On March 13, 2023, the United States Environmental Protection Agency (“EPA”) issued a prepublication notice of a proposed rule that would set the first binding nationwide drinking water standard for six per- and polyfluoroalkyl substances (“PFAS”) under the federal Safe Drinking Water Act (“SDWA”).  The proposal, if finalized, would regulate PFOA and PFOS, the two most well-known and widely used PFAS, as individual contaminants with a regulatory limit of 4 parts per trillion (“ppt”) in public drinking water systems throughout the country.  The proposed regulatory standard is lower than the non-binding lifetime Health Advisory Level (“HAL”) set in 2017 (70 ppt for PFOA and PFOS combined) but higher than the interim HALs set in 2022, which were 0.004 ppt and 0.02 ppt for PFOA and PFOS, respectively.  EPA notes that 4 ppt is the lowest concentration that laboratories can reliably measure for PFOA and PFOS, and indicates it would have selected a lower standard if feasible by proposing that the health-based value, or Maximum Contaminant Level Goal “(MCLG”), for PFOA and PFOS should be zero.  The proposed rule would also regulate four other PFAS chemicals (PFNA,  PFHxS, PFBS and GenX) as a group, using a new hazard index calculation that would determine if combined levels posed a potential risk to human health. 

If finalized, the rule would require public water systems nationwide to monitor for these chemicals and to notify the public and reduce PFAS if levels exceed the proposed standards.  Public drinking water systems will have to implement programs for monitoring, notification, and plans for PFAS remediation if and when needed.  Other entities that may be sources of PFAS contamination, including entities that manufacturer PFAS or PFAS-containing products, municipal solid waste landfills, and airports, can expect that the new standards will increase both regulatory and public scrutiny and increase the potential for regulatory enforcement and/or private party lawsuits.  

This rule may be just the tip of the iceberg for federal regulation of PFAS via the SDWA, as there are thousands of different PFAS compounds, and EPA is already in the process of testing water systems for over twenty more types of PFAS beyond those covered in this proposal. 

Note that the proposed drinking water standard also comes as EPA is the process of finalizing another significant PFAS rulemaking: its proposal to designate PFOA and PFOS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act.  The designation would expand EPA’s authority to investigate and remediate sites with PFAS contamination and create liability for various entities deemed responsible for PFAS releases. 

Together, these rules are foundational to the Biden Administration’s PFAS Strategic Roadmap. In addition to these two rules, however, further EPA action to address PFAS also is expected over the next few years, such as a proposal to regulate certain PFAS under the Resource Conservation and Recovery Act, as well as agency guidance on key topics like its PFAS enforcement policy and revised guidance on PFAS disposal and destruction.  Stay tuned.

For a link to the pre-publication version of EPA’s Proposed Rulemaking to set the nation’s first PFAS drinking water standards under the SDWA, click here. 

For more information on EPA’s Proposed Rulemaking to designate some PFAS as CERCLA hazardous substances, visit our client alert on that regulatory proposal here.

For more information about PFAS, the proposed rule, or how PFAS regulation or liability may impact your organization, please contact Thomas A Bloomfield, Polly B. Jessen, Sara V. Mogharabi, or Nicholas M. Clabbers.