Zone 7 Meeting - September 17, 2025

Director Benson moved to approve the minutes of the regular Board meeting held on August 20, 2025. The motion was seconded by Director Palmer and approved unanimously by a voice vote of 7-0.

Item 8 -

8. Consent Calendar

Under Item 8d, the Board considered the official appointment of the Board Secretary. Director Benson commended Donna Fabian for her dedication and contributions, noting it was an honor for the Board to take this action and expressing appreciation for her continued support and professionalism. Director Gambs agreed, adding that the Agency is fortunate to have Ms. Fabian in this role, praising her problem-solving skills, work ethic, and professionalism. Director Green also thanked Ms. Fabian for her service, recognizing her efforts in keeping the Board organized and on track.

Director Benson moved to approve Consent Calendar Items 8a through 8d. The motion was seconded by Director Gambs and approved by a roll call vote of 7-0.

Item 9 -

9. Livermore Valley Hydrogeological Investigations and Groundwater Model Update >

Ken Minn, Water Resources Manager, introduced the item and emphasized its importance in supporting the Agency's strategic goals related to water supply diversification, PFAS management, and sustainable groundwater management. He explained that the Agency's existing groundwater model, developed nearly ten years ago, required refinement to incorporate new data and advanced methodologies. The update aimed to define basin characteristics more accurately, minimize assumptions on hydrogeology, and develop a more accurate conceptual model of the basin. He noted that the Department of Water Resources had previously recommended expanding the model to cover the entire basin, including upland fringe areas not captured in earlier versions.

Consultants Aaron Lewis, lead hydrogeologist and project manager, and Anona Dutton, Vice President and Director of Water Resources at EKI Environment & Water, attended. Mr. Lewis presented the findings of the two-year project. He described the field investigations conducted to fill data gaps, including aquifer pumping tests and geophysical surveys, which helped refine the understanding of aquifer properties, connectivity, and recharge mechanisms. These data, along with decades of Zone 7 monitoring information, were integrated into a three-dimensional geologic model using Leapfrog software. The model incorporated more than 1,000 boreholes, multiple geophysical datasets, and historical cross-sections to create a detailed stratigraphic framework of the basin.

Mr. Lewis reported that the updated model significantly improves upon the 2016 version by extending coverage through water year 2023, expanding the model boundaries to the full basin, refining grid cell size in production areas, and directly representing surface water features and lakes. Hydraulic properties are now informed by empirical data rather than uniform assumptions, resulting in a well-calibrated model that meets or exceeds industry standards. He emphasized that the model can now reliably simulate groundwater levels, streamflow, and water quality trends, and provides a robust tool for forecasting future conditions under varying hydrologic and operational scenarios.

Directors asked questions regarding the representation of faults, the value of pumping tests, the potential for barriers or subsidence, and outstanding data gaps. Mr. Lewis explained that while faults were not explicitly included in the model, geologic variability was represented through stratigraphy and aquifer properties, and no significant hydraulic barriers or faults had been observed during field investigations. He acknowledged that uncertainties remain, particularly regarding the northern extent of the basin, but overall the updated model reflects the most comprehensive understanding to date such as it integrated electrical resistivity logs, geophysical data, aerial electromagnetic data and pumping test data. Directors also discussed recharge potential in the Chain of Lakes, basin boundaries, and the model's value in guiding long-term drought planning and SGMA compliance.

President Narum asked about recalibration frequency, and Mr. Lewis recommended reviewing the model every five years and updating it with new data as needed.

Mr. Minn then explained how staff applied the model to evaluate the Regional Groundwater Facility project in partnership with the City of Pleasanton. Various scenarios were tested, including maximum pumping at potential new well sites and implementing PFAS management strategies. The model confirmed that the basin would remain sustainable under these scenarios, with no significant interference to other basin users such as SFPUC or the Alameda County Fairgrounds. PFAS mobilization was also analyzed, and results indicated that concentrations would not exceed the USEPA's maximum contaminant level, with wells designed and operated to sustainably manage the groundwater basin.

Directors discussed the PFAS modeling, the influence of pumping on plume behavior, and the importance of continued monitoring.

Public comment was received from Pleasanton resident Jim Lehrman.

Mr. Minn concluded that the study demonstrated the basin's sustainability, the effectiveness of Zone 7's PFAS management strategy, and the viability of pursuing new regional wells. He noted that the next step would be completing the feasibility study and returning to the Board in November with recommendations on cost allocation between Pleasanton and Zone 7, schedules, and developing production wells, pipeline and treatment facility upgrade.

Item 10 -

10. Declaration of Flood Preparedness Week: October 18-25, 2025 >

Ms. Pryor presented the annual resolution to declare October as Flood Preparedness Week, noting this is the 13th year of the statewide event in partnership with the Department of Water Resources. She highlighted Zone 7's digital outreach campaign featuring the Flood Ready Freddy videos, additional social media posts, and the upcoming in-person "Water Wonders of Zone 7" Open House on Saturday, October 18, from 10:00 a.m. to 2:00 p.m., which will include information on water supply and reliability, with an emphasis on flood preparedness.

Director Gambs moved to adopt the resolution, seconded by Director Green. The motion passed by a roll call vote of 7-0.

Item 11 -

11. Committees

There were no Board comments on the Legislative, Water Resources, and Finance Committee meeting notes.

Item 12 -

12. Reports - Directors

President Narum reported attending, along with Director Green, a workshop with the Pleasanton City Council and Planning Commission regarding the Chain of Lakes. She emphasized the importance of protecting groundwater quality and noted that recreational uses such as kayaking and fishing were discussed. President Narum added that the key outcome was that the City Council, Planning Commission, City Manager, and property owner all heard the same information.

Director Palmer reported that ACWA is continuing its Executive Director search, with findings expected at the upcoming board meeting. She also attended the Alameda County Special Districts Association (ACSDA) meeting on September 10 at CVSan, which included a Brown Act review, discussion on handling hate speech during meetings, and a tour of CVSan's new office. She encouraged Board members interested in leadership opportunities and certificates to explore ACSDA programs. She also noted the ACSDA annual dinner fee increase to $75 and highlighted upcoming events: the ACWA Region 5 event at SFPUC on September 25-26, the ACWA Region 2 tour, and the Water Education Foundation's Water Summit on October 1, 2025.

Item 13 -

13. Items for Future Agenda

No items were requested for consideration at a future Board meeting.

Item 14 -

14. Staff Reports

There were no comments or questions on any staff reports.

Item 15 -

15. Adjournment

President Narum adjourned the meeting at 9:14 p.m.

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Zone 7 Meeting - September 17, 2025

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