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Figure 1. PFHxS Concentration in City Water Supply Wells 5 and 6 compared to new notification and response levels 3 ng/L and 20 ng/L respectively. Public Health Goals Report As a water purveyor, every three years the City must prepare a special report for the public_with information about water quality constituents detected in the drinking water and how they relate to State of California Public Health Goals (PHGs). PHGs are water quality goals established by the California Office of Environmental Health Hazard Assessment (OEHHA). A PHG is the level of chemical constituents in drinking water that does not pose a significant risk to health, and they are not regulatory standards. The OEHHA uses these constituents in health risk assessments and therefore keeping track of them is very important in assessing trends. In addition, State law requires that drinking water standards be set as close to the corresponding PHGs as is economically and technologically feasible. In some cases, it may not be feasible to set the drinking water standard at the same level as a PHG because the technology to treat the chemicals may not be available, or the cost of treatment may be excessive. The State must consider these factors when developing a drinking water standard. In the last three years, PHGs were exceeded for copper and uranium. While the potential health protection benefits or treating for copper and uranium are not clear, to install and operate a reverse osmosis system to remove copper and uranium would cost approximately $10.7 million/year for the life of the system. DISCUSSION PFHxS Health Advisory and City Water Well Operation On October 31, 2022, the City received a new Monitoring Order from DDW for PFHxS. The new order directs the City to monitor for PFHxS and comply with HSC 116378 if a water supply source exceeds the response level. Compliance with HSC 116378 requires the water source be taken out of use or provide public notification of the contamination within 30 days of the confirmed PFHxS detection. This order becomes effective the first quarter of 2023. PFHxS concentration in the City's remaining two water supply wells 5 and 6 exceeded the new notification and response levels, such that the City took wells 5 and 6 offline on November 2, 2022. Given this, the City will no longer be able to access its annual 3,500 Acre-Foot (AF) groundwater supply allotment, which means that the City will need to purchase water from Zone 7. Zone 7 has indicated that it can provide the additional water, initially through a short-term arrangement. Public Health Goals Report Under Section 116470(b) of the California Water Code, public water systems with more than 10,000 service connections (Pleasanton currently has approximately 22,000 service connections) that detect one or more constituents in drinking water that exceed the applicable PHGs must prepare a PHG report. In the report, the water provider is required to: Page 4 of 5