Evolving regulations of per- and polyfluoroalkyl substances(PFAS) and implications for CERCLA PFOA and PFOS designations

Abstract

Per- and polyfluoroalkyl substances (PFAS) are a broad class of synthetic chemicals used across a wide variety of industrial and commercial applications since the 1950s. Their unique physical and chemical properties impart stability, water and grease resistance, and surfactant behavior. As a result of their long-term use, PFAS have entered the environment throughmultiple release mechanisms, including industrial waste and effluent discharges, landfillleachate, firefighting foams, wastewater treatment residuals, and biosolid applications. Once released, they exhibit both persistence and mobility. PFAS have been detected globally in all environmental media and are now generally considered ubiquitous. Recent studies have identified associations between human exposure to certain PFAS and adverse health effects ,elevating them from an emerging contaminant class to one of primary concern. Regulatory agencies, including the United States Environmental Protection Agency(EPA), have increasingly focused on PFAS in recent years. By 2019, EPA had clearly signal edits intent to regulate these chemicals. EPA outlined a whole-of-agency approach, including short-and long-term actions, in its PFAS Strategic Roadmap published in 2021. The first momentous regulatory achievements occurred in 2024, including finalization of legally enforceable drinking water standards for six PFAS under the Safe Drinking Water Act (SDWA) and the designation of two of the most widely studied PFAS, perfluorooctanoate (PFOA) and perfluorooctane sulfonate(PFOS), as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). These CERCLA hazardous substance designations are the most consequential regulatory actions to date. They provide EPA with statutory authority o address existing PFAS contamination, mitigate future releases, and hold responsible parties financially accountable. The designations also bring PFOA and PFOS within the scope of all appropriate inquiries (AAI) for commercial real estate transactions. Additional PFAS regulations under the other environmental statutes are expected in coming years. Given the complexity of the PFAS contaminant class and the advent of their regulation, environmental professionals (EPs) should be familiar with their classifications, properties, release mechanisms, and associated human health effects, as well as the current regulatory measures that apply to them under the various environmental statutes and regulatory tools. This research paper synthesizes that information and examines the implications of the recent CERCLA designations as they relate to both National Priorities List (NPL) cleanups and Phase I Environmental Site Assessments, a core service provided by EPs.