CITY COUNCIL REGULAR MEETING AGENDA PACKET 2-3-26

ITEM NO. 11 ORIGINATING SECTION: Groundwater CONTACT: Colleen Winey/Ken Minn AGENDA DATE: January 21, 2026 SUBJECT: Update on the Regional Groundwater Facilities Improvement Project – Phase I Feasibility Study Results SUMMARY: •To support the Mission to deliver safe, reliable, efficient, and sustainable water, Zone 7 Water Agency (Zone 7) partnered with the City of Pleasanton to evaluate the feasibility of a Joint Regional Groundwater Facilities Project (the joint project) in the Bernal subbasin. This action supports Strategic Plan Goal B – Reliable Water Supply and Infrastructure, Goal C – Safe Water, and Goal D – Groundwater Management. It is also to implement Strategic Plan Initiative #5 – Develop a diversified water supply plan and implement supported projects and programs, Initiative #9 – Implement the PFAS Management Strategy, and Initiative #11 - Manage the Groundwater Sustainability Agency and implement the Groundwater Sustainability Plan. •Zone 7 has been exploring the Bernal subbasin to recover the groundwater production capacity, which has been reduced due to out-of-commission wells and per- and polyfluoroalkyl substances (PFAS) treatment process, and to meet projected future demands. The City of Pleasanton is also planning to install new groundwater wells to recover its annual groundwater pumping quota of 3,500 acre-feet. •If feasible, installing additional groundwater wells in the Bernal subbasin will enable Zone 7 to become more resilient to multi-year droughts by providing additional groundwater supply, operational flexibility, and redundancy, thereby increasing water supply reliability. The project could be upsized to accommodate Pleasanton’s groundwater pumping quota. •Developing a joint project with the City of Pleasanton will be mutually beneficial, as it will enable both parties to achieve significant cost savings through economies of scale, minimize the impact on the local community and environment, and gain operational efficiencies through centralized treatment. •Zone 7’s existing infrastructure, including the distribution system and the water treatment facilities at Hopyard well field, can be upgraded to make integrating new production wells to the existing system more cost-effective and efficient without the need to construct a new (non-PFAs) groundwater treatment facility. Groundwater treatment typically includes the addition of standard disinfectants. Page 24 of 80