EPA Guidance Reinforces That PFAS Should Be Considered in Phase I Environmental Assessments

In December 2025, the U.S. Environmental Protection Agency (“EPA”) clarified that recipients of pending Brownfield grants must demonstrate that they are not liable for PFAS contamination under CERCLA. In 2024, EPA designated perfluorooctanoic acid (PFOA) or perfluorooctane sulfonic acid (PFOS), as well as their salts and structural isomers, as CERCLA hazardous substances under CERCLA. In September 2025, EPA announced that it would retain this designation and that it would defend its designation in the pending litigation challenge. 

To demonstrate that they are not liable under CERCLA for PFAS contamination, grant recipients will need to establish that liability protections, such as the bona fide prospective purchaser defense, are in place where PFOA or PFOS could be present. This requires conducting All Appropriate Inquiries that meet the current ASTM standards. Under the current standards for Phase I Environmental Site Assessments, purchasers must consider “conditions indicative of releases or threatened releases” of hazardous substances. This guidance now clarifies that this includes considering the potential presence of PFOA or PFOS, which could be indicated, for example, by a history of biosolids application or flammable liquid fires.

EPA’s guidance reinforces the need for potential site owners and developers seeking bona fide prospective purchaser status, as well as environmental professionals conducting Phase I assessments, to ensure PFAS contamination is considered as part of the Environmental Site Assessment, to ensure that the All Appropriate Inquiries standard is met.

For more information, contact Liskow attorneys Emily von Qualen and Clare Bienvenu, and visit Liskow’s Industrial Insights Hub.