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Section 7 2025 Urban Water Management Plan Water Supply Reliability Assessment City of Pleasanton Public Draft | May 2026 7-7 EKI Environment & Water, Inc. Zone 7 continues to study the groundwater basin and utilize new tools (e.g., a recently improved groundwater model) to better understand the volumes of groundwater extraction possible under various Basin conditions while maintaining groundwater elevations above the historic-low groundwater elevations that have been reached in certain portions of the Main Basin (“historic lows”). Zone 7 also plans to augment its ability to recharge the Main Basin (e.g., through the COLs) to increase local storage and allow for more pumping when necessary. Recharging the Main Basin will improve both water supply reliability and salt management. Zone 7 is evaluating opportunities to construct and operate an additional demineralization facility to continue to decrease the salt content of the Main Basin. Finally, the City and Zone 7 are advancing the Joint Groundwater Wells Study to evaluate the feasibility of adding new municipal production wells in the Bernal Subbasin. The goal of these additional wells is to increase groundwater production capacity, enhance drought resiliency, and provide greater operational flexibility in managing groundwater sustainability during extended droughts or surface water supply constraints. The City has a GPQ of 3,500 AFY from the Main Basin, which comprises approximately 20% of its water supply. The City may also carry-over any unused portion of its annual GPQ up to a total of 700 AF. The successful completion of the Joint Groundwater Wells project will allow the City to once again pump its full GPQ and reduce the risk of future PFAS contamination. Zone 7 established GPQs for the Main Basin based on the natural sustainable yield. As such, the City’s groundwater supply from its GPQ is considered reliable under all hydrologic conditions. 7.1.3 Recycled Water The recycled water that the City receives comes from DSRSD’s RWTF and the LWRP, which are described in Section 6.5.2. Both facilities produce Title 22 disinfected tertiary recycled water. The City anticipates no significant changes to the land uses in either DSRSD’s or Livermore’s wastewater service area; therefore, it does not anticipate any changes to the quality of the wastewater effluent used to produce recycled water. The City does not expect recycled water quality issues to impact its ability to reliably deliver recycled water to its customers. On March 25, 2019, DERWA found that it cannot meet the combined peak demands and projected demands of its member agencies (DSRSD and EBMUD) and its retailer, Pleasanton. DERWA approved Resolution No. 19-3 (Appendix E) requesting that its member agencies take action to reduce recycled water demands and implement a connection moratorium. As discussed in Sections 6.5.2 and 6.5.4, the City maintains the first right to use the secondary effluent produced from wastewater originating from the City’s wastewater collection system for recycling. As of 2023, the City also owns the treatment capacity rights of up to 2.7 MGD of recycled water from DSRSD’s RWTF While the City’s recycled water supply is limited by the secondary wastewater effluent from its service area and the treatment capacity of DSRSD’s RTWF, this supply is expected to meet the City’s current and projected recycled water demands. 7.1.4 Water Quality Impaired water quality also has the potential to affect water supply reliability. Pleasanton has and will continue to meet all state and federal water quality regulations. All drinking water standards are set by the EPA under the authorization of the Federal Safe Drinking Water Act of 1974. In California, the SWRCB’s  CWC §10634 The plan shall include information, to the extent practicable, relating to the quality of existing sources of water available to the supplier over the same five-year increments as described in subdivision (a) of Section 10631, and the manner in which water quality affects water management strategies and supply reliability.