EPA Proposes Changes to PFAS Drinking Water Rules, Extends Key Deadlines

EPA proposed major amendments to federal PFAS drinking water regulations on May 18, 2026.

On May 18, 2026, the U.S. Environmental Protection Agency (EPA) introduced two significant updates to federal regulations on per- and polyfluoroalkyl substances (PFAS) in drinking water.

• The first proposal would rescind regulatory determinations and drinking water requirements for four PFAS compounds: perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), hexafluoropropylene oxide dimer acid (HFPO-DA, also known as GenX), and certain mixtures including perfluorobutane sulfonic acid (PFBS). The agency cites procedural errors as the reason and pledged to revisit these compounds "the right way."
• The second proposal would extend the compliance deadline for water systems meeting standards for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) by up to two years, from April 2029 to April 2031, for systems that request additional time.
• The EPA maintains that monitoring and reporting deadlines under the April 2024 rule are unchanged. Administrator Lee Zeldin emphasized that science backing limits for PFOA and PFOS is among the strongest for any regulated contaminant, and that these actions are about making the standard "workable, not weaker."
• A virtual public hearing on the proposed changes is set for July 7, 2026.

To aid compliance and mitigation, the EPA announced nearly $1 billion in grant funding for small or disadvantaged communities under the Emerging Contaminants Grant program.

Legal and compliance professionals should track final regulation timing and requirements as industries adjust to evolving federal PFAS standards.

Yes, but: Criteria for water systems to qualify for the extension and the timeline for reevaluating the rescinded PFAS are not detailed.

What's next: EPA will hold a virtual public hearing on July 7, 2026, to discuss the proposed amendments.