On September 17, 2025, the U.S. Environmental Protection Agency (EPA) announced that it will continue to defend the agency's decision to list two per- and polyfluoroalkyl substances (PFAS) chemicals – perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) – as hazardous substances under the federal Superfund law. PFOA and PFOS were initially designated as hazardous substances under Section 102(a) of the Comprehensive Environmental Response Compensation, and Liability Act (CERCLA)[1] during the Biden administration in EPA's final rule entitled "Designation of Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic Acid (PFOS) as CERCLA Hazardous Substances" (Rule) issued on May 8, 2024.[2] The Rule became effective on July 8, 2024.
What You Need to Know:
- The EPA has decided to retain an existing Biden administration regulation designating two PFAS chemicals (PFOA and PFOS) as hazardous substances under the federal Superfund law, also known as CERCLA.
- Under the rule, entities must report releases of PFOA and PFOS exceeding certain thresholds and are subject to cleanup and other requirements applied to releases of other hazardous substances under CERCLA.
- The EPA also seeks input from Congress and industry groups on a liability framework aimed at holding polluters accountable while protecting passive receivers.
- Passive receivers are those who did not introduce PFAS into the environment, such as current property owners that do and did not use PFAS, wastewater treatment plants to the extent they receive PFAS-impacted influent, waste disposal facilities when receiving PFAS-impacted household waste, and drinking water suppliers with PFAS-impacted surface or groundwater supplies.
- The EPA intends to initiate future rulemaking to establish a uniform framework governing designation of hazardous substances under section 102(a) of CERCLA going forward.
This follows an announcement by the EPA on May 14, 2025, that the agency will keep the current National Primary Drinking Water Regulations (NPDWR) for PFOA and PFOS, which set nationwide limits for these "forever chemicals" in drinking water.
Once used in products such as nonstick cookware, stain-resistant fabrics, and firefighting foam, "forever chemicals" have been linked to cancers, impacts to the liver and heart, and immune and developmental damage to infants and children.
Under the Rule, entities are required to report releases of PFOA and PFOS that exceed certain thresholds. As with other CERCLA actions, the EPA can investigate and cleanup releases and require entities that leak, spill, or release such chemicals to file official reports. Federal and state governments and private parties can also sue in cost recovery or contribution actions, as is customary in CERCLA cases, to recover costs from potentially responsible parties.
The 2024 enforcement discretion relating to the Rule includes community water systems and publicly owned treatment works, municipal separate storm sewer systems, publicly owned or operated municipal solid waste landfills, publicly owned airports and local fire departments, and farms that apply biosolids to lands.
In November 2024, the U.S. Chamber of Commerce (Chamber) sought review of the Rule citing scientific and legal flaws in EPA's designation process for PFOA and PFOS under CERCLA section 102(a)."[3] In January 2025, the U.S. Department of Justice (DOJ) submitted a response on behalf of the EPA asking the court to deny the Chamber's petition for review of the Rule. In February 2025, the Court granted DOJ's motion to hold the case in abeyance pending the new EPA leadership's review of the Rule.
On September 17, 2025, the DOJ submitted a court filing on behalf of the EPA in this litigation. Consistent with EPA's announcement, in the filing, DOJ confirmed that the EPA intends to defend and retain the Rule designating PFOA and PFAS as hazardous substances. DOJ also moved the Court to lift the abeyance.
A Declaration of John Evans (Senior Advisor for Implementation in the EPA Office of Land and Emergency Management) appended to the September 17th filing notes that the EPA will continue its outreach to Congress and industry groups to establish a clear liability framework holding polluters accountable while at the same time protecting passive receivers that did not manufacture or generate PFOA or PFOS. This is an important consideration for owners of wells impacted by PFAS and anyone withdrawing surface or groundwater water contaminated with PFAS, including drinking water providers. They will want to pay close attention to regulatory and legislative developments as they evolve, including how the term "passive receiver" is formally defined by the EPA.
EPA will also be initiating future rulemaking to establish a uniform framework governing designation of hazardous substances under section 102(a) of CERCLA going forward. Through the framework, the agency aims to provide greater certainty for future designations. This may include how EPA considers the costs of proposed hazardous substance designations under CERCLA to manufacturers, passive receivers, consumers, and the economy at large.
The Environmental Group at Saul Ewing will track developments on the designation of PFAS as hazardous substances as they arise.
[1] Section 102(a) authorizes the EPA to "promulgate and revise as may be appropriate, regulations designating as hazardous substances . . . such elements, compounds, mixtures, solutions, and substances which, when released into the environment may present substantial danger to the public health or welfare or the environment . . . . " 42 U.S.C. § 9602(a).
[2] See "Designation of Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic Acid (PFOS) as CERCLA Hazardous Substances," 89 Fed. Reg. 39124 (May 8, 2024).
[3] Chamber of Commerce, et al. v. U.S. Envt'l Protection Agency, et al., No. 24-1193 (D.C. Cir. Nov. 4, 2024).
