On April 10, 2024, the Environmental Protection Agency (EPA) finalized the first federal regulation limiting the amount of certain per- and polyfluoroalkyl substances, known as PFAS, found in drinking water. The final National Primary Drinking Water Regulation (NPDWR) establishes drinking water standards for six PFAS, with compliance phased in over the next several years.

As discussed in greater detail in prior articles, PFAS are a large category of organic chemicals that have been used since the 1940s to repel oil and water and resist heat. While they are a key component in certain products, such as nonstick cookware, stain-resistant clothing, and firefighting foam, there is significant evidence that exposure to certain PFAS over an extended period can cause cancer and other illnesses. Studies have also shown that PFAS exposure during critical life stages, such as pregnancy or early childhood, can lead to adverse health impacts.

While many U.S. manufacturers have stopped using PFAS in favor of safer alternatives, prior discharges have resulted in very high levels of PFAS in many public and private water systems. According to EWG, more than 320 military sites across the U.S. have PFAS contamination, and more than 200 million Americans may be drinking contaminated water.

Over the past several years, the Biden Administration has taken several steps to address PFAS contamination, including the creation of a PFAS Strategic Roadmap. As part of this initiative, the EPA has established methods to better measure PFAS; added seven PFAS to the list of chemicals covered by the Toxics Release Inventory (TRI); enacted a final rule under the Toxic Substances Control Act (TSCA) to require manufacturers of PFAS and PFAS-containing articles to report information to EPA on PFAS uses, production volumes, disposal, exposures, and hazards; named PFAS as a National Enforcement and Compliance Initiative for 2024-2027; and proposed designating certain PFAS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).

Establishing PFAS water drinking standards was a central goal of the EPA's PFAS Strategic Roadmap. Under the Safe Drinking Water Act, the EPA has the authority to set enforceable National Primary Drinking Water Regulations (NPDWRs) for drinking water contaminants and require monitoring of public water systems.

The new National Primary Drinking Water Regulation establishes legally enforceable levels, known as Maximum Contaminant Levels (MCLs), for five individual PFAS in drinking water – PFOA, PFOS, PFHxS, PFNA, and HFPO-DA – and for PFAS mixtures containing at least two or more of PFHxS, PFNA, HFPO-DA, and PFBS, the new rule uses a Hazard Index MCL to account for the combined and co-occurring levels of these PFAS in drinking water (a PFAS mixture Hazard Index greater than 1 indicates an exceedance of the health-protective level). Below is a summary:

  • Perfluorooctanoic acid (PFOA) MCL = 4.0 parts per trillion (ppt)
  • Perfluorooctane sulfonic acid (PFOS) MCL = 4.0 ppt
  • Perfluorohexane sulfonic acid (PFHxS) MCL = 10 ppt
  • Perfluorononanoic acid (PFNA) MCL = 10 ppt
  • Hexafluoropropylene oxide dimer acid (HFPO-DA) MCL = 10 ppt
  • Mixtures containing two or more of PFHxS, PFNA, HFPO-DA, and PFBS = 1 unit

Additionally, the NPDWR requires public water systems to determine whether PFAS is in their drinking water and take actions such as notifying consumers and reducing the levels of PFAS, as needed. Below is a summary of the key requirements:

  • Public water systems must monitor for the regulated PFAS and have three years to complete initial monitoring (by 2027), followed by ongoing compliance monitoring. Water systems must also provide the public with information on the levels of these PFAS in their drinking water beginning in 2027.
  • Public water systems have five years (by 2029) to implement solutions that reduce these PFAS if monitoring shows that drinking water levels exceed these MCLs.
  • Beginning in five years (2029), public water systems that have PFAS in drinking water that violates one or more of these MCLs must take action to reduce levels of these PFAS in their drinking water and must provide notification to the public of the violation.

The EPA is holding three informational webinars for communities, water systems, and other drinking water professionals about the final PFAS NPDWR. These webinars are scheduled on April 16, April 23, and April 30, 2024. You can find information here.

The federal government is also providing funding to assist public water utility companies in complying with the new drinking water standards. A total of $1 billion will be available to states and territories to implement PFAS testing and treatment at public water systems. That money is part of a $9 billion investment authorized under the 2021 Bipartisan Infrastructure Law to assist communities impacted by PFAS contamination.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.