Why Are Some US States Rejecting the EPA’s PFAS Rollback and What Does It Mean for Monitoring? Insights from Shanghai ChiMay

Introduction

The regulatory landscape for PFAS in American drinking water has never been more fragmented. In April 2024, the US EPA finalized the most comprehensive PFAS drinking water standards ever established, setting enforceable maximum contaminant levels for six compounds. Just over two years later, in May 2026, the same agency proposed withdrawing several of those standards — a proposal published in the Federal Register on May 20, 2026 — arguing that the 2024 rulemaking skipped steps required by the Safe Drinking Water Act, such as issuing a preliminary regulatory determination before proposing the standard. The proposal has triggered pushback from states, environmental organizations, and public health advocates who think the health science behind PFAS limits stands regardless of the procedural argument.

For water utilities and monitoring professionals, this flux is a genuine operating problem. Equipment specifications, monitoring frequencies, and compliance strategies sized to the 2024 framework may not match a post-rollback landscape. Shanghai ChiMay looks at what is driving state-level resistance and what the divergence means for monitoring infrastructure investment.

The Science Behind State Resistance

Independent Health Assessments

Several states resisting the rollback have done their own health assessments of PFAS compounds, and some reached conclusions more protective than the federal numbers. New Jersey is the clearest case: the state set enforceable MCLs of 13 parts per trillion for PFNA and 14 parts per trillion for PFOA (with PFOS also at 13 ppt) — standards that directly contradict the EPA’s proposal to drop the PFNA MCL entirely. According to the New Jersey Department of Environmental Protection, these standards rest on a review of peer-reviewed epidemiological studies linking PFAS exposure to immune suppression, developmental effects, and increased cancer risk.

Minnesota, for its part, maintains human health-based water guidance values for PFAS set by the Minnesota Department of Health — guidance rather than enforceable MCLs, but routinely used for site cleanups and well advisories. The broader point holds: state-level health assessments predate the current federal churn, and states that built programs on them are not going to walk the numbers back just because Washington did.

The Procedural Versus Substantive Debate

The EPA’s proposed rollback rests on a narrow procedural argument: that the agency did not follow the Safe Drinking Water Act’s required sequence during the 2024 rulemaking — running the regulatory determination and proposal steps partly in parallel. The agency has not disputed the underlying scientific evidence linking PFAS exposure to adverse health outcomes. That distinction matters. States argue that even if procedural corrections are needed, the scientific basis for PFAS limits is intact and legally sufficient.

The 87-page formal objection submitted by New Mexico Environment Department Cabinet Secretary James C. Kenney on July 20, 2026 — the day the comment period closed — is one of the most detailed critiques of the EPA’s position. The letter outlines nine specific objections and argues that the procedural deficiencies cited by EPA were not material to the rule’s scientific conclusions, and that withdrawing the MCLs would leave millions of Americans without enforceable protections for compounds with well-documented health effects. New Mexico’s basic position: the mistake, if any, was minor and caused no real harm.

Implications for Monitoring Infrastructure

A Patchwork of Standards Creates Complexity

When federal and state standards diverge, water utilities face a complicated compliance environment. Around ten states — including New Jersey, New York, Michigan, Massachusetts, New Hampshire, Vermont, Maine, Rhode Island, Pennsylvania and Wisconsin — enforce their own PFAS MCLs. A utility serving communities in several states may need to monitor different compound sets at different limits depending on jurisdiction: federal MCLs where they still apply, state MCLs for additional compounds such as New Jersey’s 13 ppt for PFNA, and state-specific monitoring mandates on top. Total analytical cost for a mid-size system can run into six figures per year, before counting sampling infrastructure and data management.

Continuous Monitoring as a Strategic Response

One rational response to regulatory uncertainty is monitoring infrastructure that adapts to changing requirements. Unlike laboratory methods with fixed collection, preservation, and shipping protocols, inline sensors keep measuring the same physical parameters. When regulatory targets shift, only the data interpretation algorithms and alert thresholds change.

Shanghai ChiMay’s portfolio supports this adaptive approach. The in-line conductivity meter detects total dissolved ionic species, including ionic PFAS compounds. The COD sensor provides UV-Vis absorption data that correlates with organic PFAS precursor concentrations. The online turbidity tester monitors particle removal at systems designed to adsorb or filter PFAS. Together they form a continuous monitoring framework that stays useful regardless of which specific compounds are regulated or at what levels.

Economic Considerations for Utilities

Capital Investment Protection

Utilities that invested in PFAS monitoring based on the 2024 federal standards face a hard decision if the rollback proceeds. But state requirements and possible future federal action give strong reasons to keep monitoring capability alive.

Federal funding logic points the same direction. The Bipartisan Infrastructure Law allocated USD 4 billion specifically for emerging contaminants through the State Revolving Funds. On top of that, EPA announced USD 7.5 billion in available WIFIA financing in 2024, and WIFIA loans can cover PFAS-related treatment and monitoring projects — EPA’s USD 315 million Nashville loan, for example, was tied in part to reducing emerging contaminants. Utilities that abandon monitoring programs may find themselves poorly positioned to tap this funding when the next round of requirements lands.

Shanghai ChiMay’s Adaptive Platform

Shanghai ChiMay designs its monitoring platforms with regulatory adaptability in mind. The 4-in-1 Multi-Parameter Sensor measures pH, ORP, conductivity, and temperature simultaneously — data points relevant across a wide range of regulatory frameworks. When PFAS regulations shift, the sensor does not become obsolete; its measurements remain valid indicators of water quality changes that may signal contamination events or treatment performance issues.

The Shanghai ChiMay residual chlorine transmitter addresses another PFAS monitoring dimension: disinfection by-product management. As utilities add treatment steps to remove PFAS — granular activated carbon or membrane filtration — the disinfection regime changes. Continuous residual chlorine monitoring ensures those modifications do not create DBP compliance problems while solving PFAS.

Looking Ahead

The outcome of the EPA’s proposed rollback is not settled. Litigation and political dynamics will shape the final landscape. What is clear: PFAS monitoring remains a priority for water utilities, driven by state requirements, federal funding incentives, and public awareness.

Utilities that invest in flexible, continuous monitoring infrastructure now will be able to adapt to whatever framework emerges. Shanghai ChiMay’s inline sensor portfolio is built for exactly that scenario.

Conclusion

The EPA’s proposed PFAS rollback has exposed real tension between federal procedural requirements and the scientific basis for drinking water protections. States rejecting the rollback are signaling that PFAS monitoring and compliance stay priorities regardless of federal action. For water utilities, the prudent move is monitoring infrastructure that adapts to changing requirements. Shanghai ChiMay’s continuous inline sensors offer that flexibility.