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

Here’s where US PFAS regulation stands in mid-2026, and it is genuinely messy. In 2024 the EPA finalized national drinking water standards for six PFAS compounds — enforceable maximum contaminant levels. Just over a year later, in May 2026, the same agency proposed withdrawing several of those standards, arguing that procedural errors in the 2024 NPDWR rulemaking process undermined their legal footing. The proposal covers MCLs for PFHxS, PFNA, and GenX chemicals. States, environmental groups, and public health advocates pushed back hard, and as of July 2026 at least 12 states have formally said they will keep their own PFAS drinking water standards regardless of what the federal government does.

For utilities and the people who spec their monitoring, this split creates a real compliance headache. The equipment, sampling frequencies, and strategies that made sense under the 2024 framework may not line up with whatever replaces it. So what is driving the state-level resistance, and what should monitoring infrastructure look like while the rules are in flux?

The Science States Are Basing Their Pushback On

State health departments have not been waiting on Washington. Several states resisting the rollback ran their own health assessments, often landing on numbers more protective than the federal ones. The Minnesota Department of Health set a health-based limit for PFOS at 7 parts per trillion in 2025, using toxicological data that did not exist during the federal rulemaking.

New Jersey went further, adopting enforceable standards of 13 parts per trillion for PFNA and 14 parts per trillion for PFHxS — levels that directly contradict the EPA’s plan to eliminate those MCLs. Per the New Jersey Department of Environmental Protection, those numbers rest on a review of peer-reviewed epidemiological studies linking PFAS exposure to immune suppression, developmental effects, and increased cancer risk.

The Procedural Argument vs. the Science

The EPA’s rollback rests on a narrow procedural claim: that the agency did not properly follow the Administrative Procedure Act’s notice-and-comment requirements during the 2024 rulemaking. Notably, the agency has not disputed the underlying science linking PFAS exposure to adverse health outcomes. That distinction matters. States opposing the rollback argue that even if the process needs correcting, the scientific basis for the limits stands on its own and remains legally sufficient.

The 87-page formal objection New Mexico submitted on July 20, 2026 lays out the counter-case in detail: the cited procedural deficiencies were not material to the rule’s scientific conclusions, and withdrawing the MCLs would leave millions of Americans without enforceable protection for compounds with well-documented health effects.

What a Patchwork of Standards Does to a Utility

When federal and state rules diverge, compliance stops being one-size-fits-all. A utility serving communities in several states may have to monitor different compound lists at different detection limits depending on jurisdiction — with the most stringent state standard sometimes as low as 1 part per trillion for certain compounds.

Run the math on a mid-size regional authority operating plants in three states: six PFAS compounds at the 4 ppt federal MCLs, another twelve compounds at varying state-level MCLs, plus unregulated PFAS under state-specific monitoring mandates. Analytical costs alone can top USD 200,000 per year before counting sampling infrastructure and data management.

Monitoring That Survives a Rollback

The counterweight to all this uncertainty is continuous monitoring that adapts as targets change. Lab methods tie you to specific sample collection, preservation, and shipping protocols. Inline sensors don’t: they measure the same physical parameters no matter what the regulation says. When thresholds shift, only the interpretation algorithms and alert setpoints need updating.

That logic carries through ChiMay’s portfolio. The in-line conductivity meter tracks total dissolved ionic species, including ionic PFAS compounds. The COD sensor delivers UV-Vis absorption data that correlates with organic PFAS precursor concentrations. The online turbidity tester watches particle removal at treatment systems designed to adsorb or filter PFAS. Together they form a monitoring layer that stays useful regardless of which compounds are regulated, or at what levels.

The 4-in-1 Multi-Parameter Sensor (pH, ORP, conductivity, temperature in one body) supports the same argument — those measurements stay valid indicators of water quality shifts, contamination events, and treatment system performance even when the rulebook changes. The residual chlorine transmitter covers the other side of the equation: as plants add PFAS treatment steps like granular activated carbon or membrane filtration, the disinfection regime changes, and continuous residual chlorine monitoring keeps those modifications from quietly creating disinfection by-product compliance problems.

The Money Already on the Table

Utilities that built PFAS monitoring programs around the 2024 rules now face an awkward question: if the rollback goes through, was that investment wasted? The short answer is no, and the funding picture explains why. The Water Infrastructure Finance and Innovation Act has committed over USD 1 billion in loans and grants to PFAS treatment and monitoring projects. Add the Bipartisan Infrastructure Law’s USD 4 billion allocation for emerging contaminants, and utilities with active monitoring programs are positioned better for federal assistance — while utilities that scrap their programs in response to the rollback could find themselves shut out of that money.

No one can say yet how the rollback lands. Public comment periods, litigation, and politics will all have a say. What is clear: state requirements, federal funding, and public awareness mean PFAS monitoring stays a priority either way. The sensible move is infrastructure that holds value across multiple regulatory outcomes — which, frankly, is why we design the sensors the way we do.