On August 18, the D.C. Circuit denied every petition for review in Chamber of Commerce v. EPA, upholding EPA's 2024 rule designating PFOA (perfluorooctanoic acid) and PFOS (perfluorooctanesulfonic acid) as hazardous substances under CERCLA, the Comprehensive Environmental Response, Compensation, and Liability Act. For most of the industry, this ruling does not change your day-to-day obligations, because the designation has been enforceable since July 8, 2024 and never stopped applying while the case worked through the courts. What the decision does is resolve the question that has been open since petitioners first filed: this court will not nullify the rule. Further appeal, a petition for rehearing or a petition to the Supreme Court, remains technically available, but the D.C. Circuit has now rejected every argument the industry raised, and that is significant because it confirms EPA's authority to use this same tool again on other PFAS or other chemicals entirely.

What the court decided

The petitioners, a coalition of seven industry groups led by the Chamber of Commerce, raised three arguments: that EPA misread CERCLA's "may present substantial danger" standard, that EPA failed to give adequate notice of its cost-benefit analysis under the Administrative Procedure Act, and that the analysis itself was arbitrary and capricious. A unanimous three-judge panel rejected all three. On the statutory question, the court applied the post-Loper Bright standard of independent review and still landed on EPA's side, reading "may" to require only a scientifically possible substantial danger, not a certainty. The court found the Regulatory Impact Analysis was a logical outgrowth of EPA's earlier Economic Assessment, so industry had adequate notice under the APA, and separately upheld the substance of EPA's cost-benefit numbers under the deferential arbitrary-and-capricious standard. This was the first appellate test of EPA's authority to designate hazardous substances under CERCLA Section 102(a), so the reasoning here will shape how far that authority extends the next time EPA reaches for it, PFAS or otherwise.

What it means if you are a Primary Responsible Party

The practical exposure has not moved. Parties responsible for a release of more than one pound of PFOA or PFOS still have to report it under CERCLA Section 103 (42 U.S.C. Section 9603). EPA can still compel a responsible party to lead a cleanup under Section 106 (42 U.S.C. Section 9606), and the federal government, states, or private parties can still pursue cost recovery under Section 107 (42 U.S.C. Section 9607). The opinion adds useful context for how that exposure actually plays out in practice. The court spent time explaining that designation does not equal automatic liability, pointing out that EPA has placed only about 3% of the 53,400 sites it has assessed since 1980 onto the National Priorities List (NPL), and that CERCLA's built-in defenses, including de minimis and de micromis protections, third-party and act-of-God defenses, and the innocent landowner exemption, remain fully intact.

That 3% figure describes the remedial action track only, the long-term cleanup process that is tied to NPL listing. It says nothing about removal actions, the shorter emergency-response cleanups that operate independent of the list, or about Section 106 orders, which EPA can issue at any site with a hazardous substance release regardless of NPL status. EPA's own guidance on the designation confirms sites can be addressed through the Superfund Alternative Approach, an EPA removal action, deferral to another program, or other enforcement mechanisms even when a site would otherwise qualify for listing. Its cost modeling for the rule built in enforcement action at 67 non-NPL sites drawn from a pool of 133 identified as having elevated PFOA and PFOS contamination likelihood. Skipping the list does not mean skipping CERCLA.

States add a layer that ignores NPL status entirely. Section 114 of CERCLA preserves state authority to impose additional liability or cleanup requirements within their own borders, and many states run their own mini-Superfund cleanup programs alongside whatever the federal designation does. EPA left the cost of state-led enforcement out of its own Regulatory Impact Analysis, citing uncertainty over when and how aggressively states will act on their own. A site with no federal NPL history can still be sitting under an active state cleanup order today.

None of this settles liability in either direction. A low NPL rate does not mean a site is safe, because removal actions, Section 106 orders, and independent state authority can all create exposure without a listing ever entering the picture. The available defenses do not mean a site is safe either, because they are fact-specific and have to be established on the record, not assumed from the fact that they exist in the statute. The right response to all of this is the same for every legacy site: with counsel, work through the actual facts, the applicable defenses, and whichever enforcement mechanism is actually in play.

What it means if you are a passive receiver

Those same defenses do not currently do much for a category of parties who never manufactured or profited from PFOA and PFOS but ended up handling them anyway: water and wastewater utilities that received PFAS-laden influent, landfills and compost facilities that accepted PFAS-containing waste streams, fire departments and airports that used AFFF under a federal mandate, and farmers who land-applied biosolids under a state or federal permit. A group called Passive Receivers filed an amicus brief in this exact case asking the court to remand the rule on their behalf. The court denied that request along with everything else, which closes the judicial path to a passive receiver carve-out and leaves Congress as the only route left.

Senator Pete Ricketts filed that kind of carve-out as SA 6429, a floor amendment to the fiscal year 2027 National Defense Authorization Act (S. 4784), on June 24. The amendment would bar CERCLA cost recovery and cleanup-compulsion actions against fire suppression entities, resource management entities such as landfills and compost facilities, airport sponsors, and water or wastewater entities, along with a separate and unconditional exemption for agricultural producers, so long as each party's handling of PFAS was lawful and permitted at the time it occurred. Water utilities would be covered for biosolids management under Clean Water Act Section 405, permitted effluent discharge under Section 402, and disposal of treatment residuals like spent granular activated carbon and filter media. Every exemption except the agricultural one comes with a five-year sunset on continued AFFF use once updated engineering standards no longer require it, and none of them protect a party that acted with gross negligence or willful misconduct. As of this filing, the amendment had been ordered to lie on the table, which is a routine procedural step that keeps it available for later floor action rather than a sign it was rejected. Its status will keep moving through the NDAA process, so confirm where it stands before you rely on it in client conversations.

The bottom line

The designation is no longer in legal doubt. The reporting and cost-recovery framework under Sections 103, 106, and 107 remains fully in force, and this ruling closes the door on the argument that opened the question in the first place. What's still unresolved isn't the rule. It's whether Congress gives passive receivers the exemption the courts just told them they won't get. PRPs and passive receivers alike should be evaluating legacy site risk now, because the rule is settled and the relief some of you are hoping for is not.