On August 18, 2026, the U.S. Court of Appeals for the D.C. Circuit rejected industry challenges to the designation by U.S. Environmental Protection Agency (EPA) of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (“CERCLA”). The decision upholds the 2024 rule, preserving EPA’s authority to investigate releases, direct certain cleanups, and pursue recovery of response costs involving these two per- and polyfluoroalkyl substances (PFAS) compounds, often called “forever chemicals.”

Key takeaways:

  • The PFOA and PFOS hazardous-substance designation remains in effect.
  • EPA need not prove certain harm from every release.
  • Detection alone does not establish a cleanup obligation or CERCLA liability.
  • Organizations should account for potential PFOA and PFOS sources in release planning, operational practices, waste and transportation arrangements, site diligence, and contracts.

The ruling has broad implications across the environmental, health, and safety landscape, including for energy, agriculture, transportation, manufacturing, construction, real estate, and waste management. By sustaining the designation, the decision preserves CERCLA mechanisms that can shift qualifying cleanup costs from public funds to responsible parties. However, the ruling recognized that not every detection of PFOA or PFOS triggers an automatic cleanup or liability event.

Read the full article for a comprehensive analysis of the D.C. Circuit’s decision upholding EPA’s PFAS hazardous-substance designation, including its impact on CERCLA liability, reporting obligations, cleanup cost recovery, environmental due diligence, and business risk management.

Photo of Melissa Thorme Melissa Thorme

Melissa Thorme counsels industrial and municipal clients in addressing their environmental compliance challenges and negotiating or litigating their regulatory enforcement actions. With nearly 35 years’ experience, Melissa advises business entities, including food processors, lumber companies, agricultural companies, contractors, marinas and boat yards, auto…

Melissa Thorme counsels industrial and municipal clients in addressing their environmental compliance challenges and negotiating or litigating their regulatory enforcement actions. With nearly 35 years’ experience, Melissa advises business entities, including food processors, lumber companies, agricultural companies, contractors, marinas and boat yards, auto dismantlers, small manufacturing companies, and oil field waste-produced water facilities, in addition to sanitation districts, counties, and cities throughout California on matters related to NPDES, wastewater, and recycled water discharge permitting and waivers, TMDLs, and enforcement actions brought by regulatory agencies or in Clean Water Act/Proposition 65 citizen suits.

Continue reading Melissa Thorme’s bio.