PFAS treatment and litigation strategies for water systems

The Biden Administration took a firm approach when it came to regulating per- and polyfluoroalkyl substances (PFAS). The administration set Maximum Contaminant Levels (MCLs) for certain PFAS chemicals in drinking water, designated PFOA and PFOS as hazardous substances under the Comprehensive Environment Response, Compensation and Liability Act (CERCLA), and proposed listing PFAS as hazardous constituents under the Resource Conservation and Recovery Act (RCRA).

The U.S. Environmental Protection Agency (EPA) announced plans to rescind and reconsider some of the MCLs, but the two strictest, PFOA and PFOS, are expected to remain. The compliance deadline for drinking water systems to meet these MCLs has been extended by two years, from 2029 to 2031. This extension is still an announcement and not a final rule.

The established MCLs, and any future revisions, are subject to significant legal challenges. The “anti-backsliding” provision of the Safe Drinking Water Act is a potential basis for lawsuits, arguing that new regulations must maintain or improve public health protection.

Prior to the federal level MCLs, states developed a patchwork of PFAS policies, guidelines and enforceable limits on drinking water, which varies by state. Many states are currently taking action regarding PFAS in wastewater, biosolids, and drinking water residuals. States like Maine and Connecticut have banned land application of biosolids due to PFAS concerns.

Cases are emerging concerning PFAS contamination in biosolids, including a high-profile class action pending in Texas.

Potential funding sources for PFAS treatment include federal grants, settlements from class actions against PFAS manufacturers, and separate litigation under CERCLA against polluters.

“CERCLA opens up a new avenue beyond tort claims to sue Department of Defense, to sue carpet manufacturers, etc., under a strict liability scheme,” said Jessica Ferrell, Partner, Marten Law, LLP, during a presentation at the American Water Works Association’s (AWWAs) 2025 Annual Convention & Exposition (ACE). “This can be another source of recovery in order to fund the necessary compliance and treatment costs in a manner that isn’t necessarily passed on to rate payers.”

A dramatic shift in regulation

In Sacramento, Dan York has seen a shift in water treatment and regulation demands over his 45-year career. As General Manager of Sacramento Suburban Water District (SSWD), York now faces complex challenges and stringent regulations.

SSWD serves roughly 200,000 people across multiple communities in a 36-square-mile service area. They primarily rely on 76 groundwater wells, cut down from 112 wells due to past regulations like PCE, Prop 65 and TCP 123. PFAS may be the next major contaminant that poses a threat to the system.

Many existing well sites in the system are in residential areas on small plots of land, making it difficult to add necessary treatment infrastructure without acquiring additional land through purchase or eminent domain.

“We’ve done eminent domain one time back in the late 1990’s, and it was ugly,” York said during an ACE presentation. “But it might be a decision that our board has to make at some point in time.”

York stated that treating PFAS is a significant cost factor that needs to be built into customer rates, impacting operations, maintenance and capital improvement projects. However, there are different routes for funding.

SSWD successfully recovered funds for past contamination, receiving $11 million for TCP. York stated that the board has considered pursuing litigation against polluters responsible for contamination, rather than passing costs to ratepayers.

Maintaining trust and transparency with customers is also crucial for SSWD. It plans to proactively inform customers about emerging contaminants like PFAS.

Opportunities for litigation

The Aqueous Film-Forming Foam (AFFF) Multidistrict Litigation (MDL) is currently the largest and most significant source of potential financial recovery for public water systems. This MDL consolidates numerous cases with similar defendants (manufacturers of AFFF).

Significant settlements have already been reached with defendants like 3M and DuPont. Public water systems with known PFAS detections as of specific settlement dates are eligible to submit claims. Payments from the 3M and DuPont settlements are being distributed in June 2025. Another settlement, Tyco/Chemguard, is expected to begin distribution by early 2026.

CERCLA also opens the door for litigation, with the designation of PFOA and PFOS as hazardous substances. Water systems can bring claims against direct dischargers in their districts using this legal cause of action.

According to Ashley Campbell, Partner, Sher Edling, LLP, over 30 states have sued PFAS manufacturers. Campbell stated at an ACE presentation that recovery from these states may trickle down to their public water systems.

Treating PFAS

HDR Drinking Water Director Chance Lauderdale, speaking during the panel, said HDR has worked on roughly 70 PFAS-related projects. A survey of 50 water utilities conducted by HDR and the Water Research Foundation (WRF Project 5175) identified PFAS as the number one current and near-term regulatory driver with the highest impact on surface water, groundwater and finished water.

During a presentation at ACE, Lauderdale proposed a full life cycle compliance approach for PFAS management. This approach encompassed assessment, planning, implementation, maintenance and stakeholder engagement.

Lauderdale stressed the importance of a well-designed sampling program that helps identify source contamination and targets sustainable PFAS treatment solutions.

The EPA proposed the best available technologies for PFAS mitigation that include Granular Activated Carbon (GAC), Ion Exchange and Reverse Osmosis. However, Lauderdale championed for the use of GAC due to its ease of implementation, ability to manage co-contaminants and relatively quick installation with existing infrastructure. Lauderdale stated that increased demand for GAC systems has led to supply limitations and cost escalation.

Long-term residuals management also poses a problem. Currently, GAC reactivation or high-temperature incineration are the only large-scale disposal options for PFAS residuals from treatment. Lauderdale stated that emerging destruction technologies are promising, but not yet ready for widespread implementation in municipal treatment plants.

When making significant financial investments in PFAS treatment, utilities should also consider opportunities to address other existing or future water quality challenges. This is part of Lauderdale’s full life cycle compliance approach. Also included in that approach is the importance of pilot or bench-scale testing to identify treatment technologies, optimize performance and reduce high life-cycle costs.

“It’s really the lifecycle costs that are going to be the highest expense for your community,” Lauderdale said at an ACE presentation. “So pilot testing allows you to get a leg up with optimization.”