Practice Areas
USEPA Proposes Much Anticipated Rules to Rescind Certain PFAS Drinking Water MCLs and Extend the Compliance Deadline for PFOA and PFOS
After a year-long wait, the U.S. Environmental Protection Agency recently published two separate rules that would (1) rescind the maximum contaminant levels (MCLs) established by EPA during the Biden Administration for three PFAS compounds and a mixture of PFAS compounds; and (2) extend the compliance deadline for the two PFAS MCLs (PFOA and PFOS) that the Trump EPA intends to keep in place. Each proposed rule is briefly discussed below and links to the Federal Register Notices are available here and here:
First, with respect to the MCL recission, EPA proposed rescinding the regulatory determinations and enforceable drinking water standards for PFHxS, PFNA, GenX, and hazard index mixtures containing those chemicals plus PFBS. In proposing to rescind these four PFAS MCLs, EPA does not attack the science relied upon by the Biden Administration to establish the MCLs. Instead, the Trump EPA states that the Biden EPA did not follow procedural requirements and that the rules could therefore be vulnerable to court challenges. Specifically, the 2024 rulemaking did not follow the sequential process established in the Safe Drinking Water Act and did not provide the public with an adequate opportunity to comment. EPA signaled their intent to restart the regulatory process for those same PFAS chemicals using the appropriate process at some point in the future. EPA’s proposal to rescind the four PFAS MCLs does not impact the MCLs for PFOA and PFOS (4 parts per trillion), which were established in the April 2024 National Primary Drinking Water Regulation. The Trump EPA will continue to defend the PFOA and PFOS MCLs against an industry challenge.
Second, EPA proposed extending the compliance deadline for the PFOA and PFOS MCLs from April 26, 2029, until April 26, 2031, and establish a “federal exemption framework” for certain water systems facing challenges such as economic hardship or lack of alternative water sources.
All monitoring and reporting deadlines for PFOA and PFOS remain in place, however, the proposed rule will extend compliance deadlines for drinking water systems from 2029 to 2031 if utilities request additional time and meet specific criteria. In addition, EPA has announced nearly $1 billion in funding through the Emerging Contaminants in Small or Disadvantaged Communities Grant to help small and rural public water systems address PFAS and other emerging contaminants.
The proposed MCL recission and compliance-extension rules are currently open for public comment until July 20, 2026. EPA has also scheduled a public hearing for July 7, 2026.
