CERCLA Contribution and Cost-Recovery Exposure for Stormwater Facilities Handling PFAS

The Bottom Line

Stormwater facilities face real but uneven Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) exposure for PFOA and PFOS. The U.S. Environmental Protection Agency (EPA) has signaled it will not enforce against “passive receivers,” but that policy has two critical limits: it is discretionary, meaning it can be withdrawn at any time, and it does not block private-party cost-recovery or contribution claims. No court has recognized a passive-receiver exemption, and the D.C. Circuit’s decision in Chamber of Commerce v. EPA did not create one. Legislative proposals are pending but have not been enacted.

How CERCLA Liability Attaches to Stormwater Facilities

Section 107(a) of CERCLA imposes strict, joint and several liability on four categories of potentially responsible parties (PRPs):

• Current owners and operators of a facility where a hazardous substance has been released or is threatened to be released. A stormwater facility that owns or operates infrastructure (detention basins, outfalls, treatment systems) where PFOA or PFOS is present can fall into this category, regardless of whether the facility put the PFAS there.
• Past owners and operators at the time of disposal. If PFAS-containing stormwater was collected, treated, or discharged during a prior owner’s tenure, that prior owner could be a PRP.
• Arrangers — any person who arranged for disposal or treatment of a hazardous substance. This is the most contested category for stormwater facilities. A municipality or utility that collects PFAS-laden stormwater and routes it to a treatment facility or discharge point could, in theory, be characterized as having “arranged for disposal.” However, the Supreme Court’s decision in Burlington Northern & Santa Fe Ry. Co. v. United States, 556 U.S. 599 (2009), limits arranger liability to entities that take “intentional steps to dispose of” a hazardous substance. Passively receiving PFAS in stormwater inflow is a strong argument against intentional arrangement.
• Transporters who selected the disposal site. A stormwater system that conveys PFAS-bearing runoff to a particular outfall or treatment works could face transporter arguments, though this theory is untested in the PFAS context.

The most likely exposure path for a stormwater facility is owner/operator liability. CERCLA’s strict liability regime does not require fault — owning or operating a facility from which a hazardous substance is released is, standing alone, enough to trigger potential liability.

Cost Recovery Under Section 107

Section 107(a) permits two types of plaintiffs to recover response costs from PRPs:

• The federal government (or a state) that has incurred cleanup costs consistent with the National Contingency Plan (NCP); and
• Any other person (including private parties) that has incurred necessary response costs consistent with the NCP.

For stormwater facilities, the practical exposure runs in two directions:

• As a target. A PFAS manufacturer, an upstream industrial discharger, or a neighboring property owner who incurs cleanup costs could sue the stormwater facility as a current owner/operator of a location where PFOA/PFOS was released. Because CERCLA liability is strict, joint, and several, a facility can be tagged for the full cost of cleanup even if it was only one of many contributors.
• As a plaintiff. A stormwater facility that incurs costs to investigate or remediate PFAS contamination — installing treatment systems, sampling, managing contaminated sludge — can bring its own Section 107 cost-recovery action against upstream arrangers or manufacturers who put PFAS into the waste stream. A recent example: in April 2026, a North Carolina utility filed a Section 107 cost-recovery action against DuPont for PFOA/PFOS contamination of its public water system and treatment infrastructure.

Important threshold: response costs must be “necessary” and consistent with the NCP. A recent district court decision held that costs incurred for PFAS investigation where no regulator had required it raised questions of fact about necessity. Facilities should document the basis for any investigation or remediation spending.

Contribution Under Section 113

Section 113(f) permits a PRP that has resolved its CERCLA liability (through settlement or judgment) to seek equitable contribution from other PRPs. Key mechanics:

• Contribution is available after a party settles with EPA or is found liable in a cost-recovery action.
• Allocation is equitable — courts consider factors like the volume and toxicity of hazardous substances contributed, the degree of involvement, the degree of care exercised, and cooperation with government authorities (the so-called “Gore factors”).
• A party that settles with the government receives contribution protection — it cannot be sued for contribution by non-settling PRPs on the same claims, under Section 113(f)(2).

For stormwater facilities, the contribution risk is this: if a PFAS manufacturer or industrial user settles with EPA at a contaminated site and obtains contribution protection, that manufacturer can then pursue contribution from any other PRP — including a stormwater facility that managed the same PFAS-bearing waste stream. The stormwater facility’s equitable share may be small, but CERCLA’s joint and several liability means the initial exposure is for the entire unreimbursed cost.

EPA’s Enforcement Discretion Policy — and Its Limits

EPA issued a “PFAS Enforcement Discretion and Settlement Policy Under CERCLA” in April 2024, updated in September 2025. Under this policy, EPA stated it does not intend to pursue response actions or costs against certain passive receivers, specifically including:

• Public water systems
• Publicly owned treatment works (POTWs)
• Municipal separate storm sewer systems (MS4s)
• Publicly owned municipal solid waste landfills
• Publicly owned airports
• Local fire departments
• Farms where biosolids were land-applied 

Critical limitations of this policy:

• It is discretionary, not statutory. EPA can revoke or narrow it at any time. A change in administration or enforcement priorities could eliminate the protection overnight.
• It does not bind private parties or states. PFAS manufacturers, upstream industrial dischargers, neighboring property owners, and state environmental agencies can still bring cost-recovery and contribution claims against stormwater facilities. EPA has acknowledged it “lacks sufficient authority” to shield passive receivers from these third-party suits.
• It has an exception for facilities that “significantly contribute to or exacerbate” PFAS contamination. A stormwater facility that, for example, concentrates PFAS in treatment sludge and disposes of it improperly, or that discharges without required permits, could lose even EPA’s discretionary protection.
• It applies only to publicly owned facilities. Private stormwater management companies, industrial stormwater systems, and privately owned treatment works are not covered.

Available Defenses

Stormwater facilities facing CERCLA claims have several potential defenses, though none is airtight:

• Third-party defense (Section 107(b)(3)). A PRP can avoid liability if it shows the release was caused solely by a third party with whom it has no contractual relationship, and it exercised due care and took precautions against foreseeable acts. This defense is notoriously difficult to establish because most stormwater facilities receive PFAS through permit-holders, service agreements, or other contractual connections.
• Innocent landowner defense. Available to property owners who acquired the property after contamination occurred, did not know and had no reason to know of the contamination, and conducted “all appropriate inquiries” before acquisition. Stormwater facilities that have operated for years with knowledge of PFAS in their systems will have difficulty meeting the knowledge element.
• Contiguous property owner defense (Section 107(q)). Protects owners whose property is contaminated solely by migration from an adjacent property, provided the owner did not cause, contribute to, or consent to the release. This may be relevant for a facility that receives PFAS solely through groundwater migration from a neighboring site, but likely does not apply to a facility that actively collects and processes PFAS-containing stormwater.
• De micromis defense (Section 107(o)). Exempts parties whose total contribution of hazardous substances is below specified thresholds (generally, a quantity that EPA has not yet set for PFOA/PFOS specifically). This defense may apply to facilities with very minor PFAS volumes, but proving the threshold in the absence of established reportable quantities can be challenging.
• Divisibility of harm (Burlington Northern). Even where liability is joint and several, a PRP can limit its share if it can demonstrate a reasonable basis for apportioning harm. A stormwater facility that can show its PFAS contributions are a tiny fraction of the total contamination at a site may successfully argue for a divided, rather than joint and several, share.

Legislative Outlook

Several bills have been introduced but none enacted:

• H.R. 1267 (Water Systems PFAS Liability Protection Act): Would exempt public water systems, treatment works, municipalities with stormwater discharge permits, wholesale water agencies, and their contractors from CERCLA liability for PFAS releases occurring in compliance with applicable law.
• Senate NDAA amendments (S. Amdt. 3363, S. Amdt. 6429): Filed by Sen. Ricketts (R-NE) to attach passive receiver protections to defense authorization bills.
• Congressional hearings in November and December 2025 featured strong bipartisan calls for a “permanent statutory solution” modeled on the brownfield liability protections Congress enacted in 2002.

EPA Administrator Zeldin has publicly stated support for working with Congress on targeted liability carve-outs for passive receivers. However, no bill has reached a floor vote, and environmental groups remain opposed. Legislation is the only path to a binding exemption — enforcement discretion and judicial decisions have not produced one.

Five Practical Takeaways for Stormwater Facilities

1. Document the passive nature of PFAS receipt. Maintain records showing the facility did not manufacture, use, or intentionally introduce PFAS. This supports both the enforcement-discretion policy and equitable-allocation arguments in contribution proceedings.

2. Track response costs meticulously. Any investigation, sampling, treatment, or remediation costs related to PFAS should be documented as NCP-consistent necessary response costs, positioning the facility as a potential plaintiff, not just a target.

3. Monitor upstream sources. Identifying the actual PFAS originators (manufacturers, industrial users, military installations) strengthens both third-party defenses and any future cost-recovery or contribution claims.

4. Watch the legislative calendar. A statutory passive-receiver exemption would fundamentally change the exposure picture. Until one passes, enforcement discretion is the only federal-level shield, and it does not protect against private suits.

5. Evaluate insurance coverage. Review environmental liability and general liability policies for PFAS-related coverage, particularly for third-party claims that fall outside EPA’s enforcement discretion.

For questions about stormwater facilities or how they may be affected by CERCLA exposure for PFOA and PFOS, contact Michael Blumenthal or any member of Frantz Ward’s Environmental Practice Group.