How State PFAS Limits Reach Compost That Never Contained Biosolids

The money leaves as a product that stops being a product. A facility that's sold Class A compost to nurseries and vegetable growers for a decade gets a letter saying the finished material is now a residual, and the same cubic yards that moved at a positive price in spring need a disposal outlet by fall. Hauling, tip fee, and a lost revenue line in one quarter. That's what PFAS in compost costs an organics processor, and the bill rarely arrives through a limit written for compost. It arrives through a feedstock definition inside a biosolids rule.

Take the sequence in the order the exposure runs, because the order decides whether you're managing a problem or reading about it in your mail.

Step one: the feedstock definition is the operative text

No federal number applies to your pile. The pollutant ceilings in 40 CFR Part 503 cover nine metals, and neither PFOA nor PFOS is among them. EPA's draft guidance on PFOA and PFOS in biosolids, issued as an Office of Water memo at the end of June 2026, is voluntary by its own terms and doesn't supersede state requirements. I read the whole document looking for the word "compost," and it isn't in there. So when a composter asks me which federal rule governs the product, the answer is that none does, and that's the worse answer. My standing rule with clients is that if you can't cite the subpart you haven't cited the rule; here there's no subpart to cite, so the binding text is whatever the state wrote, and the states wrote theirs around sludge.

The federal starting point has been unstable enough to matter here. EPA now says the one-part-per-billion concentration in its January 2025 draft risk assessment was read wrong, that it was a modeling start point and was never meant as a safe level for sewage sludge. I've written before about why a non-binding EPA memo still shrinks land application, and the same logic runs downstream into organics: processors and their customers price risk off the number in circulation, whatever its legal status.

State drafting works off a narrower hook. A composting facility is defined, in most state solid-waste programs, by what it accepts. Permit your site for biosolids co-composting and the sludge rule reaches you directly. Maine went furthest: its 2022 ban covers sludge and sludge-derived compost by name, the cleanest drafting I've seen on the point and also the most expensive. EPA's memo notes that about forty percent of Maine's sewage sludge had been land applied annually, and that the ban drove cost increases at utilities with limited landfill capacity and no in-state incinerator.

But the interesting case is the facility that never took a pound of sludge.

Blending provisions are how a sludge rule travels into a compost yard. Maryland's and Virginia's tier structures both let a generator blend material down under a threshold, and composting is blending: feedstock plus bulking agent plus time. A regulator who accepts blending has accepted that the number gets measured on the mixture, which makes the mixture the regulated object, which puts finished compost in scope whenever the sludge-bearing fraction is. New York's draft revision to its organics program policy takes the next step and would have permitted composting and organics recycling facilities sample for PFAS, with results published by the department. Sampling requirements aren't limits. They're the inventory a limit gets built from.

Step two: find your tier, and what the tier attaches to

The architecture is the same almost everywhere, borrowed from Michigan's interim strategy: a concentration below which you proceed normally, a middle band that buys a reduced application rate plus a source-reduction plan, and a ceiling above which land application stops (the middle band is where all the arguing happens). Roughly twenty parts per billion, fifty, and a hundred, depending on the state and the analyte. Michigan has been ratcheting the ceiling down, prohibiting land application above a hundred parts per billion PFOS where the figure stood at a hundred and fifty in 2021.

Across the five states that matter most to an organics processor, the tiers sit like this, according to the state instruments themselves and the state survey appended to EPA's June 2026 memo:

State	Threshold that stops distribution	What the limit attaches to
Maine	None; prohibition regardless of concentration, 2022 (per LD 1911)	Sludge and sludge-derived compost, named
Michigan	100 ppb PFOS (per EPA's state survey)	Land-applied biosolids, via wastewater permits
Maryland	50 ppb, prohibition from October 1, 2028 (per S.B. 719)	Land application; blending allowed below
Virginia	50 ppb either analyte, from July 2027 (per H.B. 1443)	Application, marketing and distribution
New York	50 ppb, interim program policy (per DMM-7)	Biosolids; draft adds composter sampling

One detail does most of the work in a diligence file on PFAS in compost, and it isn't a number. Michigan's tiers were never derived from health endpoints. EPA's guidance says so plainly: the concentrations were set so the state could find its largest industrial dischargers, and on that score the strategy worked, with seven treatment plants reaching up to a ninety-nine percent reduction in sludge PFOS through pretreatment. That's useful policy and a terrible basis for arguing that material sitting just under a tier is safe, which is the argument I keep getting asked to write.

Pennsylvania's draft general permit would add the same structure, and an early Mid Atlantic Biosolids Association estimate quoted during the comment period put about half of the state's generators into an actionable tier. Who ends up holding unsaleable inventory when a threshold moves mid-season?

Step three: food scraps carry their own PFAS, and no state has written a limit for it

Source-separated food scraps aren't clean by default. Goossen, Schattman and MacRae published a small comparison of finished composts in Biointerphases in 2023; the pile built largely from "compostable" food serviceware carried twenty to forty-five times the total PFAS of the food-waste composts, and one food-waste pile came back non-detect. Three samples from a single fair isn't a dataset, and the authors say as much. But the direction is the one every operator should assume, because the mechanism is plain: fluorochemical grease-proofing on molded fiber bowls and clamshells doesn't compost. It transforms into shorter-chain perfluoroalkyl acids and stays in the product you sell.

Product rules have moved faster than compost rules here, which creates an odd asymmetry. California bars calling a product compostable unless it meets specified criteria including no added PFAS, and its packaging statute has prohibited regulated PFAS in plant-fiber food packaging since January 2023. Washington phased its own packaging bans through 2023 and 2024 and requires third-party certification on compostable items. Those rules protect your pile, and they regulate somebody else entirely. Your inbound stream still carries whatever was manufactured before them, imported around them, or mislabeled under them.

Which leads to the point I'd put in front of any municipality writing an organics contract this year: the contamination risk in food scraps compost sits in the serviceware, and serviceware gets bought by a procurement department long before it reaches a windrow. A city can fix it with a purchasing specification months ahead of any regulator writing a number. Most don't.

The same gap shows up in corporate diversion reporting. A composting outlet is what lets a manufacturer claim organics are handled inside its zero-waste-to-landfill programs, and the claim survives audit on tonnage. It says nothing about what's in the finished material, which is the question a buyer's counsel will eventually ask.

Where sampling plans measure the pile after the decision is made

The error I see most: a sampling plan tests for PFAS in compost quarterly or annually, which tells you what you already sold. By the time a composite from the cured windrow comes back under EPA Method 1633, the material's been screened, stockpiled and in many cases delivered. Method 1633 runs dozens of analytes with a turnaround measured in weeks (longer when the lab is queued behind a drinking-water program), and per the Wisconsin State Laboratory of Hygiene's published fee schedule a compost or soil PFAS sample listed at $550 as of November 2025. Nobody's testing every batch at that rate.

So move the test upstream. Sample the feedstock, and sample the overs.

The overs do the most work. Run the screen on a Doppstadt trommel and the oversize fraction concentrates exactly what you care about: film, fragments of molded fiber, the serviceware that didn't break down. That stream is both your contamination indicator and your evidence file, and characterizing it costs one sample instead of twelve. Pair it with inbound load records keyed to generator, which is the one place waste intelligence software earns its budget in an organics program, and you can tell a regulator which hauler, which account, which month. A facility that can do that gets a source-reduction condition; one that can't gets a limit.

I'd flag where none of this binds. If you take only yard trimmings and no food scraps, and your state legislated data collection before thresholds, as Washington, Oregon and Florida did according to the same EPA survey, you have reporting exposure and no product exposure. Below roughly ten thousand tons of annual throughput the per-sample economics stop working, and the realistic answer is feedstock control plus contractual representations from haulers. None of the state tiers speak to home-compost products, bagged retail blends, or compost sold across a state line into a jurisdiction with a lower threshold, and that last gap is the one I expect to get litigated first. Material that clears no tier anywhere needs a destruction outlet rather than a soil outlet, which is a different capital conversation involving landfill, combustion, or the pyrolysis systems now being permitted for sludge; the cost jump that Superfund designation put into leachate is a fair preview of how that pricing moves.

The conditions arrive at renewal, and the feedstock description is what they attach to

I'll put a stake in the ground: a good share of permitted composting capacity won't survive its first renewal under monitoring rules like these. Most of that capacity sits on a feedstock description written years before anyone sampled for PFAS, and that description is the hook. When the permit comes up, an agency doesn't need new rulemaking to add a sampling condition or narrow the accepted list. It needs a renewal cycle and a reason, and it now has both.

The worst surprise I've had on this pattern wasn't in a solid-waste file at all. In 2023 a Title V air permit came up for renewal, and a modification every party in the room had called minor tripped PSD review and delayed the project eight months. Nothing in the underlying rule had changed. The permitting path changed, because the renewal reopened a description everybody had stopped reading. Organics permits are smaller, slower and less contested, and they work the same way.

That's also where biosolids compost PFAS limits will stop being a biosolids question. A state program manager with a sampling mandate and a published dataset has every reason to extend the accepted-feedstock review to the facilities that generated the data, and nobody in that building has to write a compost standard to do it. The tier table becomes a condition in a permit, and the condition travels with the site.

So the first move isn't a lab order. Pull your facility permit and read the authorized feedstock list word for word, then write the renewal date at the top of the page. Against that list, mark which inbound streams could carry sludge-derived material and which could carry certified compostable serviceware, and get a one-page representation from each hauler covering both. Sample the trommel overs once, before anyone asks you to, so that when a sampling condition does show up you're arguing from your own data rather than the agency's. The operators who come out of this decade still selling a product will be the ones who did that paperwork in a year when it was optional, and who can show a buyer the circular economy case for organics recycling with a number behind it.

Disclosure: I advise waste-to-energy and organics developers on permitting and ESG compliance, and this column is published by Renewable Waste Energy, which sells services in this market.

Sources & Notes

• The federal posture, the Michigan program history, the ninety-nine percent pretreatment reduction and the Maine cost consequences all come from the memo itself: EPA's draft guidance on reducing risk from PFOA and PFOS in biosolids, Office of Water, June 2026. Voluntary, docketed, and silent on compost.
• State thresholds and effective dates in the table were cross-checked against a state-by-state review of biosolids recycling rules in the PFAS era. Verify any tier against the enacted statute or the issued permit before you rely on it; several are still drafts.
• For the serviceware finding, see Goossen, Schattman and MacRae in Biointerphases, 2023, summarized with the authors' own caveats about sample size by MOFGA's write-up of the compost sampling.
• Pennsylvania's draft limits and the generator-impact estimate: trade coverage of the DEP proposal during the 2026 comment period.
• Lab pricing for Method 1633 on solids is from the Wisconsin State Laboratory of Hygiene PFAS fee schedule, effective November 2025. Academic rates run below commercial ones, so treat $550 as a floor.