EPA Publishes Proposed PFAS Drinking Water Regulation

The U.S. Environmental Protection Agency (EPA) on March 29, 2023, published in the Federal Register its long-awaited proposal to regulate per- and polyfluoroalkyl substances (PFAS) under the Safe Drinking Water Act (SDWA) through issuance of a proposed National Primary Drinking Water Regulation (NPDWR) for six PFAS compounds. The NPDWR would establish nationwide, legally enforceable drinking water Maximum Contaminant Levels (MCLs) for six PFAS compounds. The proposed NPDWR would also set nonenforceable, health-based Maximum Contaminant Level Goals (MCLGs) for the same six PFAS compounds. Once finalized, public water systems would have three years to implement required monitoring and reporting, and extensions of up to an additional two years may be authorized by the EPA, according to its Frequently Asked Questions. EPA anticipates finalizing the regulation by the end of 2023.

Covered PFAS Compounds

The six specific PFAS compounds covered include:

• Perfluorooctanoic acid (PFOA)
• Perfluorooctane sulfonic acid (PFOS)
• Perfluorononanoic acid (PFNA)
• GenX Chemicals: hexafluoropropylene oxide dimer acid (HFPO-DA)
• Perfluorohexane sulfonic acid (PFHxS)
• Perfluorobutane sulfonic acid (PFBS)

The MCLs and MCLGs proposed are:

For PFOA and PFOS, the EPA has proposed an enforceable limit that it has determined is the lowest level that can be reliably quantified under current analytical methods (Method 537, 537.1 or 533). The EPA is using a Hazard Index approach for the remaining four PFAS (PFNA, PFHxS, PFBS and GenX Chemicals). This more complicated method considers the additive effects of multiple PFAS when occurring together. Specifically, the Hazard Index is made up of a sum of fractions. Each fraction compares the level of each PFAS measured in the water to the highest level determined not to have risk of health effects. A description of the methodology can be found in EPA's Fact Sheet.

State Testing and Compliance

The EPA evaluated data from 23 states that had publicly available PFAS drinking water test results in addition to data collected under the Third Unregulated Contaminant Monitoring Rule (UCMR3) between 2013 and 2015. Many of these states had enacted state-level MCLs or established guidance, some based upon the prior (2016) EPA Health Advisories, which were set at 70 ppt for the sum of PFOA and PFOS. In June 2022, the EPA updated its Interim Health Advisory for PFOA and PFOS, and added health advisories for PFBS and HFPO-DA (aka GenX) that guided EPA's proposal. In September 2022, the Governmental Accounting Office published a study of drinking water data collected from six states that showed at least 18 percent of the 5,300 water systems studied had PFOA and/or PFOS exceeding the proposed MCLs of 4 ppt. These systems served 9.5 million people (29 percent of the total population). Additional nationwide data is currently being collected for an expanded list of 29 PFAS compounds under the Fifth Unregulated Contaminant Monitoring Rule (UCMR5), which extends the collection process through December 2025. Importantly, UCMR5 expanded data collection requirements to include small water systems serving less than 10,000 persons (subject to lab availability and appropriations). This will lead to a more robust data set and potentially enhanced laboratory capacity beyond the list of EPA-certified labs.

State programs across the country vary widely in terms of which PFAS compounds are included in the monitoring programs and how MCLs are calculated. The Interstate Technology Regulatory Council publishes a database of various state regulatory programs. Many states, including several in New England, utilize a sum of all monitored PFAS contaminants as their state MCL. Some states include PFAS compounds that are not included in EPA's proposed NPDWR. All of these programs will have to be conformed to comply with the federal level once it becomes effective, even where they may continue portions of their state programs that do not conflict with the federal rule. For the approximately 25 states that have no statewide drinking water requirements for PFAS, they will need to establish such programs and ensure that adequate certified labs are available to meet the demand. Fortunately, funding is available under the Bipartisan Infrastructure Law and Inflation Reduction Act, including specific grant opportunities for small and disadvantaged communities. These new grant opportunities build on the preexisting state revolving fund opportunities as described in EPA's Funding Sources Comparison.

Next Steps

Comments can be provided via the Regulations.gov website under Docket ID: EPA-HQ-OW-2022-0114 until May 30, 2023. (However, the EPA would prefer comments by April 28, 2023.) The EPA will also hold a public hearing on May 4, 2023, to solicit public comment from those who register in advance by April 28, 2023. In addition, the EPA held public webinars on March 16 and March 29, 2023. Recordings, along with additional information, can be found on the EPA NPDWR Website.

Information contained in this alert is for the general education and knowledge of our readers. It is not designed to be, and should not be used as, the sole source of information when analyzing and resolving a legal problem, and it should not be substituted for legal advice, which relies on a specific factual analysis. Moreover, the laws of each jurisdiction are different and are constantly changing. This information is not intended to create, and receipt of it does not constitute, an attorney-client relationship. If you have specific questions regarding a particular fact situation, we urge you to consult the authors of this publication, your Holland & Knight representative or other competent legal counsel.