Agmt21 Environmental Science Associates Transit District

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Proposed Work Program June 2021 City of Redwood City / Transit District Subsequent EIR 10 Environmental science associates REV: 06-22-21 MI Utilities and Infrastructure Utilities and Infrastructure: The DTPP Final EIR determined all utilities/infrastructure impacts under the DTPP to be less than significant. The Transit District would accommodate an increase in development and population in the DTPP area, and consequently, would generate an increase in demand for utilities services, including water supply and distribution, wastewater collection and treatment, and stormwater collection. These effects will be addressed in the SEIR. With respect to water supply, the City serves as the water supplier for the City, including the DTPP area. The City is currently completing its 2020 Urban Water Management Plan (UWMP), and is expected to adopt its Final 2020 UWMP by June 2021. The analyses of potable and recycled water, wastewater collection and treatment, and stormwater collection and conveyance will be conducted by technical subconsultants. Each of these three scopes is presented below. Potable Water and Recycled Water (West Yost) West Yost’s scope is presented here in summary form. The detailed scope is provided in Appendix B. The analysis of potable water and recycled water will comprise four tasks: Task 1. Perform Water System Analysis: This task will entail an update of the City’s existing water system hydraulic model to include conceptual pipelines identified in the Preliminary Utility Study and allocate project demands (assumed to be calculated by others). Calibration of the model will be completed using field hydrant flow test data provided by the City. West Yost identify locations for new fire flow tests to be conducted by the City, which will also provide flow rates and pressure information at the SFPUC turnouts that supply the City’s Main Pressure Zone and the time of day that the tests were performed. West Yost will perform a minimum of three fire flow test calibrations of the hydraulic model, or up to four hours of model calibration, and will adjust roughness coefficients as needed. West Yost will work with the City to estimate the water demand in the Main City area and, if needed, zone demand based on seasonal and diurnal information developed for the Water Master Plan. The calibrated hydraulic model will be submitted to the City as an EPANET file. West Yost will conduct a maximum day fire flow analysis (based on requirements provided by the Fire Department) to determine available fire flows in the project area under existing hydraulic model demand conditions and for water system buildout conditions with the project demands. If available fire flows are inadequate with project demand included, West Yost will identify necessary improvements. West Yost will also perform a normal day, peak hour demand evaluation for existing conditions and system buildout with the project. Should the City identify a resulting deficiency, West Yost will identify necessary improvements. Task 2. Evaluate Recycled Water Systems: West Yost will update the City’s existing recycled system hydraulic model (to be provided by the City) by allocating irrigation and dual-plumbing demands provided by the City for the project area. West Yost will also perform a peak hour demand evaluation for the recycled water system at buildout conditions including project demands to determine the hydraulic impact of the project on the City’s recycled water system, based upon City-provided hydraulic evaluation criteria. It is assumed that the revised layout plan for the recycled water pipelines in the downtown area that was previously developed with the City will be used for this analysis. It is assumed that no further revisions to this plan will be needed. Task 3. Prepare Engineering Report: West Yost will prepare an Engineering Report summarizing the hydraulic findings and conclusions, assumed to include a summary of the analyses and will one to two exhibits per ATTY/AGR.2021.149/ESA (Transit District CEQA) (Page 20 of 26)