Navigating PFAS regulation: what utilities need to know now

In April 2024, the U.S. Environmental Protection Agency (EPA) finalized the first-ever National Primary Drinking Water Regulation (NPDWR) for PFAS, establishing enforceable Maximum Contaminant Levels (MCLs) for six compounds, including PFOA and PFOS. [epa.gov]

Under this rule, public water systems are required to:

• Complete initial monitoring by 2027
• Begin compliance monitoring and public reporting thereafter
• Implement solutions to meet MCLs by 2029

However, recent developments signal a shift in approach. In May 2026, EPA introduced proposals to:

• Retain MCLs for PFOA and PFOS (4 ppt)
• Rescind regulations for four additional PFAS compounds (PFHxS, PFNA, GenX, and PFBS mixtures)
• Extend compliance deadlines from 2029 to 2031 for some systems 

This reflects both legal challenges and practical considerations, including feedback from utilities on the feasibility of meeting aggressive timelines.

• 2024: Final PFAS drinking water rule issued, establishing enforceable limits for six PFAS
• 2024–2027: Initial monitoring and reporting period
• 2027: Public disclosure of PFAS levels begins
• 2029: Original compliance deadline for treatment implementation
• 2025–2026: EPA signals regulatory revisions and reassessment of certain PFAS
• 2026 (proposed): Extension of compliance deadlines to 2031 and rescission of select compounds

This timeline illustrates a regulatory environment that remains active and subject to change, particularly as legal and scientific considerations evolve.

PFAS encompasses a large class of fluorinated synthetic chemicals used since the 1940s. A defining characteristic is their persistence, they break down very slowly and accumulate in the environment and human body over time.
 
Exposure pathways are widespread, including drinking water, air, food, soil, and consumer products (i.e. food containers, water proofing agents and cookware). As a result, most people in the United States have been exposed to some level of PFAS.
 
Scientific understanding of health impacts continues to evolve. Research has identified associations between PFAS exposure and a range of effects, including impacts on cholesterol levels, immune response, liver function, and developmental outcomes.
 
At the same time, there remain gaps in toxicity data for both legacy and emerging PFAS compounds. There are also limitations in the understanding of low-level, long-term exposure and combined effects of different PFAS compounds. As highlighted in technical discussions, this creates a nuanced challenge: regulations are advancing while the underlying science is still developing.

The current regulatory environment presents a balancing act. While EPA continues to refine the scope and timeline of its PFAS rules, utilities must make near-term decisions on monitoring, treatment, and investment.

Based on current regulations and industry discussions, several practical considerations stand out:

1. Continue planning against established standards
   Even with proposed revisions, the MCLs for PFOA and PFOS remain in place. Designing solutions that meet these thresholds positions utilities to remain compliant regardless of future changes.
2. Build flexibility into treatment strategies
   Treatment technologies capable of addressing multiple PFAS compounds, beyond just PFOA and PFOS, provide resilience in a shifting regulatory environment.
3. Prioritize monitoring and data collection
   Early and robust monitoring helps utilities understand their baseline conditions and make informed decisions, particularly as public disclosure requirements take effect.
4. Track regulatory developments closely
   With ongoing rulemaking and potential legal challenges, staying informed is essential. The direction of regulation may continue to evolve over the next several years.
5. Be transparent with customers
   Users just want to know the water they drink is safe, and trust utilities to provide it. Communicating changes, improvements or new regulations should be done regularly and often through news media, direct communications and advertising. Thoughtful approaches to gauge user sentiment and adjusting a communications plan around that will go a long way to helping utilities retain trust and reputation regardless of regulatory changes.
   
    

PFAS regulation is entering a new phase, one defined not just by enforceable standards, but by uncertainty in how those standards will ultimately be interpreted and applied.

For utilities, a purely reactive approach is no longer sufficient. The most effective strategy is proactive and pragmatic: act on what is known, prepare for what may change, and invest in solutions that deliver long-term resilience. This includes providing flexible treatment solutions that will allow for advances in PFAS removal media, especially activated carbon, ion exchange resins, and specialty media that may be developed in the future.

GHD is working alongside utilities and public agencies to navigate this complexity with confidence. From regulatory interpretation and monitoring strategies to treatment selection and funding pathways, our teams bring together technical, scientific, and delivery expertise to help clients make informed, defensible decisions now, not later.

Whether you are:

• Evaluating PFAS risk and compliance exposure
• Selecting or piloting treatment technologies
• Developing phased investment plans aligned to evolving regulations
• Or communicating findings to stakeholders and communities

We help you move from uncertainty to action.

In a rapidly shifting landscape, the organizations that succeed will be those that combine sound science with practical implementation. GHD is ready to support you, turning regulatory complexity into clear, actionable pathways forward.