The Emerging Landscape of PFAS Civil Liability
The legal landscape around PFAS has shifted dramatically over the past three years. AFFF manufacturers have settled mass tort litigation for billions of dollars. Utilities are suing industrial PFAS users for contamination remediation costs. Landowners are pursuing property damage claims against responsible parties. And increasingly, the question of whether a PFAS treatment system was “adequate” — whether it removed the compounds it was supposed to, to the concentrations required — is entering courtrooms as a contested factual question.
For private sector entities — manufacturers, industrial facilities, real estate developers, commercial property owners — this litigation environment has created a new category of procurement risk. The filter technology they buy, and the documentation they maintain about how it performs, is no longer just an operational and regulatory compliance matter. It is potential evidence in future litigation.
What “Filter Adequacy” Means in a Litigation Context
Filter adequacy, in the litigation context, refers to whether a treatment system was appropriate for the contamination present and whether it performed as warranted. Courts examining this question look at several factors: whether the system was designed to address the compounds actually present in the water; whether the vendor’s performance claims were accurate and verified; whether the system was operated according to specifications; and whether the operator took reasonable steps to verify ongoing performance.
The 2024 EPA MCL rule has given courts a concrete regulatory benchmark against which adequacy can be measured. A treatment system that meets MCLs is defensible; one that does not — particularly if the gap relates to short-chain compounds that the MCL rule explicitly covers — creates significant exposure. Private sector entities that made PFAS treatment decisions before the rule are now revisiting those decisions in light of the new benchmark.
This retroactive scrutiny is particularly relevant for companies that installed PFAS treatment systems based on PFOA/PFOS performance data alone, without verifying short-chain performance. Those systems may now fail the adequacy standard that courts will apply, even if they met the standards in effect at the time of installation.
How Legal Risk Is Changing Procurement Decisions
Legal risk awareness is now a driver of PFAS filter procurement decisions in ways it was not two years ago. Corporate environmental, health and safety managers — who typically own the procurement decision — are increasingly consulting with environmental counsel before finalizing treatment technology selections. The questions being asked are: If this system fails to meet MCLs, what is our liability exposure? If we select Technology A over Technology B, and Technology A later proves inadequate for short-chain compounds, have we made a defensible procurement decision?
These questions are pushing procurement decisions toward more thoroughly documented technology evaluations, more rigorous vendor qualification processes, and stronger performance warranties with clear remediation provisions if performance targets are not met. They are also pushing procurement toward technologies with independent third-party verification — because a vendor’s self-reported performance data is a much weaker litigation defense than independently verified test results.
Documentation Practices That Reduce Legal Exposure
Environmental legal practitioners advising private sector clients on PFAS treatment procurement are recommending several documentation practices that reduce legal exposure. First: document the basis for technology selection, including the compounds addressed, the performance data reviewed, and the rationale for choosing the selected technology over alternatives. This documentation creates a record of reasonable decision-making that is valuable in litigation.
Second: require vendors to provide compound-specific, third-party verified performance data as a contract deliverable — not just a marketing claim. The distinction between “certified to NSF 53 for PFAS reduction” and “certified to NSF 53 for PFOA, PFOS, PFHxS, and PFNA reduction at specified concentrations by [named laboratory]” is legally significant. Third: establish ongoing monitoring protocols that generate a documented record of treatment system performance over time. Continuous compliance documentation is a meaningful litigation defense; intermittent spot checks are not.
The Vendor Relationship in a Liability-Aware Market
The legal risk environment is also changing the vendor relationship in PFAS treatment procurement. Vendors who can provide robust, independently verified performance documentation — and who stand behind it with meaningful warranties — are being selected over vendors who cannot, even at higher contract prices. The calculation is straightforward: the cost of a stronger warranty and better documentation is small compared to the potential cost of a treatment adequacy dispute.
For filter media and equipment suppliers, this means that investment in third-party performance verification, comprehensive compound testing, and clear warranty language is not just a marketing cost — it is a market access requirement in a segment of the market where buyers have become sophisticated about legal risk. The vendors who understand this dynamic earliest will capture a disproportionate share of private sector PFAS treatment contracts as the litigation environment continues to develop.