CITY COUNCIL REGULAR MEETING AGENDA 9-15-26

26 Water Supply During Drought. The California Water Code asks agencies to evaluate their water service reliability by examining the impact of drought on their water supplies and comparing those reduced supplies to water demands. Specifically, agencies calculate their water supplies during a single dry year and five consecutive dry years using historical records. This water supply reliability assessment is documented within the City’s Urban Water Management Plan (UWMP), which is closely tied to Zone 7’s water supply reliability assessment. Under the City’s current 2025 UWMP, the water supply reliability assessment projects the City will have adequate supply to meet a single dry year and indicates Zone 7 is expected to have adequate supply reliability to meet the City’s current and projected demands through 2045. Furthermore, the analysis projects a potential small shortfall for Pleasanton (10 percent) in a five-year drought scenario beginning in 2045, specifically in the fifth consecutive year of drought. This shortfall is considered manageable through conservation measures consistent with the City’s Water Shortage Contingency Plan. Currently, the City does not project a water supply shortfall in the upcoming year. Regulatory Requirements General. The applicable drinking water standards for the Water System are set forth primarily in the California Code of Regulations, Title 22, Division 4, Chapter 15, Domestic Water Quality and Monitoring Regulations, together with other applicable state law requirements. These regulations implement California’s drinking water program in a manner consistent with, and at least as stringent as, applicable requirements of the U.S. Environmental Protection Agency under the federal Safe Drinking Water Act, originally enacted as Public Law 93-523. The regulations establish, among other things, monitoring and reporting requirements, sampling requirements, treatment requirements, and maximum contaminant levels for drinking water and are subject to periodic revision and amendment. The Water System reports required data to the State Water Resources Control Board, Division of Drinking Water, and provides its annual Consumer Confidence Report to customers each year. PFAS. In June 2019, City Well 8 was taken out of service after PFAS were detected above DDW advisory levels. In November 2022, Wells 5 and 6 were taken out of service after PFAS were detected above the revised DDW advisory levels. In 2024, USEPA laid out formal regulations for PFAS with the establishment of MCLs and allows water systems five years to comply. As a result, the City has lost the ability to utilize its groundwater production quota and is currently required to purchase 100 percent of its water supply from Zone 7. This leads to higher water supply costs, reduced diversification of local water supplies, and concerns about long- term reliability, particularly during drought conditions. To address these concerns, the City conducted a Water Supply Alternatives Study to assess multiple strategies including rehabilitating the City’s existing wells with PFAS treatment, developing new groundwater wells outside the PFAS plume, and continuing to rely entirely on purchased water from Zone 7. In October 2023, the City Council approved the study's recommendation to pursue development of new groundwater wells in the Bernal groundwater subbasin through the establishment of the City Groundwater Supply Project. Additional engineering studies were completed with Zone 7 to confirm the technical feasibility of building new groundwater wells in the Bernal groundwater subbasin and found that doing so in partnership would be beneficial to both agencies. In April 2026, the City Council approved proceeding with the implementation of the City Groundwater Supply project. Groundwater supply improvements would be implemented in partnership with Zone 7 and would include the development of two new groundwater production wells at Tennis and Community Park and Hansen Park, a new transmission pipeline connecting the wells to the Zone 7 Hopyard Chloramination Facility, and upgrades to the Zone 7 Hopyard Chloramination Page 236 of 318