000 $2,729,000 BAC $451,000 $451,000 Microfiltration $3,843,000 $3,843,000 Advanced Oxidation and Disinfection $1,009,000 $1,009,000 Clearwell $3,696,000 $3,696,000 Chemicals $552,000 $552,000 Drinking Water Coagulation/Flocculation - $565,000 Drinking Water MF (or UF) - $7,954,000 Drinking Water UV - $431,000 Drinking Water Chloramination - $383,000 Subtotal $19,567,000 $21,993,000 30% Construction Contingency $5,870,000 $6,598,000 25% Implementation Costs $6,359,000 $7,148,000 Total Capital Cost $31,796,000 $35,739,000 Operation and Maintenance Costs Items Annual O&M Cost Conveyance and Pumping $149,000 $15,000 Ozone $89,000 $89,000 BAC $15,000 $15,000 Microfiltration $155,000 $155,000 Advanced Oxidation and Disinfection $48,000 $48,000 Clearwell $20,000 $20,000 Chemicals $101,000 $101,000 Drinking Water Coag/Floc - $11,000 Drinking Water MF (or UF) - $133,000 Drinking Water UV - $25,000 Drinking Water Chemicals - $77,000 Total Annual O&M Cost $577,000 $689,000 DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 61 1/19/2017 Payment Cost Annual Capital Payment 5% interest for a 30 year term $2,068,000 $2,325,000 Year 1 O&M $577,000 $689,000 Total Annual Payment $2,645,000 $3,014,000 Net Present Value $45,276,000 $51,844,000 Unit Cost based on 1,800 AFY $1,470 $1,670 Notes: 1 RO or NF treatment was not considered in this analysis. There is a chance that such a technology would be required if demonstration testing does not meet treatment requirements. 2 It is anticipated that the potable reuse UV/AOP will be independent of the UV/AOP having a UV dose of more than a magnitude greater than the WRRF Project UV disinfection system. 3 O&M considered energy, chemicals, and materials and maintenance. Staffing was excluded from the analysis. It is anticipated that the 1.75 to 2.25 full time employees (FTEs) would be required over a calendar year for this alternative. 4 O&M considered energy, chemicals, and materials and maintenance. Staffing was excluded from the analysis. It is anticipated that the 2.0 to 2.5 full time employees (FTEs) would be required over a calendar year for this alternative. Advantages and Disadvantages Alternative 4 would provide additional water resiliency to the City by diversifying its water supply portfolio, and potable water demand is year-round allowing the City to realize the full available yield of recycled water from the WRRF. Disadvantages of Alternative 4 include a lack of regulations for DPR, and unclear level of treatment as this alternative might require RO treatment (preliminary cost estimates do not reflect this). DPR would most likely require the highest level of advanced treatment of the five alternatives evaluated, and social acceptance for this alternative will most likely be the most challenging to obtain. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 62 1/19/2017 ALTERNATIVE 5: CONSTRUCT A NEW SATELLITE WRRF TO SERVE CAL POLY AND THE SURROUNDING AREAS Background This alternative explores the implementation of a satellite WRRF to serve Cal Poly and the surrounding areas with recycled water produced from Cal Poly’s wastewater flows. The cornerstone of this alternative is the ability to treat wastewater at its source while serving as an educational facility for Cal Poly. An aerial schematic of a potential siting location at Cal Poly is provided in Figure 18. For this analysis, a value of 270 AFY is used for yield, which is based on average monthly sewer flows at Cal Poly (2005-2013 data). Figure 18. Potential Satellite WRRF Siting Location at Cal Poly The satellite WRRF technology did not go through a rigorous screening exercise to identify a preferred technology. Rather, two technologies were considered: an engineered hydroponic system (EHS) and an MBR at Cal Poly. 7.5.1.1 Engineered Hydroponic System The EHS involves a series of interconnected bio-reactors with lush vegetation growing above them. Figure 19 contains a schematic of an EHS from Sustainable Water©. Possible Plant Location Possible Users DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 63 1/19/2017 Figure 19. Engineered Hydroponic System Technology Schematic for a Satellite WRRF (Source: Sustainable Water©) Prior to treatment by the EHS, the waste stream is subjected to primary treatment. The primary treated waste stream (i.e., solids clarification or screening) is delivered to the modules over a set period of time. Following primary treatment, the water is sent into a series of hydroponic reactors. While in the hydroponic reactors: “Plant roots extend into the reactors to provide a natural habitat for fixed-film and suspended microbeal organisms that consume organic waste. This creates more complex and diverse ecosystems that quickly digest or remove organic pollutants from water. Plants enhance the treatment process through greater oxygen diffusion and microbiological habitat creation. Sustainable Water uses artificial media to mimic that natural root system in order to extend the surface area for this growth. Compared to traditional biological treatment systems, hydroponic treatment allows for significant reductions in physical footprint, sludge production, and energy use,” (Sustainable Water©). The EHS treated water is subsequently subjected to further treatment to meet unrestricted Title 22 requirements, which includes filtration and disinfection. The flow is entirely sub-surface which alleviates concerns over exposure to the general public. Cal Poly is interested in the prospect of an EHS because it combines both natural and mechanical treatment. This technology provides a low-tech natural treatment approach requiring minimal energy, is an approved technology for unrestricted Title 22, and is an eco-educational attraction of interest to students and the community. 7.5.1.2 Membrane Bioreactor In contrast, the MBR is a technology that encompasses primary, secondary, and tertiary treatment all within a single compact reactor. As stated before, MBR is also the technology being implemented as part of the City’s WRRF Project. A process flow schematic and a picture of a membrane cartridge is provided in Figure 20. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 64 1/19/2017 Figure 20. MBR Technology Schematic for a Satellite WRRF (Left: Process Flow Schematic and Right: Membrane Cartridge) An MBR is an activated sludge mechanical process that relies on membranes to separate solids from treated water. A process flow schematic of a Satellite WRRF MBR is presented in Figure 21. The MBR was included in Alternative 5 due to the compact footprint, proven treatment performance, consideration as the industry standard for satellite plants, and minimal operator attention (a few hours per week). Despite all these benefits, the MBR turns out to be more expensive than an EHS for both capital and O&M. Figure 21. Process Flow Schematic for a Satellite WRRF Membrane Bioreactor Description and Analysis This alternative includes estimates for both an EHS and an MBR, and a 0.5 mile pipe and pump to distribute the water to reuse sites on campus once treated. Waste Activated Sludge Headworks Return Activated Sludge Membrane Bioreactor Disinfection Sewer to the WRRF Recycled Water To the WRRF DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 65 1/19/2017 7.5.2.1 Use Volume and Seasonal Variations A preliminary analysis was performed on existing sewer flows at Cal Poly and the irrigation demands. The current average monthly sewer flows range from 5 to 35 AF per month. The lower range represents flows during the dry season when Cal Poly is not in session (about 3 months per year). During this period, the recycled water demand is greatest at approximately 17 AF per month. Thus, on-site product water storage would be required to meet the recycled water demands during such peak demand months. It is unclear if Cal Poly has sufficient storage to accommodate such demands. Preliminary discussions with Cal Poly identified approximately 34 AF of available storage. Such a volume would be insufficient to meet a consecutive 3-month demand at 17 AF per month with only approximately 5 AF per month of flow water entering the satellite WRRF. A more detailed water supply balance is recommended to confirm the inability to store sufficient volumes for meeting the dry season irrigation demands at Cal Poly using product water from a satellite WRRF. As stated previously, a value of 270 AFY is used for recycled water yield, which is based on average monthly sewer flows at Cal Poly (2005-2013 data). The impact on the City’s collection system caused by diverting Cal Poly sewer flows to a satellite WRRF was evaluated as part of this alternative. Diversion of flows results in reduced flow velocities in the City’s collection system, which would have the following impacts: 1. Potential strain on collection system pumping stations due to flows below the pumps’ desired flows; 2. Enhanced solids settling in the collection system; 3. Increased odors from reduced velocities; 4. Increased hydrogen sulfide production which has the potential to reduce the life-span of the pipeline; and 5. Increased maintenance due to the contributing factors described above. Diverting flows from the City’s collection system would also have the following potential impacts on the WRRF: 1. Reduced flows entering the WRRF; 2. More grit at the WRRF during storm events (due to enhanced solids settling in the collection system that gets pushed to the WRRF); 3. Increased odors that were created in the collection system; 4. Increased time frame until flow and load projections are met; 5. More pronounced wet weather flow and loading peaking factors; 6. Carbon-to-nitrogen and alkalinity-to-ammonia ratios potentially impacted (unclear as to which direction); and 7. Increased waste stream concentrations problematic at the WRRF. Rather than rely on storage volume at Cal Poly to meet peak dry season irrigation water demands, an alternative strategy might be to augment low dry season campus flows by diverting flows from the neighboring City of San Luis Obispo collection system. This strategy might be the only viable approach to addressing the low campus sewer flows during peak recycled water demands. Such a strategy would require a more rigorous analysis on the impacts to City revenue, the collection system, and the WRRF. Moreover, such a strategy may further amplify the impacts listed above on the collection system and WRRF. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 66 1/19/2017 7.5.2.2 Potential Upgrades and Regulatory Considerations The potential upgrades for a satellite WRRF will vary by technology. The common upgrade elements would be as follows: 1. Site location at Cal Poly (see Figure 18) 2. Headworks to remove grit and screenings 3. Disinfection to meet unrestricted Title 22 requirements 4. Discharge pumping and conveyance pipelines to recycled water users The additional elements specific for either an EHS or MBR are as follows: Engineered Hydronic System: 1. Equalization basin 2. Media 3. Hydroponic basins (shallow) to hold the media and provide depth for treatment 4. Chemical feed facilities (if necessary for alkalinity) 5. Chemical feed facilities for cleaning media (if necessary) 6. Internal recirculation pumps 7. Filters to satisfy unrestricted Title 22 requirements MBR: 1. Aeration basins 2. Aeration system 3. Membrane tanks 4. Membrane racks 5. Membrane permeate pumps 6. Chemical feed facilities (if necessary for alkalinity) 7. Chemical feed facilities for clean-in-place membrane tanks 8. Internal recirculation pumps 9. Return activated sludge and waste activated sludge pumps This alternative has more permitting and documentation requirements than the other Title 22 alternatives as a new facility would be constructed and there are water rights issues as Cal Poly currently sends it sewer flows to the WRRF. Overall, implementation of a satellite WRRF would require permits/documentation associated with constructing new facilities, those associated with operating a satellite WRRF, and adherence to Title 22 water distribution and storage regulations. The permitting requirements include various infrastructure permits (e.g. NPDES General Construction Permit), those associated with Title 22, a SNMP, and a change petition regarding water rights as this sewer flow was designed for conveyance to the WRRF. If carried forward in the future, it is recommended that Cal Poly initially meet with RWQCB to obtain coverage for the proposed satellite WRRF and waste effluent discharge under a Water Discharge Requirement (WDR) and/or Water Reclamation Requirement (WRR) permit. From a documentation standpoint, Cal Poly should plan to prepare an Initial Study (IS) followed by an Environmental Impact Report (EIR) for the recommended project. In anticipation of applying for federal funding sources, Cal Poly may also prepare an Environmental Assessment (EA) and an Environmental Impact Statement (EIS) to comply with the National Environmental Policy Act (NEPA). DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 67 1/19/2017 Preliminary Cost Estimate The preliminary cost estimate for Alternative 5 in Table 23 include lower end costs for the EHS, upper end costs for an MBR, and a pipeline and pump to distribute the treated recycled water on campus. Table 23. Alternative 5: Preliminary Cost Estimate Capital Cost Items Capital Cost Engineered Hydroponic System 1 Membrane Bioreactor 2 Conveyance and Pumping $492,000 $492,000 Satellite WRRF $2,231,000 - $4,385,000 $4,385,000 - $11,000,000 Subtotal $2,723,000 - $4,877,000 $4,877,000 - $11,492,000 30% Construction Contingency $817,000 - $1,463,000 $1,463,000 - $3,448,000 25% Implementation Costs $885,000 - $1,585,000 $1,585,000 - $3,735,000 Total Capital Cost $4,425,000 - $7,925,000 $7,925,000 - $18,675,000 Operation and Maintenance Costs Items Annual O&M Cost 3 Conveyance and Pumping $34,000 $34,000 Satellite WRRF O&M $200,000 $350,000 Total Annual O&M Cost $234,000 $384,000 Payment Cost Annual Capital Payment 5% interest for a 30 year term $288,000 - $516,000 $516,000 - $1,215,000 Year 1 O&M $234,000 $384,000 Total Annual Payment $522,000 - $750,000 $900,000 - $1,599,000 Net Present Value $9,896,000 - $13,401,000 $16,907,000 - $27,652,000 Unit Cost based on 270 AFY $1,930 - $2,780 $3,330 - $5,920 Notes: 1 Engineered Hydroponic System. The facility is sized for current maximum month flows (0.36 mgd). Flows that exceed maximum month will use the existing collection system and flow to the WRRF. 2 Membrane Bioreactor. The facility is sized for current maximum month flows (0.36 mgd). Flows that exceed maximum month will use the existing collection system and flow to the WRRF. 3 O&M considered energy, chemicals, and materials and maintenance. Staffing was excluded from the analysis. The staffing onus would fall on Cal Poly. Advantages and Disadvantages The satellite WRRF could serve as an educational facility on campus and uses proven technologies that have approval for unrestricted Title 22 water. Additional advantages include reducing the conveyance distance of recycled water by having the facility near the source water and diversifying and increasing the reliability of Cal Poly’s water supplies. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 68 1/19/2017 Disadvantages include required staffing to operate and maintain the system, potential for increased odors at the WRRF and Cal Poly site, reduced flows to the WRRF and associated impacts on the WRRF and the City’s collection system, and challenges associated with operating a satellite WRRF with such wide ranging seasonal flows. Additionally, recycled water production is lowest when demands are the highest (i.e., dry season), which would require a series of storage basins or additional water from a neighboring sewer line to make the alternative more attractive. NO PROJECT ALTERNATIVE The No Project Alternative would involve no change in the recycled water treatment processes at the WRRF and would cost no additional capital or operation and maintenance costs. Customer demands would increase according to the 2015 UWMP, but no additional beneficial use of recycled water would be realized. This alternative would not fulfill the City’s beneficial use goals for recycled water. ALTERNATIVE SUMMARY Table 24 summarizes the yield and costs for each alternative. Table 24. Alternatives Summary Table Value Alternative 1: Edna Valley Irrigation Area Alternative 2: Cal Poly Recycled Water Alternative 3: Indirect Potable Reuse Alternative 4: Direct Potable Reuse Alternative 5: Satellite WRRF Potential Recycled Water Demand (AFY) 1,000 82 900 1,800 270 Total Capital Cost $991,000 $7,996,000 $9,454,000 $31,796,000 - $35,739,000 $4,425,000 - $18,675,000 One Year of O&M $79,000 $91,000 $134,000 $577,000 - $689,000 $234,000 - $384,000 Net Present Value $2,830,000 $10,120,000 $12,586,000 $45,276,000 - $51,844,000 $9,896,000 - $27,652,000 Unit Cost ($/AF) $140 $7,450 $830 $1,470 - $1,670 $1,930 - $5,920 Weighted Score 86 74 80 76 40 Note: These costs are 2016 costs, and do not include escalation corresponding to implementation schedules shown in Section 9. ALTERNATIVE ASSESSMENT PROCESS Through the Study process, the five alternatives were narrowed down to the three top alternatives through a “triple bottom line” (environmental, social, and economic) screening process while maintaining consistency with local policies. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 69 1/19/2017 The Kickoff Meeting was conducted on January 8, 2016 to review the Study goals and objectives, clearly define each of the five alternatives, and identify the Study team and stakeholders. Representatives from different sectors within the City’s Utilities department and the WRRF Project Team participated in the meeting. This meeting concluded with discussion of the study schedule and data requests. The Alternatives Screening Workshop was held on February 22, 2016. In this meeting, the preliminary analysis of the five alternatives was presented. The triple bottom line criteria for the alternatives screening, listed below, were reviewed, and the alternatives were scored by the Study team. Three alternatives rose to the top in this workshop. Maximize Resource Recovery Sustainable Management of Salts and Nutrients Regulatory Complexity Flexibility for Meeting Future Regulations Partnerships Community Asset to Foster Learning Operational Complexity Environmental Impacts (Construction and Operation) Energy and Chemical Intensity Ease of Implementation Consistent with Community Priorities An explanation of these criteria and the meaning of the scores used in this screening exercise can be found in Appendix F. Alternatives Screening Criteria. During the Alternatives Screening Workshop, each alternative was evaluated using the above criteria. Scores from 1 to 3 were given for each criteria, with 3 being the highest/best. For example, the Direct Potable Reuse alternative was given a score of 3 for Maximizing Resource Recovery. Then, the criteria themselves were given a weight from 1 to 5, with 5 being the highest/most important. For example, for all alternatives, the criteria of Flexibility for Meeting Future Regulations was given a weight of 3. To obtain overall weighted scores for each alternative, the weights were multiplied by the criteria scores, and all of these weighted scores were added together for each alternative. The results from the screening workshop will be presented in the following section. Following the screening, the top three alternatives were evaluated more thoroughly, and more robust cost estimates were developed. The Alternatives Evaluation Workshop was conducted on April 20, 2016 in order to review the in-depth analysis conducted for the top alternatives. This analysis included review of the preliminary implementation schedule and discussion of next steps. ALTERNATIVES SCREENING AND EVALUATION RESULTS Table 25 shows the non-weighted and weighted results from the Screening Workshop. The full results table is included in Figure 22. As a reminder, each alternative was scored against the criteria, and then the criteria were each given a weight. DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 70 1/19/2017 Table 25. Alternatives Screening Results Alternative Non-Weighted Score Weighted Score Alternative 1: Deliver Recycled Water to The Edna Valley irrigation area Agricultural Interests 28 86 Alternative 2: Deliver Recycled Water to Cal Poly 24 74 Alternative 3: Indirect Potable Reuse 24 80 Alternative 4: Direct Potable Reuse 22 76 Alternative 5: Construct a New Satellite WRRF to Serve Cal Poly and the Surrounding Areas 14 40 DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 71 1/19/2017 Figure 22. Alternatives Screening Criteria and Results Table DRAFTCity of San Luis Obispo 7. Project Alternatives Analysis Recycled Water Facilities Planning Study - Final Draft 72 1/19/2017 Alternative 1 scored the most favorable for both non-weighted and weighted scores. It did not score 1 in any of the categories. It scored 3 in Regulatory Complexity, Flexibility for Future Regulations, Operational Complexity, Environmental Impacts (Construction and Operation), Energy and Chemical Intensity, and Ease of Implementation. The high scores in these categories indicate that this alternative is relatively simple in regulation, construction, and operation, and allows for future flexibility. Alternative 2 scored second highest, tied with Alternative 3, for non-weighted scores, but second lowest for weighted scores. This means that the outcomes of this alternative did not align strongly with the City’s water resources goals when compared to the other alternatives. Alternative 2 scored 1 in Maximize Resource Recovery, Community Asset to Foster Learning, and Consistent with Community Priorities. The low scores in these categories show that though this would result in additional use of recycled water, it is more of an expansion of the current system than a novel alternative. This alternative scored 3 in Regulatory Complexity, Flexibility for Future Regulations, Operational Complexity, Environmental Impacts (construction and operation), Energy and Chemical Intensity, and Ease of Implementation. The high scores in these categories show that this alternative is thought to be relatively simple to implement and operate with few impacts to the surrounding environment and natural resources. Alternative 3 scored second most favorable for both weighted and non-weighted scores. Of the 11 categories scored, it scored 1 for Operational Complexity and Ease of Implementation. It scored 3 in Sustainable Management of Salts and Nutrients, Partnerships, Community to Asset to Foster Learning, and Consistent with Community Priorities. The high scores in these categories indicate that this alternative has long-term sustainable benefits to the community that align with community priorities. Alternative 4 scored third most favorable for non-weighted and third most favorable for weighted scores. Of the 11 categories scored, it scored 1 for Operational Complexity, Environmental Impacts, Energy and Chemical Intensity and Ease of Implementation. It scored 3 in Sustainable Management of Salts and Nutrients, Partnerships, Community to Asset to Foster Learning, and Consistent with Community Priorities. The high scores in these categories indicate that this alternative, while potentially involving more treatment upgrades and heavy regulation, has long-term sustainable benefits to the community that align with community priorities. Alternative 5 had the lowest scoring of the five alternatives evaluated. The satellite WRRF did not score 3 for any of the values, showing that it would not fulfill the City’s goals for water resource management. After reviewing the results with the City at the Screening Workshop, it was decided that the top three alternatives that would be carried through to the Evaluation workshop would be Alternatives 1 (Edna Valley irrigation area), 3 (IPR), and 4 (DPR). DRAFTCity of San Luis Obispo 8. Recommended Facilities Project Plan Recycled Water Facilities Planning Study - Final Draft 73 1/19/2017 8 RECOMMENDED FACILITIES PROJECT PLAN Delivery of recycled water to the Edna Valley irrigation area and/or other outside-City interests and potable reuse (IPR and DPR) are recommended for implementation. The following sections outline the representative next steps for these potential projects. DELIVER RECYCLED WATER TO THE EDNA VALLEY IRRIGATION AREA As previously discussed, the Edna Valley irrigation area growers have requested 1,000 AFY of recycled water from the City. This alternative has the potential to provide a scalable and flexible beneficial use of the City’s recycled water. It may also support the continuation of agricultural operations surrounding the City, which is consistent with the City’s Land Use Element (5). This alternative requires an extension of the City’s current recycled water distribution system along Orcutt Road to the City limits, and turnout infrastructure at the end of the extension. It is recommended that the recommendations from the Production Analysis be implemented prior to delivery of water to the Edna Valley irrigation area. This project would also require an agreement for water pricing and a seasonal delivery schedule between the City and the Edna Valley irrigation area growers. The length of recycled water delivery commitment to outside-City interests should also be considered carefully considering the City's water supply needs. It is recommended that the contract language reflect: • Flexibility in the delivery schedule over time, including supply interruption; • Water delivery flow, pressure and water quality criteria; • Length of the contract and renewal options; and • Infrastructure responsibilities. The cost estimates for Alternative 1, which can be found in Table 19 in Section 7.1.3, show that this alternative has a preliminary cost of $140/AF. The City would not bear the cost of delivery of recycled water to outside-City interests such as to the Edna Valley irrigation area growers. This preliminary cost estimate is not intended to reflect a potential pricing structure for a water delivery agreement with the Edna Valley growers, nor is it a comprehensive representation of the actual costs related to implementation of this alternative. It is strictly intended to identify the costs of new infrastructure within the City limits that is required for this alternative. Additionally, costs to extend the pipeline to the points of use are not included, and this estimate does not include additional maintenance costs at the WRRF for increased recycled water production. Finally, this estimate does not include any “buy-in” costs to the existing infrastructure. DRAFTCity of San Luis Obispo 8. Recommended Facilities Project Plan Recycled Water Facilities Planning Study - Final Draft 74 1/19/2017 POTABLE REUSE: INDIRECT AND DIRECT REUSE Potable reuse could be realized through IPR (groundwater recharge by percolation or injection), by DPR direct into the City’s distribution system or by DPR with transportation of the advanced-treated water to the City’s Water Treatment Plant. IPR is assumed to have a yield of 900 AFY assuming streambed percolation, but yield could be increased if more efficient recharge strategies were developed (e.g. direct injection). DPR is assumed to have a yield of 1,800 AFY. Additional treatment for IPR would include ozone, BAC, and UV/AOP. The treatment train for DPR would build upon the IPR treatment train by adding an MF/UF membrane to increase the number of treatment barriers, a 24-hr clearwell to provide sufficient time to divert flows in the case of compromised process performance, and drinking water treatment before distribution if not sent to the City’s Water Treatment Plant. The drinking water treatment facilities would treat water to meet applicable U.S. Environmental Protection Agency (EPA) and DDW requirements. The regulations are already in place for IPR by groundwater replenishment. A summary of the key groundwater recharge requirements are: • Virus/Crypto/and Giardia log removal of 12/10/10, respectively • Meet all Safe Drinking Water Act Maximum Contaminant Levels • Total nitrogen of <10 mg N/L • Total organic carbon of <0.5 mg/L Extensive demonstration testing would be required to confirm that the proposed IPR treatment train meets treatment requirements, in particular since the proposed train does not include the State recommended RO treatment technology. This project would require further analysis focused on: 1) The San Luis Obispo Valley Groundwater Basin to confirm the water supply yield; 2) Siting location for the IPR treatment train considering space constraints and O&M requirements; 3) Detailed hydrogeology analysis to determine the feasibility and expected performance of groundwater recharge via percolation and injection; and 4) Confirm that groundwater recharge will not violate any groundwater quality objectives, specifically for TDS and assimilative capacity. Unlike the IPR by groundwater replenishment alternative, the State does not have regulations in place for DPR. In addition to the regulations required for IPR by groundwater replenishment, the draft regulations suggest that additional monitoring and a clearwell between the DPR effluent and drinking water plant will be required. Also similar to IPR by groundwater replenishment, extensive demonstration testing would be required. DPR would require further analysis focused on: 1) Siting location for the DPR treatment train; 2) Development of a social acceptance plan, as this can be more challenging than the technical related issues; and 3) The ability to blend the two water types in the distribution system; The cost estimate for IPR can be found in Table 21 in Section 7.3.4, and the cost estimate for DPR can be found in Table 22 in Section 7.4.3. DRAFTCity of San Luis Obispo 9. Implementation Plan Recycled Water Facilities Planning Study - Final Draft 75 1/19/2017 9 IMPLEMENTATION PLAN The strategy for implementing the recommended projects includes delivering water to the Edna Valley irrigation area growers on an expedited schedule in parallel with the development of a potable reuse project in San Luis Obispo. This implementation plan outlines the project costs for the three alternatives, permitting requirements, expected environmental documentation required, regulatory considerations, and an implementation schedule. EDNA VALLEY IRRIGATION AREA PROJECT Implementation Schedule The following implementation schedule outlines the major tasks and milestones that would be required to implement the delivery of recycled water to the Edna Valley irrigation area growers. It is expected that getting to delivery of recycled water to the Edna Valley irrigation area would take 2 years. It was assumed for this analysis that the recommendations from the Production Analysis will take 6 months to complete. City Council authorization is required before negotiations with the Edna Valley irrigation area growers can commence. Table 26. The Edna Valley Irrigation Area Project Implementation Schedule Estimated Project Cost The Edna Valley irrigation area project cost estimate in Table 27 includes escalation (3.5% per year) to the mid-point of construction (1.5 years from today’s dollars for demonstration, as the actual escalation would depend on the start date of the project). As stated previously, the City would not bear the cost of delivery of recycled water to outside-City interests such as to the Edna Valley irrigation area growers. This preliminary cost estimate is not intended to reflect a potential pricing structure for a water delivery agreement with the Edna Valley growers, nor is it a comprehensive representation of the actual costs related to implementation of this alternative. It is strictly intended to identify the costs of new infrastructure within the City limits that is required for this alternative. Additionally, costs to extend the pipeline to the points of use are not included, and this estimate does not include additional maintenance costs at the WRRF for increased recycled water production. Finally, this estimate does not include any “buy-in” costs to the existing infrastructure. Implementation Schedule Outside Interests Project Tasks and Milestones Develop and execute a contract with outside City interests Implement Recycled Water Improvements at the WRRF Design, CEQA, and permitting Construction of pipeline and turnout Deliver water to outside City interests ♦ YEAR Year 1 Year 2 DRAFTCity of San Luis Obispo 9. Implementation Plan Recycled Water Facilities Planning Study - Final Draft 76 1/19/2017 Table 27. Edna Valley Irrigation Area Project Implementation Cost Estimate, including escalation to mid-point of construction Capital Costs Cost Total Capital Cost $1,043,000 Operation and Maintenance Costs Total Annual O&M Cost $79,000 Payment Annual Capital Payment $68,000 Year 1 O&M $79,000 Total Annual Payment $147,000 Net Present Value $2,892,000 Unit Cost based on 1,000 AFY $150 / AF Permitting Requirements Please see Section 7.1.2.2 for information regarding permitting requirements. Environmental Documentation It is expected that this project would require completion of CEQA documentation in the form of an EIR for impacts in the City and in the Edna Valley irrigation area. Any additional permits required would be identified after the EIR has been completed. There is a streamlined response (per California Executive Order B-29-15) for State permitting agencies to prioritize review and approval of water projects and programs that increase local water supplies. This could potentially apply to this project. The project would also be required to conform with the City’s Climate Action Plan. Coordination and Governance City Council authorization is required before negotiations with outside-City interests can commence, and the length of recycled water delivery commitment to interests outside of the City should be considered carefully relative to the City's own short- and long-term water supply needs. It is assumed that the City will continue to take the lead on moving this project forward, including coordinating and collaborating with the Edna Valley irrigation area growers on an agreement and contract terms and working through developing a cost model for recycled water pricing if directed by City Council. Additionally, consideration should be given to the potential considerations under SGMA. POTABLE REUSE PROJECT Implementation Schedule Considering groundwater replenishment regulations are in-place, an IPR project is estimated to take 5 to 7 years to implement, considering the need to demonstrate an alternative, non-RO based advanced treatment train. Table 28 shows an estimated implementation schedule for an IPR project. Considering final regulations for DPR have not yet been developed, a detailed schedule for DPR implementation is not included. DRAFTCity of San Luis Obispo 9. Implementation Plan Recycled Water Facilities Planning Study - Final Draft 77 1/19/2017 Table 28. Indirect Potable Reuse Implementation Schedule Indirect Potable Reuse Project Tasks and Milestones Public outreach Groundwater modeling, including assimilative capacity study if necessary Treatment technology studies and piloting Pathogen log reduction credits for MBR* Preliminary engineering Environmental documentation (CEQA) Permitting Pursue funding Design Construction Delivery ♦ *Anticipated in the next few years. This is imperative for meeting the pathogen log reduction credit requirement and must be completed prior to permitting. Year 6 Year 7 Implementation Schedule Year 1 Year 2 Year 3 YEAR Year 4 Year 5 DRAFTCity of San Luis Obispo 9. Implementation Plan Recycled Water Facilities Planning Study - Final Draft 78 1/19/2017 Estimated Project Cost The project cost estimate in Table 29 includes escalation (3.5% per year) to the mid-point of construction (5 years for IPR; 7 years for DPR). Table 29. Potable Reuse Project Implementation Cost Estimate, including escalation to the mid-point of construction Capital Costs IPR Cost DPR Cost1 Total Capital Cost $11,228,000 $40,453,000 - $45,470,000 Operation and Maintenance Costs Total Annual O&M Cost $134,000 $577,000 - $689,000 Payment Annual Capital Payment $730,000 $2,632,000 - $2,958,000 Year 1 O&M $134,000 $577,000 - $689,000 Total Annual Payment $864,000 $3,209,000 - $3,647,000 Net Present Value $14,354,000 $53,946,000 - $61,575,000 Annual Yield 900 AFY 1,800 AFY Unit Cost $960/ AF $1,780 - $2,030 / AF Notes: 1 A range is given here to show costs for both drinking water treatment at the WRRF and transportation to the City’s Water Treatment Plant. IPR Hydrogeological Analysis As part of the preliminary design for an IPR project, it is recommended that a groundwater model for the San Luis Obispo Valley Groundwater Basin be developed to estimate yield, seasonal recharge periods, evaluate operational scenarios for developing planning level design recommendations, and assist with developing a SNMP. Such a model will enable modeling simulations that identify the preferred recharge strategy and associated design and operational criteria. The preliminary design recommendations will address the quantity of recharged water into the aquifer, percent of water recoverable, monitoring requirements, and groundwater extraction impacts on the local and regional groundwater levels. These are critical considerations that require further refinement for detailed design of an IPR by groundwater replenishment project. Furthermore, such a model could be used to optimize the City’s groundwater production strategy and to assist in the development of a SNMP. Permitting Requirements Please see Section 7.3.3.2 for information regarding permitting requirements. Additionally, it is anticipated that the City will need to obtain multiple permits to construct the recommended project including, but not limited to, the following: 1) Caltrans encroachment permits for pipelines within Caltrans Right-of-Way (limited to potable reuse alternatives) 2) Grading permits for treatment upgrades and recharge sites 3) NPDES General Construction Permit DRAFTCity of San Luis Obispo 9. Implementation Plan Recycled Water Facilities Planning Study - Final Draft 79 1/19/2017 4) Building permits 5) Streambed Alteration Agreement through CDFW for any stream crossings 6) Authority to Construct (ATC) and Permit to Operate (PTO) the wastewater treatment plant upgrades from the Air Quality Management District 9.2.4.1 Salt and Nutrient Management Plan It is anticipated that a SNMP would be developed by the City in conjunction with the project permitting process. The SNMP will consider the Basin Plan water quality objectives, the existing groundwater quality data, and determine the basin assimilative capacity. The SNMP findings may impact permit requirements for either potable reuse project because both FAT effluent water qualities may be inferior to the water quality objectives. The basis for this argument is that neither proposed FAT process flow schematics (see and Figure 21) includes RO treatment that would effectively remove salts and/or nutrients. The SNMP will need to include an implementation plan and monitoring program to meet the salt and nutrient objectives. The monitoring plan should be coordinated with the current basin monitoring efforts as well as the additional monitoring required for either potable reuse alternative to optimize monitoring facilities and operations. Environmental Documentation In accordance with CEQA, it is anticipated the City will prepare an IS followed by an EIR for the recommended project. In anticipation of applying for federal funding sources, the City may also prepare an EA and an EIS to comply with the National Environmental Policy Act (NEPA). The project would also be required to conform with the City’s Climate Action Plan. Coordination and Governance It is anticipated that the City could form a partnership with other participating organizations. With this model, the City would construct the facilities located within their jurisdiction and would negotiate reimbursement agreements with partnering organizations for cost sharing based on the agreed-upon shares of project benefit. DRAFTCity of San Luis Obispo 10. Financing Plan Recycled Water Facilities Planning Study - Final Draft 80 1/19/2017 10 FINANCING PLAN Expanding the City’s recycled water program to provide recycled water to the Edna Valley irrigation area and to develop a potable reuse project(s) may require a significant upfront capital investment depending on negotiations and treatment required. Additionally, adequate funding for annual O&M is necessary to ensure successful operation of a potable reuse facility. It is anticipated that the capital project costs will be funded through a combination of grants, low interest loans, and cost-sharing contributions from project partners. FUNDING OPPORTUNITIES Pursuing project funding may require an upfront investment by the City depending on the project. The City will seek external grant and loan funding through various state and federal programs if needed. The recommended recycled water alternatives are anticipated to be attractive to funding agencies because they meet several objectives commonly prioritized by funding programs, including: • Relies upon and strengthens local partnerships • Develops a new, local, sustainable drinking water supply • Improves water supply reliability • Improves groundwater basin quality Grant funding is limited and highly competitive. While the City’s goal is to maximize grant funding, the City also recognizes that a low-interest loan will likely be required to fully fund the projects. The following section presents potential grant and loan funding opportunities that may be available for the projects. Grant and Loan Programs Funding opportunities for recycled water projects are available from several state and federal sources, including the SWRCB, Department of Water Resources (DWR), United States Bureau of Reclamation (USBR), United States Department of Agriculture (USDA), California Energy Commission (CEC), and the EPA. Several of these programs are responsible for administering the funds made available by the 2014 Water Bond (Prop 1). Funding programs are available to fund project activities from preliminary planning to construction. A summary of eligible funding programs is presented in Table 30. Partnerships Partnerships may also play a key role in funding the projects. The City is committed to developing partnerships to support expansion of the City’s recycled water program. Key project partners for the City may include: • The Edna Valley irrigation area growers • Cal Poly • County of San Luis Obispo The City is building these partnerships through focused stakeholder outreach. Through this effort, the City will collaborate with project partners to identify opportunities for financial and in-kind contributions to the support the project. DRAFTCity of San Luis Obispo 10. Financing Plan Recycled Water Facilities Planning Study - Final Draft 81 1/19/2017 Table 30. Eligible Funding Programs Funding Program Applicability to City Available Funding Project Deadlines Disadvantaged Communities (DAC) Eligibility Application Schedule Reimbursable Funds Prior to Start Date Required Documents Water Recycling Funding Program- Construction Grant/Loan Program Funding for construction of water recycling projects Grant funding currently not available, and loan funding currently limited. Guidelines allow grants up to 35% up to maximum of $15 million, and loans/financing available for 100% of eligible costs. Repayment term up to 30 years. Interest rate is set to half of the most recent General Obligation bond rate. Total eligible project capacity shall be delivered within 5 calendar years of operation from the date of Initiation of Operations 50% of eligible project capacity must serve existing users Median Household Income (MHI)<80% of Statewide annual MHI1; Projects that benefit DAC communities will be prioritized for funding Applications are accepted on a continuous basis The applicant may satisfy the local match requirement through other sources, including its own revenues, for example, where it has incurred and paid costs for studies and other directly associated planning and design incurred prior to the grant award date CEQA+ Clean Water State Revolving Fund- Wastewater Treatment Projects and Recycling Funding Low interest financing for wastewater treatment facilities. Construction of publically owned treatment facilities. Wastewater treatment, local sewers, sewer interceptors, water reclamation, storm water treatment, combined sewers Loan funding currently limited. 30 year financing term at interest rate set to half of the most recent General Obligation bond rate2 No specific project timeline. Projects prioritized by "Readiness to proceed" MHI<80% of Statewide annual MHI1; Projects that benefit DAC communities will be prioritized for funding Applications are accepted on a continuous basis Applicants may start construction prior to the effective date of the financing agreement, but will not receive reimbursement of construction costs incurred prior to the effective date, and are not guaranteed financing approval and an executed financing agreement. CEQA+ USBR WaterSMART Water and Energy Efficiency Grant Project can demonstrate a benefit to an endangered threatened species, and reduce water and energy consumption. Would support alternatives for groundwater recharge Funding Group I: Up to $300,000 up to two years. Funding Group II: Up to $1,500,000 up to three years 2 Years for Funding Group I. 3 Years for Funding Group II No preference/requirement for DAC Deadline has passed for 2016 grants. Application released between October- December, and due approximately 3 months after release date. Applicants should receive funding by summer of the following year Any costs including design, construction plans, environmental compliance costs incurred prior to the date of award may be submitted for consideration for reimbursable expense NEPA USBR WaterSMART Title XVI Water Reclamation and Reuse Program Funding for construction of projects that reclaim and reuse. Reclaimed water can be used for a variety of purposes such as environmental restoration, fish and wildlife, groundwater recharge, municipal, domestic, industrial, agricultural, power generation, or recreation Financing for construction projects is less than $20 million or 25% of total project cost. Funding for projects approved by congress and sponsored by congressman. 6 years since last construction authorization. Typically 24-36 months to complete tasks in agreement3 No preference/requirement for DAC Deadline has passed for 2016 grants. Application released between October- December of this year. Applications due approximately 3 months after release date. Applicants should receive funding by summer of the following year Any costs including design, construction plans, environmental compliance costs incurred prior to the date of award may be submitted for consideration for reimbursable expense NEPA USBR WaterSMART Title XVI Water Reclamation and Reuse Program Funding for planning/feasibility study for recycled water project. Reclaimed water can be used for a variety of purposes such as environmental restoration, fish and wildlife, groundwater recharge, municipal, domestic, industrial, agricultural, power generation, or recreation Federal share for 50% of Feasibility Study Typically 18 months to complete tasks in agreement3 No preference/requirement for DAC Deadline has passed for 2016 grants. Applications likely to be released in January of 2016 Any costs including design, construction plans, environmental compliance costs incurred prior to the date of award may be submitted for consideration for reimbursable expense NEPA Integrated Regional Water Management (IRWM) - Implementation Grant Program Provides funding for implementation projects that support integrated water management Minimum local funding match of 25% No specific time to completion listed. Project must be implementation ready to apply for funding MHI<80% of Statewide annual MHI Deadline has passed for 2016 grants. Applications for 2017 likely to be due August 2016, and awarded January 2017 Reimbursable funds after effective date are for engineering, design, land and easement, legal fees, preparation of environmental documentation, environmental mitigation, and project implementation. Grant application preparation prior to effective date is reimbursable CEQA I-Bank Infrastructure State Revolving Fund Provide financing for infrastructure and economic development projects $50,000 - $25 million. Most recent interest rates between 2-3% No specific time to completion listed. Project must be implementation ready to apply for funding No DAC requirement; staff may adjust interest rate based on factors including MHI on a case by case basis Continuous application process CEQA Notes: 1. DACs are those with MHI<80% of Statewide MHI. Severely DACs are those with MHI<60%. 2. Current interest rate for Water Recycling Funding Program and Clean Water State Revolving Fund is 1.6%. No funding limit. 3. Extensions are allowed on a case-by-case basis. DRAFTCity of San Luis Obispo 11. References Recycled Water Facilities Planning Study - Final Draft 82 1/19/2017 11 REFERENCES 1. HDR, Inc. Water Resource Recovery Facility Facilities Plan. 2015. 2. McInnis, Rodney R. s.l. : United States Department of Commerce National Oceanic and Atmospheric Administration National Marine Fisheries Service, November 3, 2005. 3. City of San Luis Obispo, Utilities Department. 2015 Urban Water Management Plan. 2016. 4. Water Systems Consulting, Inc. City of San Luis Obispo Recycled Water Production Analysis. 2016. 5. City of San Luis Obispo. General Plan. 2015. 6. Wallace Group. City of San Luis Obispo Draft Recycled Water Master Plan Update. 2014. 7. —. City of San Luis Obispo Final Potable Water Distribution System Operations Master Plan. 2015. 8. CH2M. City of San Luis Obispo Water Resource Recovery Facility DRAFT Predesign Report. 2016. 9. 30% Design - Facility Layouts Workshop 3D Model Review. CH2M. May 25, 2016. Water Resource Recovery Facility Project. 10. Regional Water Quality Control Board, Central Coast Region. Water Quality Control Plan for the Central Coast Basin. June 2011. 11. CH2M. San Luis Obispo Potable Reuse Alternatives. REV0 2016. 12. The Sustainability of Agriculture in the City of San Luis Obispo's Edna Valley Greenbelt. 2016. 13. California Polytechnic State University. Campus Operations. Administration & Finance. [Online] 2014. https://afd.calpoly.edu/sustainability/campusoperations.asp#content. 14. Cleath, Timothy S. Overview of Groundwater Recharge of Recycled Water San Luis Obispo Groundwater Basin. s.l. : Cleath-Harris Geologists, Inc., March 2016. 15. Demonstrating Redundancy and Monitoring to Achieve Reliable Potable Reuse. Trussell et al. s.l. : Direct Potable Reuse in California: Specialty Seminar at UC Berkeley in September 2015, 2015. 16. Walking the Talk: Water Recycling & Energy Efficiency Intertwined at an Eco-Tourism Resort. Falk, M.; Dinsmore, C.; Kennedy, K.; Kirksey, W. Seattle, WA : Annual WateReuse Symposium, 2009. 17. Water Systems Consulting, Inc. City of Pismo Beach Recycled Water Facilities Planning Study - Final. 2015. 18. City of San Luis Obispo. 2015 Water Status Report. 2015. 19. Harris, Kenneth A. Order No. R3-2014-0033/NPDES No. CA0049224. City of San Luis Obispo : California Regional Water Quality Control Board, Central Coast Region, September 25, 2014. 20. Briggs, Roger G. Waste Discharge/Master Reclamation Requirements Order No. R3-2003-081. s.l. : State of California California Regional Water Quality Control Board Central Coast Region, Ocotober 24, 2003. 21. Association for the Advancement of Cost Engineering, Inc. AACE International Recommended Practice No. 17R-97; Cost Estimate Classification System; TCM Framework: 7.3 - Cost Estimating and Budgeting;. 2011. DRAFTCity of San Luis Obispo Recycled Water Facilities Planning Study - Final Draft A 1/19/2017 APPENDIX A. RECYCLED WATER PRODUCTION ANALYSIS Page 1 of 20 Date: 5/20/2016 To: David Hix City of San Luis Obispo 879 Morro Street San Luis Obispo, CA 93401 CC: Howard Brewen and Aaron Floyd Prepared by: Emily Iskin, EIT, Jasmine Diaz, EIT, and Jeroen Olthof, P.E. Reviewed by: Lianne Westberg, P.E. and Josh Reynolds, P.E. Project: City of San Luis Obispo Water Resource Recovery Facility Project SUBJECT: Recycled Water Production Analysis 1. Executive Summary This memorandum summarizes the recycled water production capacity of the City of San Luis Obispo’s (City) Water Resource Recovery Facility (WRRF). The analysis focuses on the tertiary treatment system’s infrastructure capacity and the secondary effluent supply to the tertiary treatment system in order to estimate how much recycled water the WRRF could produce. Based on the analysis described in this memorandum, WSC estimates that the WRRF’s infrastructure is capable of producing and delivering up to 3.5 MGD at any given time, while the average daily secondary effluent supply available for recycled water ranges between 1.5 and 1.9 MGD (based on 2015 data). Therefore, recycled water production is currently limited by secondary effluent supply, not recycled water treatment infrastructure or distribution pump station capacity. WSC has provided recommendations for the City to consider in order to maximize the production of recycled water at the WRRF in the near-term, before the Water Resource Recovery Facility Project (WRRF Project) is complete. These recommendations include operational changes, automation improvements, and delivery schedule alternatives. 2. Purpose The purpose of this Recycled Water Production Analysis is to conduct a capacity evaluation of the existing recycled water system at the City’s WRRF. This evaluation determines current infrastructure production capabilities, and evaluates secondary effluent supply and recycled water demand. It also provides recommendations to assist the City and WRRF staff in optimizing current practices and/or updating infrastructure to maximize recycled water production, prior to the WRRF Project upgrades (currently in the preliminary design phase). This memorandum includes the following sections: 1. Executive Summary 2. Purpose City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 2 of 20 3. Regulatory Context 4. Recycled Water Production Capacity 5. Conclusion & Recommendations 3. Regulatory Context The WRRF produces recycled water for unrestricted irrigation following the requirements contained in Title 22 of the California Code of Regulations and administered by the California State Water Resources Control Board (SWRCB). Specifically, the WRRF produces disinfected tertiary recycled water, which means “[…] a filtered and subsequently disinfected wastewater that meets the following criteria: (a) The filtered wastewater has been disinfected by either: (1) A chlorine disinfection process following filtration that provides a CT (the product of total chlorine residual and modal contact time measured at the same point) value of not less than 450 milligram-minutes per liter at all times with a modal contact time of at least 90 minutes, based on peak dry weather design flow; or (2) A disinfection process that, when combined with the filtration process, has been demonstrated to inactivate and/or remove 99.999 percent of the plaque forming units of F- specific bacteriophage MS2, or polio virus in the wastewater. A virus that is at least as resistant to disinfection as polio virus may be used for purposes of the demonstration. (b) The median concentration of total coliform bacteria measured in the disinfected effluent does not exceed an MPN of 2.2 per 100 milliliters utilizing the bacteriological results of the last seven days for which analyses have been completed and the number of total coliform bacteria does not exceed an MPN of 23 per 100 milliliters in more than one sample in any 30 day period. No sample shall exceed an MPN of 240 total coliform bacteria per 100 milliliters,” (1). In addition to the production of disinfected tertiary recycled water, the City has a minimum discharge requirement to San Luis Obispo Creek. To satisfy environmental requirements in the biological opinion developed by the National Oceanic and Atmospheric Administration (NOAA) National Marine Fisheries Service (NMFS), the WRRF is required to discharge a minimum daily average year-round release of 2.5 cubic feet per second (cfs) (approximately 1.6 million gallons per day (MGD)) into San Luis Obispo Creek (2). The flow that is discharged to the creek is treated to meet the water quality standards set forth by the City’s National Pollutant Discharge Elimination System (NPDES) permit (3). Under normal operation (non-storm flows), all secondary effluent is filtered and then is split into two separate flow streams: one stream is disinfected, dechlorinated, and discharged into San Luis Obispo Creek; and the other stream is disinfected and delivered to the recycled water storage tank for distribution. The WRRF is required to keep these two streams separate due to the different water quality permit requirements. City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 3 of 20 4. Recycled Water Production Capacity The production capacity of tertiary recycled water at the WRRF depends on two main constraints: infrastructure capacity and availability of secondary effluent. The following sections provide an estimate of the maximum capacity of the WRRF’s recycled water infrastructure, and provide an analysis of secondary effluent supply and recycled water demand. This analysis estimates recycled water production capacity under normal dry weather operation; recycled water is not typically produced during storm events. Infrastructure Figure 1 presents a schematic of the recycled water production system at the WRRF. The infrastructure analysis focuses on the configuration and capacities of the filters and pumps, nitrified effluent diversion box (NEFF box), recycled water vault, chlorine contact channels, and recycled water tank and pumps to determine the recycled water production capacity of the infrastructure at the WRRF. City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 4 of 20 Figure 1. Conceptual Layout of Recycled Water Infrastructure and Connections City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 5 of 20 Table 1 summarizes the approximate capacities of the tertiary recycled water system and the sources of information used for this analysis. Table 1. Existing Recycled Water Infrastructure Capacity Infrastructure Infrastructure Approximate Capacity Notes and (Source) Filter Feed Complex Pumps 2.6 MGD × 3 pumps 5.2 MGD Approximate capacity based on pump design capacity. Assumes one pump out of service. (4) Filters 240 ft2/filter × 4 filters 5.2 MGD (3 filters) 6.9 MGD (4 filters) Capacity calculated for 5 gpm/ft2 flux rate. Three filters online represent one filter in backwash mode. If a higher flux rate were to be approved by the State Board, the filters would have a larger capacity. (4) Chlorine Contact Channels #3 and #4 Chlorine contact channels #3 and #4; a total volume of 0.38 MG 6 MGD Calculated using a 90-minute minimum modal contact time and a 450 mg-min/L minimum contact time, per Title 22. (1), (5), and (6) Recycled Water Storage Tank 600,000 gallon tank 0.6 MG Current storage capacity. (5) Recycled Water Pump Station 40 hp × 2 pumps 125 hp × 3 pumps 3.5 MGD Calculated based on Recycled Water System Assessment, where 2 × 125-hp pumps operating at full speed deliver approximately 2400 gpm. Assumes one pump out of service. Existing Filters: The filter feed complex includes 3 filter feed pumps and 4 filters. With one pump out of service and one filter out of service for backwash, the complex has a total capacity of 5.2 MGD. Subtracting the creek allocation of 1.6 MGD means the overall filter capacity available for recycled water is 3.6 MGD. With 4 filters online, the filtration capacity increases to 6.9 MGD (5.3 MGD subtracting the creek allocation), but the total filter capacity is still limited by the number of pumps online at any given time. Under normal operation, only two pumps are typically online. Thus with two pumps feeding the filters and all four filters in service, the total filter complex capacity is 5.2 MGD, with 3.6 MGD of this capacity available for recycled water production. Note that in this scenario the filters are operating at a lower flux rate (less than 5 gpm/ft2). Existing Cooling Towers: The recycled water does not have a temperature requirement and, therefore, the cooling towers are not required to produce recycled water. However, with the current configuration, flows to the creek and flows to the recycled water system are not separated until after the cooling towers and filters. Thus, the WRRF has essentially been cooling the entire flow through the plant and has only exceeded the creek temperature requirement a few times in the past few years (4). The amount of water cooled will not change with increased recycled water production, therefore cooling tower capacity is not expected to limit to recycled water production. Note that ideally the only the creek discharge would be cooled, but this would require separating flows upstream of the cooling towers and major reconfiguration of piping and pumping, which would be a major capital project. This was evaluated in the WRRF Project Facilities Plan and is being considered in the design of the upgrades (4). City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 6 of 20 Existing Nitrified Effluent Diversion Box: The NEFF box is the structure where flow is split between the recycled water stream and the creek discharge stream. Although downstream of the NEFF box, the valve in the recycled water vault is what controls the flow split as described in the following Vault section. It is not anticipated that the box would limit the production capacity of recycled water because it can handle wet weather flows greater than those that the recycled water system can currently treat. Existing Vault: The recycled water vault consists of a 24” diameter pipe, a butterfly valve, and a flow meter. Constricting the flow through the valve in the recycled water vault controls the split of flow in the NEFF box. It is not anticipated that the vault would limit the production capacity of recycled water. Existing Chlorine Contact Channels: The treatment capacity of chlorine contact channels #3 and #4 was calculated to be 6 MGD based on Title 22 criteria and total volume of the two channels. Chlorine contact channel #3 has the flexibility to be used for disinfection for creek discharge or recycled water production; it is currently used for disinfection prior to creek discharge. Gates in the channels are used to control the flow and whether channel #3 is used for creek disinfection or recycled water disinfection. The recycled water chlorine contact channel capacity is not expected to limit the production capacity at the WRRF. Existing Storage: The recycled water storage tank can hold a maximum 0.6 MG of recycled water at any given time. There is approximately 6 ft of headspace above the maximum fill line in the tank (5), due to the hydraulics of the recycled water system. Increasing the storage capacity by using the headspace in the tank would require a hydraulic analysis of the recycled water system to determine the upstream effects of increasing the hydraulic head at the tank, as well as a seismic analysis to ensure adequate freeboard to meet sloshing requirements. Any potential improvements to accommodate a higher hydraulic grade in the system would likely be capital intensive. Adjusting and optimizing recycled water delivery schedules may be a more cost-effective strategy to increase recycled water production and fully utilize existing storage volume. Possible delivery schedules will be discussed in the following Storage section. Existing Pump Station: The recycled water pump station does not necessarily limit the production of recycled water, but it does limit delivery of recycled water from the WRRF, therefore its capacity is included in this discussion. Two of the large (125 hp) pumps operating at full speed provide an approximate flow rate of 3.5 MGD. This capacity could potentially be increased in the future, if greater capacity was required, by operating all three large pumps at the same time. The WRRF currently has room for the installation of two additional pumps, further increasing the pumping capacity. Summary: Overall, the recycled water treatment infrastructure has a maximum estimated capacity of 3.6 MGD (5.2 MGD filter capacity minus 1.6 MGD for creek flow). The recycled water pump station has an estimated capacity of 3.5 MGD (assuming two large pumps in service). Therefore, the WRRF can treat and deliver a maximum of approximately 3.5 MGD (instantaneous flow) of recycled water. The onsite storage and delivery of recycled water, which will be discussed in the Storage section, will depend on the delivery schedule and rate of delivery to customers throughout the day. This will be limited by the 3.5 MGD pump station capacity. Note that this analysis does not consider the capacity of distribution infrastructure beyond the pump station at the WRRF (e.g. distribution pipelines). City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 7 of 20 Opportunities for Optimization Recycled Water Vault: As discussed previously, the WRRF is required to discharge approximately 1.6 MGD of treated water to San Luis Obispo Creek. Head loss across the recycled water vault’s butterfly valve controls the split between creek flow and recycled water flow. This valve is operated manually; the more open the valve, the more filter effluent is split to the recycled water system. Analysis of several years of flow data from various meters at the WRRF indicates that more than the required minimum flow of 1.6 MGD is routinely discharged to the creek. This means that there is potential to produce additional recycled water with flow that is currently being diverted to the creek. The WRRF could benefit from automating the valve. This could be accomplished by repairing the current actuator on the existing butterfly valve (assuming it has control capabilities and is in good condition), or by replacing it with a valve with more precision. Exchanging the butterfly valve with another type of valve with more precise control, such as a Cla-Val flow control valve, would provide the operators with more accurate data and control, and allow them to increase the amount of recycled water treated. The benefits would be amplified when paired with chlorine dosing automation (discussed below), yielding a more adaptive recycled water system. When flows in excess of 1.6 MGD enter the filter complex, which happens almost daily (Figure 2), the system will be able to pass the excess to the recycled water chlorine contact channels and produce Title 22 compliant recycled water. Chlorine Dosing Automation: It is recommended that the chlorine dosing system be automated in order to vary chlorine dosing in response to changing flow through the contact channels while meeting Title 22 requirements for contact time and modal contact time. Chlorine dosing is currently controlled by a pump that is manually operated. Automation would fine-tune the process so that only the chlorine that is needed is used while still meeting Title 22 requirements. This would streamline the recycled water disinfection process and make it more adaptable to changing flow conditions. Filter Feed Complex Pump Automation: Along with automation of the recycled water vault and chlorine dosing, it is recommended that the filter feed pumps also be automated to ensure full adaptability of the tertiary system. The filter feed pumps are currently operated manually. This automation would eliminate jumps in flow rate into the filters that result from manual operation, as well as unintended impacts on the cooling towers. The flow into, and subsequently out of, the filters would be smoother, thus easing the strain that would otherwise be on the rest of the automated system. This would also result in increased operational efficiency. Backwashing Practices: In 2014/2015 the WRRF underwent a series of upgrades as part of the WRRF Energy Efficiency Project, including upgrades to the filter towers. The improvements consisted of installing mono-media material (pea gravel) to replace the dual-media material (anthracite and sand) that had been in place since 1994. In addition to replacing the media, the underdrain system was replaced, and the backwash controls were updated. New backwash pumps with variable frequency drives (VFDs) will be installed in 2016. As seen in Figure 2, the 2015 daily average flow into the filter towers (filter influent flow) and the sum of the daily average flow to the creek and to recycled water customers (combined flow referred to hereafter as total plant effluent) do not align well (more information on this data is provided in Appendix I, Table 2). The percent difference between the two data sets ranges from 0% to 60%, with an average of 12% difference. The filter influent flow data often indicates that there is more water available than the total plant effluent flow indicates. City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 8 of 20 This significant gap could be due to backwash practices, system time delay, and/or inaccurate data 1. Though the water that is diverted from the filters for backwashing is eventually recycled to the plant influent so that no water is lost, there is a delay between the time that water enters to the time it leaves the plant. This delay could cause a percent difference between filter influent and plant effluent data. It is difficult to approximate the difference in flow that is due to backwashing and time delay due to the questionable accuracy of the data. This diversion of water for backwashing does, however, affect the immediate amount of water available for recycled water because a portion of the filter effluent is diverted to the backwash water tank for backwashing. Backwashing also affects the amount of filter capacity available because one filter is offline for cleaning. The estimates in Table 1 are still reasonable as they assume one filter offline. As recycled water demands increase, the scheduling of the backwashing operation could affect the amount of recycled water available. With this in mind, it is recommended that backwashes be performed during times of low recycled water demand to keep all filters online in order to maximize recycled water production when it is needed. Based on typical demand patterns in which most recycled water is used at night, the backwash operation could be scheduled during the day. This would ensure that as much tertiary effluent is available for recycled water customers as possible during times of high demand, as long as the recycled water tank is able to be filled while backwashing occurs (see Storage section for discussion on tank filling schedule). Rescheduling backwashes to occur during the day could affect the WRRF’s Pacific Gas & Electric (PG&E) energy and demand charges. The main plant is on the PG&E E-19P electric rate schedule, which means there is both a demand component (kW) and energy usage (kWh) component of the bill, and both vary based on time of day. The impact to the demand charges should be less once the VFDs are installed on the backwash pumps, but they should still be assessed prior to performing rescheduling of the filter backwash cycle. Assessing the impact on the demand costs requires obtaining a current electric load profile for the plant to understand if the demand of the backwash pumps exceeds the current billed maximum demand during the peak period (12 pm to 6 pm during summer) and partial-peak period (8:30 am to 12pm and 6 pm to 9:30 pm during summer). The potential changes in energy usage charges can also be assessed at that time. WRRF staff should wait to perform any rescheduling of backwashes until the electric load analysis is performed and VFDs are installed. 1 The recycled water tank effluent data for August 31 to September 22 was replaced with 2014 data due to negative values in 2015 (Total Plant Effluent = Recycled Water Tank Effluent + Creek Discharge). These negative values could have been due to maintenance on part of the system (such as the water reuse PLC being switched out on August 31, 2015 (6)). It has been observed that system maintenance and instrument calibration affects the accuracy of flow meter data at the WRRF. Additionally, there has been uncertainty in the accuracy of the flow meter data at the WRRF during different time periods, sometimes showing effluent exceeding influent flow (4). City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 9 of 20 *8/31/15 to 9/22/15 recycled water tank effluent data replaced with 2014 data due to negative values in 2015 (Total Plant Effluent = Recycled Water Tank Effluent + Creek Discharge). Figure 2. Illustration of Backwash Delay in Recycled Water Production System City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 10 of 20 Available Secondary Effluent In addition to the capacity limits of the recycled water production system, recycled water production capacity is also limited by the amount of secondary effluent available to be treated for recycled water. The WRRF is affected yearly by the ebb and flow of students at Cal Poly, among other factors. Flows to the WRRF decrease by approximately 0.4 MGD when Cal Poly is not in session (under average dry weather flow (ADWF) conditions, based on the WRRF Facilities Plan) (4). Influent data shows that plant influent decreases significantly during the following school breaks: Thanksgiving, winter break (December/January), spring break (March/April), and summer break (June-August). In addition, conservation efforts in response to the statewide drought have resulted in a decrease in water consumption citywide and reduction in sewage flows entering the WRRF. All of these factors impact the total influent the WRRF treats each day. Although the WRRF is permitted for ADWF flows of 5.1 MGD, current ADWF flows are approximately 3.1 MGD (3.5 MGD with Cal Poly in session) and vary both throughout the day and throughout the year (4). Plant influent flow and the 1.6 MGD flow obligation to San Luis Obispo Creek limit the recycled water system production. Figure 3 compares the daily average filter influent flow to the daily average total plant effluent flow. Considering the limitations on the accuracy of the data, the 2015 flow data show that there was typically additional water available for recycled water production in 2015. Figure 3 shows that there was a daily average of between 3.1 and 3.5 MGD available in the system for recycled water and creek discharge in 2015. This corresponds to approximately 1.5 to 1.9 MGD of water available for recycled water production for a year like 2015, once the minimum creek discharge has been met. This is approximately 10 times as much recycled water as the WRRF currently produces on an annual average (4). A range is used here because of the uncertainty about how much water is actually available in the tertiary system; the filter influent flow data suggests 3.5 MGD, and the total plant effluent flow data suggests 3.1 MGD. This range of available flow for recycled water production is well within the capacity capabilities of the recycled water production infrastructure. Therefore, the secondary effluent supply to the recycled water system is more of a limiting factor on recycled water production than infrastructure capacity. Figure 4 presents the same filter influent flow and total plant effluent flow data as in Figure 3 for May 1, 2015 through October 31, 2015 (a total of 184 days) to approximate the summer irrigation season when recycled water demand is the highest. The figure shows a range of flow (Y MGD) (between the filter influent flow and plant effluent flow lines on the figure) that could be delivered X% of the irrigation season, on a daily average basis. For example, 95% of time between May and October, between 0.8 and 1.3 MGD could be delivered as recycled water (shown as an example on Figure 4). The percent ranges represent the reliability of delivering a certain flow rate during the irrigation season based on 2015 data. Table 2 has further examples of percentages and flow ranges from Figure 4. The 1.6 MGD creek commitment has been subtracted from the data in Figure 4. City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 11 of 20 *8/31/15 to 9/22/15 recycled water tank effluent data replaced with 2014 data. Figure 3. 2015 Recycled Water Supply and Demand City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 12 of 20 *8/31/15 to 9/22/15 recycled water tank effluent data replaced with 2014 data. Figure 4. 2015 Potential Recycled Water Production from May to October ~ 1.3 MGD ~ 0.8 MGD City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 13 of 20 Table 2. Daily Average Water Available for Recycled Water based on May 1 to October 31, 2015 Data Daily Average Amount of Recycled Water (MGD) Percent of Irrigation Season that Recycled Water Could Be Delivered at Specified Flow Number of Days that Recycled Water Could be Delivered at Specified Flow (out of 184 days) 0.3-0.7 99.5% 183 days 0.6-1.2 97.8% 180 days 0.9-1.3 92.4% 170 days 1.0-1.4 87.0% 160 days *8/31/15 to 9/22/15 recycled water tank effluent data replaced with 2014 data. Storage As previously discussed in Table 1, there is a finite amount of usable storage volume in the recycled water tank: 600,000 gallons. This storage volume could be leveraged to deliver more than 600,000 gallons of recycled water in a 24-hour period by optimizing the delivery schedule, thus effectively increasing the recycled water storage capacity to match the infrastructure capacity previously discussed. A schedule that can use both storage and pumping to deliver the amount of recycled water the WRRF can produce would be a practical solution for increasing the working volume of the recycled water tank. Three possible 24-hour scenarios are presented below. Note that these scenarios are based on an hourly calculation, and assume that a constant flow into the tank is possible for the entire 24-hour period. The schedules presented below are not intended to represent a fully optimized system, and the flow rate from the recycled water tank will be limited to 3.5 MGD due to the capacity of the recycled water pumps. City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 14 of 20 Scenario 1 Scenario 1 utilizes the full storage volume while delivering recycled water only at night (11:00 PM to 6:00 AM). As seen in Figure 5, the storage volume (blue) has a range from 0 of 600,000 gallons during the 24-hour period. Water fills the tank at a constant rate of 625 gallons per minute (gpm) (about 0.9 MGD; this could occur approximately 90% to 98% of the irrigation season) over the entire 24 hours, and is delivered at a rate of 1,875 gpm (about 2.7 MGD) at night by the recycled water pump station (purple). The tank is completely empty at 6:00 AM, and is full at 10:00 PM. Over the 24-hour period, a total of 900,000 gallons (0.9 MGD) of water would be delivered. This is 1.5 times the volume of the storage tank. Figure 5. Tank Volume and Recycled Water Demand with Night Delivery City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 15 of 20 Scenario 2 Scenario 2 also utilizes the entire storage volume, but introduces some daytime delivery from 7:00 AM to 10:00 PM. As seen in Figure 6, the storage volume (blue) has a range from 0 of 600,000 gallons during the 24-hour period. Water fills the tank through at a constant rate of 1,000 gpm (about 1.4 MGD, chosen from Table 2) over the entire 24 hours, and is delivered at a rate of 2,250 gpm (about 3.2 MGD) at night and 375 gpm (about 0.5 MGD) during the day (purple). The tank is completely empty at 6:00 AM, and is full at 10:00 PM. Over the 24- hour period, a total of 1,440,000 gallons (1.44 MGD) of water would be delivered. This is 2.4 times the volume of the storage tank. Figure 6. Tank Volume and Recycled Water Demand with Night and Day Delivery City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 16 of 20 Scenario 3 Scenario 3 utilizes the entire storage volume, but includes more daytime delivery from 7:00 AM to 10:00 PM than Scenario 2. As seen in Figure 7, the storage volume (blue) has a range of 0 to 600,000 gallons during the 24- hour period. Water fills the tank at a constant rate of 1,250 gpm over 24 hours (about 1.8 MGD; this flow may be available approximately 18% to 55% of the irrigation season). This large range indicates the uncertainty of this amount of water being available during the irrigation season and the data discrepancies discussed previously. In this scenario, water is delivered at a rate of 2,500 gpm (about 3.6 MGD) at night and 625 gpm (about 0.9 MGD) during the day (purple). The tank is completely empty at 6:00 AM, and is full at 10:00 PM. Over the 24-hour period, a total of 1,800,000 gallons (1.8 MGD) of water would be delivered. This is 3 times the volume of the storage tank. The caveat with this scenario is the nighttime pumping rate of about 3.6 MGD exceeds the estimated current pumping capacity of 3.5 MGD at the recycled water pump station. If the WRRF is able to fill the tank at a constant rate of 1.8 MGD over 24-hours (which it may not be currently able to do), then is it possible that the pump station would need to be expanded to realize the full working volume of the recycled water tank. Figure 7. Tank Volume and Recycled Water Demand with Night and Day Delivery City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 17 of 20 This storage analysis, summarized in Table 3, shows that though there is a fixed volume in the storage tank of 600,000 gallons, up to three times as much working volume can be achieved if the delivery schedule of recycled water is adjusted to allow some water to flow through the tank during the day assuming secondary effluent is available as described above. This strategy could increase the production capacity of the recycled water system at the WRRF. Table 3. Summary of Storage Analysis Scenarios Scenario Constant Flow Rate Into Tank1 Flow Out of Tank: Night Flow Rate of Tank: Day Volume of Water Delivered in 24 hours Scenario 1 625 gpm, 0.9 MGD 1,875 gpm, 2.7 MGD - 0.9 MG Scenario 2 1,000 gpm, 1.4 MGD 2,250 gpm, 3.2 MGD 375 gpm, 0.5 MGD 1.4 MG Scenario 3 1,250 gpm, 1.8 MGD 2,500 gpm, 3.6 MGD 625 gpm, 0.9 MGD 1.8 MG 1Refer to Figure 4 to understand the reliability of delivering these flow rates to the storage tank. 5. Conclusion and Recommendations The recycled water production system has an infrastructure capacity of 3.5 MGD, and a daily average secondary effluent supply limit of 1.5 to 1.9 MGD (based on 2015 data). Although the infrastructure capacity could be increased by bringing more treatment equipment online (filters, pumps, etc.) this will not increase the secondary effluent supply available at the WRRF. The supply limitation requires an optimized system to obtain the maximum benefit considering the constraining constituent. Therefore, recommendations have been presented, such as automation, that will help the City treat more of the available secondary effluent to Title 22 disinfected tertiary standards. In order to achieve maximum recycled water production prior to implementation of the WRRF Project, it is suggested that the WRRF implement the recommendations presented in this analysis. Below is a summary of the recommendations presented to the City to increase recycled water production capacity at the WRRF: I. Recycled Water Vault Valve Automation: repair the existing actuator on the butterfly valve to achieve automation or replace the butterfly valve to more finely control the flow that goes to the creek versus recycled water. This is key in reducing the amount of treated effluent discharged to the creek to the minimum requirement, to the extent that recycled water demand is available. One option for a replacement valve would be a Cla-Val flow control valve. II. Chlorine Dosing Automation: automate the recycled water chlorine dosing system to increase adaptability of the system to changing flow through the channels, to ensure only the chlorine that is needed to meet Title 22 standards is used, and to streamline the process for the operators. III. Filter Feed Complex Pump Automation: automate filter feed pumping in order to reduce large jumps in flow into the filters, increase stability in the rest of tertiary system, and improve operational efficiency. City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 18 of 20 IV. Backwashing Schedule: adjust the backwashing schedule so that backwashes occur during times of low recycled water demand. Consider peak electricity demand charges when selecting backwashing schedule. V. Delivery Schedule: deliver some recycled water to customers during the day in order to increase recycled water deliveries and increase the working volume of the recycled water storage tank. Additional analysis could be performed in order to optimize the schedule to align with operator practice and contracts with the City for recycled water. City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 19 of 20 6. Works Cited 1. Regulations Related to Recycled Water. [Online]. s.l. : California Environmental Protection Agency State Water Resources Control Board, July 16, 2015. 2. McInnis, Rodney R. United States Department of Commerce, National Oceanic and Atmospheric Administration. Long Beach : National Marine Fisheries Service, 2005. Letter. 3. Jr., Kenneth A. Harris. City of San Luis Obispo Water Resource Recovery Facility Limitations and Discharge Requirements. WDR Order No. R3-2014-0033 NPDES No. CA0049224. San Luis Obispo : California Regional Water Quality Control Board, Central Coast Region, September 25, 2014. 4. HDR, Inc., Water Systems Consulting, Inc., RRM Design Group. Water Resource Recovery Facility Facilities Plan. San Luis Obispo : s.n., June 2015. 5. Brown and Caldwell. Water Reclamation Facility Improvements. Part C - Drawings February 2003. Vol. III. Specification No. 99124-90553 A. 6. Briggs, Roger W. Waste Discharge/Master Reclamation Requirements. WDR Order No. 03-2003-0081. San Luis Obispo : California Regional Water Quality Control Board, Central Coast Region, October 24, 2003. 7. Ouellette, Pam and Chris Lehman. Standard Operating Procedure: Storm Operation Settings. San Luis Obispo : Water Resource Recovery Facility, 2016. 3. City of San Luis Obispo Water Resource Recovery Facility Project Recycled Water Production Analysis Page 20 of 20 7. Appendix I: Data Used in this Analysis The data used to create the Figures 2 and 3 is tabulated below. Table 4. Data Used to Compare Filter Influent and Plant Effluent in Figure 2 Data Set Hach WIMS Tagname Units Time step Questionable Data Daily Average Filter Influent Flow WRF.DPCJ_FLTRINFL_CHNL_FLW.F_CV gpm 15-minute NA Daily Average Total Plant Effluent WRF.FIT101_FLOW.F_CV & WRF.FIT140_FLOW.F_CV gpm & MGD 15-minute & 15-minute Aug. 31 to Sept. 22 & NA Percent Difference |𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐷𝐷𝐴𝐴𝐴𝐴 𝐹𝐹𝐷𝐷𝐷𝐷𝐹𝐹𝐴𝐴𝐴𝐴 𝐼𝐼𝐼𝐼𝐼𝐼𝐷𝐷𝐼𝐼𝐴𝐴𝐼𝐼𝐹𝐹−𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐷𝐷𝐴𝐴𝐴𝐴 𝑇𝑇𝑇𝑇𝐹𝐹𝐷𝐷𝐷𝐷 𝑃𝑃𝐷𝐷𝐷𝐷𝐼𝐼𝐹𝐹 𝐸𝐸𝐼𝐼𝐼𝐼𝐷𝐷𝐼𝐼𝐴𝐴𝐼𝐼𝐹𝐹|12 (𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐷𝐷𝐴𝐴𝐴𝐴 𝐹𝐹𝐷𝐷𝐷𝐷𝐹𝐹𝐴𝐴𝐴𝐴 𝐼𝐼𝐼𝐼𝐼𝐼𝐷𝐷𝐼𝐼𝐴𝐴𝐼𝐼𝐹𝐹+𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐷𝐷𝐴𝐴𝐴𝐴 𝑇𝑇𝑇𝑇𝐹𝐹𝐷𝐷𝐷𝐷 𝑃𝑃𝐷𝐷𝐷𝐷𝐼𝐼𝐹𝐹 𝐸𝐸𝐼𝐼𝐼𝐼𝐷𝐷𝐼𝐼𝐴𝐴𝐼𝐼𝐹𝐹)∗100% Table 5. Date Used to Compare Recycled Water Supply and Demand in Figure 3 Data Set Hach WIMS Tagname Units Time step Questionable Data Daily Average Filter Influent WRF.DPCJ_FLTRINFL_CHNL_FLW.F_CV gpm 15-minute NA Daily Average Recycled Water Tank Effluent WRF.FIT101_FLOW.F_CV gpm 15-minute Aug. 31 to Sept. 22 Daily Average Required Creek Discharge Calculated from 2.5 cfs requirement No. SectionPage, Part CommentReviewer Note1 Recommendations Recom. 2Recommendation #2 (backwashing during the day...): I agree with the reasoning to do backwash during the day. My concern is it has a possibility of putting us into a peak demand charge, which we will be charged for every day for the remainder of the billing cycle. We should probably run some scenarios on what the additional energy costs (PG&E) would be incurred. We do not have to let these numbers dictate our decision but we should have them available for our decision making process.H. BrewenThis has been addressed in the final TM in the "Backwashing Practices" section on page 8. VFDs should decrease the impact to the demand charges, but the impact should still be assessed prior to performing rescheduling of backwashing by obtaining a current electric load profile for the plant.2Existing System & Regulatory Requirements7, Figure 1I think we need to better identify the NEFF box in figure 1 on page 7. Its not specifically IDed as the NEFF box on the figure, rather called chamber #1 and #2 of the Nitrified Diversion Box, and the figure suggests two locations rather than one. This needs some clarification.D. Hix Color and labels were added to provide clarification.3Existing System & Regulatory Requirements9On page 9, first paragraph; what project elements were not constructed? If we had those elements would we be having this discussion. At a minimum they should be on the original plans. Please be specific or take this out.D. Hix References to construction were removed.4Existing System Data Analysis18Page 18, recycled water storage. Can the head space above 118.75 feet be utilized as extra storage if the tank was modified to hold more?D. HixThis has been addressed in the final TM in the "Existing Storage" section on page 6. The headspace is most likely due to system hydraulics; using this space would require a hydraulic and seismic analysis of the recycled water system.5Existing System Data Analysis18One of my comments regarding the storage tank was about utilizing the head space. I know we say 600,000 gallons of storage, but could you prove the dimensions of the tank along with the elevations, and include the hydraulic profile? I think we need to discuss the back flowing of water after the tank is full during production and possibilities for more storage in the existing tank. D. Hix See comment above. This is addressed in the "Existing Storage" section on page 6. 6Potential Recycled Water Production25 Page 25, I think we have around 38 construction permits at this time.D. HixThis table has been removed. This is part of the RW demand analysis that was conducted as part of the first draft, and will be incorporated into the Recycled Water Facilities Planning Study. 7Potential Recycled Water Production26Page 26, recycled water deliveries. We do have water demand during the day, we know incidentally things like some irrigation, construction and street sweeping take place. Small but we should mention.D. HixWording within the final TM has been modified to address day usage. An example of the wording is "most recycled water is used at night". 8Potential Recycled Water Production29Page 29, recycled water storage and volume. Please provide daily acre/feet. Looking at figure 19 from page 23 and the possible deliveries of up to 1.2 MGD a day, it looks pretty close. I understand these are averages with not great data, but adding some text in here regarding low summer flows could reduce this amount during a daily summer time day period would be helpful.D. HixThe final TM addresses reliability of providing flows during irrigation season and includes the following note in the "Storage" section on page 13: these scenarios are based on an hourly calculation, and assume that a constant flow into the tank is possible for the entire 24‐hour period. The schedules presented below are not intended to represent a fully optimized system. 9Potential Recycled Water Production30 Please provide daily MGD and Acre Feet on table 4 on page 30.D. HixThis table has been removed. This is part of the RW demand analysis that was conducted as part of the first draft, will be incorporated into the Recycled Water Facilities Planning Study. 10 Recommendations 32Page 32, recycled water storage. Like my previous comment; in the short term, if we can raise the operating level in the existing storage tank? How much more could we get and/or should we explore?D. Hix See Note for comment 4.11Potential Recycled Water Production28, 29Related to page 28 and 29, would automation be necessary to produce 1.26 MGD or could this volume be produced if storage was available?J. MetzThe TM is now organized to determine the infrastructure capacity and secondary effluent available. Automation would increase adaptability and amount of secondary effluent that goes to the recycled water contact channels, thus increasing recycled water production.12 Recommendations Recom, 2Related to recommendation #2, can the language “When recycled water demand rises” be clarified to include a specific trigger? Such as “When daily recycled water demand exceeds 400,000 gallons per day” or whatever the appropriate figure would be to change the filter backwashing protocol? Is this already a consistent practice amongst the operators when demand increases in the summer time?J. MetzWe recommend that backwashing occur at times when RW demand is the lowest. The TM recommends automating portions of the system, including backwashing programming. The programming would consist of an algorithm that takes different inputs (influent meter, filter head pressure, filter effluent turbidity, etc.), to calculate a time that is most appropriate to conduct a backwash based on the RW demand and the different inputs.13 Recommendations Recom. 3, 4Is the automation that is recommended in #3 and #4 costly? or cost effective in the short‐term? As I understand it, these components will be replaced with the facility upgrade. As these improvements could potentially be funded by the Water Fund, it would be helpful to know the costs and the gains that would be realized in the short‐term.J. MetzTo fully understand the cost of automation, it would require an analysis of the existing SCADA system to determine how the system would need to be modified to implement the automation‐related recommendations. A SCADA analysis and implementation plan is outside the scope of this analysis, but a preliminary cost estimate of these improvements and a high level schedule will be provided in the Recycled Water Facilities Planning Study.14 Executive SummaryPlease include daily production capacity (in gallons) in the Executive Summary with acre feet per month.J. Metz A daily average MGD value is presented in the Executive Summary. 15GeneralAs this production memo is intended to inform the Recycled Water Master Plan, please describe that relationship in the memo somewhere. Recommendation #5 for exploring storage opportunities is part of the Recycled Water Master Plan scope. This production memo is a great help as it provides background for the sizing of a future storage tank.J. MetzThe purpose of this analysis was two‐fold: (1) to better understand RW production capacity, and (2) to identify operational improvements to maximize RW production. The City could either reference applicable portions of this TM from the Recycled Water Master Plan, or this TM could be revised to include a short description if necessary.Revised 5/25/1616Available Secondary Effluent14‐16During the storage tank scenarios, the tanks are shown to become empty at one point or another. The tanks cannot be empty for two (2) reasons, 1) the pumps may cavitate if the level falls below a certain depth and as a result, they are programed to shut off automatically when water levels fall below 3‐5 feet (needs to verify); 2) due to the soil characteristics surrounding the tank, the soil is saturated with water and if there isn't enough water in the tank, it can "float" away. H. BrewenThe scenarios described in the TM are theoretical and assume that the entire volume of 600,000 gallons could be used to accommodate demand for the purposes of the analysis. If 600,000 gallons is not truly the usable volume of the storage tank, then the working volume would need to be determined and the analysis adjusted.17GeneralThe analysis was well done. Unfortunately it doesn't address two (2) key items: 1) schedule of implementation: when would it be ideal to implement the recommendations and in what order; 2) a recommendation cost analysis: would assist with helping us understand feasibility of the recommended improvementsH. BrewenThose are two key items that unfortunately where not part of the scope of this analysis. It is understood that conducting a cost analysis and compiling an implementation schedule would help the City understand if the recommendations are worth implementing. The purpose of this analysis was to conduct a capacity evaluation of the existing recycled water system and to provide recommendations to the City to optimize the system. The Recycled Water Facilities Planning Study will provide a preliminary cost estimate of these improvements and a high level schedule. Recycled Water Production Analysis: Final Comment Log 7/29/2016 DRAFTCity of San Luis Obispo Recycled Water Facilities Planning Study - Final Draft B 1/19/2017 APPENDIX B. WRRF NPDES PERMIT AND TSO Order No. R3-2014-003, NPDES permit No. CA0049224, and TSO No. R3-2013-0036 can be found on the State Water Resources Control Board website here: http://www.waterboards.ca.gov/centralcoast/board_decisions/adopted_orders/ DRAFTCity of San Luis Obispo Recycled Water Facilities Planning Study - Final Draft C 1/19/2017 APPENDIX C. RECYCLED WATER TREATMENT REQUIREMENTS Recycled Water Facilities Planning Study – Appendix C Recycled Water Treatment Requirements C-1 Recycled Water Treatment Requirements This Treatment Requirements appendix will describe the level of treatment and treatment technology required for both non-potable and potable water reuse. NON-POTABLE REUSE The Water Quality Control Plan for the Central Coast Basin (Basin Plan) states that the “California Code of Regulations, Title 22, are hereby incorporated as applicable reclamation requirements,” (Regional Water Quality Control Board pp. IV-11). Accordingly, the Title 22 requirements for water reuse will be summarized in the following sections. The Basin Plan also states that “[Water quality management] systems shall maximize their capacities for wastewater reclamation, assure efficient management of, and meet potential demand for reclaimed water,” (Regional Water Quality Control Board pp. V-5). The Recycled Water Facilities Planning Study (Study) aids in this Basin Plan Management Principle. In addition to the City of San Luis Obispo’s (City) Water Resource Recovery Facility’s (WRRF) National Pollution Discharge Elimination System (NPDES) permit, the facility also has a water reuse permit, Waste Discharge/Master Reclamation Requirements (WDR Order No. R3-2003-081), for recycled water production and use. The permit includes a Monitoring and Reporting Program. The permit outlines the specifications for recycled water (commonly referred to as Title 22 water), with a few key ones copied here (Harris pp. 3): • Discharge of recycled water to areas other than approved reclamation areas is prohibited; • The median concentration of total coliform bacteria in the disinfected effluent shall not exceed a Most Probable Number (MPN) of 2.2 per 100 milliliters (mL), utilizing the bacteriological results of the last seven days for which analyses have been completed and the MPN shall not exceed an MPN of 240 total coliform bacteria per 100 mL; • The filtered wastewater shall be disinfected by a chlorine disinfection process that provides a CT (chlorine concentration times modal contact time) value of not less than 450 milligram-minutes per liter at all times with a modal contact time of at least 90 minutes, based on peak dry weather flow; and • Proper backflow and cross-contamination protection for domestic water services and irrigation well shall be provided. The Regional Water Quality Control Board (RWQCB) and the Division of Drinking Water (DDW) have a memorandum of understanding in which the DDW agrees that the RWQCB will be the agency responsible for permitting recycled water programs. The RWQCB Master Permit for Recycled Water is the guiding document for most of the City’s requirements. In accordance with the Master Permit, the City complies with the following: 1. Meter the total quantity of reclaimed water distributed daily; 2. Monitor and record chlorine residual concentration at a point after the final chlorine contact basin; 3. Provide guidance to recycled water users including a user manual and other guidance as needed; 4. Provide instruction to all City field staff to report incidents of unauthorized daytime irrigation activity or runoff; Recycled Water Facilities Planning Study – Appendix C Recycled Water Treatment Requirements C-2 5. Cooperate with County Environmental Department of Health Services to ensure backflow devices are present, tested and repaired or replaced if found defective; 6. Inspect the operation of reuse sites; 7. Perform cross connection testing; 8. Conduct site supervisor training and quarterly interviews to verify system operation; and 9. Quarterly review of monthly meter readings with follow-up on change in patterns of use In addition to recycled water production, the City also complies with the minimum daily average discharge requirement of approximately 1.6 MGD from the Water Resource Recovery Facility (WRRF) to San Luis Obispo Creek for protection of downstream biological resources as required by the NOAA NMFS (City of San Luis Obispo, pp. 5-1). POTABLE REUSE Potable reuse faces unique challenges in comparison to water from conventional sources, including pathogens, a broad range of contaminants, unregulated trace organics, and disinfection byproducts. A robust process train with built-in redundancy is critical for public health and safety. Furthermore, community outreach and public acceptance of potable reuse is vital. For these reasons, many states are still in the process of developing potable reuse regulations. California is currently in the process of developing regulatory limits for indirect potable reuse (IPR) and direct potable reuse (DPR). IPR refers to the augmentation of a drinking water source (surface water or groundwater) with recycled water followed by an environmental buffer that precedes normal drinking water treatment. DPR eliminates the environmental buffer – purified municipal wastewater is introduced into a water treatment plant intake or directly into the water distribution system and includes an engineered storage buffer. 1.2.1.1 Indirect Potable Reuse The Title 22 requirements for IPR under Section 13561(c) “Indirect potable reuse for groundwater recharge” means the planned use of recycled water for replenishment of a groundwater basin or an aquifer that has been designated as a source of water supply for a public water system, as defined in Section 116275 of the Health and Safety Code. Groundwater and surface waters are considered environmental buffers for providing public health protection benefits, such as contaminant attenuation dilution, and time to detect and respond to failures before final treatment and distribution. IPR can use advanced treated water, but can also be accomplished with tertiary effluent when applied by spreading (i.e., groundwater recharge) to take advantage of soil aquifer treatment (SAT). In 2014, California adopted standards for regulating IPR via groundwater recharge (GWR). By Quarter 1 of 2017, California is expected to have draft regulations in place for surface water augmentation (SWA) with DPR regulations to follow in the coming years, which are anticipated to be to be as restrictive as or more restrictive than the current GWR regulations. In this evaluation, SWA is not included as one of the alternatives because the distance to any of the existing reservoirs is not practical and is cost prohibitive when compared to GWR and DPR. The other two types of GWR are detailed below. • IPR GWR by Surface Spreading (Article 5.1): Recycled Water Facilities Planning Study – Appendix C Recycled Water Treatment Requirements C-3 Recycled water for surface spreading is required to be effluent treated to tertiary standards at a minimum, i.e. properly oxidized, filtered and disinfected, then introduced into an environmental buffer such as a groundwater basin by spreading before it is extracted for potable water purposes. Percolation of the water through the ground’s vadose zone provides significant treatment, often including substantial reduction in nitrogen, organics, and pathogens. A minimum of six months underground retention is required, for which a 10-log reduction of Cryptosporidium and Giardia is credited; and a 1-log enteric virus removal credit is given per month of underground retention. The initial maximum recycled water contribution shall not exceed 20% of the total volume of the recycled water and credited diluent water. An alternative initial recycled water contribution needs an approval by DDW. • IPR GWR by Subsurface Injection (Article 5.2): Recycled water for groundwater replenishment by direct injection is required to receive full advanced treatment (FAT) where oxidized wastewater is treated at minimum using a reverse osmosis and an oxidation treatment process. The treatment train shall consist of at least three separate treatment processes. For each pathogen (i.e., virus, Giardia cyst, or Cryptosporidium oocyst), a separate treatment process may be credited with no more than a 6-log reduction, with at least three processes each being credited with no less than a 1-log reduction. The treatment train shall demonstrate at least 0.5-log (or 69%) reduction of 1, 4-dioxane by advanced oxidation. The requirement for underground retention and its pathogen reduction credit are the same as in Article 5.1 for Groundwater Replenishment by surface spreading. The key requirements and criteria for GWR either by surface spreading or subsurface injection are listed in Table 1. Table 1. California Water Quality Parameters for Potable Reuse via Groundwater Recharge Parameter Criteria Enteric Virus > 12 log10 reduction Giardia > 10 log10 reduction Cryptosporidium > 10 log10 reduction Safe Drinking Water Act Contaminants Meets all Maximum Contaminant Levels (MCLs) Total Nitrogen < 10 mg N/L Total Organic Carbon < 0.5 mg/L Notes: 1. TOC is measured on the undiluted recycled wastewater or after the zone of percolation 1.2.1.2 Direct Potable Reuse Water Code Section 13561(b) states that “Direct potable reuse” is the planned introduction of recycled water either directly into a public water system, as defined in Section 116275 of the Health and Safety Code, or into a raw water supply immediately upstream of a water treatment plant. There are no current CCR requirements regulating DPR. In 2013, the Independent Advisory Panel (IAP) initiated an evaluation of suggested microbial and chemical criteria for DPR from raw wastewater to properly protect public health for potable reuse projects. A final report was published by the IAP in August 2016 (Olivieri et al., 2016). In December 2016, the SWRCB submitted a Report to the Legislature titled Investigation on the Feasibility of Developing Uniform Water Recycling Criteria for DPR. The Report to Recycled Water Facilities Planning Study – Appendix C Recycled Water Treatment Requirements C-4 Legislature was based on the SWRCB’s analysis of recommendations provided by two independent groups: an Expert Panel of scientists and engineers, and an Advisory Group of stakeholders. The Report to Legislature concluded that it is feasible to develop uniform water recycling criteria for DPR, but that there are key knowledge gaps and key research recommendations that must be addressed before DPR regulations can be adopted. Microbial Criteria: As measured from the raw wastewater to finished water suitable for drinking, DPR treatment plants should provide the following pathogen removals: 12-log removal for enteric viruses, 10-log removal of Cryptosporidium ssp., and 9-log removal of Total coliform bacteria. The IAP concluded that “…these criteria would ensure that reclaimed water would be free of pathogenic microorganisms with a large margin of safety (probably greater than being achieved for many conventional water supplies) and therefore could be safely used for potable purposes.” Chemical Criteria: DPR treatment trains capable of producing water that meets published guidelines or health advisory levels; compliance with all regulated chemicals by the USEPA is required. Compliance with five disinfection byproduct limits should be met (Trihalomethanes (THMs), HAA5, nitrosodimethylamine (NDMA), bromate, and chlorate). Two other categories of chemicals should be monitored to evaluate the efficiency of treatment train performance in removing trace organics: 1) unregulated chemicals of interest from the standpoint of public health if present in wastewater (e.g., 1,4-dioxane), and 2) compounds useful for evaluating the effectiveness of organic chemical removal by treatment trains (e.g., pharmaceuticals). The IAP also indicated that monitoring of surrogate parameters, such as TOC, is useful in confirming process performance. These criteria were not intended to pre-empt the regulatory decision-making process for permitting DPR, but were developed as guidelines to be used to evaluate proposed treatment train performance. 1.2.1.3 Potable Reuse Treatment Approach Potable reuse treatment application poses unique challenges related to treatment goals, regulatory requirements, and implementation practicality which have a significant impact on the final treatment train selection. FAT with a multi-barrier approach is considered the standard treatment train for potable reuse. FAT typically consists of microfiltration (MF), reverse osmosis (RO), and an advanced oxidation process (AOP) along with supporting chemical facilities (CDPH 2013). • Microfiltration or Ultrafiltration (MF/UF): Microfiltration is the first step in the membrane filtration process, also called low pressure membrane filtration. Water passes through membranes with a pore size typically ranging from 0.1 to 10 µm, removing small particulates that cannot be removed by conventional means, e.g. sand filtration. The membrane is not small enough to remove viruses, but can achieve 4-log removal for select pathogens, like Cryptosporidium and Giardia. MF/UF is a necessary pretreatment step before RO, as the particulates removed in this process would quickly clog the much smaller pores in the RO membranes. • Reverse Osmosis (RO): RO is the second and final step in the membrane filtration process, also called high pressure membrane filtration. It is a similar process to microfiltration, requiring a pressure drop across a semipermeable membrane to achieve contaminant removal. In the case of RO, the pressure applied is greater than osmotic pressure, which separates the water from larger ions and molecules. In addition to some pathogen removal, RO serves as a pretreatment Recycled Water Facilities Planning Study – Appendix C Recycled Water Treatment Requirements C-5 process to maximize the efficiency of the advanced oxidation process. Advanced oxidation is especially sensitive to the clarity of the water, and reverse osmosis is a very effective method of removing suspended solids that would interfere with the final advanced treatment stage. • Advanced Oxidation Processes (AOP): A typical AOP for potable reuse applications consists of ultraviolet (UV) irradiation at photolysis dose level and a chemical which serves as a source of hydroxyl radicals, e.g. hydrogen peroxide. A UV-AOP (e.g., UV/H2O2) process is a powerful and efficient two-pronged process for the removal of pathogens and trace organics. UV/AOP is required for photolysis of recalcitrant compounds (e.g., NDMA); and creates hydroxyl radicals (OH∙) for oxidizing recalcitrant compounds. • Chemical Facilities: Typical chemicals needed in a FAT process are a coagulants, membrane clean in place chemicals (CIP), anti-scalant for the RO membranes, alkalinity addition, and H2O2 for advanced oxidation. California IPR regulations for GWR by subsurface injection require FAT including the use of RO as part of the IPR treatment train. RO is used to achieve the low total organic carbon (TOC) limit (≤ 0.5 mg/L) in California’s IPR regulations. However, the implementation of FAT with RO is hindered by a number of sustainability issues, including the need to discharge concentrated brine streams that results from the RO process. The regulations include a provision that allows the use of alternative treatment processes if the process is demonstrated to assure at least the same level of protection to public health. The approval process requires the project proponent to perform pilot testing of the proposed alternative treatment process and engage an independent scientific advisory panel to review the testing plan, process, and results. Final acceptance of the alternative treatment process is subject to approval by DDW and the RWQCB. A number of ozone-based alternatives are increasing in popularity. A multi- barrier process with ozone followed by Biological Activated Carbon Filtration (BAC) has demonstrated its potential for significant reduction of TOC to the level that is required in California IPR regulations. • Ozone: In an ozone treatment system, ozone is generated from oxygen and injected into the liquid stream. Ozone is a powerful oxidant, breaking down organic material and heavy metals. Ozone is sometimes used in drinking water treatment plants as a form of disinfection since it typically creates less of the regulated toxic byproducts, such as THMs, which are formed during chlorine disinfection. For the purposes of advanced wastewater treatment, the ozone treatment facility would primarily be used for the removal of organics upstream of filtration and RO. The total organic matter concentration has been shown to be significantly reduced in both the RO feed and the brine when pretreated with ozone (Trussell et al., 2015). • Biological Activated Carbon Filtration (BAC): A BAC filter provides three forms of treatment to the FAT process, i.e. adsorption, physical removal, and biological activity. The design of BAC is similar to that of a conventional sand filter, but uses granular activated carbon (GAC) as media. The filter is included in advanced treatment primarily for removal of degradable organics when ozone is upstream. Ozone produces degradable organics by oxidizing recalcitrant complex organics into simpler/degradable forms. The combination of ozone and BAC is expected to be particularly important for DPR alternatives where limits and redundancy are anticipated to be key criteria. With its demonstrated capability for TOC reduction, ozone and BAC introduces many FAT alternatives for potable reuse treatment where disposal of RO concentrate may be economically and environmentally challenging. Approval from DDW would be required for treatment configurations not Recycled Water Facilities Planning Study – Appendix C Recycled Water Treatment Requirements C-6 using RO-based treatment. A graphic depicting the various unit processes for full advanced treatment (FAT) trains following secondary treatment is provided in Figure 1. Additionally, the figure provides the corresponding hypothetical pathogen log removal credits and removal mechanism(s) for each unit process. Each of these unit processes are discussed in the sub-sections thereafter. Figure 1. List of Potable Reuse Unit Processes and the Corresponding Pathogen Log Removal Credits and Removal Mechanism (Adapted from Trussell et al., 2015) 1.2.1.3.1 Membrane Bioreactor at the WRRF Upstream of Potable Reuse The City’s WRRF Project will be replacing the existing conventional activated sludge (CAS) treatment with a Membrane Bioreactor (MBR) process that consists of a biological reactor integrated with MF or loose UF membranes that combine clarification and filtration into a single step process. MBR takes the treated effluent water quality to much higher level than CAS with the addition of a nutrient removal process. MBR has been implemented in treatment processes for potable reuse. One example is the potable reuse project at Cloudcroft, New Mexico, where the treatment train consists of an MBR, RO, and UV/AOP with hydrogen peroxide. To date, however, a data gap exists in terms of the effectiveness of MBR on pathogen removal for achieving the potable reuse pathogen reduction requirements. Studies so far have shown that MBRs consistently deliver complete removal of protozoa (Giardia and Crypto) and around 6- log reduction of bacteria; however, virus removal by MBR varies significantly depending on the type of virus, the indicator, or the source of virus that are being monitored. Studies based on MBR systems in operation discovered that the MF or UF membranes typically used in MBRs are not capable of retaining viruses by size exclusion (Hai et. al. 2014); and viruses and phages (virus indicator) removal is also dependent on membrane integrity and MBR operation and maintenance activities, such as periodic backwash and chemical cleaning. Biological Adsorption Phys Rem Oxidation Chem Inactivation Biological Adsorption Phys Rem Phys Rem Oxidation Inactivation UV Light Phys Degradation Brine Reject Secondary Effluent Ozone Biol Active Filter MF RO UV-AOP Total Minimum Virus 2 6 ----1-2 6 15-16 12 or 13 Crypto 1 2-4 --4 1-2 6 14-17 10 or 11 Giardia 2 6 --4 1-2 6 19-20 10 or 11 Recycled Water Facilities Planning Study – Appendix C Recycled Water Treatment Requirements C-7 Membrane bioreactors, which are commonly used in wastewater treatment, may replace MF/UF in a potable reuse train if proper membrane integrity testing can be provided by manufacturers to confirm adequate pathogen log removal, or with an approved monitoring technique. A graphic depicting the potential unit processes for FAT trains following MBR at the WRRF is provided in Table 2. Additionally, the figure provides the corresponding hypothetical pathogen log removal credits for each unit process. Each of these unit processes were discussed previously in this section. Table 2. Potential Pathogen Log Reduction Credits for a MBR and Advanced Treatment Technologies (In Order of Treatment from Left to Right) PATHOGEN Tertiary Treatment MBR1 O32 BAC3 UV/AOP4 TOTAL Minimum Requirements Enteric Virus 0 4 0 6 13-Log 12-Log Cryptosporidium 4 0 0 6 12-Log 10-Log Giardia 4 3 0 6 15 Log 10-Log Notes: 1. MBR equipped with pressure decay test would have to be used to verify log reduction credits listed. 2. Assuming a temperature of 15°C or higher, Giardia reduction is 3 log at a CT of 0.95 mg/min/L (U.S. EPA, 2003). At the same temperature, 4-log reduction of virus occurs at a CT of 0.6 mg/min/L (U.S. EPA, 2003). A 5-Log virus disinfection approval for ozone disinfection is based upon a minimum CT of 1.0 mg/min/L (Ishida et al., 2008). Trussell et al. (2015) documented similar virus kill. Both projects consistently demonstrated 7+ log reduction of MS2 conservatively equivalent to 5-log reduction of poliovirus (Ishida et al., 2008; Fontaine and Salveson, 2014a). 3. BAC is used to degrade ozone DBPs and further polish the water. 4. UV systems can provide 4-log reduction of adenovirus at 186 mJ/cm2 (U.S. EPA, 2006b). Extrapolation to 6-log reduction results in a minimum UV dose of 235 mJ/cm2. The alternative treatment train with MBR has shown to result in accumulated pathogen reduction achieving water quality criteria, therefore it may be proposed for use in a multi-barrier approach for potable reuse, but would be subject to approval by DDW and requires substantial demonstration that assures at least the same level of protection of public health. 1.2.1.3.2 Ozone Treatment Facility In an ozone treatment system, ozone is generated from oxygen and injected into the liquid stream. Ozone is a powerful oxidant, breaking down organic material and heavy metals. Ozone is sometimes used in drinking water treatment plants as a form of disinfection since it typically creates less of the regulated toxic byproducts, such as THMs, which are formed during chlorine disinfection. For the purposes of advanced wastewater treatment, the ozone treatment facility would primarily be used for the removal of organics upstream of filtration and RO. A graphical representation of the organic concentration in RO brine with and without upstream ozone/BAC filter pretreatment is shown in Figure 2. Fluorescence, an indirect measurement of the total organic matter concentration, is shown to be significantly reduced in both the feed and the brine when pretreated with ozone. Recycled Water Facilities Planning Study – Appendix C Recycled Water Treatment Requirements C-8 Figure 2. Effluent Organic Matter Transformation by Fluorescence (Source: Trussell et al., 2015) 1.2.1.3.3 Biological Activated Carbon Filtration (BAC) A BAC filter provides three forms of treatment to the FAT process – adsorption, physical removal, and biological activity. The design is similar to that of a conventional sand filter, but uses granular activated carbon (GAC) as media. The filter is included in advanced treatment primarily for the sake of redundancy, water conditioning upstream of membrane filtration, and removal of degradable organics (if ozone is upstream). Ozone located upstream will produce degradable organics by oxidizing recalcitrant complex organics into simpler/degradable forms. Ozonation and BAC are expected to be particularly important for SWA and DPR alternatives where limits and redundancy are anticipated to be key criteria. 1.2.1.3.4 Microfiltration or Ultrafiltration (MF/UF) Microfiltration is the first step in the membrane filtration process, also called low pressure membrane filtration. Water passes through membranes with a pore size typically ranging from 0.1 to 10 µm, removing small particulates that cannot be removed by conventional means, e.g. sand filtration. The membrane is not small enough to remove viruses, but can achieve 4-log removal for select pathogens, like cryptosporidium and giardia. MF/UF is a necessary pretreatment step before RO, as the particulates removed in this process would quickly clog the much smaller pores in the RO membranes. 1.2.1.3.5 Reverse Osmosis (RO) RO is the second and final step in the membrane filtration process, also called high pressure membrane filtration. It is a similar process to microfiltration, requiring a pressure drop across a semipermeable membrane to achieve contaminant removal. In the case of RO, the pressure applied is greater than osmotic pressure, which separates the water from larger ions and molecules. In addition to some pathogen removal, RO serves as a pretreatment process to maximize the efficiency of the advanced oxidation process. Advanced oxidation is especially sensitive to the clarity of the water, and reverse Recycled Water Facilities Planning Study – Appendix C Recycled Water Treatment Requirements C-9 osmosis is a very effective method of removing suspended solids that would interfere with the final advanced treatment stage. 1.2.1.3.6 Disinfection and AOP Disinfection has the option of either being stand-alone disinfection (e.g., UV) or a combination of disinfection and AOP (e.g., UV/H2O2). The decision to use either is based on a combination of potable reuse regulations and feed water quality. For facilities only requiring disinfection, the prescribed unrestricted Title 22 disinfection facilities are recommended (e.g., 100 mJ/cm2 UV dosing at 65% UV Transmittance). The latter would be recommended for additional pathogen log removal credits as well as water quality objectives. A UV/AOP (e.g., UV/ H2O2) process is a powerful and efficient two-pronged process for the removal of pathogens and trace organics. The UV dosing in such an arrangement is greater than unrestricted Title 22 (upwards of 1,200 mJ/cm2) due in large part to the dosing requirements for i) photolysis of recalcitrant compounds (e.g., NDMA) and ii) create the H2O2 hydroxyl radicals (OH∙) for oxidizing other recalcitrant compounds. While UV/AOP treatment provides a more robust process than stand-alone UV disinfection, it might not be required for each water supply. For this analysis, UV/AOP is assumed for each alternative. 1.2.1.3.7 Chemical Facilities Typical chemicals needed in a FAT process are a coagulant upstream of the BAC (most likely), membrane clean-in-place chemicals (CIP), anti-scalant for the RO membranes, alkalinity addition, and H2O2 for advanced oxidation. Chemical facilities, including pumps, storage tanks, and contact basins, are included in a cost and sizing analysis. 1.2.1.3.8 Unit Process Sizing Criteria This section provides information on the basis for sizing each unit process. 1.2.1.3.8.1 Ozone Treatment Facility The footprint of the ozone treatment facility is divided into two subsections: equipment housing and contact basin. The equipment housing area is estimated based on a unit floor space per lb O3/d produced, which decreases as production increases due to economies of scale. The contact basin size is determined based on typical hydraulic residence time (HRT) (20 mins for cryptosporidium inactivation), typical depth (20’), ozone transfer efficiency (95%), and the amount of ozone needed for treatment in lb O3/d. The contact basin is not always necessary, assuming high efficiency ozone generation and venturi injectors in place of conventional diffusers. However, a contact basin is typical for conventional ozone treatment, and is relatively small compared to the equipment housing footprint. 1.2.1.3.8.2 Biological Activated Carbon Filtration The footprint of a BAC filter is limited by the allowable surface loading rate (SLR). Depth and bed volume are determined by empty bed contact time (EBCT). Typical values of 4.5 gpm/sf and 20 minutes were used for SLR and EBCT, respectively. For footprint analysis, the total surface area needed was calculated Recycled Water Facilities Planning Study – Appendix C Recycled Water Treatment Requirements C-10 by dividing the design flow rate by the SLR. An adder of approximately 30% was used to account for ancillary equipment. 1.2.1.3.8.3 Microfiltration or Ultrafiltration The footprint of a MF/UF facility is limited by the allowable flux rate across the membrane surface. A typical flux rate for a low-pressure membrane filter, such as a MF membrane ranges about 20 gal/sf/d. From this design parameter and the flow rate, the required total membrane surface area is calculated. The footprint may be adjusted by optimizing the filter replacement frequency. An estimated footprint was determined by using HDR records of membrane filtration facilities flux and the corresponding footprint. 1.2.1.3.8.4 Reverse Osmosis RO facilities are designed similarly to an MF/UF facility, limited by the allowable flux rate across the membrane surface. A typical maximum flux rate for a high-pressure membrane, like an RO membrane, is about 10 gal/sf/d. RO units will require more unit floor space per filter due to higher pumping and pressure requirements. RO reject water treatment, if required, is not included in this footprint analysis. A separate facility may be required to address RO reject water treatment if it is required in the future. The analysis is based on the assumption that any RO reject water can be discharged to San Francisco Bay via the East Bay Discharger Authority’s effluent discharge pipe. The footprint may be adjusted by optimizing the RO filter unit placement. An estimated footprint was determined by using HDR records of membrane filtration facilities to determine the unit floor space per filter. 1.2.1.3.8.5 Disinfection and Advanced Oxidation An advanced oxidation system is sized by the power input needed for disinfection in kW/MGD. The system can be divided into a series of panels, including UV lamps and associated equipment, and sized according to an estimated footprint per panel. The transmittance will increase with the addition of ozone/BAC. Advanced oxidation requires a target dose of about 1,200 mJ/cm2, or approximately 0.30 kWh/1,000 gal for a standard UV/AOP system. The corresponding power supply ranges from 25 to 125 kW systems for the water supply options considered. From these design criteria, the estimated number of lamps can be estimated. 1.2.1.3.8.6 Chemical Facilities The costs of the chemical facilities are based on feed flow, the chemical type, and the desired storage time. Typical chemicals needed in a FAT process are a coagulant upstream of the BAC (most likely), membrane CIP, anti-scalant for the RO membranes, alkalinity addition, and H2O2 for advanced oxidation. Liquid chemical feed costs were determined by inputting the design criteria into cost curves, which estimates total capital and operation and maintenance costs based on parametric estimates. Recycled Water Facilities Planning Study – Appendix C Recycled Water Treatment Requirements C-11 REFERENCES City of San Luis Obispo, Utilities Department. 2015 Urban Water Management Plan. 2016. Hai, F.I., Nghiem, L.D., Khan, S.J., Price, W.E., Yamamoto, K. 2014. Wastewater reuse: removal of emerging trace organic contaminants. in: Membrane Biological Reactors, (Eds.) F.I. Hai, K. Yamamoto, C.-H. Lee, IWA publishing, UK (ISBN 9781780400655), pp. 163-203. Harris, Kenneth A. Order No. R3-2014-0033/NPDES No. CA0049224. City of San Luis Obispo : California Regional Water Quality Control Board, Central Coast Region, September 25, 2014. Olivieri, A.W., J. Crook, M.A. Anderson, R.J. Bull, J.E. Drewes, C.N. Haas, W. Jakubowski, P.L. McCarty, K.L. Nelson, J.B. Rose, D.L. Sedlak, and T.J. Wade (2016). Expert Panel Final Report: Evaluation of the Feasibility of Developing Uniform Water Recycling Criteria for Direct Potable Reuse. Prepared August 2016 by the National Water Research Institute for the State Water Resources Control Board, Sacramento, CA. Regional Water Quality Control Board, Central Coast Region. Water Quality Control Plan for the Central Coast Basin. June 2011. Trussel et al. (2015) Demonstrating Redundancy and Monitoring to Achieve Reliable Potable Reuse. Direct Potable Reuse in California: Specialty Seminar at UC Berkeley in September 2015. DRAFTCity of San Luis Obispo Recycled Water Facilities Planning Study - Final Draft D 1/19/2017 APPENDIX D. WATER REUSE PERMIT DRAFTCity of San Luis Obispo Recycled Water Facilities Planning Study - Final Draft E 1/19/2017 APPENDIX E. COST ESTIMATING ASSUMPTIONS AND METHODOLOGY City of San Luis Obispo Appendix E. Cost Estimating Assumptions and Methodology Recycled Water Facilities Planning Study ‐ Final Internal Draft E‐1 COST ESTIMATING ASSUMPTIONS AND METHODOLOGY The cost opinions (estimates) included in this Study are prepared in conformance with industry practice and, as planning level cost opinions, will be ranked as a Class 4 Conceptual Opinion of Probable Construction Cost as developed by the Association for the Advancement of Cost Engineering (AACE) Cost Estimate Classification System (1). The AACE classification system is intended to classify the expected accuracy of planning level cost opinions, and is not a reflection on the effort or accuracy of the actual cost opinions prepared for the Study. According to AACE, a Class 4 Estimate is intended to provide a planning level conceptual effort with an accuracy that will range from ‐30% to +50% and includes an appropriate contingency for planning and feasibility studies. The conceptual nature of the design concepts and associated costs presented in this Study are based upon limited design information available at this stage of the projects. At this planning‐level stage, two percentages were applied to the costs, shown in Table 1. In order to estimate annual payments for the five recycled water alternatives, some assumptions were made and are also tabulated below in Table 1. The costs were calculated using the annual payment method, and the $/acre‐foot values were calculated using the estimated yield from each alternative as described in the body of the Study. Table 1. Cost Estimating Assumptions and Contingencies Assumption Value Construction Contingency 30% of Capital Cost Implementation Costs 25% of Capital Cost and Construction Contingency Inflation Rate 3.5% Interest Rate 5% Discount Rate 5% Loan Term 30 years Table 2 through Table 4 include the assumptions, values, and equations used to estimate costs for the five alternatives in the Recycled Water Facilities Planning Study. City of San Luis Obispo Appendix E. Cost Estimating Assumptions and Methodology Recycled Water Facilities Planning Study ‐ Final Internal Draft E‐2 Table 2. Alternatives 1 and 2 Cost Details Parameter Alternative 1 Alternative 2 Recycled Water to Outside City Interests Recycled Water to Cal Poly Recycled Water Main 2,600 ft of 10” main $200/LF O&M: 1% of mainline capital costs 4.6 miles of 8” pipe $185/LF for smaller diameter pipe O&M: 1% of mainline capital costs Other Infrastructure Water meter for an 8” pipe at $6,500, rounded to the nearest 1000 Turnout infrastructure includes vaults, valves, piping, and flow control valve SCADA controls estimated at $25,000 total O&M: 1% of infrastructure capital costs Energy costs: Assumes $0.16/KWhr, includes estimated energy cost associated with delivering the City’s existing RW customers at a higher pressure of 140 psi to meet pressure requirements for the Edna turnout. – Pump Station – Assumes yield of 82 AFY, 8 months of irrigation at 10 hours per day and a peaking factor of 3, which gives a flow rate of 549 gpm Calculated using the following cost curve formula: 2.45244*(Flow0.8182)*103 O&M: 5% of pump station capital costs Energy costs: Assumes $0.16/KWhr, a residual pressure of 40 psi City of San Luis Obispo Appendix E. Cost Estimating Assumptions and Methodology Recycled Water Facilities Planning Study ‐ Final Internal Draft E‐3 Table 3. Alternatives 3 and 4 Cost Details Parameter Alternative 3 Alternative 4 Additional Comment Indirect Potable Reuse Direct Potable Reuse to City Water Treatment Plant Direct Potable Reuse Direct to City Water Distribution Conveyance and Pumping $200/LF $260k raw estimate for pumping station Friction = 0.01 ft/ft Same as IPR, plus: 400’ head to City Water Treatment Plant Same as IPR, plus: $50k to tie‐in to the distribution Ozone 3 generators producing 54 lb ozone per day (4 mg/L dose) 13 kWh/lb O3 produced Maintenance & Materials: 1.5% of raw capital cost Same as IPR Same as IPR The calculations are based on a study carried out by Carollo for the City of Palo Alto. Adjustment of LOX chemical cost may be necessary if a LOX system is utilized. Costs for LOX in SLO need to be accounted for. Equipment repair and replacement costs were estimated off a standard assumption value used for the City of Palo Alto and many other studies. The assumption is that 1.5% of the total equipment costs will estimate the cost of repairing and replacing parts such as instrumentation, valving, and pumps. BAC 35’ filter feed head at 70% pumping efficiency Alum dose = 20 mg/L Maintenance & Materials: o 10% loss of media ($2/lb) o 1.5% of raw capital cost The cost for GAC media replacement is based on the amount of GAC used (estimated by the EBCT and bed volume) and the cost of GAC. Plumlee et al. states that GAC was $1.65/lb in 2014 (assumed $2/lb for this study). The Plumlee et al. article estimates that media will be replaced every 8 years. In HDR’s experience, ozone‐BAC facilities typically do not do a full media replacement, but rather replace media as it is lost. For that reason, a conservative 10% yearly attrition rate of GAC value was used to estimate continuous yearly GAC replacement. A 1.5% repair and replacement cost (of total equipment cost) was added for maintenance of the BAC system (similar to ozone). Micro‐Filtration – 95’ filter feed head (41 psi) at 75% pumping efficiency Citric Acid and Sodium Hypochlorite for Clean In Place (CIP) Maintenance & Materials: o Membrane replacement is the key cost (assumed a 10‐year life‐span so 10% replacement each year) Same as DPR to City Water Treatment Plant The calculations are based on Chapter 12 of EPA’s 2016 Potable Reuse Supplement to the Guidelines for Water Reuse. This document is soon to be released. This chapter is titled “Cost of Potable Reuse”. The EPA document developed average O&M costs for membrane based potable reuse facilities based on a 10 MGD hypothetical facility. Costs are also based on actual compiled operating costs. Since the costs were developed for 2016, no inflation rate was applied. UV/AOP Dose = 1,200 mJ/cm2 UVT = 80% Energy demand = 0.25 kWh/kgal treated Hydrogen Peroxide dose = 4 mg/L Maintenance & Materials: Lamp and ballast replacement is the key driver in cost Same as IPR Same as IPR Based on previous work by HDR’s June Leng for the WRRF City of San Luis Obispo Appendix E. Cost Estimating Assumptions and Methodology Recycled Water Facilities Planning Study ‐ Final Internal Draft E‐4 Clearwell – Volume based on a 24‐hr hydraulic residence time $2/gal used for calculating the capital cost estimate Maintenance & Materials: $20,000 line item added Same as DPR to City Water Treatment Plant Drinking Water Coagulation/ Flocculation – – Capital and O&M includes (11 hp): o Coagulation tanks o Coagulation storage and feed o Floc tanks o Polymer storage o Auxiliaries and piping Alum dose = 15 mg/L Well documented industry values for a technology with several decades of data Drinking Water Micro‐Filtration – – Same as FAT train MF, except: Feed head at 75’ (32 psi) instead of 95’ (42 psi) to account for water better conditioning for membrane filtration Membrane life‐span increases from 10 to 12 years which reduces the annual membrane replacement cost See Micro‐Filtration comments above Drinking Water UV/ Chloramination – – Dose = 40 mJ/cm2 UVT = 80% Energy demand = 0.27 kWh/kgal treated (includes chloramination) Sodium Hypo dose = 5 mg/L Aqueous Ammonia dose = 1 mg/L Maintenance & Materials: Lamp and ballast replacement is the key driver in cost City of San Luis Obispo Appendix E. Cost Estimating Assumptions and Methodology Recycled Water Facilities Planning Study ‐ Final Internal Draft E‐5 Table 4. Alternative 5 Cost Details Parameter Alternative 5 Engineered Hydroponic System (EHS) Membrane Bioreactor (MBR) Conveyance and Pumping 6” diameter pipe for 0.5 miles $170/LF Pump station with a vertical turbine pump (0.5 MGD pumping capacity) $190,000 for 1.5 MGD pumping capacity O&M: assumes 35’ of head, 0.01 ft/ft friction, and 70% pumping efficiency Same as EHS Satellite WRRF 8‐16 $/gpd * Would include headworks, flow equalization, primary treatment, hydroponic system, filtration, and disinfection O&M: Based on $2.2/gal, from scaled values in (2), and includes headworks, pumping and UV disinfection 16‐40 $/gpd Would include headworks, flow equalization, membrane bioreactors (no primaries), and disinfection O&M: Based on $3.8/gal, from scaled values in (2), and includes headworks, pumping, pumping water across membrane, and UV disinfection City of San Luis Obispo Appendix E. Cost Estimating Assumptions and Methodology Recycled Water Facilities Planning Study ‐ Final Internal Draft E‐6 REFERENCES 1. Association for the Advancement of Cost Engineering, Inc. AACE International Recommended Practice No. 17R‐97; Cost Estimate Classification System; TCM Framework: 7.3 ‐ Cost Estimating and Budgeting;. 2011. 2. Walking the Talk: Water Recycling & Energy Efficiency Intertwined at an Eco‐Tourism Resort. Falk, M.; Dinsmore, C.; Kennedy, K.; Kirksey, W. Seattle, WA : Annual WateReuse Symposium, 2009. DRAFTCity of San Luis Obispo Recycled Water Facilities Planning Study - Final Draft F 1/19/2017 APPENDIX F. ALTERNATIVES SCREENING CRITERIA DRAFTCity of San Luis Obispo Recycled Water Facilities Planning Study - Final Draft G 1/19/2017 APPENDIX G. THE EDNA VALLEY IRRIGATION AREA GROWERS WHITE PAPER P 1 P age | 1 I. Exec The g the grow importa a const econom This wh relates t of recyc San Lui II. Intr Agric approxim County a significan ranches. 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In 201 agricultural ops, dry farm g Highway 2 ey, particula ultural Area le wine pro na Valley Su in the Cent The two maj ally been re pply for com time of drou years have lt first by th esidents rely water sourc eservoirs are of Agric Luis Obi reenbe Febru mmon threa ny forms. G yclical droug analyzed th spo’s recycle cal informat supplies and owers and th y and acco 14, San Lui operations med grain, a 227 south o arly south of a. Cattle ran duction faci ub‐basin and tral Coast hy or water so eadily access mmunities a ught. Droug been droug hose most de ying on well ce. Drought e depleted an culture ispo’s lt uary 2016 ad among Given the ghts, and he social, ed water. tion as it d the use he City of ounts for s Obispo include a and cattle of Biddle f the San nches are ilities are d the San ydrologic urces for sible and along the ghts are a ght years ependent ls in low- t impacts nd water Page | 2 February 2016 The success of agricultural production in the Edna Valley is dependent on a sustainable groundwater resource. Even with the employment of the best crop, soil, and water management practices, the growers know the importance of exploring alternative means and methods to support the long-term health of this important industry. Agriculturists are well known for their stewardship, forward-thinking, and their pro-active pursuit of the latest technology and practices. They are experts at finding balance in the midst of the vagaries of Mother Nature and other influences. The Edna Valley growers’ pursuit of City recycled water to maintain the City’s Greenbelt exemplifies these notable traits. The objective of this white paper is to provide information to enable a well-informed and considerate discussion of the provision of City recycled water to the growers in the Edna Valley, located within the City’s designated Greenbelt. Topics in this white paper include a review of state and local water resource policies that will impact water management practices into the future. A section on agricultural water use will provide an overview of current and future water use in the Edna Valley. As importantly, you will find a discussion regarding infrastructure and the costs related to the distribution of recycled water, and the potential for phasing distribution. Under the topic of legal concepts, you will find information about the agreement between the growers and the framework for a draft agreement between the growers and the City. And, finally, the white paper will offer the many benefits associated with the proposal. III. Background For the past 6+ years, growers in the Edna Valley have coordinated their efforts to pursue the purchase of recycled water from the City. Collaboration with the Utilities Department and Community Development staff members resulted in discussions regarding the respective roles and responsibilities, rate structures, pipeline alignment, and conceptual agreements. While there is staff support for the proposal in general, it is now incumbent upon the policy makers to provide direction to further these important discussions and negotiations. III. State & Local Policies The City’s Land Use and Circulation Element Update, finalized in 2015, acknowledged the importance of recycled water. Great care and thought went into crafting the appropriate policy language with regards to the provision of recycled water outside the City limits. In addition to compliance with other policies in the Water and Wastewater Element2, specific findings3 must be made to support the provision of recycled water outside the City limits. The growers in the Edna Valley stand ready, willing, and able to agree to the four (4) findings, as noted. From an historical perspective, on November 13, 2015, Governor Brown issued Executive Order B-36-15 (EO B-36-15) that calls for an extension of restrictions to urban potable water 2 §A 7.3.4 Consider the potential to deliver available recycled water supplies to customers outside the city limits, including analysis of policy issues, technical concerns, and cost recovery, provided it is found to be consistent with the General Plan. 3 §1.13.2 Provision of recycled water outside of City limits may only be considered in compliance with Water and Wastewater Element Policy A 7.3.4 and the following findings: A. Non‐potable/recycled water is necessary to support continued agricultural operations. B. Provision of non‐potable/recycled water will not be used to increase development potential of property being served. C. Non‐potable/recycled water will not be further treated to make it potable. D. Prior to provision of non‐potable/recycled water, the property to be served will record a conservation, open space, Williamson Act, or other easement instrument to maintain Page | 3 February 2016 usage until October 31, 2016, should drought conditions persist through January 2016. EO B-36- 15 is the fifth in a series of Executive Orders by Governor Brown on actions necessary to address California's severe drought conditions, which directed the State Water Board to implement mandatory water reductions in urban areas to reduce potable urban water usage by 25 percent statewide. On May 5, 2015, the State Water Board adopted an emergency conservation regulation in accordance with the Governor's directive. The provisions of the emergency regulation went into effect on May 18, 2015. For the first time in California history, the Sustainable Groundwater Management Act (SGMA) empowers local agencies to adopt groundwater management plans that are tailored to the resources and needs of their communities. Good groundwater management will provide a buffer against drought and climate change, and contribute to reliable water supplies regardless of weather patterns. The Sustainable Groundwater Management Act and related statutory provisions from SB1168 (Pavley), AB1739 (Dickinson), and SB1319 (Pavley) were amended in 2015 (effective January 1, 2016). As communities attempt to determine how to administer SGMA on a local basis, success will be based upon a number of items, some of which include: coordinated water management within a basin, regulatory oversight, improved data management, funding and resources, and as importantly, communication and outreach. The growers in the Edna Valley accept the goals, objectives, and actions required under SGMA and its implementation via the Department of Water Resources guidelines. They are committed to assist the City by offering SGMA knowledgeable legal expertise, in an effort to ensure that the provision of recycled water to the growers in Edna Valley will be in substantial conformance with SGMA. Notably, the City’s consultant, Water Systems Consulting, Inc., proposes to work directly with the City’s water rights counsel. The growers suggest that this task be pursued immediately to provide early and proper guidance. IV. H20 & Recycled H20 Use In California today, agriculture represents 40 percent of the end users of recycled water. The following describe four case studies in communities that provide recycled water to agriculture. Monterey County – Northern Monterey County has long been water short, resulting in over pumping of the aquifer, declining well water levels, and seawater intrusion. Since 1980, the County has been involved in a pilot project that included major infrastructure improvements – 45 miles of distribution piping, 22 supplemental wells, and coverage of 12,000 acres. Today, this is the largest raw-eaten food crop area in the world irrigated with recycled water. Since 1988, these fields have been irrigated with 13,000 acre feet/year of recycled water. Watsonville – Watsonville is a recent convert to the use of recycled water for growing vegetables and fruit – primarily strawberries, comprising 70 percent of all strawberries consumed in the USA. Since 2007, approximately 4,000 acre feet/year of recycled water has been to a network of pipelines serving the farming areas. Santa Rosa – The Santa Rosa Water Reclamation System comprises 6,130 acres and utilizes 45 pump stations that deliver recycled water to irrigate a variety of unrestricted crops – vegetables, fruits, orchards, and pasture. Page | 4 February 2016 Sea Mist Farms - Sea Mist Farms, located in the Salinas Valley, has successfully used recycled water since 1998. Sea Mist grows artichokes, spinach, lettuce, and variety of other crops on its nearly 11,000 acres of land. Recycled water comprises roughly two thirds of the farm’s total water use and is applied to roughly 80% of its acreage. Sea Mist uses well water only when its water demand exceeds the supply of recycled water. Edna Valley – To put overall agricultural water use in the Edna Valley into perspective, the growers represent approximately 3,697 acres of irrigated crops ranging from citrus to row crops, vineyards to a very small amount of pasture. Water use, depending upon the crop, can range from 0.5 (vineyards) – 5.0 (pasture) acre feet/acre. On average, these crops represent an estimated water use of 2,908 acre feet of water on an annual basis. Since the original vineyard plantings in the early 1970s, the growers have implemented extensive water conservation improvements while continuing to invest, manage, and improve their approach to framing. This has included improved crops/root stock and implementation of the latest supplemental irrigation technologies (e.g., the noted average annual water use on one acre of vineyard is less than 0.5 acre-feet of water, which represents a 50% reduction compared to irrigation practices prevalent 20 years ago.) Modern citrus plantings utilize high efficiency irrigation systems to conserve water. Water is applied through drip emitters or micro-sprinklers that have a 92% to 96% efficient application rate. Water application is designed to match soil infiltration rates for zero runoff. Total annual water use is 1.2 to 1.3 acre-foot/acre/year, less than half compared to past irrigation practices. Citrus is a perennial evergreen that can utilize water year-round, with water demand even in the winter when other trees are dormant. It is noteworthy that, in addition to water usage during the active growing season, agriculture irrigation will also be performed during the winter months. This winter application is not solely relegated to irrigating winter vegetable row crops, but would be utilized to maintain hydration of the deep soil profile for tap roots of permanent crops, such as wine grapes and citrus. This is a key consideration for the City’s distribution of recycled water since existing urban users do not require nor can they typically use recycled water during the wet season of the year. The Edna Valley growers are able, therefore, to use recycled water year round. V. Infrastructure Recycled Water Infrastructure – The City’s Water Resource Recovery Facility (WRRF), located off of Prado Road near Highway 101, currently produces approximately 3.4 mgd (3,800 AFY) of recycled water on an annual basis. Recycled water is regulated by treated to Title 22 California Code of Regulations California Department of Public Health’s Recycled Water Regulations. The City’s recycled water is treated to Title 22 tertiary 2.2 quality4, the highest grade 4 "Disinfected tertiary‐2.2 recycled water" means recycled water that has been oxidized and disinfected so that the median concentration of total coliform bacteria in the disinfected effluent does not exceed a most probable number (MPN) of 2.2 per 100 milliliters utilizing the bacteriological results of the last seven days for which analyses have been completed, and Page | 5 February 2016 recycled water, thus allowing for such uses as irrigation of direct food crops. The City is undertaking a detailed study to determine the actual amount of recycled water supply available for additional in-City uses, and for non-City uses outside of the City limits. The availability of recycled water varies depending on a number of factors, which include constraints to plant processes, maintenance of required discharge to San Luis Obispo Creek (1,800 AFY), availability of wastewater during summer months when Cal Poly is out of session, limited recycled water storage at the plant, peak summer demands, and other factors. Due to the current drought, aggressive water conservation measures have reduced the wastewater flows to the plant, and thus the production of recycled water. However, the City’s current recycled water program delivers only 180 AFY of recycled water to landscape irrigation customers, with an anticipated ultimate recycled water use of 870 AFY. Strictly “doing the math”, this means that approximately 1,100 AFY of recycled water could be theoretically available for outside uses. To maximize such deliveries to outside customers, deliveries must consider commitments to existing and future City customers, the trends and variability of their needs and peak demands (generally night-time for landscape irrigation), recycled water storage and pumping facilities, and the existing distribution system. To maximize deliveries to non-City customers, such as the Edna Valley growers, consideration must be given to receiving recycled water during off-peak periods to the extent possible. Distribution and Pumping System – The City’s recycled water distribution system was initially installed in 2006, and is comprised of 8 miles of ductile iron and high density polyethylene (HDPE) distribution mains ranging in size from 8-inch to 18- inch diameter. One short segment of 20-inch diameter pipe is on the WRRF connecting to the pump station. The existing distribution system currently extends to Tank Farm Road at Orcutt Road, where an existing 8- inch diameter ductile iron pipe terminates across Tank Farm Road at Islay Hill Park. See aerial photo inset. Islay Hill Park, since its inception, has been irrigated with recycled water. Preliminary design plans have been prepared to extend the right-of-way pipeline east to the City limits (See Exhibit A - Preliminary Design), and further east to Moretti Canyon Road (See Exhibit B - Conceptual Design Alternatives). Preliminary hydraulic calculations were performed, based on delivery of 100 AF/month to the Edna Valley growers, and it was envisioned that deliveries would be optimized by pumping over an extended period, i.e., 16 to 24 hours per day, to keep pipeline velocities lower and hydraulic head losses to a minimum. Recycled Water Pumping Station – The City’s existing right-of-way pump station is designed to provide up to 1,750 gpm at a discharge pressure of 133 psi (432 feet). The hydraulic model, prepared for the City’s system, indicates that delivery pressure at Tank Farm Road/Orcutt Road would be within the range of 65 to 75 psi. It is envisioned that an in-line booster station the number of total coliform bacteria does not exceed an MPN of 23 per 100 milliliters in more than one sample in any 30 day period. Page | 6 February 2016 would be needed to convey recycled water to the point of delivery near Moretti Canyon Road. Whether the City will need to upgrade the existing booster station, and/or the timing thereof, is uncertain and highly dependent on future customers and their corresponding delivery pressure needs and peak delivery demands. Regardless, the recycled water delivery system extension to the Edna Valley Growers will likely need to include a privately-owned booster station to provide regional services to the growers. A carbon filtration system to remove free chlorine is also anticipated, until such time as the City changes its method of disinfection to ultraviolet light. Costs – The initial extension of the recycled pipeline to the City limit, recommended to be 10- inch diameter to minimize system pressure losses, will be approximately 2,000 linear feet (LF), with an estimated cost of approximately $300,000. It is envisioned that a metering station and in- line booster station would be required at some point to serve the proposed green belt area. The pipeline extending to the east, to tie-in with the Cross Creek Mutual Water Company pipeline, would be approximately 3.2 miles, with an estimated cost of approximately $1.7 million (estimated at $100/LF). This alignment would be predominantly outside of County right of way on Orcutt Road. The total infrastructure cost to extend the recycled water delivery system is expected to be in the range of $2 million. Recycled Water Pricing Considerations – Metering & Turnouts – The Edna Valley growers would form and manage a single entity for the purpose of receiving and distributing recycled water, and therefore a single turnout is anticipated. Energy Optimization – To minimize energy costs for delivery of recycled water, it would be desirable to pump mostly during the night-time hours to take advantage of lower PG&E energy rates. However, night-time coincides with peak demand (particularly during summer irrigation season) for landscape irrigation, and coincidently with lowest recycled water production at the WRRF. This is due to diurnal fluctuation and low night-time wastewater flows. Thus, in order for the Edna Valley growers to receive deliveries of recycled water from the City, timing of deliveries will need to be primarily focused around availability of recycled water at the WWRF, which during the irrigation season will be during the day time. VI. Legal Concepts The Association of Edna Valley Growers have joined together to share their common goals and objectives, information, and to pursue recycled water from the City of San Luis Obispo. To formalize this coordinated effort, a Memorandum of Understanding (MOU) was created. In essence, the MOU includes, in concept, the following recitals. The signatories to the MOU are limited to agricultural properties that are located wholly or partially within the City’s adopted Greenbelt. (See Exhibit C – Aerial Photograph – Eligible Growers w/in City’s Greenbelt) A commitment to form an appropriate legal entity to ensure long-term equitable management of recycled water, obtain funding for capital projects, and be a key stakeholder should a basin-wide Groundwater Sustainability Agency be formed. As time is of the essence, fund necessary infrastructure for the delivery of recycled water, execute agreements with the City, and construct the required system improvements. Page | 7 February 2016 During discussions with City staff, a draft Agreement for Provision of Recycled Water for Agricultural Use Outside the City Limits but within the City’s Greenbelt Area was prepared and presented for review. The salient items in the agreement include the following. Provision of recycled water would be solely for the use of agricultural properties within the City’s Greenbelt. The growers (“Customer”) would solely be responsible for the costs attributed to the separate water connection, the design, construction and maintenance of the distribution pipelines. Unless otherwise agreed to in writing by both parties, water service shall be year round and the maximum annual water available to Customer shall be 1,000 acre feet per calendar year. There is no minimum annual water quantity. The preliminary term of the agreement is for three (3) years and 6 months, commencing on a date to be determined, and continue thereafter from calendar year to calendar year until cancelled by either party. The term of the agreement shall reflect the Customer’s financial investment to fund the design, construction, and maintenance of the system. The City may, at its sole discretion, interrupt or discontinue water service, in whole or in part, in case of an actual or anticipated shortage of water supply, storage, or delivery capacity. VII. Project Benefits As we develop our understanding of the interdependence between water, farmland, habitat, and urban development, it is imperative that we bring our management decisions for each of these into alignment. Rather than see them as competing land uses, we can try an approach that would serve to integrate our finite resources into our management practices in order to simultaneously produce food, steward our water and natural resources, and support healthy populations of humans and wildlife. Recycled water is one management tool that can provide a variety of benefits from energy optimization to known environmental benefits. For example, recycled water requires 400 kilowatt hours per acre-foot (kWh/AF) compared to 550 kWh/AF for groundwater pumping, and 4,400 kWh/AF for desalination. From an environmental perspective, significant benefits can be obtained through the use of recycled water that includes enhanced flows for fish and wildlife, the reduction of a high level of treatment of the City’s wastewater based upon more stringent discharge requirements, and the offset of withdrawals from surface and groundwater. Basin management, a key objective of SGMA, can now be locally controlled by the proposed cooperative relationship between the Edna Valley growers and the City. As noted, the Edna Valley growers represent a substantial acreage that the City claims as their Greenbelt. The provision of recycled water to the growers would also represent the City’s continued commitment to maintaining this important agricultural and recreational/visitor-serving Greenbelt that surrounds our urban core. From an economic perspective, the growers, in addition to working collaboratively with the City and other interested agencies, have committed their own resources to fund the design, construction, and maintenance of the infrastructure to supply recycled water to the Edna Valley. With the grower’s purchase of recycled water from the City, this new source of revenue would enable the City to promote and better distribute recycled water to its urban customers. Page | 8 February 2016 VIII. Schedule Based upon the history of interest and negotiations with the City thus far, the growers are poised to immediately coordinate with City to forward this important project. The City’s interest is now supported by the retention of an outside consultant to assist them with better defining and understanding the overall goals and objectives of a comprehensive recycled water plan. As a stakeholder, the growers are willing to fully participate in this process and, in doing so, forward the immediate provision of recycled water to the Edna Valley. Attachments: ▪ Exhibit A – Preliminary Design ▪ Exhibit B – Conceptual Design Alternatives ▪ Exhibit C – Aerial Photograph – Eligible Growers w/in City’s Greenbelt ▪ Exhibit D – Summary of Hydraulic Considerations MORRETTI CANYON RDBRIDGE CREEK RDA V O C A D O L N LEWIS LN LA LOMITA WAYVIA PIEDRAB ID D L E R A N C H R DSPANISH OAKS DRCROSS CREEK WAYT A N K F A R M R D ORCUTT RD O R C U T T R D RIGHETTI RDORCUTT RD5 4 1 2 3 8 1 6 6 7 8 5 3 4 7 2 Source: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity M:\826-Paragon Vineyard Co\001-Supplimental Water Feasibility Analysis\07 GIS\Map Document\Conceptual Waterline Alignment\0826-0001 Conceptual Alignment.mxd; Author: ¯ 612 CLARION C OURTSAN L UIS OBISPO, CA 934 01T 805 5 44-4011 F 805 5 44-4294www.w al l ace g ro u p.u s CIV I L EN G IN EE RI NGCONSTRUCTION M AN AG E ME NTLANDSCAPE A RC HI TE CT UR EMECHANICAL E NG I NEE RI NGPLANNINGPUBLIC W O RK S A DM IN IS T RAT IO NSURVEYING/G IS SO LU TI O NSWATER RE S O URC ESWALLACE S WA NS O N IN T ER NAT I O NA L CO NC EPTU AL RE CYC LE DWATERLINE AL IG N MENT In de x Map 1 in ch = 70 0 fee t 0 1,400 LEGEND COUNT Y RO W CONCEPTUALALIGNMENTS AL IG NM ENT A AL IG NM ENT B * WAL LA CE G RO UP DID N O T P E RFO RM SURV E Y S ERV ICE S FO R THIS M AP. NO T A LE G A L DO CUM EN T. BEG INNI NG OF SEGMENT 1 (SEE CALCULATIONS ON THIS SHEET) EN D OF SEGMENT 2(SEE CALCULATIONS ON THIS SHEET) EN D OF SEGMENT 1/BEGI NNING OF SEG MENT 2(SEE CALCULATIONS ON THIS SHEET) Te xt *THE P ROP O SE D A LIG NME NT TRAV E RSE SPRIVATE PR OP ERTY, WHICH WILL RE QUIRE ANEASEMENT PRIO R TO IMP LE ME NTATIO N. THISCONCEPTUAL DO CUMEN T DO ES NO T IMP LYTHAT AN E AS EM ENT HAS BE EN G RAN TED. EHO EHO EHO EHO EHO EHO ORCUTT RD Source: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity M:\826-Paragon Vineyard Co\001-Supplimental Water Feasibility Analysis\07 GIS\Map Document\Conceptual Waterline Alignment\0826-0001 Conceptual Alignment Sheet 1.mxd; Author: ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munity CO NC EPTU AL RE CYC LE DWATERLINE AL IG N MENT In de x Map 612 CLARION C OURTSAN L UIS OBISPO, CA 934 01T 805 5 44-4011 F 805 5 44-4294www.w al l ace g ro u p.u s CIV I L EN G IN EE RI NGCONSTRUCTION M AN AG E ME NTLANDSCAPE A RC HI TE CT UR EMECHANICAL E NG I NEE RI NGPLANNINGPUBLIC W O RK S A DM IN IS T RAT IO NSURVEYING/G IS SO LU TI O NSWATER RE S O URC ESWALLACE S WA NS O N IN T ER NAT I O NA L 1 in ch = 40 fe et 0 8040¯EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO ORCUTT RD Source: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity¯BE GINNING O F PRO P OS ED CONCE P TUAL AL IGNM ENT A ND INL INE B OO STE R STATION LO CATIO N LEGEND CO NCEPTUALALIGNMENTS ALIG NM ENT ALIG NM ENT B * Co un ty RO W EHO OVERHEADELECTRICAL SH EET 1 OF 8ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munity CREE K CRO S SING (CULV ERT) In de x MapMATCHLINE - SEE BELOWMATCHLINE - SEE ABOVEMATCHLINE - SEE SHEET 2WAL LA CE G RO UP DID N O T P E RFO RM SURV E Y S ERV ICE S FO R THIS M AP. NO T A LE G A L DO CUM EN T. *THE P ROP O SE D A LIG NME NT TRAV E RSE SPRIVATE PR OP ERTY, WHICH WILL RE QUIRE ANEASEMENT PRIO R TO IMP LE ME NTATIO N. THISCONCEPTUAL DO CUMEN T DO ES NO T IMP LYTHAT AN E AS EM ENT HAS BE EN G RAN TED. EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO ORCUTT RD LA LOMITA WAYSource: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity M:\826-Paragon Vineyard Co\001-Supplimental Water Feasibility Analysis\07 GIS\Map Document\Conceptual Waterline Alignment\0826-0001 Conceptual Alignment Sheet 2.mxd; Author: ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munity 612 CLARION C OURTSAN L UIS OBISPO, CA 934 01T 805 5 44-4011 F 805 5 44-4294www.w al l ace g ro u p.u s CIV I L EN G IN EE RI NGCONSTRUCTION M AN AG E ME NTLANDSCAPE A RC HI TE CT UR EMECHANICAL E NG I NEE RI NGPLANNINGPUBLIC W O RK S A DM IN IS T RAT IO NSURVEYING/G IS SO LU TI O NSWATER RE S O URC ESWALLACE S WA NS O N IN T ER NAT I O NA L ¯EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO O R C U T T R D Source: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity¯ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munity CREE K CRO S SING (CULV ERT)MATCHLINE - SEE BELOWMATCHLINE - SEE ABOVEMATCHLINE - SEE SHEET 3MATCHLINE - SEE SHEET 1CREE K CRO S SING (BRIDG E) CO NC EPTU AL RE CYC LE DWATERLINE AL IG N MENT In de x Map 1 in ch = 40 fe et 0 8040 SH EET 2 OF 8 In de x Map LEG END CONCE PT UALALIGNMENTS ALI G N ME NT ALI G N ME NT B* Coun ty R O W EHO O VE RH EA DELECTRICA L WAL LA CE G RO UP DID N O T P E RFO RM SURV E Y S ERV ICE S FO R THIS M AP. NO T A LE G A L DO CUM EN T. *THE P ROP O SE D A LIG NME NT TRAV E RSE SPRIVATE PR OP ERTY, WHICH WILL RE QUIRE ANEASEMENT PRIO R TO IMP LE ME NTATIO N. THISCONCEPTUAL DO CUMEN T DO ES NO T IMP LYTHAT AN E AS EM ENT HAS BE EN G RAN TED. EHO EHOEHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO O R C U T T R D Source: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity M:\826-Paragon Vineyard Co\001-Supplimental Water Feasibility Analysis\07 GIS\Map Document\Conceptual Waterline Alignment\0826-0001 Conceptual Alignment Sheet 3.mxd; Author: ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munity 612 CLARION C OURTSAN L UIS OBISPO, CA 934 01T 805 5 44-4011 F 805 5 44-4294www.w al l ace g ro u p.u s CIV I L EN G IN EE RI NGCONSTRUCTION M AN AG E ME NTLANDSCAPE A RC HI TE CT UR EMECHANICAL E NG I NEE RI NGPLANNINGPUBLIC W O RK S A DM IN IS T RAT IO NSURVEYING/G IS SO LU TI O NSWATER RE S O URC ESWALLACE S WA NS O N IN T ER NAT I O NA L ¯EHOEHO EHOEHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHOAVOCADO LNO R C U T T R D Source: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity¯ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munityMATCHLINE - SEE BELOWMATCHLINE - SEE ABOVEMATCHLINE - SEE SHEET 4MATCHLINE - SEE SHEET 2CO NC EPTU AL RE CYC LE DWATERLINE AL IG N MENT In de x Map 1 in ch = 40 fe et 0 8040 SH EET 3 OF 8 In de x Map LEGE ND CONCE PT UALALIGNMENTS ALI G NM E NT A ALI G NM E NT B* Coun ty R O W EHO O VE RH EA DELECTRICAL WAL LA CE G RO UP DID N O T P E RFO RM SURV E Y S ERV ICE S FO R THIS M AP. NO T A LE G A L DO CUM EN T. *THE P ROP O SE D A LIG NME NT TRAV E RSE SPRIVATE PR OP ERTY, WHICH WILL RE QUIRE ANEASEMENT PRIO R TO IMP LE ME NTATIO N. THISCONCEPTUAL DO CUMEN T DO ES NO T IMP LYTHAT AN E AS EM ENT HAS BE EN G RAN TED. EHOEHOEHOEHOEHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO ORCUTT RD Source: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity M:\826-Paragon Vineyard Co\001-Supplimental Water Feasibility Analysis\07 GIS\Map Document\Conceptual Waterline Alignment\0826-0001 Conceptual Alignment Sheet 4.mxd; Author: ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munity 612 CLARION C OURTSAN L UIS OBISPO, CA 934 01T 805 5 44-4011 F 805 5 44-4294www.w al l ace g ro u p.u s CIV I L EN G IN EE RI NGCONSTRUCTION M AN AG E ME NTLANDSCAPE A RC HI TE CT UR EMECHANICAL E NG I NEE RI NGPLANNINGPUBLIC W O RK S A DM IN IS T RAT IO NSURVEYING/G IS SO LU TI O NSWATER RE S O URC ESWALLACE S WA NS O N IN T ER NAT I O NA L ¯EHO EHOEHOEHOEHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO ORCUT T RD Source: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity¯ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munityMATCHLINE - SEE BELOWMATCHLINE - SEE ABOVEMATCHLINE - SEE SHEET 5MATCHLINE - SEE SHEET 3CREE K CRO S SING (CULV ERT) CO NC EPTU AL RE CYC LE DWATERLINE AL IG N MENT In de x Map 1 in ch = 40 fe et 0 8040 SH EET 4 OF 8 In de x Map LEGE ND CONCE PTU ALALIGNMENTS ALI G NM E NT A ALI G NM E NT B * Count y RO W EHO O VE RHE A DELECTRICAL WAL LA CE G RO UP DID N O T P E RFO RM SURV E Y S ERV ICE S FO R THIS M AP. NO T A LE G A L DO CUM EN T. *THE P ROP O SE D A LIG NME NT TRAV E RSE SPRIVATE PR OP ERTY, WHICH WILL RE QUIRE ANEASEMENT PRIO R TO IMP LE ME NTATIO N. THISCONCEPTUAL DO CUMEN T DO ES NO T IMP LYTHAT AN E AS EM ENT HAS BE EN G RAN TED. EHOEHOEHOEHOEHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHOEHOEHOEHOEHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO ORCUT T RD Source: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity M:\826-Paragon Vineyard Co\001-Supplimental Water Feasibility Analysis\07 GIS\Map Document\Conceptual Waterline Alignment\0826-0001 Conceptual Alignment Sheet 5.mxd; Author: ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munity 612 CLARION C OURTSAN L UIS OBISPO, CA 934 01T 805 5 44-4011 F 805 5 44-4294www.w al l ace g ro u p.u s CIV I L EN G IN EE RI NGCONSTRUCTION M AN AG E ME NTLANDSCAPE A RC HI TE CT UR EMECHANICAL E NG I NEE RI NGPLANNINGPUBLIC W O RK S A DM IN IS T RAT IO NSURVEYING/G IS SO LU TI O NSWATER RE S O URC ESWALLACE S WA NS O N IN T ER NAT I O NA L ¯EHOEHO EHO EHOEHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHOEHOEHOEHOEHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO RI GHETTI RDORCUTT RD Source: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity¯ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munity CULV ERT CRO S SING MATCHLINE - SEE BELOWMATCHLINE - SEE ABOVEMATCHLINE - SEE SHEET 6MATCHLINE - SEE SHEET 4CULV ERT CRO S SING CO NC EPTU AL RE CYC LE DWATERLINE AL IG N MENT In de x Map 1 in ch = 40 fe et 0 8040 SH EET 5 OF 8 In de x Map CULV ERT CRO S SING LEG END CONCE PT UALALIGNMENTS ALI G N ME NT ALI G N ME NT B* Coun ty R O W EHO O VE RH EA DELECTRICA L WAL LA CE G RO UP DID N O T P E RFO RM SURV E Y S ERV ICE S FO R THIS M AP. NO T A LE G A L DO CUM EN T. *THE P ROP O SE D A LIG NME NT TRAV E RSE SPRIVATE PR OP ERTY, WHICH WILL RE QUIRE ANEASEMENT PRIO R TO IMP LE ME NTATIO N. THISCONCEPTUAL DO CUMEN T DO ES NO T IMP LYTHAT AN E AS EM ENT HAS BE EN G RAN TED. EHO EHO EHO EHOEHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHOEHOEHOEHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHOEHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHOORCUTT RD Source: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity M:\826-Paragon Vineyard Co\001-Supplimental Water Feasibility Analysis\07 GIS\Map Document\Conceptual Waterline Alignment\0826-0001 Conceptual Alignment Sheet 6.mxd; Author: ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munity 612 CLARION C OURTSAN L UIS OBISPO, CA 934 01T 805 5 44-4011 F 805 5 44-4294www.w al l ace g ro u p.u s CIV I L EN G IN EE RI NGCONSTRUCTION M AN AG E ME NTLANDSCAPE A RC HI TE CT UR EMECHANICAL E NG I NEE RI NGPLANNINGPUBLIC W O RK S A DM IN IS T RAT IO NSURVEYING/G IS SO LU TI O NSWATER RE S O URC ESWALLACE S WA NS O N IN T ER NAT I O NA L ¯EHOEHOEHOEHOEHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHOEHOEHOEHOEHOEHO EHO EHO EHO EHO EHO EHO EHO EHO EHOORCUTT RD BIDDLE RANCH RDSource: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity¯ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munity CULV ERT CRO S SING MATCHLINE - SEE BELOWMATCHLINE - SEE ABOVEMATCHLINE - SEE SHEET 7MATCHLINE - SEE SHEET 5CULV ERT CRO S SING CO NC EPTU AL RE CYC LE DWATERLINE AL IG N MENT In de x Map 1 in ch = 40 fe et 0 8040 SH EET 6 OF 8 In de x Map LE GE N D CO N C E P TUA LALIGNMENTS ALIG NME NT A ALIG NME NT B * Count y RO W EHO OV ERHEADELECTRICAL WAL LA CE G RO UP DID N O T P E RFO RM SURV E Y S ERV ICE S FO R THIS M AP. NO T A LE G A L DO CUM EN T. *THE P ROP O SE D A LIG NME NT TRAV E RSE SPRIVATE PR OP ERTY, WHICH WILL RE QUIRE ANEASEMENT PRIO R TO IMP LE ME NTATIO N. THISCONCEPTUAL DO CUMEN T DO ES NO T IMP LYTHAT AN E AS EM ENT HAS BE EN G RAN TED. EHOEHOEHOEHOEHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHOEHOEHOEHOEHO EHO EHO EHO EHOORCUTT RD BIDDLE RANCH RDSource: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity M:\826-Paragon Vineyard Co\001-Supplimental Water Feasibility Analysis\07 GIS\Map Document\Conceptual Waterline Alignment\0826-0001 Conceptual Alignment Sheet 7.mxd; Author: ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munity 612 CLARION C OURTSAN L UIS OBISPO, CA 934 01T 805 5 44-4011 F 805 5 44-4294www.w al l ace g ro u p.u s CIV I L EN G IN EE RI NGCONSTRUCTION M AN AG E ME NTLANDSCAPE A RC HI TE CT UR EMECHANICAL E NG I NEE RI NGPLANNINGPUBLIC W O RK S A DM IN IS T RAT IO NSURVEYING/G IS SO LU TI O NSWATER RE S O URC ESWALLACE S WA NS O N IN T ER NAT I O NA L ¯EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO EHO O R C U T T R D CROSS CREEK WAYSource: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity¯ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munity CREE K CRO S SING (BRIDG E)MATCHLINE - SEE BELOWMATCHLINE - SEE ABOVEMATCHLINE - SEE SHEET 8MATCHLINE - SEE SHEET 6CO NC EPTU AL RE CYC LE DWATERLINE AL IG N MENT In de x Map 1 in ch = 40 fe et 0 8040 SH EET 7 OF 8 In de x Map LEGE ND CONCEP TUA LALIGNMENTS ALI G NM E NT A ALI G NM E NT B * Count y RO W EHO O VE RHE A DELECTRICAL WAL LA CE G RO UP DID N O T P E RFO RM SURV E Y S ERV ICE S FO R THIS M AP. NO T A LE G A L DO CUM EN T. *THE P ROP O SE D A LIG NME NT TRAV E RSE SPRIVATE PR OP ERTY, WHICH WILL RE QUIRE ANEASEMENT PRIO R TO IMP LE ME NTATIO N. THISCONCEPTUAL DO CUMEN T DO ES NO T IMP LYTHAT AN E AS EM ENT HAS BE EN G RAN TED. EHO EHO EHOEHOEHOEHO EHO EHO EHO EHO EHO EHO EHO EHO ORCUT T RDCROSS CREEK WAYSource: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity M:\826-Paragon Vineyard Co\001-Supplimental Water Feasibility Analysis\07 GIS\Map Document\Conceptual Waterline Alignment\0826-0001 Conceptual Alignment Sheet 8.mxd; Author: ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munity 612 CLARION C OURTSAN L UIS OBISPO, CA 934 01T 805 5 44-4011 F 805 5 44-4294www.w al l ace g ro u p.u s CIV I L EN G IN EE RI NGCONSTRUCTION M AN AG E ME NTLANDSCAPE A RC HI TE CT UR EMECHANICAL E NG I NEE RI NGPLANNINGPUBLIC W O RK S A DM IN IS T RAT IO NSURVEYING/G IS SO LU TI O NSWATER RE S O URC ESWALLACE S WA NS O N IN T ER NAT I O NA L ¯EHO EHO EHO EHO EHO EHO EHO EHO EHO ORCUTT RD MORRETTI CANYON RDSource: Esri, Digit alGlo be, GeoE ye, Earthstar Ge ographics, CNE S/A irbus DS, US DA, USGS, AE X, Getma ppin g, A erogrid, IGN, IGP, swisstopo, and th e GI S User Commu nity¯ORCUTT RDEDNA RDRIGHETTI RDM I R A C I E L O Source: Esri, Digit alGlo be,Geo Eye, Ea rth starGeographics, CNES /Airb usDS, US DA, US GS , A EX ,Getm apping, Aerogrid, IGN,IGP, swisstopo, a nd the GISUser Com munity CONNE CTIO N TO CRO SSCREEK MUTU AL WATE R COMPA NY WATE RLINE MATCHLINE - SEE BELOWMATCHLINE - SEE ABOVEMATCHLINE - SEE SHEET 7CO NC EPTU AL RE CYC LE DWATERLINE AL IG N MENT In de x Map 1 in ch = 40 fe et 0 8040 SH EET 8 OF 8 In de x Map LEGEND CONCEPTUALALIGNMENTS AL IG NM ENT A AL IG NM ENT B * Cou n ty R OW EHO OV ERHEA DELECTRICAL WAL LA CE G RO UP DID N O T P E RFO RM SURV E Y S ERV ICE S FO R THIS M AP. NO T A LE G A L DO CUM EN T. *THE P ROP O SE D A LIG NME NT TRAV E RSE SPRIVATE PR OP ERTY, WHICH WILL RE QUIRE ANEASEMENT PRIO R TO IMP LE ME NTATIO N. THISCONCEPTUAL DO CUMEN T DO ES NO T IMP LYTHAT AN E AS EM ENT HAS BE EN G RAN TED. Ala n Vanderhorst Paragon Righetti Vineyard Righetti & O thers Odyssey Tolosa John Silva Jack Ranch Lewis Lewis Carroll Gallo Schiebelhut Wolff Bee Sweet BaggettChristiansen Darway E. Green Gate Hamish Bee Sweet Avila Lopes Stoller Paragon LindseyMelschau Biddle RanchHoss Edna Ranch Source: Esri, DigitalGlobe, GeoEye, i-cubed, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP,swisstopo, and the GIS User Community ¬ Leg end Greenbe lt MEMORANDUM Edna Valley Growers 826-0001 Date: January 29, 2016 To: Ron Munds, WSC Project Manager From: Rob Miller, PE Subject: Summary of Hydraulic Considerations Wallace Group recently conducted a series of hydraulic model runs to confirm the feasibility of delivering up to 1,000 acre-feet of recycled water to the Edna Valley agricultural area. As described in the white paper, the growers include a diverse cross section of crop types and irrigation requirements, but they also share similar characteristics with respect to soil type and efficient irrigation management. The following four key principles should be considered when analyzing the hydraulic issues associated with the Edna Valley recycled water alternative: 1. The growers are willing to receive the water on an “as available” basis, including 24 hour delivery at a constant rate if practical for the City. Water deliveries may also be interrupted when the City is irrigating either French Park or Islay Park. 2. The growers plan to provide in-line pressure boosting as needed, and therefore the recycled water may be delivered at a pressure of 20 psi to enhance pipeline capacity. For the purpose of analysis, a minimum residual pressure of 30 psi at the Islay Park node was assumed. 3. Water should be delivered at a single metered turnout on the Vanderhorst property as shown in the conceptual schematics, after which point the pipelines and distribution system will be managed by the agricultural mutual water company. 4. The recycled water pump station at the WRRF may require improvements to optimize its efficiency to deliver consistent volumes to the Edna Valley, and therefore the assumption can be made that the upgraded pump system provides a relatively constant hydraulic grade line (HGL) at the WRRF. The electronic water model files are included for WSC’s use and analysis. When reviewing the distribution model under various Edna Valley scenarios, it becomes apparent that the existing 8” recycled water pipeline from the intersection of Broad Street and Tank Farm Road to Islay Park is the primary restriction that dictates the instantaneous flow rate that may delivered to the Edna Valley. The growers intend to extend a 10” pipeline to minimize additional losses. Figure 1 summarizes a compilation of hydraulic model runs at various flows, and the following conclusions can be derived: • Outside of the City irrigation season, the existing system can deliver approximately 800 gallons per minute, or 106 acre-ft per month. Mr. Ron Munds January 29, 2016 Page 2 of 2 • Water deliveries to the growers may need to be interrupted when the City irrigates Islay Park or French Park, in order to minimize the potential for low pressure conditions and insure efficient use of irrigation facilities. • Given that minimal system losses are observed from the WRRF to the intersection of Tank Farm and Broad Street, the future recycled water pipeline along the Broad Street corridor to the airport area could be used at a future date to further increase instantaneous volumes available to the growers. At this time, this future option is not being explored in detail. In order to confirm the overall volume of water that may be available for the growers, the current irrigation practices for Islay Park and French Park were reviewed. The current practices are summarized as follows: Quantity French Park Islay Park Max irrigation demand 400 gal/min 200 gal/min Normal summer period operating hours (June through August) 3 nights per week, 7 hours per night (91 hours/month) 5 nights per week, 8 hours per night (173 hours/month) Estimated total hours of irrigation – winter period (December through February) 40 hours over 3 months 80 hours over 3 months, neglect overlap with French Park Estimated total hours of irrigation – spring period (March through May) 120 hours over 3 months 220 hours over 3 months, and assume overlap with French Park Estimated total hours of irrigation – fall period (September through November) Assume equivalent to summer – 270 hours over 3 months Assume equivalent to summer – 520 hours over 3 months, assume overlap with French Park Assuming the grower demand does not occur concurrently with the above referenced park demands, the volume of recycled water available is expected to vary seasonally as follows: • Winter period: 100 ac-ft/month • Spring period: 95 ac-ft/month • Fall period, accounting for concurrent French/Islay irrigation: 80 ac-ft/month • Summer period – to be determined, but may be limited by overall recycled water availability Depending on the availability of recycled water during the summer period, the overall grower program could deliver up to 1,000 acre-ft. As indicated above, an additional grower turnout may be possible along the Broad Street corridor, adjacent to the East Airport Commerce Park. 3.03.54.04.55.05.56.06.57.01520253035404550600 650 675 700 725 750 775 800 850 875 900 925 950 1000VELOCITY AT ISLAY PARK NODE (FT/S)PRESSURE AT ISLAY PARK NODE (PSI)FLOW AT ISLAY PARK TERMINUS (GPM)Paragon Winery Future Demand Scenario City of San Luis Obispo Recycled Water Distribution System Pressure Assessment at Islay Park Terminus Alternative: Daytime pumping to Paragon with no other system demands.PressureVelocity DRAFTCity of San Luis Obispo Recycled Water Facilities Planning Study - Final Draft H 1/19/2017 APPENDIX H. PRELIMINARY COST ESTIMATES AND IMPLEMENTATION TIMELINE TECHNICAL MEMORANDUM Technical Memorandum 9/23/2016 Page 1 of 2 Date: 9/23/2016 To: Dave Hix 879 Morro Street City of San Luis Obispo CC: Howard Brewen Prepared by: Emily Iskin, EIT Reviewed by: Lianne Westberg, P.E. Project: Recycled Water Production Analysis SUBJECT: PRELIMINARY COST ESTIMATES AND IMPLEMENTATION TIMELINE Summary of Recommendations In 2015, the City, with Water Systems Consulting, Inc. (WSC), conducted a Recycled Water Production Analysis to better understand the treatment capacity of the existing recycled water system at the Water Resource Recovery Facility (WRRF). The analysis evaluated the treatment capacity of the recycled water system infrastructure as well as historical secondary effluent flow data to understand how much recycled water could be produced. The findings showed that while the current recycled water system infrastructure is capable of produce 3.5 million gallons per day (MGD) of recycled water (prior to the WRRF Project upgrades), the available secondary effluent is less. The results showed that the WRRF has a daily average secondary effluent supply (also known as recycled water supply) of approximately 1.5 to 1.9 MGD (based on 2015 data). A daily average recycled water supply of 1.5 to 1.9 MGD equals approximately 1,700 acre-feet per year (AFY) to 2,100 AFY of recycled water available per year. Refer to the Recycled Water Production Analysis Technical Memorandum (TM) for more information on the analysis. The supply limitation requires an optimized system to maximize the amount of recycled water that can be produced. The Recycled Water Production Analysis TM identified low-cost upgrades and strategies that the City can implement to increase the amount of secondary effluent that can be treated to Title 22 disinfected tertiary standards. These recommendations are summarized below: I. Recycled Water Vault Valve Automation: repair the existing actuator on the butterfly valve to achieve automation or replace the butterfly valve to more finely control the flow that goes to the creek versus recycled water. This is key in reducing the amount of treated effluent discharged to the creek to the minimum requirement, to the extent that recycled water demand is available. One option for a replacement valve would be a Cla-Val flow control valve. II. Chlorine Dosing Automation: automate the recycled water chlorine dosing system to increase adaptability of the system to changing flow through the channels, to ensure only the chlorine that is needed to meet Title 22 standards is used, and to streamline the process for the operators. Recycled Water Production Analysis Preliminary Cost Estimates and Implementation Timeline 9/23/2016 Page 2 of 2 III. Filter Feed Complex Pump Automation: automate filter feed pumping in order to reduce large jumps in flow into the filters, increase stability in the rest of tertiary system, and improve operational efficiency. IV. Backwashing Schedule: adjust the backwashing schedule so that backwashes occur during times of low recycled water demand. Consider peak electricity demand charges when selecting backwashing schedule. V. Delivery Schedule: deliver some recycled water to customers during the day in order to increase recycled water deliveries and increase the working volume of the recycled water storage tank. Additional analysis could be performed in order to optimize the schedule to align with operator practice and contracts with the City for recycled water. Implementation A preliminary implementation schedule for the recommendations is provided in Figure 1. One option for the implementation of these improvements would be to phase the automations and the schedule modifications. If the improvements were implemented this way, the automation upgrades should be completed first, as they will have the most impact on the amount of recycled water that the WRRF can produce. As recycled water deliveries increase, the City should then review daily and seasonal recycled water deliveries and adjust backwashing schedule and delivery schedule as feasible. Figure 1. Conceptual Implementation Sequence for the Recommendations WSC and WRRF staff worked with contractors to obtain quotes for recommendations 1 through 4. The estimates range from $20,000 to $40,000, depending on the vendor and level of service. DRAFTCity of San Luis Obispo Recycled Water Facilities Planning Study - Final Draft I 1/19/2017 APPENDIX I. CLEATH-HARRIS GEOLOGISTS TECHNICAL MEMORANDUM Technical Memo 1 3/21/2016 TECHNICAL MEMORANDUM Date: March 21, 2016 To: Water Systems Consulting, Inc. From: Timothy S. Cleath, CHG 81 CEG 1102 PG 3675 President Subject: Overview of Groundwater Recharge of Recycled Water San Luis Obispo Groundwater Basin Cleath-Harris Geologists reviewed factors related to the potential for groundwater basin recharge in the San Luis Obispo groundwater basin using recycled reclaimed water and prepared a power point presentation to the City of San Luis Obispo wastewater reclamation facilities staff and consulting team on January 28, 2016. This Technical Memorandum summarizes the information presented in the “Groundwater Recharge of Recycled Water, City of San Luis Obispo, January 2016” powerpoint presentation. The powerpoint graphical/tabular exhibits are included as figures and tables in this Technical Memorandum. San Luis Obispo Valley Groundwater Basin The San Luis Obispo Valley Groundwater Basin is identified by the California Department of Water Resources in the Bulletin 118 as the San Luis Obispo Valley Basin, Basin #3-9 (Figure 1). The basin is a15-square mile basin drained by San Luis Obispo Creek and by Pismo Creek and its tributaries in Edna Valley upstream of Price Canyon. The City of San Luis Obispo is within the San Luis Obispo Creek watershed portion of the basin. The basin includes aquifers within the alluvium, older terrestrial deposits of the Paso Robles Formation, and marine sands of the Pismo Formation. The San Luis Obispo Creek area aquifers (Figure 2- Cross Section location map, Figure 3 Cross Section) have a relatively limited storage capacity as compared with the Edna Valley aquifers. Upstream of Prado Road, the basin sediments are alluvial deposits less than 100 feet deep. Downstream of Prado Road to the southwestern hills, the basin sediments include alluvial, older alluvial/Paso Robles Formation and marine sediments in a wedge that deepens to about 200 feet the Los Osos Valley fault. In the area to the east, toward Highway 227/Broad Street, the basin sediments thin to less than 100 feet thickness. The Edna Valley area aquifers have a greater amount of groundwater storage than San Luis Obispo Creek aquifers. The alluvial gravels in the tributary valleys upstream of Orcutt Road are less than 80 feet deep but the sedimentary aquifers (alluvial, Paso Robles Technical memo 3/21/2016 2 Formation and Pismo Formation beds) from Orcutt Road to San Luis Hills reach a depth of 500 feet between Orcutt Road and Highway 227/Corbett Canyon Road. Similar to the San Luis Obispo Creek subbasin area, faults bound the southwestern edge of the basin. Groundwater Levels The quantity of groundwater stored within the aquifers of San Luis Obispo groundwater basin fluctuates based on inflow and outflow to the basin. The groundwater surface is observed as a water level in a well. The water level is different in shallow unconfined aquifers and in the deeper confined aquifers. The trend of the groundwater level is an indicator of the stress placed on groundwater in storage by pumping or reduced recharge. Groundwater levels in the San Luis Obispo Creek area fluctuate much less than in the Edna area (Figure 4). Annual fluctuations in the San Luis Obispo Creek area are between 20 and 40 feet. During periods of high water level, the water level in the deep aquifer is above ground surface, resulting in artesian flow from some wells near Los Osos Valley Road. Groundwater in shallow aquifers drain to San Luis Obispo Creek and its tributaries. While there have been periods of groundwater level declines in the past, the groundwater level trend is stable, reflecting lower groundwater extractions due to the conversion of agricultural lands to urban uses and reduced pumpage by the City of San Luis Obispo. Groundwater production is much more intensive in the Edna Valley area for agricultural uses. Groundwater levels in the Edna Valley area have shown over 100 feet of decline over long term. As a result, there is available reservoir capacity for enhanced groundwater recharge. Groundwater Quality Groundwater quality in the San Luis Obispo Basin is generally suitable for domestic and agricultural uses with some treatment for specific mineral constituents. The water quality does vary with location, however (Table 1 and Figure 5). In the area within the City of San Luis Obispo and the airport area, the main mineral constituents are within maximum contaminant levels for drinking water but there are some areas where nitrates and halogenated hydrocarbons occur. East of the airport, the groundwater has a higher salinity due to lesser dilution from recharge and wastewater disposal contributions. In the Edna Valley area, the main mineral constituents are within maximum contaminant levels for drinking water but there are some areas where nitrates and some naturally occurring hydrogen sulfide, arsenic and selenium concentrations occur in the groundwater within the older sedimentary formations. Another naturally occurring mineral that may exceed the MCL in the Paso Robles and alluvial aquifer of the San Luis Obispo Basin groundwater is hexavalent chromium. Technical memo 3/21/2016 3 Groundwater Production and Use Groundwater production occurs for domestic and agricultural uses in the San Luis Obispo Valley Basin. Consumptive use of the produced groundwater results in a reduction in groundwater in storage. The non-consumed groundwater returns to the basin via domestic wastewater percolation and agricultural returnflow. Additional water supply in the area comes from imported water that, when disposed of, can be a source of recharge to the basin. The domestic groundwater production has been by municipal and private water purveyors and by rural residences. The City of San Luis Obispo historically has used up to 2,000 acre-feet per year but most of their wells are currently inactive. Private water purveyors are located in the airport area and the rural housing tracts east of the City of San Luis Obispo. The main purveyors that produce water from the basin include Golden State Water Company, Edna Ranch East Mutual Water Company, Edna Ranch West Mutual Water Company and Varian Ranch Mutual Water Company. Individual rural residences that rely on wells for water are scattered across the basin. Agriculture produces the most groundwater from the basin. For the purpose of this basin overview, CHG estimates that the water produced from agricultural wells is roughly 1,000 acre-feet per year in the vicinity of the City of San Luis Obispo and 5,000 acre-feet in the area east of the City of San Luis Obispo, including the Edna Valley. The crops grown in the basin area are mainly wine grapes, row crops and citrus/avocadoes (Figures 6 and 7). There is some minor industrial groundwater use in the airport area. Groundwater Recharge Groundwater recharge occurs naturally through percolation of rainfall and stream runoff percolation. This natural recharge is supplemented, where groundwater storage is available, by artificial recharge. While no formal artificial recharge facilities ex ist in the basin, incidental recharge currently occurring is from wastewater percolation and agricultural returnflow. The City of San Luis Obispo could enhance groundwater recharge through additional efforts to percolate/inject highly treated wastewater effluent (Figure 8). Groundwater recharge has the greatest potential within the Edna Valley portion of the San Luis Obispo Valley Basin but there is some potential for groundwater recharge in the San Luis Obispo Creek Valley area. Groundwater recharge could be enhanced by changing the creek discharge during periods of available groundwater storage from near Los Osos Valley Road to between Prado Lane and Madonna Road. Percolation basins in this same area could be operated to perform a similar recharge effect. Injection of highly treated Technical memo 3/21/2016 4 effluent in the area from Prado Road to Los Osos Valley Road could be an alternative method to place water in a strategic location as a part of an injection/extraction type of groundwater management operation. Impacts resulting from artificial groundwater recharge would include: Reduce groundwater level depth Stabilized water level fluctuations Reduced subsidence Reduced stream flow losses A blending of recharge water quality with existing water quality (positive or negative impact, depending on quality of recharge waters) Increase the groundwater available for use Enhanced groundwater recharge of highly treated wastewater effluent could benefit different groundwater users and land owners, depending on where the recharge is placed and when it occurs. Some of the potential beneficiaries could be the City of San Luis Obispo, other water purveyors, California Polytechnic State University at San Luis Obispo, individual rural property owners, agricultural landowners, and riparian Vegetation and Wildlife. Figure 1 Groundwater Basin Area from DWR Bulletin 118 Cleath-Harris Geologists Figure 2 Location Map showing Hydrogeologic Prole Alignment Cleath-Harris Geologists Circles indicate wells/test holes Red circle is well with water level hydrograph Figure 3 Hydrogeologic Prole Along Hwy 101 San Luis Obispo Valley groundwater basin Cleath-Harris Geologists Figure 4 Groundwater Level Hydrographs San Luis Obispo Valley groundwater basin Cleath-Harris Geologists Figure 5 Water Quality San Luis Obispo Valley Groundwater Basin Cleath-Harris Geologists Figure 6 Agriculture San Luis Obispo Valley groundwater basin Cleath-Harris Geologists 298 60 2673 1730 332 29 25 8 1 12 0 500 1000 1500 2000 2500 3000 Avocado Strawberries Vineyards Rotational Citrus Other Peas Olives Greenhouse Squash Acres (2015) 16 af/yr 25 af/yr 498 af/yr 2768 af/yr 2940 af/yr 625 af/yr 19 af/yr 126 af/yr Figure 7 Crop Area/Estimated Groundwater Production San Luis Obispo Valley groundwater basin Cleath-Harris Geologists Groundwater production estimates are for conceptual/comparative purposes only and should not be used for quantitative analysis Figure 8 Groundwater Recharge Areas City of San Luis Obispo Cleath-Harris Geologists Table 1 Water Quality WWRF Reuse Water, City of San Luis ObispoSan Luis Obispo CreekMitchell Park Well, City of San Luis ObispoCorp Yard Well, City of San Luis ObispoCalle Joaquin Agricultural Reserve Well (CJAR), City of San Luis ObispoFire Station Well, Madonna Rd, City of San Luis ObispoGolden State MWC 5061 Hacienda Test WellGolden State WC Test Well, South of Golf CourseGolden State WC Lewis Lane #4Edna Ranch East MWCVarian Ranch MWC Well #34/10/14 7/18/54 6/21/01 10/27/14 10/27/14 6/20/01 2/6/13 5/15/14 10/1/08 3/18/94 10/13/14 Electrical Conductance µmhos/ cm 1600 1270 970 989 1010 1030 801 2040 1280 1100 780 840 Total Dissolved Solids mg/l 1000 760 626 590 600 630 500 1040 780 730 465 470 pH 7.3 8.2 7.1 7.5 7.2 6.3 6.9 7.2 7.57 6.9 7.9 Hardness as CaCO3 mg/l 313 468 480 444 468 379 777 300 510 320 340 Calcium mg/l 43 64 72 71 69 39 120 69 98 61 92 Sodium mg/l 123 36 27 52 48 21 86 153 52.0 35 45 Potassium mg/l 20 2 ND ND ND ND 2 10 3.3 2 ND Magnesium mg/l 50 75 73 71 72 71 116 31 65 43 27 Sulfate mg/l 500 113 82 82 69 77 30 89 15.8 150 37 31 Bicarbonate mg/l 150 468 530 500 510 430 420 500 463 360 260 Chloride mg/l 500 155 47 29 51 43 38 427 135 65 53 110 Nitrate as NO3 mg/l 45 153 14 7.9 5.9 20 10.4 10 0.6 6.7 7.2 3.8 Fluoride mg/l 2 0.4 0.1 0.1 ND ND ND 0.3 ND 0.26 0.3 0.65 Iron µg/l 300 130 x 280 80 80 ND ND 120 --34 ND Manganese µg/l 50 ND x 20 30 ND ND ND 40 6.6 9 0.02 µmhos/cm = micromhos per centimeter mg/l = milligrams per liter µg/l = micrograms per liter MCL = maximum contaminant level ND = not detected at laboratory detection limit Edna Valley Area Wells Reclaimed Water SLO Creek SLO Area Wells Analyte/Date Units MCL Sample Date Source ID Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Tim Cleath Cleath-Harris Geologists Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists Benefits •Increase the groundwater yield for indirect potable reuse by the City of San Luis Obispo or other water purveyors •Provide indirect potable reuse for agriculture •Revenue to City •Enhance local water resources •Improve some water quality constituents Groundwater Basin Area, DWR Bulletin 118 Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists Bulletin 118 Groundwater Basin Area Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists Hydrogeologic Profile along Hwy 101 Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists Geologic Cross Section Along Hwy 101 Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists Comparison of Basin Water Levels Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists Groundwater Quality for Select Wells Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists Analyte/Date Units MCL Source ID City of SLO WWRF Reuse WaterSLO CreekCity of SLO Mitchell Park WellCity of SLO Corp Yard WellCalle Joaquin Agricultural Reserve Well (CJAR)Fire Station Well, Madonna RdGolden State MWC 5061 Hacienda Test WellGolden State WC Test Well, South of Golf CourseGolden State WC Lewis Lane #4Edna Ranch East MWCVarian Ranch MWC Well #3Sample Date 4/10/14 7/18/54 6/21/01 10/27/14 10/27/14 6/20/01 2/6/13 5/15/14 10/1/08 3/18/94 10/13/14 Electrical Conductance µmhos/cm 1600 1270 970 989 1010 1030 801 2040 1280 1100 780 840 Total Dissolved Solids mg/l 1000 760 626 590 600 630 500 1040 780 730 465 470 pH 7.3 8.2 7.1 7.5 7.2 6.3 6.9 7.2 7.57 6.9 7.9 Hardness as CaCO3 mg/l 313 468 480 444 468 379 777 300 510 320 340 Calcium mg/l 43 64 72 71 69 39 120 69 98 61 92 Sodium mg/l 123 36 27 52 48 21 86 153 52.0 35 45 Potassium mg/l 20 2 ND ND ND ND 2 10 3.3 2 ND Magnesium mg/l 50 75 73 71 72 71 116 31 65 43 27 Sulfate mg/l 500 113 82 82 69 77 30 89 15.8 150 37 31 Bicarbonate mg/l 150 468 530 500 510 430 420 500 463 360 260 Chloride mg/l 500 155 47 29 51 43 38 427 135 65 53 110 Nitrate as NO3 mg/l 45 153 14 7.9 5.9 20 10.4 10 0.6 6.7 7.2 3.8 Fluoride mg/l 2 0.4 0.1 0.1 ND ND ND 0.3 ND 0.26 0.3 0.65 Iron µg/l 300 130 x 280 80 80 ND ND 120 --34 ND Manganese µg/l 50 ND x 20 30 ND ND ND 40 6.6 9 0.02 µmhos/cm = micromhos per centimeter mg/l = milligrams per liter Reclaimed Water µg/l = micrograms per liter SLO Creek MCL = maximum contaminant level SLO Area Wells ND = not detected at laboratory detection limit Edna Valley Area Wells Water Quality Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists Agricultural Land use Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists Water Production for Agriculture Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists 298 60 2673 1730 332 29 25 8 1 12 0 500 1000 1500 2000 2500 3000 Avocado Strawberries Vineyards Rotational Citrus Other Peas Olives Greenhouse Squash Acres (2015) 16 af/yr 25 af/yr 498 af/yr 2768 af/yr 2940 af/yr 625 af/yr 19 af/yr 126 af/yr Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists HISTORIC ANNUAL LEVELS OF GROUNDWATER PRODUCTION* •City of San Luis Obispo: 0-2,000 acre-feet •San Luis Obispo Area agriculture: 1,000 acre- feet •Edna Valley Area agriculture: 5,000 acre-feet * Production values are gross estimates and are for comparison purposes only Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists GROUNDWATER RECHARGE OPTIONS •Stream Discharge •Percolation Basin •Injection well field •Recharge/Extraction Recharge Areas Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists PERCOLATION BASIN CRITERIA •Shallow depth to permeable gravels •Maximum depth to water •Maximum distance to stream channel •Sufficient property size to allow for operational activities Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists Recharge/Extraction Example Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists GROUNDWATER RECHARGE POTENTIAL IMPACT ISSUES •SITE AVAILABILITY •REGULATORY COMPLIANCE •RESIDENCY TIME –duration before recharged water is captured by another well or stream •ARTESIAN FLOW CONDITIONS •SUBSIDENCE WITH EXTRACTIONS •WATER QUALITY DEGRADATION •WHO WILL BENEFIT? Groundwater Recharge of Recycled Water City of San Luis Obispo January 2016 Cleath-Harris Geologists QUESTIONS? THIS PAGE LEFT INTENTIONALLY BLANK City of San Luis Obispo 2017 Recycled Water Master Plan B-1 Appendix B. Recycled Water to Augment Lake Level at Laguna Lake As part of the work to update the 2004 Master Plan, the City hired the Wallace Group to evaluate the potential to augment Laguna Lake with recycled water. This section is a summary of that analysis. Laguna Lake Park is a 375-acre City park, with the main entrance located at the corner of Madonna Road and Dalidio. The park includes group barbecue and picnic areas, fitness and recreational facilities, hiking trails, and provides habitat for waterfowl and other wildlife. Recreational activities at the Lake include sail boating, row boating, power boating (under one horsepower}, and fishing (from shoreline and boat). According to the 1982 Laguna Lake Management Plan, swimming is allowable in the central and southeast portions of the Lake so long as CDPH water quality/bacteriological standards are met. According to the City, swimming activity at the Lake is infrequent. The lake is approximately 110-acres in surface area, and has a full capacity volume of approximately 800 AF. The lake level is maintained by stormwater runoff only, which eventually discharges to Prefumo Creek, tributary to San Luis Obispo Creek. The watershed to Prefumo Creek includes over 7,500 acres from the Prefumo Creek, Sycamore Canyon, Los Osos and O'Conner Valley watersheds. The high elevation of the lake is 120 feet above mean sea level (MSL), and generally ranges from 115 to 116 feet MSL. It is estimated that the Lake loses an average of 450 AFY to evaporation, corresponding to a lowering of the lake level by three to four feet annually. Based on CIMIS Weather Station 52, San Luis Obispo, annual average evapotranspiration is approximately 52 inches, or 4.33 feet. Also, evaporation data from Bulletin No. 54, Department of Water Resources (DWR), also shows local evaporation data for Salinas Reservoir (1942 to 1945 records) at 52 inches. Although this data is outdated somewhat, it matches very closely to the modern CIMIS data on evapotranspiration. These values of referenced evapotranspiration and evaporation data correlate well to the 1982 Laguna Lake Management Plan estimates of annual losses to evaporation in conjunction with corresponding lowering of lake levels. Lake depths range from 12 feet at the downstream terminus, six to eight feet in the central portion of the lake, and zero to four feet in the various marsh areas and inlets to the north and west. The 1976 to 1978 drought nearly completely dried up the Lake; this incident help promote community interest in the Lake and to help preserve its environmental, recreational and aesthetic value to the City and nearby residents. In the 1982 Laguna Lake Management Plan, five management alternatives were identified to maintain and preserve the qualities of the Lake: Maintain at least three to four feet of lake depth at seasonal low water level. Reduce or eliminate existing aquatic weeds. Provide for ongoing aquatic weed control. City of San Luis Obispo 2017 Recycled Water Master Plan B-2 Prevent Prefumo Creek watershed sediment from reaching the lake. Preserve the characteristics of the lake which are important to existing wildlife habitat, flood protection, and recreational opportunity. The City is again considering utilizing recycled water to augment the lake level. Based on the earlier discussion on lake losses, the estimated quantity of recycled water that can be utilized year to year is approximately 450 AFY. The 1982 Laguna Lake Management Plan recognized use of recycled water as one option to enhance Lake levels to meet the above objectives, but technical/environmental review of the recycled water constituents suggested recycled water use in the lake would not be advisable (due to increased nutrient loading to the lake). It was decided at that time, that weed abatement and focused excavation in areas of sediment deposition would be the most favorable long-term plans to preserve the Lake's attributes. According to Title 22 regulations, surface impoundment in non-restricted recreational impoundments is allowable. Discussions with CDPH confirm that this is an acc eptable use, and that the City would be exempt from Section 60305(c) (supplemental monitoring) since the City treats tertiary recycled water by conventional means (conventional sand filtration followed by disinfection, as opposed to a direct filtration plant). As part of the approval process, the City will need to verify that there are no public/domestic water wells within 100 feet of the impoundment. The following considerations must be taken into account if recycled water is to be used to augment the lake levels: Signage will be required around the Lake, similar to "CAUTION RECYCLED WATER - DO NOT DRINK". Although swimming would be allowable so long as bacteriological standards for public beaches are met, the City may wish to discourage or ban swimming a s a recreational use. With recycled water introduction into the Lake, CDPH requires signs to be posted that fish caught in the Lake cannot be consumed. Nutrient Loading Considerations The 1982 Laguna Lake Management Plan, Technical Appendix B provides results of water quality sampling from 1979 to 1980. The Lake also goes through an annual limnological cycle from winter to spring, to fall and summer, with varying concentrations of dissolved oxygen, turbidity , pH and nutrient concentrations year-round with the cycle of aquatic plant growth and die-off. The following summarizes some of the key water quality considerations: Dissolved oxygen (DO). DO concentrations appear to be maintained above 2 mg/L year-round, ranging from around 6 to 10 mg/L in Spring/Summer. The higher concentrations are above DO saturation in water, and would likely be due to algal production of oxygen (photosynthesis). Significant wind action offers re-aeration of water throughout the year, and keeps the water profile mixed. pH. Summertime pH maintained around 8.0 to 8.2, slightly alkaline. City of San Luis Obispo 2017 Recycled Water Master Plan B-3 Nitrate concentrations range from 10 to 20 mg/L during the Fall and Winter, and from around 8 to 12 mg/L during Spring and Summer months. Total phosphorus ranged from 0.3 to 0.7 mg/L year-round, but spiked as high as 1.3 mg/L during late Fall to early Winter. Temperature. The lake remains well mixed, and does not have thermal stratification. Temperatures range from 50 degrees to 60 degrees Fahrenheit during the winter months, and 55 to 75 degrees Fahrenheit during the warmer summer season. Optimum temperatures for growth of algae generally range from 68 to 75 degrees Fahrenheit. Nutrient loading of recycled water to the lake may be of concern from a water quality perspective, with potential for increased algae generation. With the City's future plans to denitrify plant effluent, this concern may lessen over time depending on how the lake responds to additional phosphorus loading, and to what degree future treatment up grades may reduce phosphorus in plant effluent. The total phosphorus levels, especially at current concentrations, may still be of concern relative to potential algal blooms. The USEPA recommends that phosphorus levels remain below 100 ug/L (0.1mg/L) and nitrate levels below 10,000 ug/L {10 mg/L) to prevent excessive growth of algae in water bodies. From the above, natural concentrations of nutrients are typically in excess of these values for algae control. In wastewater, total phosphorus levels are typically 4 to 12 mg/L, and have the potential to be well above recommended levels for algae control. Sources of phosphorus addition include human waste, food and certain soaps and detergents. The City's recycled water quality (based on 2012 analyses) indicates the total phosphorus in the effluent is 4.5 mg/L (annual average) and total nitrogen is 0.17 mg/L (annual average). The recycled water addition to the Lake would not likely impact nitrogen loading based on historic levels naturally occurring in the lake; however, there would be a significant increase in Total Phosphorus to the Lake. This must be carefully considered as to the degree of impact on algal production from using recycled water. During Spring/Summer months, Laguna Lake has the potential for significant algal blooms with the shallow lake depths, pooled water, abundant sunlight, expected water temperature ranges, and abundance of nutrient loading. It is also envisioned that if this alternative were employed, the recycled water would enter the Lake at a single location with no mixing other than by wind action. It is likely the recycled water would be dominant in the southeast portion of the Lake, near the main Park entrance, and unsightly algal blooms could have higher incidence in this area. If this option were employed, consideration of more than a single source of introduction to the Lake might be prudent, possibly adding a point of discharge in the area of Laguna Middle School in addition to the Park Entrance area. Midge (fly) Outbreaks In the 1970s, there were several outbreaks of midge flies. These flies were of particular nuisance to the surrounding community as they were small enough to enter homes through window screens. According to the technical studies performed , and as summarized in Appendix B of the Laguna Lake Management Plan Report, potential midge outbreaks increase with increased City of San Luis Obispo 2017 Recycled Water Master Plan B-4 production of phytoplankton. Thus, there is concern that any potential for increased nutrient loading to the Lake could cause increased algal production and therefore midge populations as well. The 1982 study recommended that recycled water NOT be used to augment the Lake levels, unless phosphorus and nitrate levels could be reduced. Although the City's WRRF treats to a much higher degree than in the 1970s, actual recommendations for target nutrient concentration goals were not stated in this past report. However, if the EPA target goals of 0.1mg/L total phosphorus and 10 mg/L nitrates serve as a guideline in this regard, the addition of recycled water would significantly increase total phosphorus levels above the minimum recommendations. This coupled with background/existing nitrate levels in the Lake of 10 to 20 mg/L, could create a higher potential for algae generation and thus midge outbreaks. Recycled Water Supply Recycled water augmentation to Laguna Lake is expected to be on average, 500 AFY. Since surface water runoff peaks during the rainy season, Lake augmentation with recycled water would be expected to begin around Summer each year, and diminish in the Fall (in anticipation of beginning of rainy season and thus surface water runoff). Monitoring and management of Lake levels will be prudent, to anticipate winter runoff peaks to minimize flooding impacts downstream on Prefumo Creek. Based on 110-acre surface area of the Lake, and using CIMIS Weather Station 52 data for historic evapotranspiration, an estimation of evaporative losses to the Lake through the year is presented in Figure F-1. Total annual evaporative losses were calculated at 477 AF per year (historical average). Figure F-1. Lake Evaporative Losses, Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec City of San Luis Obispo 2017 Recycled Water Master Plan B-5 It is possible that delivery of recycled water to the Lake could be from multiple outlets. If the City delivers water to Laguna Lake from two locations, such as near Laguna Middle School and near the Park entrance off of Madonna Road, recycled water would be delivered through an eight-inch diameter and 14-inch diameter pipe, respectively. Based on pipe diameter and capacity/velocity considerations, a 14-inch diameter pipe can convey three times the amount of water in an eight-inch diameter pipe. if it is assumed that recycled water deliveries are split between the two location s by this ratio, the following table (Table B-1) summarizes the range of pipe velocities that would be seen in the pipes given a range of delivery times and amount of delivered recycled water in a given month. Based on this table, even an eight-hour delivery window would yield desirable pipe velocities. If all water were delivered through the 14-inch pipeline on Madonna Road, the pipe velocity would still be below five feet/second when delivering 100 AF/month (delivering eight hours per day, every day for a month). Table B-1. Summary of Pipeline Velocities at Potential Turnouts Pipe Diameter, Inch Total Delivery to Lake, AF/Month 1 Pipe Velocity, ft/s 8-hour Day 10-hour Day 12-hour Day 16-hour Day 24-hour Day 14 50 1.8 1.4 1.2 0.9 0.6 8 14 75 2.7 2.1 1.8 1.3 0.9 8 14 100 3.6 2.9 2.4 1.8 1.2 8 1Assumes flow is split hydraulically between eight-inch turnout and 14-inch turnout. City of San Luis Obispo 2017 Recycled Water Master Plan B-6 Recommendations The City of San Luis Obispo met on the Laguna Lake Management Plan in 2015, and indicated that future plans will include the potential to supplement Laguna Lake with recycled water. This was generally accepted by the public. Based on the above findings, future considerations for use of recycled water to augment Laguna Lake include: Study to verify water quality parameters of the Lake such as nitrates, phosphates, temperature, pH and dissolved oxygen, in conjunction with evaluating recycled water quality parameters, particularly phosphorus removal based on future WRRF process upgrades. Such results should then be used to assess potential for algae blooms in the Lake. Further study and consideration of mixing and dispersion of Lake water may be warranted, in conjunction with alternative points of discharge of recycled water to assess dispersion/dilution of nutrients in the Lake. Continue to update the public on this potential future use of recycled water at Laguna Lake, and stay up to date on any regulatory changes that may occur over the coming years that could impact this proposed use. City of San Luis Obispo 2017 Recycled Water Master Plan C-1 Appendix C. Storage Analysis City of San Luis Obispo 2017 Recycled Water Master Plan C-2 THIS PAGE LEFT INTENTIONALLY BLANK City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-1 Appendix D. High Priority Irrigation System Retrofit Projects Retrofit Project 1.1 Retrofit Project 1.1 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 4 Connections $4,000 $16,000 On-site retrofit cost 4 Properties $2,500 $10,000 Contingency @ 20% $5,200 Construction Estimate Total $31,200 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-2 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 1.1 1490 Descanso Laguna Linda Homeowners 0.92 Y 0 1492 Prefumo Canyon Prefumo Canyon Estates 0.50 Y 0 1496 Prefumo Canyon Prefumo Canyon Estates 0.28 Y 0 1445 Prefumo Canyon Laguna Green Home Assoc 0.80 Y 0 Project 1.1 consists of the relocation of four point of connections that provide irrigation service to three homeowners associations. The northernmost meter serving the Laguna Linda Homeowners Association at 1490 Descanso Street could be relocated to an easement that runs between Laguna Hills Park and the property. This easement is approximately 20 feet from the existing recycled water main that serves Laguna Hills Park. This property could be retrofitted to recycled water without working in Los Osos Valley Road and would only require abandonment of the existing potable water service that currently feeds the irrigation meter at this property. Projected recycled water demand for this property is approximately one acre-feet per year. Prefumo Canyon Estates, accessed from Prefumo Canyon Road and Descanso Street, is served by two irrigation meters at separate sides of the property. Depending on the layout of the irrigation system it may be possible to consolidate these two meters into a single point of connection at either the intersection of Los Osos Valley Road and Descanso Street or at the intersection of Los Osos Valley Road and Prefumo Canyon Road. Consolidation of these two meters and changing the point of connection would require a new recycled water service line to be run from Los Osos Valley Road to the new meter location. Without the consolidation of these two meters, two new service lines would need to be installed on Los Osos Valley Road, each roughly 35 feet long. If connected to recycled water, both existing potable service lines would need to be abandoned. Both services are located within the Prefumo Canyon Estates property on privately maintained roadway. Projected recycled water demand for this property is 0.77 acre-feet per year. South of Prefumo Canyon Estates is Laguna Green Homeowners Association at 1445 Prefumo Canyon Road. The landscaping on this property is served by a single irrigation meter which is located near the center of the property. In order to connect this property to the recycled water system the meter would need to be relocated through an existing walkway that leads to Los Osos Valley Road. This relocation would allow for a new 35-foot-long service line to be installed in Los Osos Valley Road. Abandonment of the existing potable service that currently supplies irrigation water to this property would be done within the property where the City’s potable water service lines currently exist. Total projected water demand for this property is 0.80 acre-feet per year. Combining these three properties into a single project the City and proposed recipients of recycled water would see significant cost savings as the properties are within close proximity to one another. The total projected recycled water demand for these three properties is 2.50 acre- feet per year. City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-3 Retrofit Project 1.2 Retrofit Project 1.2 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 2 Unit $4,000 $8,000 On-site retrofit cost 2 Properties $2,500 $5,000 Contingency @ 20% $2,600 Construction Estimate Total $15,600 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 1.2 1106 Oceanaire Windermere Homeowners 1.15 Y 0 11295 Los Osos Valley Cedarwood Inc. / HOA 1.37 Y 0 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-4 Project 1.2 consists of the relocation of two point of connections that provide irrigation to two home owners associations. The eastern most meter that serves the Windermere Homeowners Association, at 1106 Oceanaire Drive, could be relocated 90 feet to Los Osos Valley Road. This meter relocation would allow for a new 60-foot-long service recycled water service line to be installed on Los Osos Valley Road. This would also require the abandonment of an existing potable water service line within the privately owned complex. Projected recycled water demand for this property is approximately 1.15 acre-feet per year. Directly across Los Osos Valley Road from 1106 Oceanaire is the Cedarwood Homeowners Association located at 11295 Los Osos Valley Road. The landscaping on this property is served by a single irrigation meter located near the center of the property. In order to connect this property to the recycled water distribution system the meter would be relocated to the front of the property along Los Osos Valley Road. This relocation would allow for the installation of a new 35- foot-long service line in Los Osos Valley Road. Abandonment of the existing potable service that currently supplies irrigation water to this property would be done within the Cedarwood Complex where the City’s potable water service lines currently exist. Total projected recycled water demand for this property is 1.37 acre-feet per year. By combining these two properties into a single project the City and proposed recipients of recycled water would see significant cost savings as the properties are within very close proximity to one another. Total projected recycled water demand for these three properties is 2.52 acre- feet per year. City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-5 Retrofit Project 1.3 Retrofit Project 1.3 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 2 Connections $4,000 $8,000 On-site retrofit cost 1 Property $2,500 $2,500 Contingency @ 20% $2,100 Construction Estimate Total $12,600 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 1.3 1704 Tonini L-1 De Tolosa Ranch 1.836 Yes None 1704 Tonini L-2 De Tolosa Ranch 1.836 Yes None City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-6 Project 1.3 consists of the connection of two existing landscape meters to recycled water and abandonment of two existing potable service lines that supply these meters . Along the north eastern property corner of 1704 Tonini, De Tolosa Ranch, are two existing landscape meters which feed De Tolosa Ranch’s with potable water for irrigation use. To connect these two meters to recycled water, the existing services would have to be abandoned in Madonna Road and two new 15-20 foot recycled water services lines would need to be installed from the recycled water main in Madonna Road. Projected recycled water demand for this property is approximately 3.67 acre-feet per year. Retrofit Project 1.4 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-7 Retrofit Project 1.4 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 2 Unit $4,000 $8,000 On-site retrofit cost 2 Properties $2,500 $5,000 Contingency @ 20% $2,600 Construction Estimate Total $15,600 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 1.4 1778 Tonini Rancho Obispo Properties 3.44 Y 0 2000 DeVaul Ranch Rancho Obispo HOA 1.15 Y 0 Project 1.4 consists of the connection of two existing landscape meters to recycled water and the abandonment of two existing potable service lines that supply these meters. This project would also require relocation of the two points of connection to Los Osos Valley Road. Along each side of DeVaul Ranch Road are irrigation meters for 1778 Tonini Street and 2000 DeVaul Ranch Road, both used for the irrigation of Rancho Obispo Properties. In order to connect these two meters to recycled water the points of connection would need to be moved from DeVaul Ranch Road to Los Osos Valley Road. This would require the meters to be moved 55 feet for the southern meter and roughly 140 feet for the northern of the two meters. Along with the moving of the points of connection, new recycled water service lines would need to be installed on Los Osos Valley Road. These two service lines would be roughly 100 feet each. Existing potable water services for these two irrigation meters would need to be abandoned, the location of these lines on DeVaul Ranch Road would allow for relatively easy abandonments. Projected recycled water demand from this retrofit project is approximately 4.59 acre-feet per year. City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-8 Retrofit Project 1.5 Retrofit Project 1.5 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 1 Connection $4,000 $4,000 On-site retrofit cost 1 Property $2,000 $2,000 Contingency @ 20% $1,200 Construction Estimate Total $7,200 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 1.5 1433 Calle Joaquin Motel 6 1.15 N 0 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-9 Project 1.5 consists of installation and connection of a new landscape meter to recycled water. There is not currently a separate irrigation meter at this property, therefore the existing line would not need to be abandoned since it would continue to be used to sup ply potable water to the hotel. This project would require additional investigation and construction on site to disconnect the irrigation system from the existing potable water meter in order to tie it into a newly installed landscape meter. In order to connect this property to recycled water a new 30 foot recycled water service would need to be run across Calle Joaquin Road to the location of the new landscape meter installation. Projected recycled water demand for this property is 1.15 acre-feet per year. Retrofit Project 1.6 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-10 Retrofit Project 1.6 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 2 Connections $4,000 $8,000 On-site retrofit cost 2 Properties $2,000 $4,000 Contingency @ 20% $2,400 Construction Estimate Total $16,400 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 1.6 1585 Calle Joaquin Rose Garden Inn 2.295 N 0 1625 Calle Joaquin Motel 6 2.295 N 0 Project 1.6 consists of the installation and connection of a two new landscape meters on the recycled water line in Calle Joaquin Road. The properties located at 1585 Calle Joaquin Road and 1625 Calle Joaquin Road do not currently have separate irrigation meters which means the existing potable water line would not need to be abandoned since they would continue to be used to supply potable water to the hotels for domestic use. This project would require additional investigation and construction on site to disconnect th e irrigation systems from the existing potable water meters in order to tie it into a newly installed landscape meters. In order to connect these properties to recycled water new 20 foot recycled water services would need to be run across Calle Joaquin Road to the location of the new landscape meter installation. Projected recycled water demand for this project is 4.59 acre -feet per year. City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-11 Retrofit Project 1.7 Retrofit Project 1.7 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 2 Connections $4,000 $8,000 On-site retrofit cost 2 Properties $3,500 $7,000 Contingency @ 20% $3,000 Construction Estimate Total $18,000 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-12 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 1.7 210 Margarita SLO Non Profit Housing 0.688 N 0 200 Via San Blas LDP Margarita Villa Association 2.754 Y 0 210 Via San Blas LDP Margarita Villa Association 2.065 Y 0 280 Via La Paz LDP Margarita Villa Association 2.065 Y 0 285 Via La Paz LDP Margarita Villa Association 1.377 Y 0 Project 1.7 consists of the consolidation of four existing landscape meters and a point of connection change for the Margarita Villa Homeowners Association at 285 Via San Blas and the new installation of a landscape meter for SLO Non-Profit Housing at 210 Margarita Avenue. In order to connect 210 Margarita Avenue to recycled water a new landscape meter would need to be installed along with a 50-foot service line to the recycled water main located in Margarita Avenue. Since there is not currently a separate landscape meter at this property, the existing line could be used entirely for potable use and would not require any type of abandonment. Margarita Villa Homeowners Association’s landscaping is currently served by four irrigation meters located within property. In order to make this project feasible, the four meters would need to be relocated to the entrance of the property along Margarita Avenue where they could be fed by the existing recycled water main. Depending on the construction of the irrigation system within the complex, it may be feasible to consolidate these meters and serve the property from two points of connection rather than four. If consolidated and moved to the entrance of the property, the four existing potable services would need to be abandoned in Via La Paz and Via San Blas and two new 30-foot-long recycled water service lines would need to be installed along with new meters. Projected recycled water demand for this project is roughly 8.95 acre-feet per year. City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-13 Retrofit Project 1.8 Retrofit Project 1.8 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 3 Connections $4,000 $12,000 On-site retrofit cost 3 Properties $2,000 $6,000 Contingency @ 20% $2,400 Construction Estimate Total $20,400 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 1.8 711 Tank Farm LDP Tank Farm Properties 1.377 Y 0 715 Tank Farm LDP Tank Farm Properties 0.459 Y 0 735 Tank Farm LDP Edna Valley Office BLDG 1.606 Y 0 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-14 Project 1.8 consists of the connection of existing irrigation meters at 711 Tank Farm, 715 Tank Farm, and 735 Tank Farm to the existing recycled water main in Tank Farm Road. In order to connect these three properties, existing potable services that currently feed th ese three meters will need to be abandoned in Tank Farm Road and three new 20-foot-long recycled water services will need to be tied into existing irrigation meters. Projected recycled water demand for this project is roughly 3.44 acre-feet per year. Retrofit Project 1.9 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-15 Retrofit Project 1.9 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 4 Connections $4,000 $16,000 On-site retrofit cost 4 Properties $2,000 $8,000 Contingency @ 20% $4,800 Construction Estimate Total $28,800 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 1.9 899 Columbine LDP REG/Santa Lucia Hills 3.098 Y 0 945 Tank Farm L-B SLO City Parks 1.147 Y 0 946 Tank Farm L-A Willowbrook II HOA 2.984 Y 0 944 Felicia LDP Willowbrook II HOA 1.182 Y 0 Project 1.9 consists of the connection of two existing irrigation meters at 945 Tank Farm to the existing recycled water main in Tank Farm Road and the relocation of the points of connection of 899 Columbine Court and 944 Felicia Way. In order to connect Santa Lucia Hills Homeowners Association at 899 Columbine to the existing recycled water main, the existing landscape meter at the end of Columbine Way would need to be relocated to the front of the HOA-owned walkway at Tank Farm Road. This relocation would require the abandonment of the existing potable service in Columbine Way and would require a new 55-foot-long service line in Tank Farm Road. Privately owned irrigation system would need to be modified to accommodate the new point of connection. Similar to the meter on Columbine, the existing landscape meter at 944 Felicia Way would need to be relocated to the frontage of the property along Tank Farm Road. This relocation would require abandonment of the existing potable service line in Felicia Way and would require a new 55-foot-long recycled water service line to be run from the recycled water main in Tank Farm to the new meter location. Privately owned irrigation system would need to be modified to accommodate the new point of connection. The two existing landscape meters located at 945 Tank Farm Road serve properties owned and maintained by the City of San Luis Obispo and Willowbrook II Homeowners Association. In order to connect these existing landscape meters to recycled water, two new 15 -foot-long recycled water service lines would need to be installed in Tank Farm Road and existing potable service lines to these meters in Tank Farm Road would need to be abandoned. No private irrigation system modifications would need to be made. The total projected recycled water demand for this project is 8.41 acre-feet. City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-16 Retrofit Project 1.10 Retrofit Project 1.10 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 4 Connections $4,000 $16,000 On-site retrofit cost 4 Properties $2,000 $8,000 Contingency @ 20% $4,800 Construction Estimate Total $28,800 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 1.10 1096 Sunrose LDP REG/Willowcreek HOA 2.065 Y 0 1024 Tank Farm LDP SLO City Parks 0.114 Y 0 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-17 949 Bluebell LDP Summerhills HOA 4.131 Y 0 1055 Bluebell LDP Summerhills HOA 2.065 Y 0 Project 1.10 consists of the connection of one existing irrigation meter at 1024 Tank Farm to the existing recycled water main in Tank Farm Road and the relocation of the points of connection of 1096 Sunrose Court, 1055 Bluebell Way and 949 Bluebell Way. In order to connect the City owned landscape meter at 1024 Tank Farm Road to the existing recycled water main, a 50-foot-long recycled water service line would need to be installed in Tank Farm Road along with the abandonment of the existing potable service line in Tan k Farm Road. Relocating the point of connection for Willowcreek Homeowners Association at 1096 Sunrose Court would require the current landscape meter to be moved to the front of the property along Tank Farm Road. This would require the installation of a 50-foot-long recycled water service line, abandonment of the existing potable service line in Sunrose Court, and potential modifications to privately owned irrigation lines. Relocating the two points of connection for Summerhills Homeowners Association at 1 1055 Bluebell way and 949 Bluebell Way would require the current landscape meters to be moved to the entrance of the property along Morning Glory Way. This would require the installation of one ten-foot-long recycled water service line for 949 Bluebell way and a 40-foot-long recycled water service line for 1055 Bluebell Way. Abandonment of the existing potable service lines in Bluebell Way would also be required along with potential modifications to privately owned irrigation piping. The total projected recycled water demand for this project is 8.37 acre-feet. City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-18 Retrofit Project 1.11 Retrofit Project 1.11 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 3 Connections $4,000 $12,000 On-site retrofit cost 3 Properties $2,500 $7,500 Contingency @ 20% $3,900 Construction Estimate Total $23,400 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 1.11 1102 Ironbark LDP Islay Hills Associates 1.193 Y 0 1223 Manzanita LDP Islay Pointe HOA 1.721 Y 0 1280 Chaparral LDP Islay Pointe HOA 3.558 Y 0 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-19 Project 1.11 consists of the relocation of the points of connection of 1102 Ironbark Street which is owned by the Islay Hills Homeowners Association and two meters owned by Islay Pointe Homeowners Association at 1223 Manzanita and 1280 Chaparral. In order to connect the existing landscape meter at 1102 Ironbark Street to the recycled water main in Tank Farm Road, the point of connection for this meter would need to be relocated to the front of the back of the property along Tank Farm Road. A 70-foot-long recycled water service line would need to be installed in Tank Farm Road along with the abandonment of the existing potable service line in Ironbark. This property would require changes to the irrigation piping in order to facilitate the new point of connection location . Relocating the point of connection for the two meters owned by Islay Pointe Homeowners Association would require the current landscape meters to be moved to the north side of the property along Tank Farm Road. This would require the installation of a 70-foot-long recycled water service line for each of the two meters and abandonment of the existing potable service lines in Manzanita and Chaparral. Potential modifications to privately owned irrigation lines would likely be required due to the point of connection changes. The total projected recycled water demand for this project is 6.47 acre -feet. City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-20 Retrofit Project 1.12 Retrofit Project 1.12 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new service lines 3 Connections $4,000 $12,000 On-site retrofit cost 3 Properties $1,500 $4,500 Contingency @ 20% $3,300 Construction Estimate Total $19,800 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 1.12 3590 Broad LDP Broad St Owners Assoc. 1.730 Y 0 3588 Broad LDP Broad St Community Assoc. 5.050 Y 0 3586 Broad LDP Sacramento Owners Assoc. 3.558 Y 0 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix D. High Priority Irrigation System Retrofit Projects D-21 Project 1.12 consists of the connection of three existing landscape meters to the recycled water main in Broad Street. In order to connect the existing landscape meters at 3590, 3588, and 3586 Broad Street to the recycled water main in Broad Street, the three existing potable service lines within the privately owned complex must be abandoned and a single service with a man ifold or three separate service lines installed from Broad Street to the current meter locations. These service lines would be roughly 70 feet in length and there would likely need to be alterations to the irrigation lines and meters to accommodate the service line feeding from Broad Street. The total projected recycled water demand for this project is 8.5 acre-feet. THIS PAGE LEFT INTENTIONALLY BLANK Appendix E. Medium Priority Projects Project 2.1 Project 2.1 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 2 Connections $4,000 $8,000 On-site retrofit costs 2 Properties $2,500 $5,000 Contingency @ 20% $2,600 Construction Estimate Total $15,600 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 2.1 11491 Los Osos Valley Pathpoint / Old SESLOC 0.55 N 0 1351 Royal LDP The Pines HOA 2.30 Y 0 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-2 This project consists connecting two new accounts to the recycled water system. This project could be moved to the high feasibility category if the point of connections could be moved to the Los Osos Valley Road frontage. If they are unable to be moved to this location additional main line would need to be added which would make this project significantly less feasible. In order for this project to be feasible, The Pines Homeowners Association at 1351 Royal Way would need to have its irrigation system converted to recycled water. To make this happen there are three options, each with varying cost and each significantly effecting the feasibility of this project. For the purposes of costing this project the most cost-effective option will be examined. Option 1: Relocation of irrigation meter from center of complex to Los Osos Valley Road frontage. This would require abandonment of existing potable water service inside the complex and the installation of a new 65-foot-long recycled water service line in Los Osos Valley Road. This option would not require a main line extension. Option 2: Extension of a 4”-6” inch water main from Los Osos Valley Road 200 feet down Royal way and the relocation of the existing irrigation meter to the front of the property along Royal Way. This option would also require abandonment of the existing potable water service line. Option 3: Extension of a 4”-6” inch water main approximately 150 feet down Royal Way from Los Osos Valley Road along with an additional 250 -foot-long extension through the private street where homes at 1351 Royal Way are located. This extension would not require a relocation of the existing irrigation meter. In addition to the adding 1351 Royal Way to the recycled water system, 11491 Los Osos Valley Road could also be added at this time but would only be feasible if a contractor was already adding infrastructure related to 1351 Royal Way. Connecting 11491 Los Osos Valley Road to the recycled water system would require the new installation of an irrigation meter on the Los Osos Valley Road frontage. This would require a new recycled water service line to be installed in Los Osos Valley Road but no abandonment of existing potable service line as it would continue to serve this property potable water for use within the building. Total projected recycled water demand for these two properties is 2.85 acre-feet per year. City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-3 Project 2.2 Project 2.2 - Estimated Project Cost – Option 2 ( LOVR-Royal Way Tie-In) Item Quantity Unit Unit Price Extended Price Installation of new services 1 Connection $4,000 $4,000 On-site retrofit costs 1 Property $2,500 $2,500 6” Main Line Installation 1050 LF $200 $210,000 Tie-in at LOVR 1 LS $5,000 $5,000 Contingency @ 20% $44,300 Construction Estimate Total $265,800 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 2.2 1375 Balboa C.L. Smith Elementary School 10.33 Y 1050 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-4 This project consists of serving C.L. Smith Elementary School with recycled water via the extension of the existing recycled water line on either Madonna Road or Los Osos Valley Road. Option number one examines the extension from Madonna Road to the front of the property and option number two examines a main line extension from Los Osos Valley Road to the back of the property on Galleon Way. C.L. Smith Elementary School currently has separate potable water meters for irrigation use and domestic use, both are located in front of the property on Balboa Street. Option #1: In order to feed C.L. Smith from Madonna Road a 4” to 6” recycled water main would need to be installed from Madonna Road at Oceanaire Drive through residential streets, for approximately 2,075 feet. This option would allow for connection to the existing irrigation line on Balboa Street without relocation of the meter or significant alteration of existing irrigation system . Option #2: Another alternative, which would be significantly more cost effective, would to serve the School from a tie in at the intersection of Royal Way and Los Osos Valley Road. In order for this alternative route to be feasible, the City would need to seek an expansion of an existing access easement from Galleon way to the back side of C.L. Smith Elementary School to allow for a recycled water service line to be run through it. If this easement was feasible, an extension of 4”- 6” main line from Los Osos Valley Road at Royal Way would need to be made. This would require roughly 800 feet of recycled water main be installed on Royal Way and 250 feet on Galleon Way. The existing potable connection used for irrigation, located on Balboa Street, would need to be abandoned and moved to the easement on Galleon way. This would allow for the installation of a new meter at this location. The location of this new meter would require alteration of on-site plumbing at the school for a tie in to the irrigation system . Option number two would also make it possible for this project to be joined with project 2.1, minimizing the overall cost for both projects. City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-5 Project 2.3 Project 2.3 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 1 Connections $4,000 $4,000 On-site retrofit costs 1 Property $2,500 $2,500 6”- 8” Main Line Installation on South Higuera and LOVR 720 LF $200 $144,000 Tie-in on South Higuera 1 LS $5,000 $5,000 Contingency @ 20% $31,100 Construction Estimate Total $186,600 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-6 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 2.3 90 Encanto Los Verdes II 1.15 Y 720 20 Perla Los Verdes II 1.61 Y 50 El Mirador Los Verdes II 1.55 Y 51 El Mirador Los Verdes II 1.95 Y This project consists of extending recycled water main line 720 feet down South Higuera and Los Osos Valley Road to reach the entrance of Los Verdes II Condos. For this project to be feasible Los Verdes II would need to abandon four existing potable irrigation meters and consolidate them into one or two meters at the entrance of the park. This project would not be feasible without having the meters moved to the front of the property due to the significant cost to extend the main through the entirety of the privately owned complex. Project 2.4 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-7 Project 2.4 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 2 Connections $4,000 $8,000 On-site retrofit costs 2 Properties $2,000 $4,000 8”- 12” Main Line Installation 800 LF $300 $240,000 Tie-in at Tank Farm/Broad Intersection 1 Unit $5,000 $5,000 Contingency @ 20% $51,400 Construction Estimate Total $308,400 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 2.4 4021 Broad Ottano Shell Station 1.26 Y 264 651 Tank Farm Mindbody 1.40 Y 700 Project 2.4 consists of extending 8” – 12” recycled water main from the intersection of Tank Farm and Broad, south on Tank Farm to serve 4021 Broad and 651 Tank Farm. These two properties have existing irrigation meters that are currently connected to potable water. This project would require abandonment of the existing service lines and the installation of two new recycled water service lines to the existing irrigation meters. There would likely be minimal on-site improvements necessary with tying these two properties over to the recycled water system. City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-8 Project 2.5 Project 2.5 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 2 Connections $4,000 $8,000 On-site retrofit cost 2 Properties $1,500 $3,000 6” Main Line Installation (down Aerovista) 260 LF $200 $52,000 10” Main Line Installation (down Broad) 2,100 LF $300 $630,000 Jack & Bore Creek Crossing at 4147 Broad 100 LF $750 $75,000 Tie in at Broad/Aerovista (6”x10”x10” tee) 1 LS $5,000 $5,000 Tie-in at Tank Farm/Broad (10” cross) 1 LS $10,000 $10,000 Contingency @ 20% $156,060 Construction Estimate Total $936,360 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-9 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 2.5 892 Aerovista Aerovista LLC 1.03 Y 2360 895 Aerovista Aeroloop LLC 4.59 Y 2360 Project 2.5 consists of installation of roughly 2100 feet of 10” recycled water main line on Broad Street between Tank Farm and Aerovista along with a 260-foot-long extension down Aerovista to serve 892 and 895 Aerovista with recycled water for irrigation use. The two properties to be served have existing irrigation meters that are currently tied into the potable water system. This project would require the abandonment of the two existing service lines and the connection of new recycled water service lines to the existing irrigation meters. Project 2.6 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-10 Project 2.6 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 3 Connections $4,000 $12,000 On-site retrofit costs 3 Properties $2,500 $7,500 6” Main Line Installation 1,980 LF $200 $396,000 6” Tie in at Tank Farm/Brookpine 1 Unit $5,000 $5,000 Contingency @ 20% $84,100 Construction Estimate Total $493,800 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 2.6 1211 Ironbark Islay Hills Owners 2.47 Y 1340 1341 Purple Sage L-B Rodriguez Adobe Park 3.49 Y 1340 4600 Spanish Oaks Islay Hills Owners 2.66 Y 1980 Project 2.6 consists of the installation of 1,340 – 1,980 feet of six-inch recycled water main to provide three properties recycled water for irrigation use. In order to serve recycled water to 1211 Ironbark and 1341 Purple Sage, 1,340 feet of six-inch recycled water main would be installed from Tank Farm Road down Ironbark to the entrance of Rodriguez Adobe Park. 1341 Purple Sage has an existing irrigation meter which means disconnection and abandonment of the existing potable service would be required along with running a new recycled water service line to t he existing meter. To provide recycled water to 1211 Ironbark, the existing service line and meter must be disconnected from the potable water system at the end of Ironbark Street and the point of connection must be moved next to the meter for 1341 Purple Sage. This would minimize the amount of recycled water main that needs to be installed by moving the meter to a location where recycled water main is proposed to be installed for the other properties associated with this project. Abandonment of the existing service line and meter on Ironbark would be required along with the installation of a new recycled water service line and meter at the end of Brookpine. Connecting 4600 Spanish Oaks would require an additional 640 feet of recycled water main line be installed on Purple Sage and would require that the current meter and point of connection be abandoned and moved northwest toward the edge of the Rodriguez Adobe Park. This part of the project would require abandonment of one potable service and meter and installation of a new recycled water service and meter along with potential alterations to the existing irrigation system to accommodate the new point of connection. City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-11 Project 2.7 Project 2.7 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 3 Connections $4,000 $12,000 On-site retrofit costs 3 Properties $2,000 $6,000 4” Main Line Installation 485 LF $300 $97,000 4” Tie in on Capitolio 1 Unit $3,500 $3,500 Contingency @ 20% $23,700 Construction Estimate Total $142,200 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-12 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 2.7 3510 Broad IOMG Inheritence LLC 0.40 Y 0 3550 Broad Broad & Capitolio 2.00 Y 305 775 Capitolio Level 3 Communications 3.33 Y 180 Project 2.7 consists of connecting two existing irrigation meters to recycled water and relocating a third irrigation meter from Sacramento Drive to Capitolio Way. In order to connect 3510 Broad to recycled water the existing landscape connection to the potable water system must be abandoned and a new service line run from the existing 4” recycled water line in front of the property on Capitolio. The existing meter could be used and would not require any type of relocation. Connecting 3550 Broad street to the recycled water system would require an extension of the existing four-inch recycled water main roughly 305 feet to the current location of the property’s irrigation meter and to extend the entire frontage of the property . This would also require that the current potable connection used for irrigation be abandoned and a new service line be run to the newly installed four-inch recycled water main. The existing irrigation meter could be used and would not require relocation. Connecting 775 Capitolio to the recycled water system would require both a main line extension of roughly 180 feet to extend the entire Capitolio Way frontage and would also require that the existing potable irrigation meter on Sacramento Drive be moved along the frontage of the property on Capitolio. This would require abandonment of the existing meter and service line and running a new recycled water service from the recycled water main in Capitolio. This would also require the installation of a new water meter in this location. City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-13 Project 2.8 Project 2.8 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 3 Units $4,000 $12,000 On-site retrofit costs 3 Properties $2,000 $6,000 4” Main Line Installation 1,760 LF $200 $352,000 4” Tie in on Capitolio 1 Unit $3,500 $3,500 4” Tie in on Sacramento 1 Unit $3,500 $3,500 Contingency @ 20% $75,400 Construction Estimate Total $452,400 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-14 Project 2.8 consists of connecting three existing landscape meters that are currently using potable water to a recycled water line that would be run from Capitolio to an existing dry line at the intersection of Sacramento and Orcutt. Connecting 803 Basil to the recycled water system would require an installation of 1,300 feet of four-inch main line from the intersection of Capitolio and Sacramento to the front of the property. This property has an existing irrigation meter which would need to be connected to the recycled water system. This would require abandonment of the existing potable service line and connection of a new recycled water service to the existing meter. Connecting 805 Bay Leaf would require an existing 300 feet of four-inch main line be installed from 803 Basil to the existing irrigation meter location for 805 Bay Leaf. The existing irrigation meter is connected to potable water which would require abandonment of the existing potable service line and connection of a new recycled water service to the e xisting irrigation meter. Connecting 3280 Sacramento would require an additional 160 feet of four-inch main line from 805 Bay Leaf to the existing dry recycled water line near the intersection of Sacramento and Orcutt. This would require an abandonment of the existing potable service and connection of the existing meter to the recycled water system via a new service line. Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 2.8 803 Basil Avivo HOA 3.44 Y 1,300 805 Bay Leaf Tumbling Waters HOA 2.75 Y 300 3280 Sacramento Creekston HOA 4.59 Y 160 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-15 Project 2.9 Project 2.9 - Estimated Project Cost Item Quantity Unit Unit Price Extended Price Installation of new services 9 Units $4,000 $36,000 On-site retrofit costs 9 Properties $2,000 $18,000 4” Main Line Installation 1,650 LF $200 $330,000 4” Jack and Bore at UPRR 150 LF $750 $112,500 4” Jack and Bore at Acacia Creek Crossing 75 LF $750 $56,250 4” Tie in on Orcutt 1 Unit $3,500 $3,500 Contingency @ 20% $111,250 Construction Estimate Total $667,500 City of San Luis Obispo 2017 Recycled Water Master Plan Appendix E. Medium Priority Retrofit Projects E-16 Prj. # Address Customer/Common Name AF/Y Has LDP Meter? Ft of Main Req. 2.9 1102 Laurel Andre Morris & Buttery 0.95 Y 0 1150 Laurel ESCORP 3.44 Y 300 904 Southwood City of San Luis Obispo 8.03 Y 800 2550 Boulevard Del Campo City of San Luis Obispo 0.73 Y 0 904 Southwood (Concessions) City of San Luis Obispo 6.89 Y 0 2800 Augusta City of San Luis Obispo 4.82 Y 200 1045 Southwood Parkwood Village 4.59 Y 150 1198 Bedford Laurelwood HOA 1.68 Y 1230 2755 Augusta SLO Coastal Unified School District 5.28 Y 70 Project 2.9 consists of the connection of nine irrigation meters to recycled water, including Sinsheimer Park and Johnson Park. In order for this project to be feasible, the section of dry pip on Orcutt road would need to have been connected to recycled water through previously mentioned projects. Connecting these nine meters to recycled water would require a jack and bore under the Union Pacific Railroad and an additional installation of 1,650 feet of four-inch recycled water main along the bike path, between the two baseball fields within Sinsheimer Park, out the entrance of the park, and down Southwood Drive to the furthest meter at the i ntersection of Southwood Drive and Bedford Court. In order to serve Johnson Park and Sinsheimer Elementary School a n additional section of main line would be required to be run through Johnson Park to where Johnson Park and the school meet. Sinsheimer Elementary School may not be feasible to connect if a jack and bore was required to cross under the creek that flows between the school and Johnson Park. All of the meters in this project would likely require relocation with the exception of 2800 Augusta (would still be needed to serve the restrooms) and 904 Southwood Con (still needed to serve concession stand and bathroom).