On 14 May 2025, Environmental Protection Agency (EPA) Administrator Lee Zeldin announced the agency’s plan to address the National Primary Drinking Water Regulations (NPDWR) for per- and polyfluoroalkyl substances (PFAS) finalized last spring, as discussed in our prior alert (22 April 2024). Administrator Zeldin announced that the agency would continue to defend the “maximum contaminant levels” (MCLs) for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) of 4 ppt, but would propose regulations intended to withdraw MCLs for four additional PFAS that were included in the NPDWR: perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), hexafluoropropylene oxide dimer acid (HFPO-DA, commonly known as GenX), and perfluorobutane sulfonic acid (PFBS). EPA is expected to reconsider the regulatory determinations for these four PFAS, which are found in various products, including water or stain protectants and surface coatings for fabrics, including carpets and rugs, as well as fire-fighting foams. Though EPA will still need to officially act on the recission, water systems are expected to still need to comply with PFOA and PFOS MCLs at 4 ppt, which will be extremely costly.

Last week’s development follows Administrator Zeldin’s 28 April 2025 announcement, discussed in our prior alert, that EPA would address “the most significant compliance challenges” under the final NPDWR published last year. In line with that statement, EPA plans to propose regulations to extend the deadline for MCL compliance from 2029 to 2031, establish a federal exemption framework, and conduct increased outreach to water systems.  EPA also committed to supporting the US Department of Justice in defending ongoing legal challenges to the NPDWR with respect to PFOA and PFOS. These challenges have been stayed in federal appellate court while EPA’s new leadership considered its path forward with the NPDWR.

EPA also appears to be prioritizing “holding polluters accountable” and protecting drinking water systems as passive receivers of PFOA and PFOS through reduction of PFAS sources in the environment. How they plan to do so is one of many open questions surrounding PFAS regulation under the new administration, including withdrawing the regulation designating certain PFAS compounds as Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) hazardous substances, which is still under EPA consideration. However, while the developments last week—including EPA’s announcement pushing back the Toxic Substances Control Act (TSCA) 8(a)(7) PFAS reporting period from 11 July 2025 to 13 April 2026, with a new submission deadline of 13 October 2026—signals some rollback, PFAS remains an active issue in the new administration.