California

California has been one of the most active states on PFAS, although it has not set enforceable drinking water MCLs at the state level. The California State Water Resources Control Board, through its Division of Drinking Water, has published notification levels and response levels that require utilities to act when certain thresholds are met. The notification levels include 5.1 parts per trillion for PFOA and 6.5 parts per trillion for PFOS, both stricter than the federal MCLs of 4 parts per trillion finalized in April 2024 but advisory rather than enforceable.

The California legislature has passed several product-level PFAS laws. AB 1200, signed in 2021, banned intentionally added PFAS in food packaging beginning in 2023. AB 652 restricted PFAS in products intended for children. AB 1817 banned PFAS in textiles starting in 2025. SB 903, introduced in 2024, proposed eliminating PFAS in most consumer products by 2030, and elements of it have advanced through committee.

State records show the Division of Drinking Water has required hundreds of California utilities to sample for PFAS beyond the federal UCMR 5 list, and the state has published source water sampling results on an interactive public dashboard. Several California cities have shut down contaminated wells and brought treatment online following detections.

Litigation has been active, with the California Attorney General joining multistate actions against 3M, DuPont, and other manufacturers. Separately, the state has investigated PFAS contamination from landfill leachate in the Chiquita Canyon area north of Los Angeles. Water systems in California are subject to the federal compliance timeline requiring initial monitoring by 2027 and treatment installation by 2029, in addition to the state notification level framework.