October 3, 2026
Significant decisions have been released in recent months regarding the U.S. Environmental Protection Agency’s (EPA’s) use of federal cleanup laws to address perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)—the two most-studied compounds of the per- and polyfluoroalkyl substances (PFAS) chemicals class—as well as other PFAS.
Resource Conservation and Recovery Act Corrective Action Rule Withdrawal
On May 8, 2026, EPA withdrew its February 2024 rule proposing to amend its Resource Conservation and Recovery Act (RCRA) corrective action regulations to clarify that the statutory definition, rather than the regulatory definition, of “hazardous waste” applies to RCRA corrective action. The statutory hazardous waste definition is broader than the regulatory definition and would have provided for greater clarity for EPA to include PFAS (among other contaminants) in corrective action permits and orders for releases from solid waste management units at RCRA-permitted treatment, storage, and disposal facilities. The agency’s reasoning for the proposed rule was that it was intended to confirm the agency’s longstanding position that the broader, statutory definition of hazardous waste applies to RCRA corrective action.
In its withdrawal of the rule, the agency reasons that the rule is not necessary given the limited impact anticipated (i.e., most corrective action permits apply to regulatory hazardous wastes) and the fact that EPA and states have other legal mechanisms by which they can include statutory hazardous wastes in corrective action permits, namely under RCRA section 3005(c)(3) (the “omnibus” authority). Because existing regulations authorize the EPA to address certain statutory hazardous wastes in corrective action, the agency concluded that the proposed rule “would have complicated, rather than contributed to, efficient implementation of cleanup at hazardous waste facilities under [RCRA]” and the rule withdrawal would “[avoid] confusion.”
D.C. Circuit Decision Upholding EPA Superfund Designations for PFOA and PFOS
On August 18, 2026, the D.C. Circuit Court of Appeals unanimously denied a petition from industry groups challenging EPA’s April 2024 final rule designating PFOA and PFOA as “hazardous substances” under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund).
Hazardous substance designation triggers reporting requirements for leaks, spills, and other releases of PFOA, PFOS, or their salts or structural isomers under CERCLA sections 103 and 111(g) and section 304 of the Emergency Planning and Community Right-to-Know Act. This includes immediate notification to the National Response Center and state, tribal, and local emergency responders of PFOA and PFOS releases of one pound or greater within a 24-hour period. Further, EPA has greater authority to require investigation and cleanup of PFOA and PFOS releases and recover such costs from responsible parties.
Additionally, when federal property is transferred outside of federal ownership, the federal government must provide notice of PFOA or PFOS storage, release, or disposal on the property and commit to the cleanup of its PFOA and PFOS contamination in accordance with CERCLA § 120(h).
In June 2024, seven industry groups petitioned the D.C. Circuit to overturn EPA’s PFOA/PFOS hazardous substance designation. They argued that (1) the phrase “may present substantial danger” in the CERCLA “hazardous substance” definition requires EPA to find that harm would result from releases of PFOA or PFOS into the environment, and that (2) the agency’s decision to regulate in light of uncertainties and (3) its cost-benefit analysis were arbitrary and capricious under the Administrative Procedure Act. The Court’s August 2026 decision rejected all three claims and found that EPA’s PFOA and PFOS hazardous substance designation is supported by the record and the agency’s statutory authority.
Pending an appeal of the decision and any associated litigation outcomes, EPA’s hazardous substance designation of PFOA and PFOS under CERCLA remains intact. Parties subject to reporting requirements resulting from the designation should continue to comply with those requirements and parties potentially responsible for releases of PFOA or PFOS into the environment should assess their liability risk and potential impacts of the CERCLA designation on their sites and business operations.