Eighteen State Attorneys General Tell EPA Its PFAS Rollback Is Illegal Under the Safe Drinking Water Act

The comment period on EPA’s proposed rescission of four PFAS drinking water standards closed July 20, 2026, and the filings that landed in the final days make one thing clear: this rule is going to court. A coalition of 18 state attorneys general and the District of Columbia, led by North Carolina’s Jeff Jackson, submitted a 17-page comment letter to Administrator Lee Zeldin arguing the rescission is not merely bad policy but unlawful — that it runs directly into the Safe Drinking Water Act’s anti-backsliding provision, a clause Congress wrote specifically to stop EPA from weakening an existing drinking water standard. WaterVerge covered the approaching comment deadline on July 22; this is what was actually filed, and why the legal theory in it matters more than the volume of comments.

Who Filed

The Jackson-led coalition comprises the attorneys general of Arizona, California, Colorado, Connecticut, Delaware, the District of Columbia, Hawai’i, Illinois, Maine, Massachusetts, Minnesota, New Jersey, New York, North Carolina, Oregon, Rhode Island, Washington, and Wisconsin.

Several AGs filed or publicized additional comments of their own on July 21 and 22 — Minnesota’s Keith Ellison as part of a nine-state group, Massachusetts’ Andrea Joy Campbell describing a 19-signatory letter, Illinois’ Kwame Raoul with 16 colleagues, Maryland’s Anthony Brown, California’s Rob Bonta, and Arizona’s Kris Mayes. The overlapping counts reflect several parallel letters rather than disagreement; the substantive legal argument is consistent across them.

The composition is worth noting. This is not a coalition of states that lack PFAS problems weighing in abstractly. North Carolina is the Cape Fear River state, subject of our GenX case study and a party to the $450 million Chemours settlement. Maine has the biosolids contamination and blood-testing program we covered in June. New Jersey, Michigan, and Minnesota wrote their own PFAS standards before EPA did, as tracked in our state-level PFAS actions coverage.

The Legal Argument: Section 1412(b)(9)

The heart of the filing is a single statutory provision.

SDWA Section 1412(b)(9) governs how EPA revises a National Primary Drinking Water Regulation. It requires that any revision “maintain, or provide for greater, protection of the health of persons.” This is the anti-backsliding provision. Congress added it because it anticipated exactly this scenario — a future administration weakening a health standard already on the books — and chose to foreclose it in the statute rather than leave it to the ordinary give-and-take of rulemaking.

The AGs’ argument follows straightforwardly. EPA’s 2024 rule set enforceable limits on six PFAS compounds. The proposal would rescind four of them — the standards for PFHxS, PFNA, HFPO-DA (GenX), and the mixture hazard index — while extending the PFOA and PFOS compliance deadline to 2031. Rescinding a standard does not maintain protection and does not increase it. It reduces it. The states characterize the action as arbitrary and illegal and argue EPA cannot use the revision authority in 1412(b)(9) to do something the same subsection forbids.

The practical consequence they emphasize: if the rescission takes effect, public water systems will no longer be federally required to test for these compounds, report the results, or treat to remove them. The monitoring obligation disappears along with the limit — which means the occurrence data that would justify re-regulating later stops being collected.

Why the Comment Letter Is Really a Litigation Document

Comment letters rarely change an agency’s mind, and the attorneys general involved are unlikely to expect this one will. The letter’s function is different.

Under administrative law, a party generally must raise an objection during the comment period to preserve it for judicial review. An argument not presented to the agency is ordinarily forfeited in court. A 17-page comment laying out a specific statutory violation, filed by the officials who will bring the challenge, is the procedural predicate for the lawsuit that follows the final rule.

That is why the anti-backsliding framing matters so much. Most challenges to a deregulatory rule are fought on arbitrary-and-capricious grounds under the Administrative Procedure Act — did the agency explain itself, consider the record, account for reliance interests? Those are real arguments but they are deferential to the agency, and the usual remedy is a remand for better reasoning, after which the agency can often reach the same result.

An anti-backsliding claim is categorically stronger. If Section 1412(b)(9) means what the states say it means, EPA does not have the authority to issue this rule at any level of explanatory quality. That is not a remand; that is vacatur. Legal analysts across the practice — including firms advising the regulated side — have flagged the anti-backsliding provision as the most serious obstacle the rescission faces.

What Happens to Utilities in the Meantime

The uncertainty is itself the problem for water systems, and it compounds a squeeze WaterVerge has documented all year.

A utility with PFAS above the 2024 limits faces a decision it cannot defer indefinitely: install treatment costing millions, or wait to see whether the obligation survives. Waiting is rational if the standard is rescinded and catastrophic if it is rescinded, litigated, and reinstated — because the compliance clock will not restart.

Two forces push toward building now. The 3M and DuPont settlement funds close to new claims on July 31 and August 1, 2026, and as we covered in our settlement deadline article, that money is available regardless of what happens to the federal standard. And state standards do not disappear with the federal ones — New Jersey, Michigan, Minnesota, Maine, and others have their own enforceable PFAS limits that a federal rescission leaves untouched. A utility in one of those states gains nothing from the rollback.

The force pushing the other way is cost. PFAS treatment is expensive, and the bill lands on ratepayers — the dynamic behind rate increases WaterVerge has tracked in Portland and San Francisco and Pittsburgh.

What This Means for Your Water

The federal fight will take years. Your exposure does not wait for it.

Find out whether your system has PFAS. UCMR 5 monitoring data covers 29 PFAS compounds for systems serving more than 3,300 people, and WaterVerge folds those results into city water profiles. Your annual Consumer Confidence Report is the other place to look.
Check whether your state has its own standard. If you live in a state whose AG signed this letter, there is a reasonable chance it does — and state limits are unaffected by the federal proposal.
Filter if you want certainty now. Reverse osmosis and certified activated-carbon systems remove PFAS at the tap irrespective of any rulemaking. See our PFAS filter guide, reverse osmosis systems guide, and NSF certification explainer — certification is what separates a filter that removes PFAS from one that claims to.
Pregnant residents and families with infants should read our pregnancy water quality guide and infant water safety guide. The developmental endpoints are the reason these limits were set at parts per trillion.
Private well owners get no protection from any federal PFAS standard, rescinded or not — see our private wells and PFAS guide.

Our PFAS explainer and PFAS contaminant page cover the underlying chemistry and health basis.

What Comes Next

EPA must now review the comment record and issue a final rule. There is no statutory deadline forcing speed, and the agency has a second proposal pending — the PFOA/PFOS compliance extension to 2031 — that may move on a separate track.

When a final rescission issues, expect petitions for review in the DC Circuit within days, filed by some combination of these state AGs and environmental organizations. The SDWA channels challenges to national primary drinking water regulations to that court. Watch for a request to stay the rule pending review: if the states obtain a stay, the 2024 limits remain operative during the litigation and utilities’ compliance planning largely continues unchanged. If they do not, systems face years of regulatory limbo.

How WaterVerge Tracks This

WaterVerge reports PFAS occurrence from EPA UCMR 5 monitoring data and compliance history from SDWIS, both of which are independent of whether a given limit is currently enforceable. If the rescission takes effect, the UCMR 5 dataset becomes the last comprehensive federal record of PFAS in American drinking water for these compounds — which is precisely why we built the city profiles on it. We will update this article as the final rule and any litigation develop.