PFAS Policies and Reductions in Drinking Water Contamination Across the United States: Incorporated Policy Perspectives from Los Angeles Residents

Many U.S. states have adopted per- and polyfluoroalkyl substances (PFAS)-related policies, but evidence on whether these actions reduce detections in drinking water is limited.

We conducted a nationwide analysis of the EPA Unregulated Contaminant Monitoring Rule (UCMR) and a community study in Los Angeles (LA). State-wide PFAS policies correlated with PFAS detections in public water systems (n = 56,856) using UCMR3 (2013-2015) and UCMR5 (2023-2025) for six PFAS (PFBS, PFHpA, PFHxS, PFNA, PFOA, PFOS). We examined associations between detections or changes in detections and two metrics: (1) total PFAS policy counts and (2) the proportion of water-related PFAS policies. In LA, we conducted focus groups/interviews (n = 29) and tested a 55-PFAS panel in household tap water (n = 23; Pasadena/Torrance n = 9; Central/Southeast LA n = 14).

Total policy counts were not associated with lower PFAS detection in UCMR5, except for a borderline reduction in PFBS (β = -0.0003, p = 0.06). A higher proportion of water-focused policies was associated with increased odds of PFAS detection, with significant associations for PFBS (OR = 3.79, 95% CI: 2.83-5.10), PFHpA (2.66, 1.64-4.33), PFHxS (3.10, 2.10-4.62), and PFOS (3.37, 2.41-4.71). Similar results were observed for changes in detection. In LA, residents reported distrust in tap water, low PFAS awareness, and emphasized independent testing, subsidized filtration, and clearer communication.

Greater concentrations of water-focused policies were linked to increased PFAS detections, likely reflecting enhanced surveillance or responses in high-burden states. Community perspectives highlight that policy also requires trust, transparency, and resources.