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PFAS Cleanup Cost: Why the First Dollar Belongs Upstream

By Antoine Walter · (don't) Waste Water · 5 November 2026 · 43 min read

Ali Ling did the arithmetic nobody in PFAS wanted to see: take just the perfluoroalkyl acids, the best-known forever chemicals, emitted in a year, pay today’s prices to pull them back out of the environment, and you get US$20 to 7,000 trillion a year, against a world economy of about US$106 trillion. So we will not clean our way out of PFAS, and she says that is the point: the number is a prioritisation tool. Because the bill drops by a factor of 1,000 when you move from the environment to the factory outlet, from millions of dollars per kilogram to hundreds or thousands, and it drops again at the drawing board, where the fix is a redesign. Two questions remain: where should the first dollar go, and, since the first dollars are already being spent on drinking water, who ends up paying, the ratepayer or the polluter?

🎧 Built on the podcast This article is the companion to a (don't) Waste Water episode. Listen on Ausha →

How much does it cost to clean up PFAS?

In 2024, Ali Ling, assistant professor of civil engineering at the University of St. Thomas in Saint Paul, Minnesota, published the only planet-scale estimate we have: removing perfluoroalkyl acids from the environment at the rate we emit them would cost US$20 to 7,000 trillion a year, in a world that earns about US$106 trillion (Science of the Total Environment, 2024).

PFAS, per- and polyfluoroalkyl substances, are a family of several thousand synthetic chemicals built around the carbon-fluorine bond, the strongest bond in organic chemistry, which is why non-stick pans, rain jackets and firefighting foams love them, and why nothing in nature takes them apart. Now, her paper looks at one branch of that family, the perfluoroalkyl acids, and asks a deliberately naive question: what if we simply removed, every year, what we add? The answer runs from 20 to 7,000 trillion dollars a year, and even the low end is a fifth of everything humanity produces.

The ladder, rung by rung

Hard to picture, so let’s climb down the ladder. One continent: the Forever Lobbying Project, coordinated by Le Monde with Ali Ling on the cost methodology, put Europe’s bill, in January 2025, at about €2 trillion over 20 years, roughly €100 billion a year, at today’s emissions.

One US state: in 2023 the Minnesota Pollution Control Agency, in a study her consulting firm co-authored, priced removing and destroying PFAS from the state’s municipal wastewater at US$14 to 28 billion over 20 years. And one kilogram, her back-of-envelope on my microphone: millions out in the environment, hundreds to thousands at the industrial discharge. I covered the European number in my newsletter in January 2025, and the shape of it only landed when she stacked the rungs.

The PFAS cost ladder: every step upstream divides the cost of a kilogram by about a thousand, and at the scale of the planet the cleanup bill, US$20 trillion to US$7,000 trillion a year, exceeds a world GDP of about US$106 trillion.Two panels on logarithmic scales. Panel 1, the cleanup bill by scale, each figure as its study states it: the planet, perfluoroalkyl acids at current emission rates, US$20 trillion to US$7,000 trillion per year (Ling 2024), 10 to 10,000 times more if all PFAS are counted; world GDP about US$106 trillion per year (as cited in Ling 2024); Europe about €2 trillion over 20 years, about €100 billion per year, if emissions stay unrestricted (Le Monde / Forever Lobbying Project 2025); Minnesota US$14 billion to US$28 billion over 20 years to remove and destroy PFAS from municipal wastewater (Minnesota Pollution Control Agency 2023). Panel 2, the cost of one pound by where it is caught: in the environment US$2.7 million to US$18 million per pound to remove and destroy from municipal wastewater (MPCA 2023); at the industrial outlet hundreds to thousands of dollars or euro per kilogram, about 1,000 times cheaper (Ali Ling, spoken estimate, S13E14); in the product, the chemical’s own price, US$50 to US$1,000 per pound (MPCA 2023); no cleanup figure exists for the design stage.The PFAS cost ladder: the later you catch it, the more it costsEach step upstream divides the cost of a kilogram by about a thousand. Left in theenvironment, the planet’s bill exceeds what the world earns in a year.1. The cleanup bill, from one US state to the planetMore than the world earns in a year: everything to the right of world GDP, about US$106 trillion per year (as cited in Ling 2024)10 bn100 bn1 tn10 tn100 tn1,000 tn10,000 tnWorld GDP: about US$106 trillion per year (as cited in Ling 2024)World GDP, about US$106 tn a yearmore than the world earnsThe planet: US$20 tn to 7,000 tn a yearperfluoroalkyl acids, at today’s emission rateThe planet: US$20 tn to 7,000 tn a year, perfluoroalkyl acids, at today’s emission rate. Source: Ling 2024, Science of the Total Environment. Counting all PFAS, not only perfluoroalkyl acids, would raise the figure by a factor of 10 to 10,000.All PFAS, not only perfluoroalkyl acids: 10 to 10,000 times more (Ling 2024), beyond the right edge of this chartall PFAS: 10 to 10,000 times moreEurope: about €2 tn over 20 yearsif emissions stay unrestricted, about €100 bn a yearEurope: about €2 tn over 20 years, if emissions stay unrestricted, about €100 bn a year. Source: Le Monde / Forever Lobbying Project 2025. Cleaning only the concentrated long-chain hotspots: €4.8 billion a year.Minnesota: US$14 bn to 28 bn over 20 yearsone US state, its municipal wastewater onlyMinnesota: US$14 bn to 28 bn over 20 years, one US state, its municipal wastewater only. Source: Minnesota Pollution Control Agency 2023. Scope: removing and destroying PFAS from municipal wastewater.Log scale: each tick is 10 times the one before. bn = billion, tn = trillion.Planet and GDP per year; Europe and Minnesota 20-year totals; US$ and € as stated.2. Why it compounds: the cost of one pound, by where you catch itAli Ling’s rule of thumb: about 1,000 times cheaper one step upstream, per kilogram.US$101001,00010,000100,0001 million10 millionEnd of pipe, in wastewater: US$2.7 million to 18 million per poundto remove and destroy it from municipal wastewater (Minnesota study)End of pipe, in wastewater: US$2.7 million to 18 million per pound, to remove and destroy it from municipal wastewater (Minnesota study). Source: Minnesota Pollution Control Agency 2023. Ali Ling on the show: millions of dollars or euro per kilogram.At the industrial outlet: hundreds to thousands per kilogramAli Ling’s estimate on the show, about 1,000 times cheaper; no study figureAt the industrial outlet: hundreds to thousands per kilogram, Ali Ling’s estimate on the show, about 1,000 times cheaper; no study figure. Source: Ali Ling, (don’t) Waste Water S13E14, 2025-10-15, 5 min 08 s. A spoken order of magnitude, drawn as 100 to 10,000.In the product (the chemical’s own price): US$50 to 1,000 per poundwhat PFAS sells for (Minnesota study); no cleanup figure exists for the design stageIn the product (the chemical’s own price): US$50 to 1,000 per pound, what PFAS sells for (Minnesota study); no cleanup figure exists for the design stage. Source: Minnesota Pollution Control Agency 2023. Ali Ling on the show: probably less, and mostly a one-time cost.Log scale. Solid: the Minnesota study, in US$ per pound.Dashed: Ali Ling’s spoken estimate, per kilogram, an order of magnitude only.Sources: Ling 2024 (Science of the Total Environment); Minnesota Pollution ControlAgency 2023; Le Monde / Forever Lobbying Project 2025; Ali Ling, (don’t) Waste Water.
At today’s emission rates, removing perfluoroalkyl acids from the environment would cost US$20 trillion to US$7,000 trillion a year, against a world GDP of about US$106 trillion. Sources: Ling 2024 (Science of the Total Environment); Minnesota Pollution Control Agency 2023; Le Monde / Forever Lobbying Project 2025.

Well, her reading of her own number is not despair. Many people see it and feel there is no hope for anything, she told me, “and that’s not what I’m trying to get at here. What I’m trying to get at here really is that prioritization.”

Why is water the most expensive place to catch PFAS?

The cost of removing PFAS from water scales with the volume you treat, Ali Ling explained in October 2025, so a kilogram caught in municipal effluent costs millions while the same kilogram caught at a factory outlet or in landfill leachate costs hundreds to thousands; the EPA’s stated intent for wastewater permits is to push PFAS upstream to industrial dischargers.

So drinking water and wastewater got regulated first, because they are the most monitored things in the United States, so we know what is in them, while nobody knows what sits in most industrial discharges or consumer products. So the utilities became the easy place to start, and they now sit in what she calls a really difficult place: a permit limit on their effluent, an upstream discharger they may not control, and, if that fix fails, a PFAS plant of their own, with its affordability problem and, per a study she is running, a lot of extra greenhouse gas emissions. Hence her law for regulators:

Whereas PFAS, some of it comes from those non-point sources, but a lot of it comes from industrial discharges and from landfill leachate. I think that’s a case where treating it in those upstream locations is gonna make a lot more sense than treating it in wastewater effluent. The cost to remove PFAS from water in any phase is generally gonna be proportional to the volume of water that you treat.
Ali Ling, Assistant Professor of Civil Engineering, University of St. Thomas, on the (don’t) Waste Water podcast, S13E14, October 2025 · hear her say it (23:17)

Where I have seen this film before

Look, micropollutants were the beginning of my career, and we all reached her conclusion, reduce at the source, before discovering how hard that is when nobody wants to give up the benefits of the molecule. Switzerland then showed where to spend: treat wastewater and you protect the whole water cycle, treat drinking water and you protect the human only until the next flush. For PFAS, given what is already out there, we will probably need both ends anyway.

The vendors agree with her law, by the way. Julie Bliss Mullen of Aclarity gave me the supplier’s version, it depends on volume and concentration, and Mirka Wilderer’s team at AqueoUS Vets showed me what removing PFAS costs a utility across more than a hundred projects.

Has source reduction ever worked?

Yes, once, and quietly: PFOA and PFOS, the two best-known PFAS, were largely phased out in the United States and Europe in the 2010s, and the CDC’s blood survey shows PFOS in Americans’ serum fell by more than 85% between 1999 and 2018, a decline Ali Ling rounds to “a factor of 10”.

She calls it a quiet success story that not a lot of people talk about, and the mechanism is the one she wants more of: companies phasing PFAS out, often voluntarily and often without announcing it, because saying “we used to have PFAS” is an invitation to a lawsuit. Now, IKEA and H&M, in her telling, took PFAS entirely out of their supply chains. And the blood data is the one number in this whole story that goes down.

If you look back at the human PFAS data in blood serum over the past 20 years, and you look at PFOA and PFOS, which were largely phased out in the 20-teens, the concentrations in blood serum have gone down for PFOS by like a factor of 10. I think that’s a quiet success story that not a lot of people talk about where PFAS was mostly phased out.
Ali Ling, Assistant Professor of Civil Engineering, University of St. Thomas, on the (don’t) Waste Water podcast, S13E14, October 2025 · hear her say it (46:20)

The regrettable-substitution trap

Now, regrettable substitution, in her definition, is substituting something and regretting it later because the replacement was not actually better. GenX, the chemical that replaced PFOA (its technical name is HFPO-DA), is the PFAS example, and HFC refrigerants replacing the CFCs that ate the ozone layer is the historical one. That trap is why Europe is trying to restrict the family as a whole rather than one molecule at a time: the European Chemicals Agency’s risk committee adopted its opinion on the universal PFAS restriction in March 2026, its socio-economic committee is expected to finish by the end of the year, and only then does the Commission write the law.

Her own standard is more modest, and I like it better than most: don’t let trying to be perfect get in the way of doing some good. I was slow on PFAS myself, which I admitted in writing in January 2025.

The treatment menu, and where the bill hides

Nothing destroys PFAS at scale without a removal step first, Ali Ling insists: granular activated carbon or ion-exchange resin concentrates the molecules, then something has to break them, and the default in Minnesota’s 2023 study was high-temperature incineration, at US$2.7 to 18 million per pound of PFAS removed and destroyed from municipal wastewater.

Now, granular activated carbon, GAC for the insiders, is charcoal engineered to be porous; ion exchange is a resin that swaps the PFAS molecule for a harmless ion; both end up as a spent medium that somebody must regenerate, landfill or burn. And her latest paper prices exactly that spent-media question, with vendor-sourced energy and operating costs, so that a utility planning a plant can read the menu before ordering. And the menu has fine print: small plants pay more than six times more per pound than large ones, Minnesota found, and the short-chain PFAS cost up to 70% more to remove than the long chains they replaced (regrettable substitution again, this time with an invoice).

The PFAS treatment menu, with Ali Ling’s verdicts (table)
Role Technology What it does What Ali Ling said in the episode Covered on dww.show
Remove Granular activated carbon (GAC) Porous carbon that adsorbs PFAS; the spent carbon must be reactivated or burned. “There’s nothing available at scale that can do destruction without the removal step.” (19:57) Her latest paper prices GAC regeneration against the alternatives. AqueoUS Vets playbook
Remove Ion exchange (IX) A resin that swaps the PFAS molecule for a harmless ion; single-use resin ends in an incinerator. Same paper: spent-media options with energy and operating costs “such that someone could look at that paper and say, okay, if we wanted to use this option or that option, here’s about how much it would cost”. (33:51) AqueoUS Vets playbook
Remove, concentrate Foam fractionation Air bubbles lift PFAS into a foam you skim off; strong on long chains, weaker on short ones. “If they can get the chemistry down where they’re removing the short-chain ones more effectively, like that’s gonna be quite a bit more cost-effective than some of the other separation technologies.” (15:29) the H2Plus review (cost comparisons)
Destroy High-temperature incineration Burns the spent media or the concentrate; the default of the Minnesota cost study. “High-temperature incineration, which was our default for that study.” (15:29) The US$2.7 to 18 million per pound rests on it. MPCA 2023 (Sources, 2)
Destroy Electrochemical oxidation A current through the water, an electrode breaks the carbon-fluorine bond; 18 vendors with PFAS claims. Destruction technologies “coming online and getting demonstrated at scale that would be more cost-effective than high-temperature incineration”. (15:29) the 32-company census · Aclarity
Destroy Supercritical water oxidation (SCWO) Water above 374 °C and 221 times atmospheric pressure oxidises everything in it. Not discussed in this episode. the 2022 SCWO episode
Destroy Plasma An electrical discharge in or above the water. “I have not heard anything super convincing from anyone doing plasma. It’s possible they just haven’t shown their data to me, but it’s not super high on my list.” (56:41)
Destroy Hydrated electrons and other reduction routes Electron donors strip the fluorine instead of oxidising the molecule. Not discussed in this episode. the H2Plus review · Oxyle
Dispose Biosolids: land application and its alternatives The sludge after treatment; drying, destruction or landfill, each with its own logistics. “There’s a lot of other logistics that people haven’t thought through.” (25:30) Maine’s scramble for landfill space is her example.
Every route still ends in a destruction step: separate first, then break the bond. Sources: the episode (timestamps link to YouTube); Minnesota Pollution Control Agency 2023; Leviathan, my water database.

Biosolids, the bill nobody has budgeted

Then come biosolids, the sludge left after treatment that farmers have spread on fields for decades. Maine stopped land application and had to scramble for landfill space, and landfilling only moves the PFAS into the leachate and the landfill gas, where it comes back out. Nobody has priced the regional drying and destruction plants that would replace the field, she notes, or the trucks to feed them.

The destruction side is getting crowded, which I will come back to, and her verdicts there are short: most technologies have some sort of Achilles heel, foam fractionation gets cheaper the day it learns short chains, and plasma is “not super high on my list”. I had Oxyle’s destruction route on the podcast in 2024 and I reviewed H2Plus’s hydrated-electron pitch in July 2025, so I can confirm that every vendor’s heel is somewhere else.

Is drinking water even the right place to look?

The EPA’s own exposure model assumes drinking water carries less than 20% of a person’s PFAS intake, Ali Ling reminded me, so even a perfect drinking-water programme caps the health benefit at about a fifth; the rest comes mostly from diet, which is falling as PFAS leaves food packaging, and from indoor dust.

Well, the exception is the hotspot: Cape Fear in North Carolina, Hoosick Falls in New York, Dordrecht in the Netherlands, places where a contamination event put very high concentrations into the tap and treatment was the right call. But outside them, she says, the risk is diffuse and relatively small, and the honest question for each utility is where its risk sits: PFAS, or arsenic, manganese, disinfection by-products, or plain pipes. Parts per trillion, the unit all of this is measured in, is one drop in twenty Olympic pools, which says how far down the plants are asked to go. Her own tap, she told me, is “almost zero”; her dust and her products are not.

There’s a lot of talk about PFAS in drinking water, but the EPA acknowledges that drinking water is less than 20% of PFAS intake […]. So even if we were to remove all PFAS in drinking water, the best we could do is 20% reduction in people’s PFAS exposure.
Ali Ling, Assistant Professor of Civil Engineering, University of St. Thomas, on the (don’t) Waste Water podcast, S13E14, October 2025 · hear her say it (21:22)

Who pays for PFAS cleanup?

Treat at the end of the pipe and the bill lands on ratepayers and taxpayers, Ali Ling told me; treat at the factory and the companies that emit pay, “where they should be routed”. The largest settlements, 3M’s US$10.3 to 12.5 billion (approved in 2024) and US$1.185 billion from DuPont, Chemours and Corteva, roughly cover one state’s 20-year wastewater bill.

So let’s do the maths: put the three settlements approved in 2024 together, 3M, the DuPont group and Tyco’s US$750 million, and you get US$12 to 14 billion, paid to drinking-water systems across the whole United States over more than a decade. And Minnesota alone, for its wastewater alone, needs US$14 to 28 billion over 20 years. The money the polluters have agreed to pay covers one state’s sludge and effluent, give or take. There is some federal money for drinking water, she notes, “but it’s not nearly enough. It’s not nearly as much as what’s been estimated.”

The three largest PFAS settlements ever approved, US$12.2 billion together and up to US$14.4 billion, roughly match the US$14 billion to US$28 billion that Minnesota alone expects to spend over 20 years on PFAS in municipal wastewater, which is why the rest of the bill lands on ratepayers and taxpayers.Two horizontal bars on one linear US$ scale from 0 to US$28 billion. Bar 1, the three largest PFAS settlements approved for US drinking-water systems: 3M US$10.3 billion present value paid over 13 years (up to US$12.5 billion depending on how many systems detect PFAS, shown as a hollow dashed extension), DuPont, Chemours and Corteva US$1.185 billion, Tyco Fire Products US$750 million; together US$12.2 billion, up to US$14.4 billion. Bar 2, Minnesota municipal wastewater, removing and destroying PFAS over 20 years: US$14 billion solid, up to US$28 billion as a hollow dashed extension. Footnote: scopes differ; Europe is not plotted: €4.8 billion a year for the concentrated long-chain hotspots only, about €100 billion a year (about €2 trillion over 20 years) if emissions stay unrestricted, across all environmental media. Sources: 3M Investor Relations 2024; settlement administrator information sheet 2024; Minnesota Pollution Control Agency 2023; Le Monde / Forever Lobbying Project 2025.The three largest PFAS settlements add up toabout one US state’s 20-year wastewater billapproved amount, or the low end of the estimatehigh end of the rangeThree largest PFAS settlements, approved, for US drinking-water systems3M settlement with US public water systems: US$10.3 billion present value, paid over 13 years. Final court approval 29 March 2024. Source: 3M Investor Relations, 2024.DuPont, Chemours and Corteva settlement: US$1.185 billion, approved. Source: settlement administrator information sheet, July 2024.Tyco Fire Products settlement: US$750 million, approved. Source: settlement administrator information sheet, July 2024.3M ceiling: up to US$12.5 billion depending on how many water systems detect PFAS. Source: 3M Investor Relations, 2024.3M: US$10.3 billionpresent value, paid over 13 yearsUS$12.2 billion togetherup to US$14.4 billionif 3M reaches its US$12.5 billion ceilingTyco Fire Products: US$750 millionDuPont, Chemours, Corteva: US$1.185 billionMinnesota alone, municipal wastewater: remove and destroy PFAS over 20 yearsMinnesota municipal wastewater: US$14 billion over 20 years, the low end of the state’s estimate to remove and destroy PFAS. Source: Minnesota Pollution Control Agency, June 2023.Minnesota municipal wastewater: up to US$28 billion over 20 years, the high end of the state’s estimate. Source: Minnesota Pollution Control Agency, June 2023.US$14 billionup to US$28 billion0US$10 billionUS$20 billionlinear scaleScopes differ. The settlements compensate drinking-water systems across the wholeUnited States; the Minnesota figure is municipal wastewater in one state. Europe is notplotted and covers all environmental media: €4.8 billion a year to clean the concentratedlong-chain hotspots only, about €100 billion a year (about €2 trillion over 20 years) ifemissions stay unrestricted.
The three largest PFAS settlements ever approved, US$12.2 billion together and up to US$14.4 billion, add up to about one state’s 20-year wastewater bill: Minnesota alone expects US$14 billion to US$28 billion. Sources: 3M 2024; settlement administrator 2024; Minnesota Pollution Control Agency 2023; Le Monde / Forever Lobbying Project 2025.

The counter-argument, from my own archive

Henry Charrabe, who led Seven Seas Water to its billion-dollar exit, gave me the other side in the episode that followed Ali’s: “ultimately, ratepayers are the polluters. We all use Teflon.” But Henrik Hagemann of Puraffinity had made the opposite case back in 2022: the utilities never earned a cent from Scotchgard or Gore-Tex. Both are right, which is exactly why the upstream route matters, because it is the only place where the bill and the benefit sit inside the same company.

And a confession: I once calculated what a human life is worth to a regulator, about US$10 million in the United States, and I still think we skipped that cost-benefit step entirely on PFAS. Ali’s answer was gentler than mine: the societal and climate costs are real, they are just very hard to put on the same scale.

Will the 4 ppt limits survive?

In October 2025 Ali Ling predicted that some form of the US limits would stick, and that dropping the four other PFAS would barely change how many systems must treat; in May 2026 the EPA proposed that: keep PFOA and PFOS at 4 parts per trillion, rescind the other four, and let opt-in systems slip from 2029 to 2031.

Now, her reasoning was mechanical rather than political: the systems above 10 ppt of PFHxS, one of the four, are the same systems above 4 ppt of PFOA and PFOS, so keeping two limits makes monitoring easier and changes very little on the ground. And an MCL, a maximum contaminant level, is the legal ceiling for a substance in drinking water, and the American Water Works Association sued over the 2024 rule; she found its arguments “very reasonable”, because asking thousands of small utilities to build PFAS treatment with limited funding, when their bigger health risk may sit elsewhere, is a problem.

EPA’s plan for PFAS in drinking water: PFOA and PFOS stay at 4 parts per trillion, the other four limits go, and the compliance clock moves from 26 April 2029 to 2031 (proposed, opt-in). Ali Ling called the outcome on the podcast on 15 October 2025, before the court rulings and the May 2026 proposal.Vertical timeline, two lanes (EPA’s rule; the court), as of 4 November 2026. 10 April 2024, in force: EPA finalises the first national PFAS drinking-water rule. Six PFAS: PFOA and PFOS at 4 parts per trillion each; PFHxS, PFNA and HFPO-DA (GenX) at 10 ppt, plus a hazard index for mixtures. Compliance by 26 April 2029. 14 May 2025, announcement: EPA says it will keep PFOA and PFOS at 4 ppt, extend compliance to 2031, and rescind the other four limits. 15 October 2025, the prediction: Ali Ling on the (don’t) Waste Water podcast: "some form of MCLs in the United States is gonna stick" (47 min 35 s), and dropping the four extra PFAS "doesn’t actually change very much how many systems need to treat it" (47 min 57 s). 21 January 2026, decided: the D.C. Circuit denies EPA’s request to vacate parts of the rule (AWWA v. EPA, No. 24-1188). 19 March 2026, decided: the D.C. Circuit denies EPA’s motion to sever and hold in abeyance the challenges to the four limits it intends to repeal. 18 May 2026, proposed (published 20 May 2026): EPA proposes two rules: rescind the limits for PFHxS, PFNA, HFPO-DA and the hazard index; an opt-in two-year extension of PFOA/PFOS compliance to 2031. 29 June 2026, decided: court order scheduling oral argument. 7 July 2026: public hearing on the proposal. 20 July 2026: comment periods close. Procedural steps. 20 July 2026: comment periods on the proposal close. 26 April 2029, in force: current compliance date for all six limits under the April 2024 rule. 2031, proposed: opt-in compliance date for PFOA and PFOS under the May 2026 proposal (a two-year extension). As of 4 November 2026 the compliance date in force is 26 April 2029 for all six limits; the 2031 date is proposed, opt-in, for PFOA and PFOS only. Solid marks: in force or decided. Hollow marks: proposed. Dashed mark: announced. Gold diamond: the prediction on the podcast. MCL = the legal maximum allowed in drinking water; ppt = parts per trillion.EPA’s plan: two limits stay, four go, the clock moves from 2029 to 2031Ali Ling called it in October 2025, before the court rulings and the May 2026 proposal.EPA’s ruleThe court2027 and 2028 skipped on this axis+2 years, opt-in, if the proposal holds4 Nov 2026today10 April 2024, in force: EPA finalises the first national PFAS drinking-water rule. Six PFAS: PFOA and PFOS at 4 parts per trillion each; PFHxS, PFNA and HFPO-DA (GenX) at 10 ppt, plus a hazard index for mixtures. Compliance by 26 April 2029. Source: EPA; Harvard Law EELP Regulatory Tracker.10 Apr 2024Final rule: six PFAS limits. PFOA and PFOS at 4 ppt,three others at 10 ppt, plus a mixtures index.Compliance by 26 Apr 2029.14 May 2025, announcement: EPA says it will keep PFOA and PFOS at 4 ppt, extend compliance to 2031, and rescind the other four limits. Source: EPA newsroom.14 May 2025EPA announces: keep PFOA and PFOS at 4 ppt,drop the other four, extend compliance to 2031.15 October 2025, the prediction: Ali Ling on the (don’t) Waste Water podcast: "some form of MCLs in the United States is gonna stick" (47 min 35 s), and dropping the four extra PFAS "doesn’t actually change very much how many systems need to treat it" (47 min 57 s). Source: episode S13E14 transcript.15 Oct 2025Ali Ling on the podcast: “some form of MCLsin the United States is gonna stick”21 January 2026, decided: the D.C. Circuit denies EPA’s request to vacate parts of the rule (AWWA v. EPA, No. 24-1188). Source: AMWA PFAS litigation page; Liskow alert.21 Jan 2026Court refuses EPA’s request to strike parts of the rule19 March 2026, decided: the D.C. Circuit denies EPA’s motion to sever and hold in abeyance the challenges to the four limits it intends to repeal. Source: AMWA PFAS litigation page.19 Mar 2026Court refuses to pause the challenge to the four limits18 May 2026, proposed (published 20 May 2026): EPA proposes two rules: rescind the limits for PFHxS, PFNA, HFPO-DA and the hazard index; an opt-in two-year extension of PFOA/PFOS compliance to 2031. Source: Harvard EELP tracker; Jones Day client alert.18 May 2026Proposal: drop the four limits; opt-in deadline 203129 June 2026, decided: court order scheduling oral argument. Source: AMWA PFAS litigation page.29 Jun 2026Court schedules oral argument7 July 2026: public hearing on the proposal. 20 July 2026: comment periods close. Procedural steps. Source: Harvard EELP tracker.Jul 2026Public hearing (7 Jul); comment period closes (20 Jul)26 April 2029, in force: current compliance date for all six limits under the April 2024 rule. Source: EPA; Harvard Law EELP tracker.26 Apr 2029Current compliance date for all six limits2031, proposed: opt-in compliance date for PFOA and PFOS under the May 2026 proposal (a two-year extension). Source: Harvard EELP tracker; Jones Day client alert.2031Proposed opt-in compliance date for PFOA and PFOSin force or decidedproposedannouncedher call on the podcastMCL = the legal maximum allowed in drinking water. ppt = parts per trillion.
Ali Ling called it in October 2025: PFOA and PFOS stay at 4 parts per trillion, the other four limits are set to go, and the compliance clock moves from 2029 to 2031 if the May 2026 proposal holds. Sources: EPA; Harvard Law EELP tracker; AMWA; the episode.

The court, the agency and the 2031 clock

The D.C. Circuit refused in January 2026 to vacate parts of the rule and in March refused to shelve the case, so the court and the agency are now racing each other to the same finish line. Her October reading sits on tape seven months before the formal proposal and before both court rulings: the agency had announced its intention in May 2025, and what she called was which parts of it would survive the lawyers, and why the rescissions would barely move the number of plants that must treat.

The next responsible step, in her view, is effluent limit guidelines on specific industries, upstream, which she doubts this administration will write. As of early November 2026 the May proposals are still proposals; this page gets updated the day they are final.

Where the money is going: 32 companies, 24 installations

The day before this episode went out, I published my own count: 32 companies market a proprietary electrochemical-oxidation process, 18 of them with PFAS-destruction claims, chasing at most 24 installations worldwide, on a little under US$120 million raised between the start-ups. As you know, I’m fun at parties.

Because electrochemical oxidation runs a current through the water and lets the electrode break the carbon-fluorine bond, it is the destruction route with the most vendors, and most of the 18 sit at TRL 7 to 9, TRL being NASA’s one-to-nine scale of how baked a technology is, with 9 meaning fully commercial. So two are at 9, Axine and AECOM, nine at 8, and only four publish a third-party-verified report of more than 90% defluorination. Investors read that crowd as a bloodbath. I read it as validation, because zero competitors would mean zero market, and by my estimate about 250 industrial facilities have acted on PFAS out of roughly 10 million (don’t quote me on the last digit).

18 vendors claim to destroy PFAS. At most 24 sites have ever installed it.Unit chart from Antoine Walter’s own census of electrochemical water oxidation vendors, October 2025 (newsletter of 2025-10-14, Why 32 Companies Fight Over 24 Deals, and the solo editorial of 2025-10-15). Left: 32 companies actively develop and market a proprietary electrochemical water oxidation technology. 18 of them claim PFAS destruction: 2 at TRL 9 (Axine Water Technologies, AECOM), 9 at TRL 8, 6 at TRL 6 to 7 (OXbyEL, Arvia, VentilAQUA, Boromond, PFASuiki, De Nora), 1 at TRL 5 (BioIonix). The other 14 do not claim PFAS yet. TRL is NASA’s 1 to 9 technology readiness scale, 9 meaning fully commercial. 4 of the 18 publish a third-party-verified report of more than 90% defluorination. The start-ups among the 18 (excluding Aquatech, Gradiant, AECOM, WSP and Ovivo) have raised a little under US$120 million in total. Right: 24 installations at most. About 19 industrial facilities worldwide went for electrochemical oxidation to treat PFAS (solid squares); 24 if every vendor claim is taken at face value (5 hollow squares). For scale, about 250 facilities worldwide have taken any action on PFAS, out of roughly 10 million industrial facilities.18 vendors claim to destroy PFAS.At most 24 sites have ever installed it.Electrochemical oxidation: breaking PFAS apart with an electric current.One square = one company (left) or one industrial site (right).32companies sell it18 of them claim to destroy PFAS (in blue)24installations, at most19 I could count, 5 more that vendors claimCompany 1 of 32: Axine Water Technologies, TRL 9, fully commercial, claims PFAS destructionCompany 2 of 32: AECOM, TRL 9, fully commercial, claims PFAS destructionCompany 3 of 32: one of 9 at TRL 8, commercial system proven, claims PFAS destruction (not named here)Company 4 of 32: one of 9 at TRL 8, commercial system proven, claims PFAS destruction (not named here)Company 5 of 32: one of 9 at TRL 8, commercial system proven, claims PFAS destruction (not named here)Company 6 of 32: one of 9 at TRL 8, commercial system proven, claims PFAS destruction (not named here)Company 7 of 32: one of 9 at TRL 8, commercial system proven, claims PFAS destruction (not named here)Company 8 of 32: one of 9 at TRL 8, commercial system proven, claims PFAS destruction (not named here)Company 9 of 32: one of 9 at TRL 8, commercial system proven, claims PFAS destruction (not named here)Company 10 of 32: one of 9 at TRL 8, commercial system proven, claims PFAS destruction (not named here)Company 11 of 32: one of 9 at TRL 8, commercial system proven, claims PFAS destruction (not named here)Company 12 of 32: OXbyEL, TRL 6 to 7, on the edge of deployment, claims PFAS destructionCompany 13 of 32: Arvia, TRL 6 to 7, on the edge of deployment, claims PFAS destructionCompany 14 of 32: VentilAQUA, TRL 6 to 7, on the edge of deployment, claims PFAS destructionCompany 15 of 32: Boromond, TRL 6 to 7, on the edge of deployment, claims PFAS destructionCompany 16 of 32: PFASuiki, TRL 6 to 7, on the edge of deployment, claims PFAS destructionCompany 17 of 32: De Nora, TRL 6 to 7, on the edge of deployment, claims PFAS destructionCompany 18 of 32: BioIonix, TRL 5, pilot stage, claims PFAS destructionCompany 19 of 32: sells electrochemical oxidation, no PFAS claim yet (one of 14, not named here)Company 20 of 32: sells electrochemical oxidation, no PFAS claim yet (one of 14, not named here)Company 21 of 32: sells electrochemical oxidation, no PFAS claim yet (one of 14, not named here)Company 22 of 32: sells electrochemical oxidation, no PFAS claim yet (one of 14, not named here)Company 23 of 32: sells electrochemical oxidation, no PFAS claim yet (one of 14, not named here)Company 24 of 32: sells electrochemical oxidation, no PFAS claim yet (one of 14, not named here)Company 25 of 32: sells electrochemical oxidation, no PFAS claim yet (one of 14, not named here)Company 26 of 32: sells electrochemical oxidation, no PFAS claim yet (one of 14, not named here)Company 27 of 32: sells electrochemical oxidation, no PFAS claim yet (one of 14, not named here)Company 28 of 32: sells electrochemical oxidation, no PFAS claim yet (one of 14, not named here)Company 29 of 32: sells electrochemical oxidation, no PFAS claim yet (one of 14, not named here)Company 30 of 32: sells electrochemical oxidation, no PFAS claim yet (one of 14, not named here)Company 31 of 32: sells electrochemical oxidation, no PFAS claim yet (one of 14, not named here)Company 32 of 32: sells electrochemical oxidation, no PFAS claim yet (one of 14, not named here)Installation 1 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 2 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 3 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 4 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 5 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 6 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 7 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 8 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 9 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 10 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 11 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 12 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 13 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 14 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 15 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 16 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 17 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 18 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationInstallation 19 of 19 I counted: an industrial site treating PFAS with electrochemical oxidationClaimed installation 20 of 24: a vendor claim I could not verifyClaimed installation 21 of 24: a vendor claim I could not verifyClaimed installation 22 of 24: a vendor claim I could not verifyClaimed installation 23 of 24: a vendor claim I could not verifyClaimed installation 24 of 24: a vendor claim I could not verifyTRL 9: 2, Axine and AECOMTRL 8: 9TRL 6 to 7: 6TRL 5: 1, BioIonixNo PFAS claim yet: 14TRL = NASA’s 1 to 9 readiness scale;9 means fully commercial.Only 4 of the 18 publish a third-party testshowing more than 90% of PFAS destroyed.19 sites I could count5 more, if every vendor claim is trueFor scale: about 250 of the world’s roughly10 million industrial sites have acted onPFAS at all, by any method.Source: my own count of electrochemical-oxidation vendors, October 2025.
Eighteen vendors claim to destroy PFAS with electrochemical oxidation, and at most 24 industrial sites have ever installed it. Source: my own count of electrochemical-oxidation vendors, October 2025.

What my Leviathan database adds

My Leviathan database widens the lens beyond one technology. Sixteen companies whose main business is removing or destroying PFAS have raised about US$196 million since 2019, 84% of it for destruction claims, and only 11 acquisitions of a PFAS treatment business are on record, four of them priced, US$111 million together, the largest being Montrose’s US$53.8 million purchase of ECT2 in 2019. So let’s do the maths one last time: all the venture money and all the deal money in the PFAS-core vertical, about US$0.3 billion over seven years, is one to two percent of Minnesota’s wastewater bill.

The consolidators are circling anyway (Axine and Veralto, Aclarity and Xylem), the way SKion did in water and the way the 2025 funding map predicted. I dissected the 32-company census in my newsletter, which is where this whole thread started; if you want the next one in your inbox, subscribe here.

Sixteen companies built only to remove or destroy PFAS have raised about US$196 million since 2019 (US$195.8 million disclosed across 31 priced rounds out of 35, 43% of it by Claros Technologies alone), and PFAS treatment companies have changed hands eleven times between 2019 and 2025, only four with a disclosed price: a vertical still small enough to count by hand.Two lanes on one year axis, 2019 to 2026. Top lane, money raised per year by the 16 companies whose whole business is removing or destroying PFAS, disclosed amounts only, gold for Claros Technologies, cyan for the other 15 companies, hollow dashed blocks for estimated amounts, hollow circles for rounds with no disclosed amount: 2019: US$11.87M in 4 rounds; 2020: no rounds; 2021: US$18.55M in 4 rounds; 2022: US$6.28M in 3 rounds, 1 without a disclosed amount; 2023: US$30.34M in 3 rounds; 2024: US$49.92M in 8 rounds; 2025: US$28.88M in 5 rounds; 2026 to September: US$49.99M in 8 rounds, 3 without a disclosed amount. Total US$195.8 million across 31 priced rounds of 35, 16 companies. Claros Technologies alone: US$84.7 million in 6 rounds, 43% of the total; its 2026 Series B is counted as US$45 million, net of a US$10 million note raised in 2025 (estimate). Bottom lane, the 11 acquisitions of PFAS treatment companies on record, solid dots with a disclosed price, hollow dots without: 2019: Montrose Environmental Group buys ECT2 (Emerging Compounds Treatment Technologies), US$53.8M; 2021: 374Water lists through a reverse merger into PowerVerde, a shell, price not disclosed; 2021: SciDev buys Haldon Industries, US$12.9M; 2021: Chart Industries buys AdEdge Holdings, US$40M; 2021: Cimbria Capital takes a minority stake in Fixed Earth Innovations, price not disclosed; 2022: Bain Capital Double Impact takes a minority stake in AqueoUS Vets, price not disclosed; 2023: Montrose Environmental Group buys Vandrensning (Denmark), US$4.73M; 2024: Rivus Capital takes a majority stake in Cornelsen Umwelttechnologie, price not disclosed; 2024: Ovivo buys E2Metrix, price not disclosed; 2025: Uniwater buys Ramson AB, price not disclosed; 2025: Chromafora buys Montrose Environmental Group Denmark, price not disclosed. Four disclosed prices add up to US$111.4 million. Source: Leviathan, verified 2026-11-04.The PFAS clean-up companies, counted by hand:US$196 million raised, eleven acquisitionsTop: money raised per year by the 16 companies built only to remove or destroy PFAS.Bottom: the 11 acquisitions of PFAS treatment companies on record, 2019 to 2025.Claros Technologiesthe other 15 companieshollow, dashed: the amount is an estimatecircle: a round with no disclosed amountClaros Technologies alone: 43% of the totalUS$84.7M across 6 rounds since 2021; its US$45M2026 Series B is the largest block2019, the other PFAS-only companies, disclosed amounts, US$11.87M in 4 rounds: Aclarity US$1M, pre-seed round; Cyclopure US$3.5M, Series A, lead The Innovation Fund; Cyclopure US$4M, Series B, lead Jacobs Engineering Group Inc.; Puraffinity US$3.37M, seed round, lead Kindred Capital.US$11.87M4 roundsno rounds2021, the other PFAS-only companies, disclosed amounts, US$11.55M in 2 rounds: 374Water US$6.55M, PIPE at the reverse merger (listed company); 374Water US$5M, placement (listed company).2021, Claros Technologies, disclosed amounts, US$5.5M in 1 round: US$5.5M, Series A, lead 3×5 Partners.2021, Claros Technologies, estimated amounts, US$1.5M in 1 round: US$1.5M, angel round (estimate).US$18.55M4 rounds2022, the other PFAS-only companies, disclosed amounts, US$6.28M in 2 rounds: Aclarity US$3.28M, seed round, lead Burnt Island Ventures; Oxyle US$3M, seed round, lead Founderful.2022: Enspired Solutions, pre-seed round, Red Cedar Ventures, amount not disclosed.US$6.28M3 rounds2023, the other PFAS-only companies, disclosed amounts, US$30.34M in 3 rounds: Aclarity US$15.9M, Series A, lead Aqualateral; Aquagga US$543,549, round; Puraffinity US$13.9M, Series A, lead Octopus Ventures.US$30.34M3 rounds2024, the other PFAS-only companies, disclosed amounts, US$26.82M in 5 rounds: 374Water US$12.23M, registered offering (listed company); CoreWater Technologies US$1.3M, round; H2Plus US$3.74M, seed round; Hexivon US$750,000, private placement (Reg D filing); Puraffinity US$8.8M, Series A, lead BGF.2024, the other PFAS-only companies, estimated amounts, US$399,000 in 1 round: Hexivon US$399,000, crowdfunding round (Reg CF) (estimate).2024, Claros Technologies, disclosed amounts, US$22.7M in 2 rounds: US$22M, round, lead Ecosystem Integrity Fund; US$700,000, round.US$49.92M8 rounds2025, the other PFAS-only companies, disclosed amounts, US$17.9M in 2 rounds: CellX Biosolutions US$1.9M, pre-seed round, lead Positron Ventures; Oxyle US$16M, Series A, lead 360 Capital.2025, the other PFAS-only companies, estimated amounts, US$980,000 in 2 rounds: Hexivon US$426,000, round (estimate); Hexivon US$554,000, round (estimate).2025, Claros Technologies, disclosed amounts, US$10M in 1 round: US$10M, convertible note.US$28.88M5 rounds2026 to September, the other PFAS-only companies, disclosed amounts, US$827,750 in 1 round: H2Plus US$827,750, convertible note (Form D filing).2026 to September, the other PFAS-only companies, estimated amounts, US$4.16M in 3 rounds: Porelio US$2.75M, pre-seed round, lead Faber Ventures (estimate); Pure Capture Innovations US$717,143, pre-seed round (estimate); Sequestro US$700,000, pre-seed round (estimate).2026 to September, Claros Technologies, estimated amounts, US$45M in 1 round: US$45M, Series B, lead Treehouse Family Capital (estimate: US$55M headline minus the US$10M note raised in 2025, which has its own row).2026 to September: AxNano, credit facility, Leonid Capital Partners, amount not disclosed.2026 to September: Cyclopure, strategic investment, Kurita Water Industries (incl. Kurita America), amount not disclosed.2026 to September: Hexivon, strategic investment, amount not disclosed.US$49.99M8 rounds20192020202120222023202420252026 to SepAcquisitions: 11 (a PFAS treatment company bought, or a stake taken)2019: Montrose Environmental Group buys ECT2 (Emerging Compounds Treatment Technologies), US$53.8M. 100%. strengthens Montrose’s PFAS treatment capabilities; ECT2’s Australian market leadership.2021: 374Water lists through a reverse merger into PowerVerde, a shell, price not disclosed. 100% stock (reverse merger). 374Water’s AirSCWO technology for PFAS elimination.2021: SciDev buys Haldon Industries, US$12.9M. 100% cash+stock+earnout. mobile water treatment and PFAS remediation capabilities.2021: Chart Industries buys AdEdge Holdings, US$40M. 100% cash. water treatment technology company focused on PFAS/PFOS remediation (heritage arsenic/metals; flagged).2021: Cimbria Capital takes a minority stake in Fixed Earth Innovations, price not disclosed. minority. specializing in microbial PFAS remediation.2022: Bain Capital Double Impact takes a minority stake in AqueoUS Vets, price not disclosed. minority growth equity. manufacturer of water treatment systems focused on emerging contaminants like PFAS.2023: Montrose Environmental Group buys Vandrensning (Denmark), US$4.73M. 100%. Danish specialist in industrial wastewater and landfill leachate treatment for PFAS and heavy metals.2024: Rivus Capital takes a majority stake in Cornelsen Umwelttechnologie, price not disclosed. majority. PFAS remediation technology via Cornelsen’s patented PerfluorAd.2024: Ovivo buys E2Metrix, price not disclosed. 100%. electrochemical oxidation for PFAS destruction; builds on a 2022 equity investment.2025: Uniwater buys Ramson AB, price not disclosed. 100%. Swedish specialist in membrane filtration for PFAS and heavy metals removal.2025: Chromafora buys Montrose Environmental Group Denmark, price not disclosed. 100%. PFAS treatment solutions incl. long-chain PFAS; Montrose becomes Chromafora shareholder; ECT2 licence.Montrose buys ECT2, US$53.8MSciDev buys Haldon, US$12.9MChart Industries buys AdEdge, US$40MMontrose buys Vandrensning, US$4.73Mprice disclosed (4)price not disclosed (7)Disclosed rounds only. Claros 2026 Series B counted net of a US$10M note (estimate):US$45M of a US$55M headline, because the 2025 note is already its own round.
Sixteen companies built only to remove or destroy PFAS have raised about US$196 million since 2019, and PFAS treatment companies have changed hands eleven times, a vertical still small enough to count by hand. Source: Leviathan, my water database, verified 2026-11-04.

What Ali Ling asks for next

Her two asks are both forward-looking. To the vendors who used to call her as a consultant with a great thing and no data: show me your data, because the consultants who put you in front of a utility trust what they understand.

To the rest of us: zoom out, stop treating PFAS as the only risk and municipal effluent as the place to spend. The 2031 clock now runs on the two limits everyone agrees will stick, which makes the upstream permit the next fight, and her thesis the one to test it against:

… we can’t afford to clean up PFAS from the environment. That needs to be like a point-specific problem type of solving thing. It can’t be just cleaning it all up. I think talking about source control and industrial discharges treatment, that’s really where we need to be talking about PFAS treatment. I think treating PFAS in wastewater, municipal wastewater effluent doesn’t really make sense.
Ali Ling, Assistant Professor of Civil Engineering, University of St. Thomas, on the (don’t) Waste Water podcast, S13E14, October 2025 · hear her say it (56:54)

The whole conversation, the regulatory rollercoaster included, is in the episode below, and the comments are open for anyone who thinks the ratepayer is the polluter after all.

Frequently asked questions

Can PFAS ever go away?

Not by cleanup at planetary scale: Ali Ling’s 2024 estimate puts removal at current emission rates at US$20 to 7,000 trillion a year, more than the world economy. They stop accumulating only when emissions stop, and the PFOS phase-out shows what that does: a drop of more than 85% in American blood levels in two decades.

What is the biggest source of PFAS in humans?

Outside the contamination hotspots, it is not drinking water. The EPA’s exposure model assumes tap water carries less than 20% of intake; diet, which is falling as PFAS leaves food packaging, and indoor dust carry most of the rest. That is why Ling questions drinking water as the best benefit per dollar.

How much does it cost to remove PFAS from water?

Minnesota’s 2023 study is the reference: US$2.7 to 18 million per pound of PFAS removed and destroyed from municipal wastewater, small plants paying more than six times more per pound than large ones, and short-chain PFAS up to 70% more than long chains. Per gallon, the AqueoUS Vets and H2Plus pieces linked above carry the vendor numbers.

Who is liable for PFAS cleanup?

The manufacturers, for drinking-water systems, through the settlements approved in 2024: 3M’s US$10.3 to 12.5 billion, US$1.185 billion from DuPont, Chemours and Corteva, US$750 million from Tyco. Everything downstream of that, wastewater and biosolids, falls on ratepayers and taxpayers unless a permit reaches the industrial discharger who emitted it.

Is source reduction really cheaper than treatment?

By about a thousand times per kilogram, in Ling’s back-of-envelope: millions of dollars once PFAS is in the environment, hundreds to thousands at the industrial discharge, and the Minnesota agency reaches the same conclusion, prevention more than 1,000 times more cost-effective than cleanup. The honest caveat is that the cost of redesigning products is not yet known; the European Chemicals Agency is counting.

What is regrettable substitution?

Substituting a chemical and regretting it later because the replacement was not actually better: GenX replacing PFOA in the PFAS family, HFC refrigerants replacing ozone-eating CFCs before that. It is the reason Europe is trying to restrict the whole PFAS family at once rather than one molecule at a time.

How long do PFAS last?

Long enough to earn the nickname: the carbon-fluorine bond does not break in nature on any human timescale, so “forever” describes the molecule’s persistence, not a cleanup horizon. Which is the whole point of putting the first dollar where the molecule is made rather than where it ends up.

Sources

  1. Ali Ling, “Estimated scale of costs to remove PFAS from the environment at current emission rates”, Science of the Total Environment, 2024. https://pubmed.ncbi.nlm.nih.gov/38325453/ (retrieved 2026-11-04)
  2. Minnesota Pollution Control Agency, “Groundbreaking study shows unaffordable costs of PFAS cleanup from wastewater”, June 2023. https://www.pca.state.mn.us/news-and-stories/groundbreaking-study-shows-unaffordable-costs-of-pfas-cleanup-from-wastewater (retrieved 2026-11-04)
  3. Le Monde / Forever Lobbying Project, “The Cost Methodology”, January 2025. https://foreverpollution.eu/lobbying/the-cost-methodology/ (retrieved 2026-11-04); NGI, “Now we know the staggering costs of cleaning PFAS pollution for Europe”, 2025. https://ngi.no/en/news/now-we-know-the-staggering-costs-of-cleaning-pfas-pollution-for-europe (retrieved 2026-11-04)
  4. Harvard Law School EELP, Regulatory Tracker “PFAS in Drinking Water” (EPA proposals of 2026-05-18). https://eelp.law.harvard.edu/pfas-in-drinking-water/ (retrieved 2026-11-04); Jones Day, “EPA Proposes to Rescind Certain PFAS Drinking Water Standards and Extend Compliance Deadlines for PFOA and PFOS”, May 2026. https://www.jonesday.com/de/insights/2026/05/epa-proposes-to-rescind-certain-pfas-drinking-water-standards-and-extend-compliance-deadlines-for-pfoa-and-pfos (retrieved 2026-11-04)
  5. EPA, “EPA Announces It Will Keep Maximum Contaminant Levels for PFOA, PFOS”, May 2025. https://www.epa.gov/newsreleases/epa-announces-it-will-keep-maximum-contaminant-levels-pfoa-pfos (retrieved 2026-11-04)
  6. AMWA, “PFAS litigation information” (AWWA v. EPA, D.C. Circuit No. 24-1188; orders of 2026-01-21, 2026-03-19, 2026-06-29). https://www.amwa.net/pfas-litigation-information (retrieved 2026-11-04)
  7. 3M, “3M Settlement with Public Water Suppliers to Address PFAS in Drinking Water Receives Final Court Approval”, March 2024. https://investors.3m.com/news-events/press-releases/detail/1836/3m-settlement-with-public-water-suppliers-to-address-pfas (retrieved 2026-11-04); PFAS settlement information sheet (DuPont/Chemours/Corteva US$1.185 billion, Tyco US$750 million), Southwest Environmental Finance Center, July 2024. https://swefc.unm.edu/home/wp-content/uploads/2024/07/PFAS-Settlement-Info-Sheet-7.3.2024.pdf (retrieved 2026-11-04)
  8. CMS, “Support for EU-wide PFAS restriction with targeted derogations: what happens next?”, 2026. https://cms.law/en/int/legal-updates/support-for-eu-wide-pfas-restriction-with-targeted-derogations-what-happens-next (retrieved 2026-11-04)
  9. CDC, NHANES PFAS fact sheet (PFOS serum decline of more than 85%, 1999 to 2018). https://stacks.cdc.gov/view/cdc/129342/cdc_129342_DS1.pdf (retrieved 2026-11-04)
  10. South Carolina Department of Environmental Services, PFAS programme page (EPA’s assumption that drinking water is about 20% of exposure). https://www.des.sc.gov/programs/bureau-water/and-polyfluoroalkyl-substances-pfas (retrieved 2026-11-04)
  11. University of St. Thomas Newsroom, “In the News: Ali Ling on the global price tag of PFAS cleanup”, 2024. https://news.stthomas.edu/in-the-news-ali-ling-on-the-global-price-tag-of-pfas-cleanup/ (retrieved 2026-11-04)
  12. Antoine Walter, “Why 32 Companies Fight Over 24 Deals”, (don’t) Waste Water newsletter, 2025-10-14. https://www.linkedin.com/pulse/why-32-companies-fight-over-24-deals-antoine-walter-dkebe/
  13. The episode: “Can We Actually Afford to Clean Up Forever Chemicals?”, (don’t) Waste Water podcast S13E14, 2025-10-15. https://www.youtube.com/watch?v=DdKSZfkvWL8