RES 2026043 - Laserfiche WebLink

Section 6 2025 Urban Water Management Plan Water Supply Characterization City of Pleasanton Public Draft | May 2026 6-14 EKI Environment & Water, Inc. The Joint Groundwater Wells project will give the City the ability to access its full GPQ. The Project is envisioned to include the following elements: • Construction of new groundwater well(s) in the Bernal Subbasin with the goal to increase Zone 7’s groundwater production capacity and drought resiliency for the overall Tri-Valley region, recover the City’s GPQ, and produce water supply that meets and exceeds all state and federal water quality standards. • Connection of the new groundwater well(s) to Zone 7’s water supply system and expansion of treatment capacity at Zone 7’s existing Zone 7 Hopyard Treatment Facility. • Delivery of the City’s GPQ via the Zone 7 water supply system (rather than the existing configuration that involves direct delivery from dedicated City wells). Zone 7 will serve as the lead agency in the evaluation, permitting, design, construction, operation, and maintenance of the project. Pleasanton will support the project by providing necessary land rights and paying the City’s share of project costs. The project is phased, as follows: • Phase 1 – In December 2025, the City and Zone 7 completed Phase 1 of the project, which involved assessing the feasibility of jointly constructing and operating new wells in the Bernal Subbasin. Phase 1 also involved drilling three test wells to confirm groundwater quality, well capacity, and aquifer sustainability. The study found that a joint groundwater supply project in the Bernal Subbasin is technically feasible, groundwater wells at Tennis Park and Hansen Park would provide sufficient water yield and quality, and Zone 7 groundwater modeling indicated the project would not affect groundwater basin sustainability 13. The feasibility study will set the basis for future phases of work including full scale design and construction of the production wells and associated infrastructure and construction. • Phase 2 – Following the feasibility study and test wells, the project will move into design and construction of the new production wells. The target completion date is end of 2029. • Phase 3 – Once the wells are installed and equipped and required permits to operate are in place, the City and Zone 7 will begin operating and maintaining the wells14. Pleasanton expects the new production wells to be operational by 2030, and therefore in this UWMP, the City is projected to utilize its full GPQ (an average of 3,500 AFY) starting in 2030. Zone 7 is managing the Tri-Valley’s broader efforts in the Basin related to PFAS. Seven of Zone 7’s nine active municipal wells have detected elevated PFAS concentrations. To date, PFAS has not been detected in Zone 7’s Hopyard Wellfield (i.e., Hop 6 and Hop 9 wells) located in the Bernal Subbasin (western portion of the Main Basin). Zone 7 has developed a PFAS management strategy consisting of expanding and refining its PFAS monitoring network, blending and treating groundwater to manage water quality, and diversifying groundwater resources. In recent years, Zone 7 has implemented the following management activities 15: 13 For more information see the project description on Zone 7’s website: https://www.zone7waterca.gov/post/joint- groundwater-wells-study 14 More information can be found on Zone 7’s website under the Joint Groundwater Wells Project (https://www.cityofpleasantonca.gov/our-government/pleasanton-water/joint-groundwater-wells-project/) 15 Zone 7 Water Agency, 2026. Annual Report for the Sustainable Groundwater Management Program, 2025 Water Year (October 2024-2025), Livermore Valley Groundwater Basin. https://www.zone7waterca.gov/sustainable-groundwater- management-and-sgma