On August 18, 2026, a unanimous panel of the U.S. Court of Appeals for the D.C. Circuit upheld the 2024 designation by the U.S. Environmental Protection Agency (EPA) of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund). (See Chamber of Commerce of the United States of America, et al. v. EPA, No. 24-1193 (D.C. Cir. Aug. 18, 2026).)
The U.S. Environmental Protection Agency (EPA) has proposed major amendments to the 2024 National Primary Drinking Water Regulations (NPDWR) for per- and polyfluoroalkyl substances (PFAS) in the form of two proposed rules published on May 20, 2026. The proposals would extend compliance deadlines while preserving enforceable limits for two PFAS compounds, PFOA and PFOS, and rescind drinking water standards for four additional PFAS compounds.
In “EPA Proposes Major Changes to PFAS Drinking Water Rule,” Cara M. MacDonald and our PFAS team explain why the proposals mark a significant shift from the Biden administration’s April 2024 PFAS National Primary Drinking Water Regulation, which established nationwide enforceable standards for drinking water for six PFAS compounds.
The Safe Drinking Water Act (SDWA) is the primary federal law that protects drinking water quality and authorizes the EPA to promulgate regulations to limit harmful contaminants in public water systems. Under § 1412(b)(1)(B)(i) of the SDWA, the U.S. Environmental Protection Agency (EPA) must publish a Contaminant Candidate List (CCL) every five years identifying emerging contaminants that are not yet subject to a Maximum Contaminant Level (MCL) but that may pose a public health risk. CCLs are the first step in the SDWA regulatory process and are used to drive research into the listed contaminants to better understand health impacts, occurrence data, and risk levels. The CCL process is used to inform future regulatory action but does not impose any regulatory requirements in itself.
There has been a flurry of recent federal activity regarding PFAS on the part of the U.S. Environmental Protection Agency (EPA). EPA has doubled down on certain regulatory fronts, defending key hazardous substance designations for PFOA and PFOS, while simultaneously scaling back certain PFAS drinking water limits. These developments, together with EPA’s latest Unified Regulatory Agenda, reveal a more targeted approach to PFAS regulation in certain respects while, on the whole, continuing the march toward increased governmental obligations.
On June 5, 2025, the U.S. Court of Appeals for the D.C. Circuit granted the EPA’s third request to continue holding in abeyance consolidated litigation challenging the agency’s national drinking water regulation for six per- and polyfluoroalkyl substances (PFAS), including PFOA and PFOS. The court’s order in American Water Works Association, et al. v. EPA, No. 24-1188, gives the agency until July 21, 2025, to advise the court how it intends to proceed.
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).
On May 12, 2025, EPA announced that it will again revise the reporting timeline for manufacturers of per- and polyfluoroalkyl substances (PFAS) under Section 8(a)(7) of the Toxic Substances Control Act (TSCA). The data submission window will now open on April 13, 2026 and close on October 13, 2026, replacing the previous window of July 11, 2025 to January 11, 2026. For small manufacturers reporting exclusively as article importers, EPA’s interim final rule provides an alterative end date of April 13, 2027—a change consistent with Administrator Zeldin’s call to not “overburden[] small businesses and article importers.”
While the Trump administration’s PFAS policy framework is beginning to take shape, uncertainties remain across the regulatory, litigation and legislative fronts. On April 28, EPA Administrator Lee Zeldin announced a set of PFAS-related actions outlining a coordinated regulatory approach to addressing PFAS contamination. However, the Agency’s only two finalized PFAS rules—both issued during the Biden administration—remain stayed in federal court, and it still unclear whether the current Administration will defend, revise or withdraw them. At the same time, congressional interest appears to be intensifying. On May 1, a bipartisan PFAS Task Force was relaunched in the House of Representatives, signaling renewed legislative focus on PFAS policy.
On April 10, 2025, at the request of the Environmental Protection Agency (EPA), the U.S. Court of Appeals for the District of Columbia Circuit extended the stay by 30 days in American Water Works Association, et al. v. EPA, No. 24-1188 (D.C. Cir. 2024) to give new leadership time to evaluate the maximum contaminant levels (MCLs) established for six PFAS under the Safe Drinking Water Act. 89 Fed. Reg. at 32,532-33; 40 C.F.R. §§ 141.900-905. The court had previously granted EPA’s February 7 request for a 60-day stay to allow for initial review of the rule. The EPA has until May 12, 2025, to file future motions in the MCL challenge.
Recently, Congress allocated approximately $17 million in EPA’s fiscal year 2025 budget to modernize outdated technical systems and accelerate chemical reviews which may help resolve ongoing concerns about the functionality and security of the agency’s Central Data Exchange (CDX), a key platform supporting the TSCA program (Sec. 1801(7) of H.R. 1968).
PFAS Observer