On March 14, 2023, the U.S. Environmental Protection Agency (EPA) announced the proposed National Primary Drinking Water Regulation (NPDWR) for six per- and poly fluoroalkyl substances (PFAS), including:
- perfluorooctanoic acid (PFOA);
- perfluorooctane sulfonic acid (PFOS);
- perfluorononanoic acid (PFNA);
- hexafluoropropylene oxide dimer acid (HFPO-DA, commonly known as GenX Chemicals);
- perfluorohexane sulfonic acid (PFHxS); and
- perfluorobutane sulfonic acid (PFBS).
If adopted, the proposed PFAS NPDWR would impose a new nationwide floor on the patchwork of state regulations for such compounds. Compliance with the proposed regulatory standards could potentially present significant challenges for the water industry.
PFAS are a set of man-made chemicals widely used in a variety of consumer and industrial products which persist in the environment once released and may be linked to health impacts. The proposed PFAS NPDWR is a culmination of many years of scientific research and work by EPA in accordance with its PFAS Strategic Roadmap. Such NPDWRs would be legally-enforceable standards applicable to public water systems that protect public health by limiting the levels of contaminants within drinking water.
The NPDWR sets both a non-enforceable Maximum Contaminant Level Goal (MCLG) (the level of a contaminant in drinking water at which no known or anticipated negative health effects occur and which allows an adequate margin of safety) and the enforceable Maximum Contaminant Level (MCL) (maximum level of a contaminant allowed in drinking water that can be delivered to users of a public water system). The proposed PFAS NPDWR would regulate PFOA and PFOA as individual contaminants and the remaining compounds as a PFAS mixture with the following proposed levels:
The adoption of the proposed set of enforceable MCLs for these compounds would be a long-awaited major step toward a national set of standards for the permissible level of PFAS in drinking water. Currently, the regulation of PFAS varies greatly from state-to-state, with states like California leading the effort by adopting notification and response levels for various PFAS compounds. If adopted, states will need to establish standards that are at least as strict as the federal rule. The impact of the rule would be greatest in states that currently have few regulations on PFAS.
The proposed rule would require public water systems nationally to monitor for these six PFAS, notify the public of the level of such PFAS and reduce the levels of these PFAS in drinking water if they exceed the proposed standards. This could include removing these chemicals through various types of treatment, or switching to an alternative water supply that meets the standard. For many public water systems, this could mean that major treatment infrastructure investments and/or abandonment of some sources of water supply will be required to comply with the new MCLs.
The proposed PFAS NPDWR does not require any actions until it is finalized. EPA anticipates finalizing the regulation by the end of 2023 and is currently requesting public comments that must be submitted within 60 days after the date that the proposed PFAS NPDWR is published in the Federal Register. After publication, comments can be submitted using Docket ID: EPA-HQ-OW-2022-0114 (further guidance on commenting.) In addition to seeking written input, EPA will be holding an online public hearing on May 4, 2023. EPA will be holding two informational webinars about the proposed PFAS NPDWR on March 16 and March 29, 2023; registration information is available on EPA's PFAS webpage.
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