No federal PFAS limit for sewage sludge spread on farmland — nine metals regulated since 1993, zero pollutants added in 33 years

What is happening?

The federal rule for sewage sludge spread on farmland, 40 CFR Part 503, sets no limit on PFAS. As of 2026-08-08 the current text of section 503.13 carries numeric limits for nine pollutants, all of them metals and all of them placed there in 1993, and no entry at all for PFOA, PFOS or any other PFAS compound. About 2.39 million dry metric tons of sewage sludge were applied to land in the United States in the 2024 reporting year, roughly 59.5 percent of the national total.

The governing statute, section 405(d)(2)(C) of the Clean Water Act, directs the Administrator to review those regulations not less often than every two years for the purpose of identifying additional toxic pollutants and promulgating regulations for them. EPA has completed nine such reviews covering 2004 through 2021, the most recent published in December 2022. Those reviews and the national surveys behind them have identified over 700 chemicals in sewage sludge, eleven of them PFAS. The number of pollutants added to section 503.13 since 1993 is zero.

Two events in the past twelve months closed the two routes that might have changed that. On 2025-09-29 the United States District Court for the District of Columbia dismissed a citizen suit seeking to force EPA to act, holding that the review duty is non-discretionary but that the statute fixes no date-certain deadline to identify or regulate anything the review finds. On 2026-07-01 EPA released a draft guidance memorandum describing its own January 2025 draft risk assessment as seriously flawed and offering voluntary recommendations in its place. As of 2026-08-08 there is no final risk assessment, no proposed rule, and no numeric threshold anywhere in the guidance.

Whose problem is this?

The body that would have to write the limit is the same body that modeled the risk and then set its own model aside. Nothing outside that body can compel a number, and a federal court has now said so in as many words.

Where does this problem end?

The boundary matters because the science question and the legal question have different answers here. One part of the government modeled the harm and another part found that nothing in the statute obliges anyone to act on it.

What is the state now, and what should it be?

Now

Needs a new measurementthe target state: no source opened here names a concentration a federal rule would set, a date by which a Part 503 PFAS limit would exist, or a criterion by which a reader could tell whether the situation is improving. The January 2025 notice said EPA expected to propose a regulation under section 405 if the final risk assessment showed risks above acceptable thresholds, and named neither the thresholds nor a schedule. The June 2026 memorandum says EPA may use public comments to inform any future agency actions, which is the only forward-looking sentence in it and commits to nothing.

How big is it?

Measured, Maine only. Maine DEP collected about 2,919 mostly residential groundwater samples at sludge and septage land-application sites, of which 20 percent exceeded the state interim drinking water standard of 20 parts per trillion for the sum of six PFAS, as of 2024-10-31. That is roughly 584 wells, or at a United States average household size of about 2.5 persons roughly 1,500 people. That sampling represents about 45 percent of the groundwater investigation, measured against 1,066 identified sites, so completing it at the same exceedance rate implies roughly 1,300 wells and about 3,200 people. Maine has about 1.4 million residents and is one state of fifty.

Scale of the material. About 4 million dry metric tons of sewage sludge were generated in the United States in the 2024 reporting year and about 2.39 million were applied to land. About 20 percent of all sewage sludge is sold directly to the public as bagged or bulk soil products, which on 2024 volumes is roughly 800,000 dry metric tons a year.

The Maine interval is a floor under a floor. It was measured against a screen five times looser than the federal drinking water limit of 4.0 parts per trillion, and Maine DEP told its legislature that applying the federal limit would enlarge the affected set beyond what the state can fund, without saying by how much.

Needs a new measurementthe affected population: no source opened here supports a national figure, and the reason it is missing is the reason the limit is missing. Three inputs would be required and none exists — the number of land-application sites outside Maine, for which there is no national register and for which the EPA count of about 2,350 reporting facilities is no substitute because it counts sludge generators rather than fields; the number of households on or adjacent to those sites and how many draw private well water; and the number of households using retail biosolids-derived soil products. The population file therefore records not-derivable. What can be stated is a measured floor from one state and the scale of the material.

Under what conditions does it arise?

1. The statute requires looking and does not require concluding. Section 405(d)(2)(C) directs EPA to review the regulations not less often than every two years for the purpose of identifying additional toxic pollutants and promulgating regulations for them. On 2025-09-29 the district court read the phrase for the purpose of as imposing at most a prospective duty, contrasting a neighboring Clean Water Act provision where Congress instead wrote that the agency shall review and, as necessary, revise. With no date-certain deadline the citizen-suit waiver of sovereign immunity does not reach the failure to regulate, and the court dismissed those counts for lack of jurisdiction.

2. The identification step carries no legal consequence, so it runs freely and changes nothing. The same opinion held that the biennial report is not final agency action because it neither determines rights or obligations nor creates legal consequences, and does not tell regulated parties what they must do to avoid liability. A finding that produces no obligation is cheap to make and safe to make. Nine reviews have named over 700 chemicals and eleven PFAS, and section 503.13 still lists the nine metals of 1993.

3. The same molecules carry an enforceable number under a different statute, with no bridge between the two. PFOA and PFOS have carried a federal drinking water limit of 4.0 parts per trillion since 2024-04-10, because the Safe Drinking Water Act has a candidate-list and regulatory-determination pipeline with statutory triggers. Section 405(d) has no equivalent trigger, and nothing carries the drinking water number into the sludge rule — even though the dominant exposure pathway in the EPA model runs from sludge to soil to groundwater to that same drinking water.

4. The disposal alternatives cost at least double, and the parties who would pay are not the parties who produced the PFAS. An October 2020 analysis prepared by a consulting engineering firm for three water-sector membership associations found average biosolids management cost up about 37 percent in response to PFAS concerns, found that facilities reverting from beneficial reuse to landfill face costs at least double their previous level, and reported no proven or established technology to remove PFAS from biosolids. A national association of publicly owned treatment works later intervened on the side of EPA in the citizen suit.

5. The occurrence data a rule would rest on has not been collected since 2006. The last national survey was the 2006 Targeted National Sewage Sludge Survey. As of the EPA page dated 2026-01-05 the next one is still being planned, with questionnaires to about 400 large treatment facilities and 200 to 300 of them selected for sampling under EPA Method 1633. No date is given for any of it.

What has been tried?

Two directions were tried at the federal level — model the risk, and then advise instead of limiting. The third direction, litigation, ran into the text of the statute. The only place a number now exists is the state layer.

What was found?

Why is it still unsolved?

Institutional gap — the clause that would produce a limit obliges EPA to look and does not oblige it to conclude, and in 2025 a federal court said so in those terms.

The first movement is the statute. Congress wrote that the Administrator shall review the regulations for the purpose of identifying additional toxic pollutants and promulgating regulations for them. On 2025-09-29 the district court read that phrase as creating at most a prospective duty, and contrasted a neighboring provision where Congress instead wrote shall review and, as necessary, revise. Because section 405(d)(2) sets no date-certain deadline, the citizen-suit provision does not waive immunity and there is no jurisdiction. The court also held that the biennial report is not final agency action, since it creates no legal consequence and tells regulated parties nothing about what they must do. Put the two holdings together and the design becomes visible. The one step the statute makes mandatory is the step that changes nothing, and the step that would change something is the step nobody can compel. Nine reviews, over 700 chemicals, eleven PFAS named, zero regulated. This is not an agency evading a rule. It is a rule that was never written to be evaded.

The second movement rules out the explanation a reader reaches for first, which is that nobody has got to it yet. The 2026 Unified Agenda for EPA carries ten PFAS rulemakings, spread across effluent guidelines, discharge permits, drinking water, hazardous waste listing and chemical reporting. It carries none for sewage sludge. The same two molecules already have an enforceable federal number of 4.0 parts per trillion in drinking water, final since 2024-04-10, because that statute has triggers that force a determination on a schedule. Two regulatory regimes touch one molecule at two points on one pathway and nothing connects them. The agency is moving on PFAS wherever a trigger exists and standing still in the single place where the material is spread on the ground.

The third movement is what fills the vacuum, and it is here that the cost story has to be placed correctly. The costs are real. The October 2020 industry analysis put the average increase in biosolids management cost at about 37 percent and found that facilities reverting to landfill face at least double their previous costs, with no established technology to remove PFAS from biosolids. That is why the parties fight, and it explains the shape of what the states did — Michigan set a threshold designed to find large industrial dischargers rather than one derived from health endpoints, and Maine, which banned outright, then discovered it had no in-state incinerator and limited landfill capacity. But cost is the content of the dispute and not the reason the dispute has no terminus. In a statute with a trigger the same fight happens inside a rulemaking, on a record, against a deadline, and it ends in a number somebody can appeal. Here the fight substitutes for the rulemaking. The closing move came in 2026, when EPA faulted its own draft for resting on no national occurrence survey and put advice in its place — a survey the agency has not run since 2006 and has not yet begun to collect. The critique is accurate and it is self-inflicted.

What observation would mean it is solved?

Candidates — (a) EPA publishes an amendment to Part 503 carrying a numeric limit for PFOA and PFOS with a stated effective date (b) national occurrence data exist, meaning a completed national sewage sludge survey and a published count of the land that receives this material (c) the share of land-applied sewage sludge covered by an enforceable numeric threshold, federal or state, rises toward all of it.

(a) alone is weaker than it looks. A number can be set where the material already sits. The state thresholds now in force run from 50 to 100 parts per billion while the EPA model started at 1 part per billion, and the documentation behind the Michigan tiers says plainly that they were not derived from health-based endpoints. A federal limit pitched at a level existing disposal capacity can absorb would satisfy this observation without moving any exposure.

(b) alone measures the ground and not the rule. Maine shows what measurement costs and what it does not buy on its own. Five years, about USD 19.9 million, a site list that grew from an estimated 700 to 1,066 as staff read decades of files, and the investigation is under half done. Measurement did lead to action in Maine, but through the state legislature. Eleven PFAS were measured and listed federally across nine reviews and nothing followed.

(c) alone counts paper across a boundary it cannot see. Coverage would be counted in state statutes, and one amicus contention in the pending appeal holds that many states treat federal biosolids standards as a ceiling rather than a floor, which if true would mean federal silence suppresses the state layer rather than leaving it free. That contention is an advocacy assertion in a brief and not a finding, and no source opened here tests it. The three have to be read together, and (a) has to be read against the number it sets.

What is it connected to?

Fills with researchPFAS in drinking water and the compliance extension proposed on 2026-05-18, industrial pretreatment programs under the Clean Water Act, landfill and incinerator capacity as the alternative disposal routes, agricultural land tenure and the market for farmland with a treatment history, and the same regulatory structure in other countries. Relation type and evidence grade were not confirmed in this round.

What these sources do not say

• How many acres receive this material. The tonnage is published and the divisor is published twice and differently — 10 dry metric tons per hectare, which is 4.05 per acre, in the January 2025 notice, and about 3 per acre in the June 2026 memorandum, a gap of about 35 percent with neither document citing the other. Dividing about 2.3 million dry metric tons by 4.05, by 3, and by the 1 per acre EPA actually used in its own footnote gives about 568,000, about 767,000 and about 2,300,000 acres a year. That arithmetic is performed here and is published by no source. EPA performs the division once, at the assumption that maximizes acreage, and converts the result straight into a percentage of American farmland without ever stating the acreage as a fact.
• How many people live on or next to those fields. The EPA model named that group as carrying the highest modeled risk. In July 2026 EPA faulted its own assessment for not estimating how often such higher-risk scenarios occur in the United States, and then did not produce the estimate. The gap is now acknowledged by the agency and still empty.
• Whether a national register of land-application sites could be built. Maine had to assemble one by reading decades of project files, and the count grew from an estimated 700 to 1,066 as staff read. No federal document opened here addresses the question. The EPA figure of about 2,350 counts reporting facilities, which are sludge generators, and one plant can supply many fields.
• What the target is. No source names a concentration a federal rule would set, a date by which it would exist, or a criterion for improvement. The 2026 Unified Agenda has ten PFAS entries and no Part 503 line, and does not say why the line is absent.
• What the state thresholds mean in health terms. The documentation behind the Michigan tiers says they were not derived from health-based endpoints and were designed to identify the most significant industrial dischargers. That disclosure survives in the EPA memorandum and generally does not survive into the reporting. No source opened here tells a reader that the EPA figure of 1 part per billion and the state thresholds of 50 to 100 parts per billion answer different questions.
• Anything about the retail channel. About 20 percent of national tonnage is sold to the public as bagged or bulk soil products, which EPA says may be applied to homes and gardens as well as parks, schools and playgrounds. No source states how many such products exist, which retailers carry them, or how many households use them. The entire federal instruction to those buyers is to research the supplier and to avoid places children may reach, and there is no labeling requirement that would let a buyer identify the supplier — so the recommendation names an action the reader has no means to perform.
• Whether a review covering 2022 and later exists. Three independent documents spanning eighteen months name December 2022 as the most recent completed review, and the EPA list updated 2026-06-22 ends at report number 9. No document opened here names a successor and none remarks on the absence. This is recorded as an absence in the record and not as a breach, because whether the two-year clock runs from publication or from the end of the reporting period is genuinely ambiguous, and the plaintiffs litigating this exact clause did not plead a failure to review.
• What a federal limit would cost. The cost literature prices state action and market avoidance, including a projected national municipal biosolids management spend rising from about USD 2.5 billion a year in 2025 to about USD 4.8 billion by 2035. No source prices a Part 503 PFAS limit, because pricing one requires a regulatory impact analysis and that requires a proposed rule. The absence of the rule also erases the number anyone would argue about.

See the evidence

Four documents were read directly and end to end — the current text of section 503.13, the memorandum opinion of 2025-09-29, the January 2025 Federal Register notice, and the June 2026 draft guidance memorandum — together with the executive summary of the Maine DEP report and of the October 2020 cost analysis. Everything else is secondary. Several claims rest on one defense-side article and are attributed to it in the text rather than stated flatly, including the count of fifteen states, the appellate briefing posture and the regulatory-ceiling contention, which is an amicus argument and not a judicial finding. The one claim of that kind that could be checked independently was checked — that no pollutant has been added since 1993 is corroborated by the rule text still carrying only the nine metals. Three disagreements are left visible rather than resolved. EPA states the land-applied share as about 56 percent in the January 2025 notice and 59.5 percent on a page dated 2025-09-26, with neither citing the other. EPA states the median application rate as 10 dry metric tons per hectare, which is 4.05 per acre, in that same notice and as about 3 per acre in the June 2026 memorandum, a gap of about 35 percent, again with neither acknowledging the other. And the posture of the Texas product liability case is given as a pending motion to dismiss by the secondary source and as a termination dated 2026-02-02 by the docket search, which could not be reconciled because the docket detail was not reachable. This is a Path A output (research-based definition), so observation_refs is empty and provenance_mode: press-derived.

People affected

Estimated range Not derivable

The reason and what is missing are listed under “What is missing” below