On March 14, 2023, the U.S. Environmental Protection Agency (EPA) announced the proposed National Primary Drinking Water Regulation (NPDWR) to establish legally enforceable Maximum Contaminant Levels (MCLs) for six PFAS substances (the “Proposed Regulation”). The EPA will hold a webinar about the PFAS NDPWR for water utilities on March 29 to provide information regarding the Proposed Regulation, as reflected on the U.S. EPA webpage here.

Here are five key things you should know about the Proposed Regulation, and how it may impact water utilities going forward:

  1. The EPA has proposed a regulation to establish MCLs for six PFAS substances in drinking water.
  2. The proposed MCL for PFOA and PFOS is 4 parts per trillion, and the proposed regulation uses a hazard index calculation to limit any mixture containing one or more of PFNA, PFHxS, PFBS, and/or GenX Chemicals.
  3. The EPA plans to finalize the regulation by the end of 2023, and public water systems will be required to monitor for these chemicals, notify the public of PFAS levels, and reduce PFAS if levels exceed the proposed regulatory standards. Drinking water suppliers will be subject to MCL limitations, and if the proposed rule is adopted, water systems with PFAS levels that exceed the proposed MCLs would need to take action to provide safe and reliable drinking water.
  4. Comments on the new regulation must be submitted to the public docket during the 60-day public comment period following the proposed rules being published in the Federal Register.
  5. EPA is also proposing health-based, non-enforceable Maximum Contaminant Level Goals (MCLGs) for the six PFAS. These levels represent the maximum level of a contaminant in drinking water where there are no known or anticipated negative health effects. The proposed MCLG for PFOA and PFOS is any amount above zero.

Also, the new proposed rule signals other likely impacts to NPDES permits, waste discharge requirements, and site clean-ups in California because new MCL standards affect each of these programs.

Key Takeaways

Water utilities will want to attend the upcoming EPA webinar, submit comments during the comment period, and begin to evaluate potential obligations, such as identifying alternative uncontaminated sources of water or designing water treatment systems that EPA believes are feasible.