On May 14, 2025, the U.S. Environmental Protection Agency announced via press release that it will reduce the scope of its April 10, 2024 National Primary Drinking Water Regulation to the two most prevalent per- and polyfluoroalkyl (PFAS) compounds, PFOA and PFOS, and extend the compliance timeline for public water systems by two years, from 2029 to 2031.

The 2024 Rule, which Kaplan Kirsch detailed here, required public drinking water providers nationwide to monitor public drinking water supplies for six PFAS compounds. If detections revealed concentrations above the new maximum contaminant levels (MCLs), providers would be required to treat drinking water supplies to meet the MCLs to protect public health. The 2024 Rule established MCLs of 4 parts per trillion (ppt) for PFOA and PFOS, individually, 10 ppt for PFNA, PFHxS, and PFPO-DA, and Hazard Index MCL of 1 for mixtures of PFHxS, PFNA, HFPO-DA, and PFBS.

Now EPA plans to retain the 2024 MCLs of 4 ppt for PFOA and PFOS, but halt regulation of the other four PFAS. EPA also plans to push back the compliance timeline by two years, allowing public water systems until 2031 to comply with the MCLs. The agency stated this was necessary to allow public water providers, especially in rural and small communities, to meet the new regulatory requirements, which in some cases require construction, installation, and operation of complex and costly treatment systems.

EPA intends to issue a proposed rule this fall and finalize it in the spring of 2026. It is clear from this announcement and another just weeks ago that EPA Administrator Lee Zeldin intends to move ahead with at least some actions to regulate PFAS during the Trump Administration.

For more information about PFAS, or how PFAS regulations or liability may impact your organization, please contact Thomas A. Bloomfield, Polly B. Jessen, Sara V. Mogharabi, or Timothy Roth.