A federal judge rejected Denver’s arguments last week for pausing or dismissing a lawsuit brought by an Adams County special district seeking to recover its costs for addressing water contamination as a result of Denver firefighting activities.

In January, the South Adams County Water and Sanitation District, which serves around 75,000 people in Commerce City and neighboring areas of Adams County, sued Denver. It sought a declaration that Denver was liable for the district’s costs of addressing water contamination and for Denver to pay those costs pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).

The district obtains water supplies from groundwater sources and from Denver Water pursuant to a 1998 agreement. The district alleged that, beginning in 2018, it noticed high levels of PFAS in water samples from Denver. PFAS, meaning “per- and polyfluoroalkyl substances,” are long-lasting chemicals associated with serious health problems over long periods. They exist in a variety of consumer products, including nonstick cookware and water-resistant fabrics.

The district alleged that PFAS-containing firefighting foam used for training at Denver’s Roslyn Street facility migrated into its water supplies.

“Upon the discovery of the PFAS contamination in 2018, the District took immediate and ongoing response actions to ensure its finished drinking water supplies are and remain safe for domestic use,” wrote lawyers for the district. “Additional response actions, including construction of an additional water treatment facility specifically designed to treat PFAS, will ensure that the District’s drinking water meets federal and State standards and guidelines into the future. The District successfully sought state and federal funding to defray the financial burden of the required response actions on its customers, but there remains a huge deficit between that funding and the District’s necessary costs of response attributable to PFAS releases from Denver’s Fire Training Facility.”

Denver moved to dismiss the lawsuit. It first argued that the complaint “does not allege that the District incurred any costs” in cleaning up PFAS. Moreover, CERCLA prohibits “double cost recovery,” and the district already received $64 million in governmental grants to address PFAS contamination.

Further, Denver pointed out that the district is participating in multidistrict litigation in South Carolina against manufacturers of PFAS-containing products.

“The combination of grants and (litigation) settlements address the PFAS related costs the District is seeking to double recover in its Complaint,” wrote Denver’s lawyers.

The city also argued that the U.S. Environmental Protection Agency only designated PFAS as “hazardous substances” in 2024, and the district was not entitled to recover costs prior to them. Finally, the federal appeals court for the District of Columbia is currently weighing whether to overturn the EPA’s designation, and Denver argued the cost-recovery lawsuit should be paused until the court issues a decision.

“This litigation will be costly for Denver, the District, the Court, and — as both parties are funded by the taxpayer — the public,” wrote Denver.

On Aug. 3, U.S. Magistrate Judge N. Reid Neureiter declined to dismiss the lawsuit.

He rejected Denver’s “somewhat perplexing” argument that the district had not incurred costs to clean up PFAS, given numerous allegations about the district’s actions to test, monitor, and remediate PFAS.

Neureiter acknowledged that CERCLA prohibits double compensation, but whether the district would actually recover the same costs from multiple sources was not something he could address in the early stages of the lawsuit.

“The Complaint alleges that there is a ‘huge deficit’ between the funding the District has received and its necessary response costs,” wrote Neureiter.

Finally, Neureiter declined to halt the litigation until the PFAS-related cases in D.C. and South Carolina are resolved.

“The District has a viable CERCLA claim under the law as it currently stands, and there exists a substantial public interest in moving the case towards a disposition and enforcing federal protections aimed at curbing the environmental and health risks posed by industrial pollution,” Neureiter concluded.

The case is South Adams County Water and Sanitation District v. City and County of Denver.