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<br />Consulting Services Agreement between <br />City of San Leandro and RMC Water and Environment—Exhibit A Page 6 of 9 <br />evaluations is to confirm the suitability of pipeline alignments, and identify any design, <br />constructability, permitting, or environmental issues that could potentially be “fatal flaws” or that <br />should be considered in project development. RMC will develop planning level cost estimates <br />based on the most viable construction method for each potential solution for the identified <br />deficiencies. <br /> <br />Subtask 5.4 Evaluate Alternatives for Valley Area <br />RMC will review the alternatives for conveying Valley Area flows to the San Leandro WPCP that were <br />developed in the 1998 Valley Area Wastewater Export Study . RMC will use the hydraulic model to confirm <br />or update the required facilities for conveying flow to the San Leandro WPCP under each of those <br />alternatives, and will update the estimated costs of the alternatives. The alternatives will be compared to <br />the estimated future costs of continued conveyance and treatment at Oro Loma Sanita ry District (OLSD). <br />Potential future capital projects that might be needed by Oro Loma Sanitary District (OLSD) to convey <br />Valley Area flows will be discussed with the District. The alternatives will be compared on the basis of <br />capital and operating costs (including cost of pumping and treatment), constructability, system reliability, <br />community and environmental impact, permitting requirements, and other factors to be discussed with the <br />City. <br /> <br />Task 5 Deliverables: <br /> Thematic maps and hydraulic grade line plots of predicted capacity deficiencies <br /> Concepts and estimated costs of proposed Capacity Improvements <br /> Concepts and estimated costs of Valley Area Alternatives. <br /> <br />Task 5 Assumptions: <br /> City will provide cost of treatment at San Leandro WPCP and facilitate o btaining similar information <br />from OLSD. <br /> No new alternatives for the Valley Area will be developed. <br /> <br />Task 5 Schedule: <br /> All items delivered by September 30, 2013 <br /> <br />Task 6 – Lift Station Reliability Evaluation <br />This task will evaluate the length of time that each of the City’s 13 lift stations may be out of service without <br />resulting in an overflow under dry and wet weather conditions, and identify potential opportunities for <br />increasing lift station reliability <br /> <br />Subtask 6.1 Determine Lift Station Time to Overflow <br />Using the information developed in previous tasks, RMC will estimate the dry and wet weather flows for <br />each lift station. For lift stations included in the modeled system, the hydraulic model will be use d to <br />simulate the shut-down of each station under typical dry weather diurnal flows and under both a design <br />storm wet weather flow condition and a more moderate storm event. The resulting hydraulic grade line <br />results from the model, elevation data for surrounding manholes in the system, and pump station design <br />drawings will be used to identify the likely overflow points under a system shut-down and the time to <br />overflow. For lift stations not included in the model, flow estimates will be calculated based on the tributary <br />area of each lift station and the flow factors developed under Subtask 4.2, and the available storage <br />upstream of the station will be estimated based on the wet well volume and upstream piping.