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Section 6 2025 Urban Water Management Plan <br />Water Supply Characterization City of Pleasanton <br /> Public Draft | May 2026 <br /> 6-15 EKI Environment & Water, Inc. <br />• Installed new PFAS treatment systems at Stoneridge Well and COLs Wellfield and began <br />operations in 2023 and 2025, respectively. <br />• Installed a new monitoring well in 2024 between the Mocho and Hopyard Wellfields to monitor <br />PFAS plume migration towards the Hopyard wells. <br />• Actively blending water pumped from the Mocho Wellfield to meet regulatory limits. <br />• Initiated design and construction of a PFAS treatment system in the Mocho Wellfield which is <br />anticipated to come online in 2028. <br />6.2.3.4.3 Chromium Management <br />Zone 7 has several wells with naturally occurring hexavalent chromium (Cr(VI)) concentrations near the <br />maximum contaminant level (MCL). In response, Zone 7 is actively managing flows from the affected wells. <br />For example, Cr(VI) levels at the Stoneridge well are being managed through system blending and/or <br />blending with other wells. <br />6.2.4 Historical Pumping and Supply Sufficiency <br />As described in Section 6.2.3.1, the City has a GPQ of 3,500 AFY in the Main Basin. Historical groundwater <br />pumping from 2021 through 2025 is shown in Table 6-2. Pleasanton decommissioned its municipal wells in <br />2022, in response to PFAS detections. This reduced the total pumped volume in 2022, and by 2023, <br />Pleasanton was sourcing nearly 100% of its supply from Zone 7 purchases. The City occasionally pumped <br />groundwater between 2023–2025 to meet peak demands and to conduct regular monitoring and testing. <br />Table 6-2 Groundwater Volume Pumped (DWR Table 6-1) <br />Groundwater <br />Type Water Type Location or <br />Basin Name <br />2021 <br />(AF) <br />2022 <br />(AF) <br />2023 <br />(AF) <br />2024 <br />(AF) <br />2025 <br />(AF) <br />Alluvial Basin Potable Livermore <br />Valley <br />Groundwater <br />Basin <br />3,332 2,449 10 4 3 <br />Total 3,332 2,449 10 4 3 <br />6.3 Surface Water <br />As described in Section 6.1.2, Pleasanton receives treated surface water from Zone 7, whose supplies <br />include imported surface water from the SWP, and local surface water captured in the Del Valle Reservoir. <br />6.4 Stormwater <br />Stormwater can be beneficially reused as a water supply source to meet local water supply demands. <br />Beneficial reuses include blending with other water supplies for groundwater recharge, redirecting it into <br />constructed wetlands or landscaping, and diverting it to a treatment facility for subsequent reuse. <br />Currently, Pleasanton does not implement any stormwater recovery systems. <br />6.5 Wastewater and Recycled Water <br /> <br /> CWC §10633 <br />The plan shall provide, to the extent available, information on recycled water and its potential for use as a water <br />source in the service area of the urban water supplier. The preparation of the plan shall be coordinated with local <br />water, wastewater, groundwater, and planning agencies that operate within the supplier’s service area.