State Water Board Sets Lower Notification & Response Levels for Some PFAS by ACWA Staff Oct 31, 2025 Water News SACRAMENTO — The State Water Resources Control Board’s Division of Drinking Water (DDW) has announced lower Drinking Water Notification and Response Levels for perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), and perfluorohexanoic acid (PFHxA). Notification and response levels are nonregulatory, health-based advisory levels established for contaminants in drinking water for which maximum contaminant levels have not been set. When chemicals are found at concentrations greater than their notification levels, certain requirements and recommendations apply. Where detected levels of PFOA and PFOS exceed the response level, water systems shall either (1) take the sources out of service immediately; (2) utilize treatment or blending; or (3) provide public notification of the response level exceedance within 30 days. The new notification and response levels for these four per- and polyfluoroalkyl substances (PFAS) are: PFOA: notification level = 4.0 ng/l, response level = 10 ng/l PFOS: notification level = 4.0 ng/l, response level = 40 ng/l PFHxS: notification level = 3.0 ng/l, response level = 10 ng/l PFHxA: notification level = 1.0 mg/l, response level = 10 mg/l More information with a link to a toolkit is available in an ACWA Advisory distributed Oct. 31. Member login is required.
