NOTICE: Proposed revised notification and/or response levels for PFOA, PFOS, PFHxS and proposed notification and response level for PFHxA

From the State Water Resources Control Board:

The State Water Board’s Division of Drinking Water (Division) is proposing:

  • A revised notification level of 4 parts per trillion (ppt) for perfluorooctanoic acid (PFOA).
  • A revised notification level of 4 ppt for perfluorooctane sulfonate (PFOS).
  • A revised response level of 10 ppt (based on a running annual average) for perfluorohexane sulfonic acid (PFHxS).
  • A notification level of 1 part per billion (ppb) and a response level of 10 ppb (based on a running annual average) for perfluorohexanoic acid (PFHxA).

All proposed levels are based on recommendations from the Office of Environmental Health Hazard Assessment (OEHHA), which included review of more than one peer reviewed study.

The informational item on the proposed is planned for the State Water Board’s August 6, 2025 meeting.

The proposed notification and response levels, the OEHHA recommendations, and links to the studies are available at the Division’s website at https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/NotificationLevels.html.