Planning Commission Agenda Packet 102225 (1)

August 7, 2025 Page 4 BKF ENGINEERS fire flows above 2,447 GPM are required, additional modeling should be performed to ensure the city system can meet the required demand. 8. Recycled Water System The City of Pleasanton owns and maintains a recycled water distribution system that provides water that can be used for landscape irrigation in lieu of using potable water. Per the City’s Recycled Water Distribution map, there are no recycled water pipes located in Owens Drive in the area where the project has frontage, but a 6-inch recycled water pipe appears to dead end near the southeast corner of the project site along Owens Drive. The project should anticipate extending this 6-inch line, likely from Willow and Owens to create a looped system. Recycled water use is estimated to be 7,000 GPD, based on 26 gallons/SF/year, and assuming that 15% of the 14.9- acre site is landscape. The 26 gallons/SF/year estimate comes from the City of Redwood City Landscaping Water Demand projection, as the City of Pleasanton does not provide demand projections for landscape water usage. Refer to Appendix C for the recycled water maps provided by the City of Pleasanton. 9. Sanitary Sewer System The sewer system in the area is owned and operated by the City of Pleasanton. An 8-inch VCP sewer main is located in Owens Drive west of Willow Road, and a 12-inch VCP sewer main is located in Owens Drive east of Willow Road. A 6-inch sanitary sewer main runs through the site, connecting the BART station to the sewer main in Owens Drive. Refer to Appendix D for the sewer map provided by the City of Pleasanton. Estimates for sanitary sewer average dry weather flow 254,000 gpd, based on a 0.65 factor applied to water demands stated in section 7 above. The 0.65 factor is based on the estimate provided in the 2005 Pleasanton Plan 2025 for multi-family residential. Peak dry weather flow is estimated to be 440 GPM, assuming flows are spread across a 24-hour day, with a peaking factor of 2.5. 10. Storm Drain System The storm drain system in the area is owned and operated by the City of Pleasanton and Alameda County. In Owens drive near the west side of the project site, a city-owned 24-inch storm drain main flows to the intersection with Willow Road, and a city-owned 42-inch storm drain flows from the intersection with Willow Road to Chabot Canal, where it outfalls into the Canal. In Owens drive near the east side of the project site, a 60-inch storm drain main flows toward Iron Horse Trail, where it meets a county-owned 66-inch storm drain main that runs through the project site along Iron Horse Trail. Some existing catch basins on the project site flow to the city mains in Owens Drive, others flow to the county main in Iron Horse Trail, and others discharge directly into Hewlett Canal to the north. Refer to Appendix D for the storm drain map provided by the City of Pleasanton. 11. Stormwater Quality The project would create more than 10,000 square-feet of impervious surface and will therefore be required to treat stormwater runoff as outlined in Provision E.12 of the Phase II Small MS4 General Permit. Provision E.12 requires Low Impact Development (LID) techniques to reduce runoff, treat stormwater, and provide baseline hydromodification management to the extent feasible. LID techniques primarily include infiltration and stormwater re-use. If infiltration will not be feasible on this site, landscape-based LID techniques such as bioretention areas are acceptable as an alternative compliance measure. Stormwater treatment strategies often compete with other site functions within the development so it is important to coordinate treatment areas early in the design process. The project may be eligible for LID treatment reduction credits based on being an affordable housing project. These credits would reduce the amount of bioretention treatment facilities required, but would require stormwater to be treated by a proprietary stormwater media filter instead. In order to qualify for LID treatment reduction credits, the DRA F T