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HomeMy WebLinkAbout05/07/2002, C3 - WATER REUSE PROJECT-AMEND DESIGN SERVICES CONTRACT council M..tig D� 5,7,02 j acEnaa nEpout „emNum6 CITY OF SAN LUIS OBISPO FROM: John Moss,Utilities Directo)*f11-- Prepared By: David Pierce,Water Projects Manager SUBJECT: WATER REUSE PROJECT—AMEND DESIGN SERVICES CONTRACT CAO RECOMMENDATION 1) Approve an addendum in the amount of$136,073 to the agreement with Brown and Caldwell for design of the Water Reuse Project. 2) Authorize the transfer of$130,000 from the Water Reuse Project CIP Construction account to the Water Reuse Project CIP Design account. DISCUSSION As the Water Reuse Project nears the 90%design milestone, several items have been identified that are not addressed in the original design agreement. The attached letter from Brown and Caldwell explains the need for each task. In summary they are: 1. provide the legal description to widen the pipeline easement between South Higuera Street and Broad Street, 2. provide the legal description for an easement adjacent to the Madonna Road bridge over Prefinno Creek in order to avoid directional drilling under that large box culvert, 3. design the facilities and process controls to use chloramines for disinfection, 4. design an extension of the potable water pipeline serving the bus maintenance facility to provide a potable water back up for the recycled water distribution system, 5. design a pipeline extending service from the trunk line on Tank Farm Road to French Park 6. design a pipeline extending service from the trunk line on South Higuera Street to the connections serving Los Verdes Park Homeowners' Associations. 7. design the recycled water chlorine contact tank to be adjacent and connected to the existing chlorine contact tanks. Disinfection of the water being discharged to the creek is accomplished with chlorine. Mixing ammonia with the chlorine to produce chloramines provides increased reliability for the disinfection process. There is adequate storage for chlorine at the Water Reclamation Facility but storage facilities will have to be designed for anhydrous ammonia. The suggestion to locate the recycled water chlorine contact tanks adjacent to the existing chlorine contact tanks and provide flexibility of operation that will meet existing and all projected future needs came out of the Value Engineering process performed by Harris and Associates as part of the 50 % design review. Bringing in another set of eyes and minds to step back and ask "Is there another way of doing this?" has generated an idea that will save several hundred thousand dollars by avoiding future expansions to both sets of chlorine contact tanks. After developing the details for this implementation Brown and Caldwell's staff said that this may set a new stand orfuch Water Reuse Project—Amend Design Services Contract Page2 facilities. FISCAL IMPACT Design costs for Agreement $781,957 Addendum No:1 $ 49,977 This Addendum S1169071 Total $968,007 The Water Reuse Project CIP (FY 2001-2003 Financial Plan appendix B page 106) Design account currently has a balance of$16,000. At this time,the construction estimate is less than the budgeted amount and thereis no indication that the Water Reuse Project will exceed the cost of the total budget. Therefore, staff recommends that money be transferred from the construction account to the design account. This recommendation is made with the knowledge that there is sufficient funding in the Water Fund Unallocated Reserves Account to cover these costs and that the cost to the City of the Water Reuse Project will be less than budgeted because of the State Water Resource Control Board grant that will cover 25%of the costs of the project. Attachment: 1. Contract Addendum No.2 2. Proposal for Additional Services,Brown and Caldwell,April 19,2002 \\879_MORRO\SYS\GROUPS\UTEL\Council Agenda Reports WRP_B&C_ADD2_CARdoc C3-2 _ .Water Reuse Project Design Services Attachment 1 ADDENDUM NO. 2 WHEREAS,The City of San Luis Obispo is constructing a Water Reuse Project and said project is requiring legal descriptions of pipeline easements, design of disinfection facilities using chloramines, design of a potable water pipeline extension to provide a backup to the recycled water distribution system;design of pipelines extending service along Poinsettia Street to French Park and along Los Osos Valley Road from South Higuera Street to Los Verdes Park, and design for locating the recycled water chlorine contact tank adjacent to the existing chlorine contact tank to provide flexibility in operation and eliminate the need for a future addition to each set of tanks; and WHEREAS,the additional work associated with the above mentioned tasks will cost $136,073.00; and WHEREAS, amendment No. 1 increased the total compensation sum not to be exceeded by $49,977.00 to a total $831,934.00 NOW THEREFORE,THE AGREEMENT dated December 3, 1997 between the CITY OF SAN LUIS OBISPO,a municipal corporation,hereinafter referred to as City, and BROWN AND CALDWELL,hereinafter referred to as consultant is amended as follows: 1) The total compensation sum not to be exceeded is increased from$831,934.00 to $968,007.00 2) The sum of$136,073 is added in Phase III to pay for those services related to defining pipeline easements,designing chloramines disinfection facilities, designing a potable water backup connection, extending service along Poinsettia Street to French Park, extending service from South Higuera along Los Osos Valley Road to Los Verdes Park,and locating the recycled water chlorine contact tank adjacent to the existing chlorine:contact tank to provide flexibility in operation and eliminate the need for a future addition to each set of tanks. These costs are enumerated in Brown and Caldwell letter dated April 19,2002. Both City and Contractor do covenant that each individual executing this agreement on behalf of each party is a person duly authorized and empowered to execute Agreements for such party. IN WITNESS WHEREOF,the parties hereto have caused this instrument to be executed this day of May 2002. CITY OF SAN LUIS OBISPO, ATTEST: A Municipal Corporation City Clerk By Allen Settle,Mayor APPROVED AS TO FORM: G v14G�'h- CONSULTANT ty me 3-3 � I Attachment 2. Dean Y1lttes�7owEr WO Espia�atie Dr:': suit?.1610'' CWtard:CA 93D30' Tel;:{805}6Pa-7890,; Faxl 05)604'78t1: April 19,2002 Mr.David Pierce Water Projects Manager City of San Luis Obispo EnnrzsN'znglEfrgnPcrd�B.tiCltq Utilities Department 879 Morro Street San Luis Obispo,California 93401 18/21632 Subject Proposal for Additional Services Re; Water Reuse Project Specification No. 97-68A Dear Mr.Pierce: As you are aware,a number of design modifications for the proposed Water Reuse Project were evaluated in.the Value Engineering (VE) Study Workshop in an effort to reduce initial construction,and future build-out and operating costs for the wastewater treatment plant. Eight of the sixteen ideas presented were ultimately selected by you for implementation into the final design. However,design work beyond the original project scope is required for some of the modifications so that the City can realize the potential benefits identified by the VE study. This proposal presents our scope, fee,and schedule for the additional VE-related work,as well as other design modifications previously discussed with you. Task 1. Cross Country Pipeline Easement A portion of the 20-inch diameter water reuse pipeline travels cross country between Prado Road and Broad Street within an existing 20-foot wide City water easement (Station 1+030 to Station 2+100 of the"Cross Country"Alignment). The present width is too restrictive to efficiently construct the new 20"diameter pipeline and allow for its long-term maintenance while protecting the existing waterline in place. The existing water pipeline occupies the centerline of the easement;we recommend that the proposed 20-inch pipeline be located approximately eight feet south of centerline. To accommodate this,a ten feet wide permanent easement should be acquired contiguous to the southerly boundary of the existing easement.An additional 10 foot wide temporary construction easement,south of the proposed permanent easement should also be acquired for the duration of initial pipeline construction. C3-4 Mr. David Pierce Attachment 2 August 19,.2002 Page 2 a. Scope:.Prepare legal description,map and area calculation for recommended permanent and temporary easernent areas. (Note:All appraisals,negotiations with property owners,and preparation of right-of-way agreement will be the responsibility of the City and are, therefore,excluded from our Scope of Work. b. Fee: $2,880.00 Task 2. Madonna Road Pipe Bridge Easement The 10-inch diameter water reuse pipeline along Madonna Road crosses a box culvert at Perfumo Creek near the Laguna Lake tributary(Station 1+230 on the"Madonna Road" alignment), Due to the high water table in this vicinity and shallow cover over the culvert,we.recommend a pipe bridge crossing.on the south side of the culvert. However, the right-of-way boundary along Madonna Road narrows on the east side of the box culvert. We therefore recommend that the City acquire temporary and permanent easements at this location for the proposed pipeline alignment. a. Scope:Prepare legal description,map and area calculation for recommended permanent and temporary easement areas. . (Note:All appraisals, negotiations with property owners,and preparation of right-of-way agreement will be the responsibility of the City and are, therefore,excluded from our Scope of Work.) b. Fee: $2,880.00 Task 3. Chloramine Disinfection Facilities Chloramination,a process often used for disinfection of drinking water and wastewater, involves mixing chlorine and ammonia to form chloramines.The relative concentrations of both chlorine and ammonia are essential for optimum disinfection. First,the chlorine will react with free ammonia to form monochloramine.As more chlorine is added,additional monochloramine is formed until all the free ammonia is consumed. When all the free ammonia is gone, the chlorine will begin to react with the monochloramine to form dichloramine. This reaction will continue until all the monochloramine is gone. If more chlorine is added, the chlorine will react with the dichloramine to form trichloramine (also called nitrogen trichloride) until all dichloramine has been reacted. This is called breakpoint and no more reactions are possible between the ammonia and chlorine. If more chlorine is added,it will remain as free chlorine in solution. Each chloramine has a different effect on disinfection and the key to chloramination is to produce the correct chloramine species.Monochloramine is an effective disinfectant C3-5 Mr. David Pierce Attachment 2 August 19,2002 Page 3 and is relatively stable in solution. Dichloramine is also a strong disinfectant but often gives an off taste and odor in drinking water. Trichloramine is unstable in solution and decomposes quickly. Although chloramine is a weaker disinfectant than chlorine,it is more stable and remains in the water distribution system for a longer period of time. Thus,as water winds through the distribution system,chloramine continues to provide disinfection. Chloramine provides more protection against bacterial re-growth in systems since the chloramine residual is more stable and longer lasting than chlorine. Chloramine,like chlorine,is effective in controlling biofilm,which is a slime coating in the pipe,caused by bacteria. Controlling biofilms also tends to reduce coliform concentrations and the corrosion of pipes. The most effective means of chloramine treatment is manufacturing onsite. The goal in chloramination is to maximize the reaction of ammonia and chlorine to form monochloramine;when monochloramine production is maximized,free ammonia is minimized,potentially at or very close to zero. For the wastewater treatment plant in San Luis Obispo,new chemical storage and feed systems would deliver aqueous ammonia to reuse water in the chlorine contact tank. An analyzer automatically controls the process by monitoring total chlorine,monochloramine, total ammonia, and free ammonia in the effluent and controlling ammonia feed rate. Chloramine disinfection can reduce operations and maintenance cost and improves reliability of reuse water. These long-term benefits are however offset by the initial capital investment to design and construct facilities and train personnel for its safe and effective use: a. Scope:The additional design services offered by BC will integrate chloramine disinfection into the City's Water.Reuse Project. This effort includes process design and preparation of construction documents for the aqueous ammonia storage area (including a fill station and vapor recovery system), feed and controls for a fully functional system. b. Fee: $54,560.00 Task 4. Backup and Flushing Water Source Regulations require that areas using reclaimed water irrigation be flushed with potable water to prevent salt build-up. This can be efficiently accomplished—with little or no inconvenience to end users—by annual deliveries of potable water through the reuse distribution system. In order to deliver potable water each year,a main line extension and service connection,with an air-gap to prevent backflow contamination,would be needed upstream of the reclaimed water pump station. C3-6 Mr. David Pierce Attachment 2 August 19,2002 Page 4 A potable water source at the reclaimed water tank has an additional benefit,in the event effluent quality did not satisfy regulatory requirements,an alternate source of water would be available for delivery.to end users. Given the potential benefits of a potable water source,we recommend a water service extension and connection to the Water Reuse Project facilities at the treatment plant.. a. Scope: Investigate potable water utility sources in the vicinity of the treatment plant;establish supply requirements and evaluate sources. Using the most cost effective water source,prepare construction documents for a potable water pipeline extension and service connection (with air gap) for the Water Reuse Project. b. Fee: $15,551.00 Task 5. Poinsetta Service:Extension In order to provide reuse water to French Park,a 335-meter lateral service extension is required. The pipeline would extend from the RW distribution pipeline on Tank Farm Road to the north in the Poinsetta Road Right-of-Way. The pipeline crosses two creek or drainages that may require trenchless installation methods. a. Scope: Engineering services for design and preparation of construction documents for a reuse water service extension;approximately 335 meter long on Poinsetta Road (to French Park). Services include geotechnical investigation,site evaluation;surveying,utility coordination,pipeline design, drafting and specifications: b. Fee: $15,009.00 Task 6. South Higuera Extension In order to provide reuse water to Los Verdes Homeowners Association;a 224-meter lateral,service extension is required. The pipeline would extend from the RW distribution pipeline on South Higuera Street to the west in the Los Osos Valley Road Right-of-Way. a. Scope: Engineering services:for design and preparation of construction documents for a reuse water service extension,approximately 224 meter long on Los Osos Valley Road (to Los Verdes Homeowners Association). Services include:geotechnical investigation,site evaluation, surveying,utility coordination,pipeline design,drafting and specifications. b. Fee: $16,321.00 C3-7 Mr: David Pierce Attachment 2 .August 19,2002 Page 5 Task 7. Split Use Chlorine Contact Tank To minimize future build-out of chlorine contact tanks for both creek discharge and reuse water, to provide additional plant capacity for peak wet weather flows,and to consolidate facilities.at the plant site,an alternative configuration was suggested for the chlorine contact tank. Under the new configuration two additional tanks will be constructed adjacent to and matching the existing the chlorine contact tanks. Tank usage would be controlled by gate positions located between adjacent compartments. a. Scope: Reconfigure construction documents to conform to Exhibit C: (Preliminary) Revised Site Plan,attached. b. Fee: $28,872.00 Based on the City's final disposition on each item above,any combination of Tasks can be selected. To account for the time delays resulting from study and development of these modifications,and additional time required for incorporating design revisions,we request a contract extension of ninety calendar days.This assumes that we will receive your approval to proceed with regards to the above items by May 15,2002. Please call Thomas Fischetti,or me,to discuss any questions regarding this proposal,or if you should need additional information.. Very truly yours, BROWN AND CALDWELL Pervaiz Anwar Senior Vice President RE: nw cc:.Thomas Fischetti C3-8