SCH Number 2023020344

Project Info

Title

Groundwater PFAS Treatment Facility

Description

Alameda County Water District (ACWD) blends local groundwater with purchased water from the San Francisco Public Utilities Commission (SF PUC) at ACWD's Blending Facility in Fremont, California. The groundwater is from ACWD's onsite Peralta-Tyson (PT) wellfield and the nearby Mowry wellfield, which each have eight production wells (total 16). The groundwater is blended with low-hardness SFPUC water to meet ACWD's hardness goals. Per- and Polyfluoroalkyl Substances (PFAS) have recently been detected in the Mowry and PT production wells. The California State Water Resources Control Board's Division of Drinking Water (DDW) has established notification levels (NLs) and response levels (RLs) for four PFAS: perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorobutanesulfonic acid (PFBS), and perfluoroctanesulfonic acid (PFHxS). California regulatory standards for PFAS are expected in the future, including NLs and RLs for PFAS and maximum contaminant levels (MCLs) for a class of PFAS including PFOA and PFOS. Additionally, a federal MCL for PFOA and PFOS is expected in 2023. While the Blending Facility has a capacity of 48 million gallons per day (MGD), current groundwater production is limited by hardness and PFAS goals. Meeting a 150-milligrams per liter hardness goal limits production to 32 to 36 MGD, while achieving a PFOS concentration below the NL further limits production to 22 to 24 MGD. Achieving the PFHxS NL would further limit the production to approximately 18 MGD.

2 documents in project