Regulating per- and polyfluoroalkyl substances (PFAS) in drinking water

The Environmental Protection Agency (EPA) finalized the PFAS National Primary Drinking Water Regulation (40 CFR Parts 141 and 142) in April 2024 to reduce PFAS exposure in drinking water. The rule contains initial monitoring requirements and sets Maximum Contaminant Levels (MCLs) for six PFAS chemicals (PFOA, PFOS, PFNA, PFHxS, PFBS, and HFPO-DA). The division is gearing up for state adoption under Regulation 11 in August 2025.

Initial monitoring is the process by which water systems collect and analyze drinking water samples for per- and polyfluoroalkyl substances (PFAS) to determine compliance with the maximum contaminant levels (MCLs) and what additional monitoring or treatment is necessary. All community and non-transient, non-community water systems must complete initial monitoring for PFAS by April 1, 2027. Please view the division’s guidance on initial monitoring requirements for more information.

If you operate a water system and have not completed initial monitoring, the division may be able to fund one-time sampling through the PFAS Grant Program to help you get started. Funding availability depends on the division’s remaining budget, which is distributed on a first-come, first-served basis. The division encourages water systems to submit a one-time sampling request form to secure available funds before they run out.

Maximum Contaminant Levels (MCLs) are the maximum level of a contaminant allowed in drinking water delivered to any consumer. The PFAS trigger levels are set at one-half the MCLs and are used to determine PFAS monitoring frequency.

• If any initial monitoring result is greater than or equal to (≥) the trigger level, the system must monitor quarterly for all regulated PFAS at each entry point that met or exceeded the trigger level at the start of the monitoring period that begins on April 1, 2027.
• If initial monitoring results are less than (<) the trigger levels for all regulated PFAS, the department may reduce the compliance monitoring frequency at eligible entry points to once every three years.
• If PFAS levels are detected above the MCLs, systems must take steps to reduce them by the anticipated deadline of April 1, 2029.
   

If your water system detects PFAS levels above the MCLs, requiring treatment or other mitigation, the division may be able to fund infrastructure improvements to help with treatment.

• Emerging Contaminants in Small or Disadvantaged Communities Grant Program (EC-SDC Grant Program). Between 2025 and 2028, the Request for Application (RFA) for the EC-SDC Grant Program is open twice a year. The next RFA will open on July 21, 2025, and close on Aug. 31, 2025. The following RFA will open in January 2026. Visit the division’s website to learn more about this program.
• PFAS Grant Program. The RFA for the PFAS Grant Program is open once a year. The next RFA will open in January 2026. Visit the division’s website to learn more about this program.