PFAS Observer
On May 14, 2025, EPA announced its intent to rescind the national drinking water standards for hexafluoropropylene oxide dimer acid (HFPO-DA or GenX), perfluorononanoate (PFNA), and perfluorohexanesulfonic acid (PFHxS), as well as the hazard index used to evaluate the combined risk of those compounds and perfluorobutane sulfonic acid (PFBS). These Maximum Contaminant Levels (MCLs) were finalized in April 2024 under the prior administration. EPA says it will reconsider the regulatory determinations “to ensure that the determinations and any resulting drinking water regulation follow the legal process laid out in the Safe Drinking Water Act” (SDWA).
While withdrawing the limitations for these PFAS, EPA announced that it will preserve the MCLs for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). However, EPA plans to extend the compliance deadline for public water systems from 2029 to 2031, providing a seven-year implementation window from the date the standards were finalized. EPA also confirmed that it will support the Department of Justice in defending the SDWA rule in American Water Works Association v. EPA, No. 24-1188 (D.C. Cir. 2024), but only as to the MCLs for PFOA and PFOS. That case is currently stayed until June 4, 2024 on EPA’s request for additional time for the new Administration to review the rule.
The decision to retain the PFOA and PFOS standards may reflect a degree of continuity from Administrator Zeldin, who, during his time in Congress, supported PFAS regulation, co-founded the bipartisan PFAS Congressional Task Force, and voted for the PFAS Action Act of 2021.
EPA expects to issue a proposed rule revising the remaining PFAS standards in Fall 2025, with final action anticipated by Spring 2026.