As discussed in a previous post, the United States Environmental Protection Agency (EPA) proposed a National Primary Drinking Water Regulation to establish maximum contaminant levels for six different PFAS compounds: perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), hexafluoropropylene oxide dimer acid (HFPO–DA) and its ammonium salt (also known as GenX chemicals), perfluorononanoic acid (PFNA), and perfluorobutane sulfonic acid (PFBS).  EPA accepted public comments regarding the proposal until May 30, 2023; per EPA’s docket, EPA received over 120,000 comments in total.  Commentators ranged from individuals to industry trade groups, chambers of commerce, state regulatory agencies, and local water authorities.

Many commentators posted substantive comments and critiques of EPA’s proposed MCLs.  Commentators include industry trade groups, state regulatory agencies, and local water service providers.  Comments ranged from the depth and adequacy of the data EPA relies on to support its proposal to EPA’s legal authority to develop its proposed MCLs.  Many commentators also identified practical barriers, such as the limited number of available laboratories that can analyze samples for PFAS using approved EPA methods.

Some industry trade groups asserted that:

  1. EPA’s determination to regulate PFHxS, HFPO-DA, PFNA, and PFBS is inconsistent with the criteria under the federal Safe Drinking Water Act;
  2. EPA’s health effects assessment selectively relies on data from a limited number of studies;
  3. Establishing a hazard index (HI) as a basis for an MCL is contrary to EPA policy;
  4. EPA should not regulate PFOA, PFOS, or other PFAS as “likely carcinogens.”

Some water service provider entities asserted that:

  1. EPA’s cost estimate for its proposal is much lower than expected costs;
  2. EPA significantly overestimates the quantifiable benefits of its proposal;
  3. EPA’s action will disproportionately impact economically disadvantaged and underserved communities.

Some state regulatory agencies asserted that:

  1. Achieving EPA’s proposed PFOA and PFOS MCLs may not be feasible given the current state of laboratory methods approved for analysis;
  2. EPA may be underestimating laboratory capacity to analyze drinking water via EPA approved methods.

Per an EPA presentation that accompanied its proposed rulemaking, EPA anticipates a final PFAS drinking water regulation to be promulgated in December 2023, and an anticipated effective date of December 2026 (i.e., three years following final rule promulgation).