The U.S. Environmental Protection Agency (EPA) recently announced two proposed rules that would preserve federal drinking water standards for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), while introducing new implementation options for public water systems (PWSs). The proposals are part of a broader per- and polyfluoroalkyl substances (PFAS) strategy that includes additional funding, expanded treatment, and destruction technology initiatives, as well as continued efforts to address PFAS contamination at its source.
Under the proposed approach, the EPA would maintain the existing Maximum Contaminant Levels (MCLs) for PFOA and PFOS, while allowing eligible drinking water systems to apply for up to 2 additional years to achieve compliance. At the same time, the agency is seeking public comment on whether portions of the 2024 drinking water regulation addressing several other PFAS compounds should be reconsidered through a separate rulemaking process.
Background on EPA’s PFAS Drinking Water Rules
EPA’s current proposals build on the agency’s broader effort to regulate PFAS in drinking water under the Safe Drinking Water Act (SDWA). In April 2024, EPA finalized the first federal National Primary Drinking Water Regulation (NPDWR) establishing Maximum Contaminant Levels (MCLs) for six PFAS, including individual standards for PFOA and PFOS as well as standards for PFHxS, PFNA, HFPO-DA (GenX chemicals), and a Hazard Index approach that also includes PFBS. The rule took effect in June 2024 and established a nationwide framework for public water systems to begin monitoring, planning, and working toward compliance. PWSs are required under the 2024 PFAS MCL rule to conduct compliance monitoring for PFOA and PFOS at a frequency based on sample results.
EPA’s final rule followed years of increasing federal attention on PFAS in drinking water. Over time, the agency issued health advisories for certain PFAS, advanced regulatory determinations, and ultimately moved toward enforceable drinking water standards as concerns grew regarding the persistence of these compounds and their potential risks to human health and the environment. Since finalizing the 2024 rule, new EPA indicated that while it intends to preserve the federal standards for PFOA and PFOS, it is actively reconsidering how other PFAS compounds are addressed in the original rulemaking and how compliance timelines should be implemented for PWSs.
Proposed Updates to PFAS Drinking Water Rules
EPA’s first proposal would preserve the current federal drinking water standards for PFOA and PFOS, while creating a process through which eligible PWSs could request up to 2 additional years to achieve compliance. Currently, the once already-extended deadline to satisfy the initial monitoring requirements is April 26, 2029. If finalized, qualifying systems could have until April 26, 2031, to meet the applicable drinking water standards.
PWSs qualifications center around:
- Major constraints (e.g., economic or technical issues)
- Operating when the rule took effect (or has no viable alternative water source)
- Does not pose an unreasonable health risk
- Cannot reasonably fix compliance through management or restructuring changes
Moreover, the PWS must meet at least one of the following criteria:
- The system cannot meet the standard prior to the April 26, 2029, deadline without capital improvements
- PWS has already entered into an agreement to obtain infrastructure financial assistance (or federal/state programs are available)
- The system is to merge with a regional water system. Also, if PFOS or PFOA results are at or exceed 12 nanograms per liter (ng/L) PWSs, need to implement at least two of the six interim exposure control measures consisting of water pitchers with filters, alternative water supplies, home treatment systems, source water controls, public education materials, and community outreach.
The caveat is that systems that do not seek or qualify for an extension would remain subject to the existing compliance timeline. Moreover, eligible PWSs must demonstrate the inability to comply and that all practicable efforts are made to move toward compliance, applying the extension to do so as “expeditiously as practicable.” The extra time is meant for the PWSs to build/improve infrastructure, find qualified operators, secure funding, collect data, as well as devise source water protection, PFAS treatment, and technology improvements strategies.
EPA’s second proposal focuses on rescinding its regulatory determination and the associated 2024 NPDWR Maximum Contaminant Level (MCL) and Maximum Contaminant Level Goal (MCLGs) provisions for perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), hexafluoropropylene oxide dimer acid (HFPO-DA), and the Hazard Index approach that also incorporates perfluorobutane sulfonic acid (PFBS). The agency is proposing this change because the 2024 NPDWR failed to follow the required procedural process of proposing and then finalizing standards for the four additional PFAS. EPA is not looking to revise any of the previous substantiative findings regarding health risks, costs, and occurrence.
Funding and Resources for PFAS Compliance
In addition to the proposed regulatory changes, the EPA announced nearly $1 billion in new grant funding through the Emerging Contaminants in Small or Disadvantaged Communities Grant program. This latest allocation brings the total funding made available through the program to approximately $5 billion over the past 5 years. The agency also highlighted other existing funding mechanisms that may be available to support PFAS-related projects, including Drinking Water State Revolving Fund resources dedicated to emerging contaminants and financing opportunities through the Water Infrastructure Finance and Innovation Act (WIFIA) program.
As public water systems evaluate treatment alternatives, infrastructure upgrades, and long-term compliance strategies, these funding opportunities may help offset some of the costs associated with addressing PFAS in drinking water.
What Could This Mean for Water Systems?
Although the proposed rules do not change the existing drinking water standards for PFOA and PFOS, they could affect how some public water systems approach compliance planning. If finalized, the proposed extension framework would provide eligible systems with additional flexibility to address technical, operational, and financial challenges associated with PFAS treatment and compliance.
For many water systems, addressing PFAS contamination may require extensive sampling, evaluation of treatment alternatives, infrastructure upgrades, workforce training, and long-term operational planning. Additional implementation time could allow utilities to better coordinate these efforts, while taking advantage of evolving treatment technologies and funding opportunities. Fewer monitored PFAS analytes, and the elimination for the Hazard Index approach is projected to reduce the overall compliance burden.
As EPA’s PFAS regulatory framework continues to evolve, water systems, municipalities, and other stakeholders should closely monitor future developments and evaluate how changing requirements may affect current and planned PFAS management activities. Proactive planning and awareness of emerging regulatory and funding opportunities can help organizations prepare for future compliance obligations while continuing to address PFAS challenges in their communities.
Bottom Line
EPA is not weakening the PFOA/PFOS standards of 4 ng/L. Instead, it is proposing to give water systems more time to comply due to practical constraints. The proposed rule also simplifies PFAS regulation by focusing on PFOA and PFOS and removing certain other PFAS provisions.
Next Steps
On July 7, 2026, there will be a public hearing for interested parties to weigh in on the deadline extension and the procedural approach for rescinding additional PFAS provisions. EPA will be taking public comments until July 20, 2026.
