This report was originally published in Le Monde.
To reach the first-ever estimate of how much it would cost to rid Europe's water and soils of 'forever chemicals,' Le Monde and its partners collected thousands of data points and developed a robust and unprecedented methodology.
How much will it cost? Over the course of their year-long investigation, the 46 journalists of the Forever Lobbying Project, coordinated by Le Monde, came to the conclusion that the massive pollution of Europe by PFAS (per- and polyfluoroalkylated substances), a large family of chemical substances, the scope of which was revealed in 2023 under the banner of the Forever Pollution Project, calls for an equally colossal decontamination.
They needed figures. A continent-wide invoice for a Europe already under treatment with pollution control technologies. Whether in Belgium, the Netherlands, Norway or elsewhere, the first "remediation" projects — the term coined by the scientists and authorities involved — are sprouting up like mushrooms, in the heart of the contamination "hotspots" mapped a year earlier.
The consortium's immediate reaction was to collect data in the field, in 16 European countries. Cleaning up the soil of a Brussels fire station, contaminated by PFAS-laden fire-fighting foam? A cost of €710,000. Creating a new drinking water catchment far from sources contaminated by the Ronneby military base in Sweden? A total of €3.5 million. Distributing PFAS-free water to users in Italy's Acque del Chiampo network, contaminated by discharges from the Miteni plant? That's €37 million over 16 years.

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However, Le Monde and its partners came up against some major obstacles. The few figures collected were difficult to compare and, above all, impossible to extrapolate. What kind of material? Water? Soil? Plants? What volumes? How long? Which techniques? For which PFAS — since the large group of chemicals requires different treatments depending on the size of the targeted substances?
Worse still, the initial feedback has given way to silence. The silence of the white zones: regions, even entire countries, barely aware of the scale of this crisis, simply unable to provide estimates.
Working with universities to combat silence
As with the 2023 investigation, the solution lay in collaboration with the academic world. Ali Ling, an assistant professor at the University of St. Thomas in Minnesota, who was behind an assessment of decontamination costs in this American state heavily affected by PFAS pollution, accepted the challenge. Ling was then joined by Hans Peter Arp, an environmental chemist at the Norwegian University of Science and Technology. The group set about developing a robust methodology.
In an article published in 2024 in the review Science of the Total Environment, Ling wrote that there probably isn't enough money on Earth to decontaminate the environment at the rate of current emissions. Based on this premise, the team focused on strategic sites, primary sources or vectors of pollution, that it would make sense to treat as a priority: contaminated soils, landfills, drinking water production units and wastewater treatment plants.
The information reported at the European level by member states — as required by directives on urban wastewater treatment, drinking water and more — was supplemented by spreadsheets from Eurostat, the European Union's statistical office, and by national inventories. This enabled the development of a comparable overview of the systems to be equipped on a European scale. For the soils to be treated, the Forever Pollution Project database provided a – conservative – number of presumed contaminated sites per country, including factories producing and using PFAS, airports and military bases.
Benchmark costs depend on the type of site. For wastewater treatment plants and drinking water production plants, Ling applied models developed in the United States that are applicable in Europe for macroscopic calculations. For soil, Arp deduced median costs by type of contaminated site, based on academic and local data gathered by the project's journalists.
PFAS - Definitions
PFAS | Per- and polyfluoroalkylated substances represent a family of over 10,000 synthetic chemicals used by industry since the 1940s. Nicknamed “forever chemicals,” they are disseminated everywhere in the environment and are indestructible without human intervention. |
Long-chain PFAS | PFAS whose molecular structure is composed of at least six carbon atoms, themselves linked to fluorine atoms. PFOA and PFOS, two substances now banned, are among the long-chain PFAS. |
Short-chain PFAS | PFAS with a molecular structure of less than six carbon atoms. Anticipating regulations, manufacturers have gradually replaced long-chain PFAS with short-chain PFAS, which have proved not only harmful but also more mobile in the environment. |
TFA | TFA Trifluoroacetic acid is an ultra-short-chain PFAS (two carbon atoms). It has many origins (pesticides, degradation of other PFAS) and is the most widespread and abundant PFAS in the environment. |
PFOA | Perfluorooctanoic acid is one of the oldest and most widespread PFAS. Classified as "carcinogenic to humans" by the International Agency for Research on Cancer (IARC), it has been banned in Europe since 2019. |
PFOS | Perfluorooctanesulfonic acid is one of the oldest and most widespread PFAS. Classified as a "possible carcinogen" by the International Agency for Research on Cancer (IARC), it has been banned in Europe since 2009. |
Limit values | Concentrations defined by regulations, not to be exceeded in water, air, food, etc., for pollutants such as PFAS or pesticides. Quality or management limits, which serve to warn of the presence of a chemical compound in a monitored environment, are rarely similar to maximum health values, which are intended to identify the real risks of water consumption, for example. |
Low-pressure reverse osmosis | Water filtration system using microscopic pores. At present, this is the only technology capable of effectively isolating short and ultrashort-chain PFAS, notably TFA. However, this process is criticized for being energy-intensive and costly and for releasing waste into the environment in the absence of solutions for destroying it. Another problem is that water fully filtered by reverse osmosis may need to be remineralized to recover the many minerals useful to human health. |
Activated carbon | Porous material that retains long-chain PFAS and some short-chain PFAS in water. The carbon must be reactivated or replaced regularly for effective PFAS filtration. |
uPFAS | Project for the "universal restriction" of PFAS under the European REACH regulation (Registration, Evaluation and Authorization of Chemicals). Presented on February 7, 2023 by the European Chemicals Agency (ECHA), this proposed ban targeting the 10,000 members of the PFAS chemical family was developed by five European countries (Germany, Denmark, Norway, Netherlands, and Sweden). If successful, it would not come into force before 2026. |
Low and high ranges
Two scenarios were selected. For the low range, that meant estimating the minimum necessary to meet current regulations, defined by the Water Framework Directive – not exceeding 100 nanograms per liter of drinking water for a sum of 20 PFAS deemed of concern. Cleaning up the most contaminated soils is essential to prevent PFAS runoff into water, which would increase the need for drinking water treatment, estimated here at just 5% of supply zones. The economically efficient treatment of PFAS in landfill leachate is also included in this estimate.
The already considerable sum of €4.8 billion per year is based on highly optimistic, even unrealistic assumptions: "On an early conception from 20 years ago that only PFOS [Perfluorooctanesulfonic acid] and other long-chain PFAS, historically used by industry, are a problem to humans and the environment," summarized Arp.
The so-called "emerging" short- and ultra-short-chain PFAS have prompted experts to envisage a second, much darker scenario. Now in the sights of legislators, these as yet little-studied substances raise fears of an even more serious crisis. Trifluoroacetic acid (TFA), the smallest of the PFAS, is currently the most widespread in the environment – and its concentrations are only increasing. Early studies point to effects on mammal liver and reproduction. "This could have serious consequences for the health and environment of future generations," warned Arp.
The strong probability that these "emerging" PFAS will one day be regulated influenced the choice to evaluate, for the high range, the cost of eliminating these ubiquitous compounds, even more mobile than their long-chain cousins. Their treatment at the selected sites would cost a staggering €100 billion a year in Europe. Not to mention the logistical headaches and environmental consequences this would entail. According to experts in the field, the scale of the costs and the seriousness of the contamination underline the urgency of banning the use of all PFAS.
Each of the scenarios in our assessment is based on a series of conservative choices, which means that the costs are almost certainly underestimated. For example, some additional infrastructure requirements to complete the destruction of PFAS are not included in these sums. The data and full methodology, reviewed and improved by several experts, are available on the project website Foreverpollution.eu.
Contributors to this report include Stéphane Horel [Le Monde], Eurydice Bersi [Reporters United], Aleksandra Pogorzelska [Dagens ETC], Daniel Värjö [Sveriges Radio], Romane Bonnemé [RTBF], Simon Dequeker, Bijou van der Borst et Emiel Woutersen [Investico], Elisabetta Tola [Facta.eu]
For a complete list of articles from Le Monde and other media partners in the PFAS investigation, go to foreverpollution.eu/lobbying/.