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HomeMy WebLinkAboutItem 07 - Engineering Services ContractMEMO TO FROM: MEETING DATE: SUBJECT: RECOMMENDATION: ITEM s HONORABLE MAYOR AND MEMBERS OF THE CITY COUNCIL ROGER NELSON, CITY MANAGER A DECEMBER 7, 2004 APPROVAL ENGINEERING SERVICES CONTRACT City Council to consider approval of an Engineering Services Contract with Malcolm Pirnie, Inc. in an amount not to exceed $38,898.00 and authorize the City Manager as signatory. FUNDING SOURCE: Funds are available in the Water and Wastewater Permanent Capital Maintenance Fund, Account 200-43360-534-0 in the amount of $38,898.00. BACKGROUND: Texas Commission for Environmental Quality requires that a disinfection residual for chloramine be maintained at a 0.50 parts per million level in the drinking water distribution system. This is to insure that all biological contaminants that could be present in the water system have been deactivated. City staff has been struggling to achieve a consistent chloramine residual in the southern part of Grapevine. The system is not in violation of any rules or in danger of falling below the required disinfection residual, but the lower than normal residual is indicative of an overall problem. The southern part of Grapevine is supplied by water from the Trinity River Authority (TRA), a regional water purveyor. The low residual problem is limited to the Mustang water tower area and south. Malcolm Pirnie is the engineering firm that provides services to TRA. They have an extensive background and expertise in water treatment and water distribution system trouble -shooting. Staff has interviewed Malcolm Pirnie and feels it is prudent to perform a study to determine the effects of the combination of the Grapevine and TRA treated water sources as well as the treatment techniques for the respective waters. The study will encompass both the Grapevine and TRA system. Malcolm Pirnie will review all data collected during a field testing program and evaluate and identify the probable cause of the premature decay issue. Alternatives will be November 30, 2004 (1:52PM) developed for resolving the problem and Malcolm Pirnie will recommend the most feasible resolution alternative specific to the Grapevine system. Staff recommends approval of an Engineering Services Contract to Malcolm Pirnie in an amount not to exceed $38,898.00. MS/ms November 30, 2004 (1:52PM) Scope of Basic Engineering Services Background The City of Grapevine (Grapevine) has one water treatment plant (WTP) that generally serves the northeast portion of Grapevine's distribution system. The remainder of Grapevine's water needs are supplied by the Trinity River Authority's Tarrant County Water Supply Project WTP (TCWSP WTP). Water from the TCWSP WTP generally serves the southern, central, and northwest portions of Grapevine's distribution system. TCWSP water is conveyed through two transmission mains into separate locations in Grapevine's distribution system; however, both water delivery locations are within the southern portion of Grapevine's distribution system. Grapevine has observed seasonal decay of chloramine residual, typically occurring during the warm summer months. This year, the problem has been more acute than in the past, spanning into other seasons. In the southern portion of the distribution system, chloramine residuals have been decaying rapidly. Grapevine has been monitoring these residuals and flushing the system to ensure they remain above the regulatory minimum. The Mustang elevated storage tank, located in the southern part of the system, which has a total chlorine monitor on the effluent, has been particularly affected by the decaying residuals. As a result, Grapevine staff have been flushing the distribution system and replacing water in the storage tanks. While chloramine residuals initially are re-established by flushing, the residuals in the south portion of the distribution system appear to decay quickly after the flushing events. In an attempt to maintain residual, Grapevine has temporarily ceased the distribution of TCWSP water into their system and is relying on supply from their WTP. While the change to their surface supply has only occurred for approximately 5 days, the chloramine residuals reportedly appear to be increasing and stabilizing. Based on the residual issues discussed above, the overall objective of this project is to evaluate the water quality issues and treatment approaches causing the decay in the residual and recommend potential resolutions. In order to fulfill the overall objective, Malcolm Pirnie will perform the following tasks: Task 100 — Meet with Staff; Collect Pertinent Data • Malcolm Pirnie will meet with Grapevine staff; tour WTP facility and southern areas in the distribution system; obtain detailed history of issues; confirm project goals and schedule; and collect WTP and water quality data including a review of the chloramination approach. • Malcolm Pirnie will submit a letter to Grapevine listing data and information needs. The letter will be submitted prior to the meeting to allow time for Grapevine to locate and assemble data and information for collection at the meeting. Data and information needs will generally include plant operations and water quality data (treated water quality data for the previous three years), and distribution system water quality data. • Malcolm Pirnie will also meet with TRA staff to discuss their chloramination procedures and water quality data. • Malcolm Pirnie will submit a letter to TRA listing data and information needs. The letter will be submitted prior to the meeting to allow time for TRA to locate and assemble data and information for collection at the meeting. Data and information City of Grapevine Chloramines Disinfection Residual Evaluation 1 11/1512004 needs will generally include plant operations and water quality data (treated water quality data for the previous three years), and distribution system water quality data. Deliverables: • Data and information needs letters • Meeting notes Task 200 — Develop and Implement Field Testing Program • Malcolm Pirnie will develop a field testing protocol to evaluate water quality in the low residual areas of the distribution system. The field testing protocol will focus on factors related to the maintenance of chloramine residual. General water quality parameters of interest to be evaluated in the distribution system will include: chloramine residual, pH, nitrites, nitrates, free ammonia, and heterotrophic plate count organisms. • The implementation of the field testing protocol will be carried out by Grapevine staff. Water quality analyses prescribed in the protocol that can not be performed by Grapevine staff in the field will be sent to a certified laboratory and tested. It is anticipated that Grapevine will directly purchase the supplies and equipment necessary to carry out field sampling and pay for the laboratory water quality analyses. • Prior to initiating the field testing program, Malcolm Pirnie will meet with Grapevine staff to discuss the protocol, methods, any necessary equipment and supplies, and scheduling. • Malcolm Pirnie will assist Grapevine staff with the field testing via an onsite presence during the initial kickoff of the field testing program. Malcolm Pirnie will further assist with field and sampling issues that arise during the field testing program as necessary. The anticipated duration of the field testing is one month. • Grapevine will forward all data collected during the field testing program to Malcolm Pirnie as soon as possible after the testing or after the data .is received from the laboratory such that adjustments can be made to improve the field sampling data as necessary. • Malcolm Pirnie's level of effort for the water quality field testing program is based upon 32 hours working in the field over a 4 week period. This is generally proportioned as 16 hours for the initial kickoff and 4 hours per week for 4 weeks. • Should the chloramine decay condition not begin within a specified period after switching back to the TRA water supply, the field testing program will be temporarily suspended until the next occurrence, at which point the project will be re -started from the beginning of the field testing program. Deliverables: _ • Field testing protocol describing the water quality testing program, analyses, methods, equipment, and locations. Task 300 — Review of System Operations and Pertinent Data; Review of Field Testing Program Data; Evaluation and Identification of the Cause of the Decaying Disinfection Residual • Malcolm Pirnie will review plant operations information; and water quality data from plants and distribution system from both Grapevine and TRA. • Malcolm Pirnie will review ail data collected during the field testing program. City of Grapevine Chloramines Disinfection Residual Evaluation 2 11/15/2004 Based on review of all available data, Malcolm Pirnie will evaluate and identify the probable cause of the premature decay of chloramine residual in the Grapevine distribution system. Task 400 —Alternatives and Recommendations • Malcolm Pirnie will develop alternatives for resolving the chloramine decay issue once the probable cause(s) has been determined. • Based on the available alternatives, NIrnieR wiCt recomri`tendt mrast feasible alternative, specific to the Grapevine systern. Task 500 — Technical Memorandum and Meeting with Staff • Malcolm Pirnie will incorporate the data review (Task 300), the evaluation and identification of the cause of the occurrences (Task 300), the resolution alternatives (Task 400), and the recommended resolution alternative (Task 400) into a technical memorandum. • Malcolm Pirnie will meet with Grapevine staff to discuss the memorandum, the outcome of the evaluation, and the recommended resolution alternative. • If necessary, Malcolm Pirnie will meet with TRA to discuss the memorandum, the outcome of the evaluation, and the recommended resolution alternative if it affects operations and water supplied by TRA. Deliverables: • Six copies of the draft technical memorandum. • Meeting notes. • Six copies of the final technical memorandum with revisions based on the review comments submitted by Grapevine staff. Optional Task 600 — Implementation of Resolution • Once an alternative for resolving the chloramine decay issue is selected, Malcolm Pirnie will assist Grapevine staff with the implementation of the selected alternative. • Optional task 600 may be added at any time via an amendment to the contract. City of Grapevine Chloramines Disinfection Residual Evaluation 3 11/15/2004 ACCREDITED PRICER PROGRAM: FEE ESTIMATOR TEMPLATE Te niplate'ver. 3-7�&-2a)4 I Client Project Name City of Grapevine Chloramines Disinfection Residual Evaluation PRICING SUMMARY BILLABLE TOTALS TASK _ DESCRIPTION B / WB— Labor 0DC'T— SUBs Total 000 Expenses YES $ - $ 1,870 $ 1,870 050 Project Management YES —YES $ 2,000 $ 73 $ 2,073 100 Meet with staff, collect data 2;554 $ 86 $ $ 2,641 200 Develop and Implement Field Frog YES $ —$ 6,548 $ 242 $ 6 79,0) 300 Data Review and Evaluation YES 11,558- $ 492 $ $ 12,050 400 Alts and Recommendation YES $ —$--9,313 3,642 $ 147 $ $ 3,789 500 Tech Memo and Meeting YES — $ 372 $ $ 9,685 TOTAL BILLABLE $ 35,615 $ 3,283 $ $ 38,898 CONTRACT FEE $ 38,898 PM: Contract Fee (Upset) SUMMARY WORKSHEET Grapevine AP Fee Templatexle I Cost Summary Page 1 11/17/20134