WATER TREATMENT
New proposed rules
In May 2026, the EPA proposed two rules that would change the NPDWR requirements. Notably, these would maintain the existing MCLs for PFOA and PFOS, while rescinding index PFAS requirements and allowing a two-year compliance extension. Both are in line with the EPA’ s 2025 announcement of its intention to uphold protection from PFAS in drinking water while offering utilities additional flexibility for compliance.
One proposed rule would allow qualifying water systems to request a two-year extension to the existing PFOA and PFOS compliance deadline, moving the deadline from 2029 to 2031. However, systems would still be required to meet the monitoring and reporting requirements established under the 2024 regulation. All systems granted an extension must notify their customers and include sample results in consumer confidence reports.
Additional requirements would apply to systems with PFOA or PFOS concentrations above 12 ppt. Those systems must implement two shortterm mitigation efforts, choosing between six options that include point-of-use treatment, alternative water supply, source water protection and public education, while working toward compliance( Table 1).
The second proposed rule would rescind portions of the 2024 regulation that apply to the index PFAS. The EPA has indicated that the sole reason for the rescission is to address concerns that the regulatory process used to establish those requirements did not fully align with SWDA procedures. The agency will continue evaluating additional PFAS for future drinking water regulation.
Where things stand
Despite ongoing litigation and proposed regulatory changes, the final rule from April 2024 remains the only enforceable federal PFAS standard for drinking water. Public water systems are still required to complete initial monitoring by 2027 and meet applicable maximum contaminant limits and hazard index requirements by 2029.
Much of the uncertainty surrounding PFAS regulation stems from confusion between proposed actions and enforceable requirements. The EPA’ s May 2025 announcement signalled the agency ' s intent to pursue changes but did not alter existing compliance obligations. Likewise, the two new proposed rules must still complete the federal rulemaking process before they can take effect.
The timeline for any final action remains uncertain. As a point of reference, the 2024 PFAS NPDWR was announced nearly 11 months following the close of public review and comment on the proposed rule. This illustrates the amount of time it could take to consider public comments and finalise a regulation.
The AWWA / AMWA litigation faced delays after EPA requested additional time, but oral arguments occurred in September. While a final court opinion could take several months, the existing rule remains in effect and the AWWA stresses that water systems should not delay compliance efforts.
Water systems considering future compliance extensions should also pay close attention to primacy, which is when a state, territory or tribal agency takes responsibility for enforcing federal water quality standards.
At the time of this writing, no entity with primacy has adopted the federal PFAS rule, but when it is adopted by a state, an EPA-granted compliance exemption would not transfer automatically. For that reason, water systems should maintain open communication with local authorities when navigating PFAS compliance strategies.
Moving forward
For drinking water systems navigating PFAS compliance, the most important fact remains the same: the 2024 National Primary Drinking Water Regulation is currently the only enforceable federal drinking water rule for PFAS.
While ongoing litigation may impact the existing rule, the EPA’ s new rules are likely to reinforce the MCLs for PFOA and PFOS. Water systems hoping for extensions should work with local primacy agencies to understand possible implications when the federal rules are adopted into their existing programs.
The index PFAS rule rescission will not have a significant impact. According to Corona Engineering, the UCMR5 data shows that only six of 1,064 impacted water systems exceed the Index PFAS limits without also exceeding MCLs for PFOA or PFOS. In other words, PFOA and PFOS will drive the need for treatment.
Ultimately, the regulatory landscape surrounding PFAS standards may continue to evolve, but the time required for planning and executing treatment and other mitigation strategies requires immediate action. Water systems that focus on preparing for compliance under existing requirements will be best positioned to adapt as future regulatory and legal developments unfold. ●
Reference: 1: https:// www. epa. gov / sdwa / and-polyfluoroalkyl-substances-pfas
J j
T. J. Stroebl
SENIOR MARKET LEADER
KURITA AMERICA t. stroebl @ kurita-water. com www. kurita-water. com
NOV / DEC 2026 SPECCHEMONLINE. COM
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