PFAS Observer
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 the other.
Hazardous Substance Listings
On September 17, 2025, EPA filed an unopposed motion to lift the EPA-requested abeyance in U.S. Chamber of Commerce v. EPA, No. 24-1193 (D.C. Cir. 2024), informing the Court that the Agency intends to keep in place the designations of PFOA and PFOS as hazardous substances under CERCLA. In a concurrent public statement, EPA confirmed that it will continue defending these designations in court and initiate a rulemaking to establish a uniform framework for future PFAS “hazardous substance” designations, including how costs will be considered.
The underlying litigation challenges the CERCLA designations as arbitrary and capricious on multiple grounds, including the alleged inadequacy of EPA’s regulatory impact analysis (discussed in detail in here). Given these arguments and the change in administration, many stakeholders anticipated that EPA would support rescission of the designations. The Agency’s recent filings, however, indicate that it intends to preserve them, signaling a continued commitment to maintaining PFOA and PFOS as hazardous substances.
On September 25, 2025, the D.C. Circuit granted EPA’s motion to lift the abeyance and set briefing to resume, with petitioners’ joint reply due November 14, 2025.
Maximum Contaminant Levels
Separately, on September 10, 2025, EPA filed a motion in American Water Works Association v. EPA, No. 24-1188 (D.C. Cir. 2024), seeking partial vacatur of certain elements of its April 2024 PFAS drinking water rule. That rule established maximum contaminant levels (MCLs) for six PFAS compounds: PFOA and PFOS, regulated individually, and PFHxS, PFNA, HFPO-DA (GenX) and certain mixtures, regulated collectively.
In May of 2025, however, EPA announced its intent to maintain its NPDWRs for PFOA and PFOS but withdraw the other four MCLs. During a July 2024 meeting of EPA’s National Drinking Water Advisory Council (NDWAC), the Agency indicated that by the end of 2025, it would propose a rulemaking to retain the MCLs for PFOA and PFOS but extend compliance deadlines to 2031. The September 10, 2025, motion is consistent with this announcement, as EPA requested that the Court vacate the MCLs for PFNA, PFHxS, HFPO-DA (GenX) and the combined Hazard Index for PFAS mixtures, while leaving the MCLs for PFOA and PFOS in place. Responses to the motion to vacate were filed; however, the case is currently stayed at EPA’s unopposed request in light of the lapse in federal appropriations.
The Unified Regulatory Agenda Indicates a More Comprehensive Regulatory Approach
EPA’s September 2025 Unified Regulatory Agenda further illustrates the Agency’s sustained yet more selective focus on PFAS regulation. Several pending and planned rulemakings indicate continued PFAS-focused regulatory activities from EPA, including:
- Clean Water Act Permitting. EPA is considering updates to PFAS-related requirements in National Pollutant Discharge Elimination System (NPDES) permits for sewage effluent treatment facilities. Currently, permit applicants are only required to report discharges of certain pollutants listed in existing regulations. (See 40 CFR 122.21.) A future rulemaking could add certain PFAS compounds to this list, though EPA has acknowledged that there are no currently approved analytical methods for PFAS in NPDES permitting.
The Agency anticipates a proposed rule by the end of 2025 and finalizing updates in 2027.
- Effluent Limitation Guidelines (ELGs). EPA is also considering ELGs for organic chemicals, plastics and synthetic fibers to address discharges from facilities at which PFAS are manufactured. ELGs set industry-specific wastewater standards based on the performance of the best available, economically achievable technology. Facilities are not required to use the specific technology EPA identifies in setting the limits, but they must meet the resulting discharge limits.
EPA first signaled its intent to revisit PFAS-related ELGs in its 2023 Effluent Guidelines Program Plan 15, which outlines the Agency’s strategy for reducing water pollution. In that plan, EPA noted that landfill ELGs should be revised to account for PFAS in landfill leachate. The September 2025 Unified Agenda indicates that a proposed ELG rulemaking is anticipated in 2026.
- TSCA Reporting Rule. EPA intends to revise the scope of the PFAS Reporting Rule under Section 8(a)(7) of the Toxic Substances Control Act (TSCA). The TSCA PFAS Reporting Rule creates a potentially time-consuming and onerous reporting obligation for any PFAS, including the importation of any PFAS incorporated within mixtures and articles. EPA has already moved to delay the PFAS Reporting Rule twice, with the required data submission window now set to open for most manufacturers on April 13, 2026, and close on October 13, 2026.
The Unified Agenda provides that “EPA plans to propose the incorporation of certain exemptions and other modifications to the scope of the reporting rule.” A proposed rule on this issue may be released by the end of 2025.
- Sixth Unregulated Contaminant Monitoring Rule (UCMR 6). The UCMR provides a mechanism for EPA to collect data regarding impacts to public water systems from “emerging contaminants,” for which the SDWA does not otherwise require sampling and mitigation. Both UCMRs 3 and 5 included PFAS among the 30 chemicals for which each rule required sampling. Although it is still unclear whether UCMR 6 will do so as well, several entities that responded to the request for comments on this rule—published in the Federal Register on February 8, 2024—advocated that PFAS be included within the sampling suite of chemicals.
Looking Ahead
Collectively, these actions indicate EPA’s apparent commitment to continuing to regulate PFAS, albeit with some targeted relaxations of regulatory requirements established under the Biden administration. Companies may find it worthwhile to stay abreast of any such developments in the fluid legal landscape involving PFAS. Pillsbury’s PFAS Task Force is monitoring these developments and assisting clients with compliance, litigation strategy and risk management amid this shifting regulatory environment.