On May 14, 2025, the United States Environmental Protection Agency ("EPA") announced that it will rescind the nationwide Maximum Contaminant Levels ("MCLs") for certain per- and polyfluoroalkyl substances ("PFAS") set by the agency in April 2024, with the exception of PFOA and PFOS. For those two chemicals, public water systems across the country will now have an additional two years to comply with the MCLs. In its announcement, EPA previewed the following anticipated actions related to the regulation of PFAS in drinking water:
- As noted above, the MCLs for PFOA and PFOS, two of the PFAS substances most regulated to date, will remain in place at 4 parts per trillion, although public water systems will now have an additional two years (until 2031, rather than 2029) to comply with these MCLs.
- EPA pledged to support the U.S. Department of Justice in "defending ongoing legal challenges" to the PFAS National Primary Drinking Water Regulation for PFOA and PFOS.
- The MCLs for four other PFAS — PFHxS, PFNA, PFBS, and HFPO-DA (commonly known as GenX) — along with the Hazard Index for combinations of these substances will be rescinded and possibly reconsidered.
- The agency is establishing a new technical assistance and outreach initiative for public water systems (in addition to continuing to offer the water technical assistance (WaterTA) service). EPA states that the new initiative, known as the PFAS OUTreach Initiative, or PFAS OUT, will prioritize outreach to public water systems in need of capital improvements to address PFAS impacts and will connect those utilities with "resources, tools, funding, and technical assistance" to position them to achieve compliance with the MCLs for PFOA and PFOS by the new deadline.
- The agency hinted at "holding polluters accountable" and prioritizing enforcement against industrial sources of PFAS contaminating public water supplies, noting that "the need for a polluter pays model has guided a lot of the work to be done at EPA in the future."
According to the agency's announcement, EPA plans to issue a proposed rule with respect to these changes to the PFAS MCLs in the fall and will finalize the rule in Spring 2026. For more information on PFAS chemicals and the regulatory and litigation risks that they pose, please visit our PFAS webpage.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
