EPA announced on May 14, 2025 that it will maintain the Maximum Contaminant Level (“MCL”), also known as the national primary drinking water standard, for two PFAS, perfluorooctanoic acid (“PFOA”) and perfluorooctanesulfonic acid (“PFOS”), at 4 parts per trillion (“ppt”) but develop a rulemaking to extend the compliance deadline for these MCLs until 2031.  EPA also announced it intends to rescind the MCLs for PFHxS, PFNA, HFPO-DA (commonly known as GenX), and the Hazard Index mixture of these three plus PFBS and would reconsider the regulatory determinations for these four PFAS.  This will require a rulemaking process.  The announcement also indicated that EPA would “establish a federal exemption framework” but details were not provided.

EPA Administrator Zeldin stated that the agency “will work to provide common-sense flexibility in the form of additional time for compliance. This will support water systems across the country, including small systems in rural communities, as they work to address these contaminants.  EPA will also continue to use its regulatory and enforcement tools to hold polluters accountable.” 

The announcement noted that EPA plans to move forward with effluent limitations guidelines (ELGs) for PFAS and to develop “other tools to ensure that polluters are held responsible.” 

As we have previously reported, the MCLs, which were issued in April 2024, have been challenged by various organizations and the cases were consolidated and are pending in the U.S. Court of Appeals for the D.C. Circuit.  EPA had asked for and the court granted an abeyance in the suit to allow EPA’s new leadership time to review the rule.  With EPA’s new announcement, it confirmed that the agency will support the U.S. Department of Justice in defending the MCLs with respect to PFOA and PFOS.