Non-polymer PFAS can build up in blood protein of animals, and is not always removed quickly. This means that predators eating PFAS-contaminated food will have higher levels in their bloodstream, and concentrations can increase up the food chain. Studies suggest that build up of PFAS is similar to those of other Persistent Organic Pollutants such as DDT.PFAS are estimated to be settling in arctic regions at rates of tens to hundreds of kilograms per year (25-850kg per year), depending on the specific PFAS chemical in question. Certain PFAS are released as gases to the environment and are blown a long way by wind and air currents in the atmosphere,. These gas PFAS will over time degrade to more persistent chemicals like PFOS and PFOA. This may be one reason why PFAS of environmental concern have been found in remote regions such as the Arctic as well as near PFAS production sitesPFAS including PFOS and PFOA have been found in air samples around Europe. The chemicals are found in small quantities, but appear in almost all samples tested. PFAS enters the atmosphere both from factories and the air inside our homes. PFAS is found in treated waste water from industrial and domestic sources and has been found in both rivers and groundwater. Conventional drinking water processes will not remove PFAS.PFAS-coated clothes that are thrown away will often end up either incinerated or in landfill. Unless incinerated at very high temperatures (>1000oC), fluorinated polymers could release more harmful PFAS during burning. PFAS of environmental concern have also been found in landfill leachate. Non-polymer PFAS are used in the production of fluorinated polymers. The manufacture of stain-resistant finishes generally releases these PFASs into the environment, both by air and water emissions. They are very hard to remove during water treatment. Workers in textiles factories are some of the population most exposed to these potentially harmful chemicals. Small quantities of PFAS will be removed during wash and wear of products containing PFAS. This includes fluorinated polymers used on stain-resistant coatings, and non-polymers that remain on clothes after production (Lassen et al. 2015).Most UK waste still ends up in landfill, and this includes PFAS-containing products. Studies have shown that the liquid coming from landfills (known as leachate) often contain non-polymer PFAS chemicals. In the USA the total quantities were estimated at 563-638 kg in 2013. To properly break down PFAS chemicals high temperature (1000oC or more) incineration is recommended. Incineration of municipal waste does not necessarily reach these temperatures (min temp. required is 850oC), and the incomplete breakdown could release non-polymer PFAS.Wash and wear of clothing that contains PFAS-based stain-resistant or water repellent finishes release PFAS to the environment. Coatings are thought to lose effectiveness after 20-30 washes. This can include non-polymer PFAS, remnant from production or as a break-down product of side-chain polymers (Lassen et al. 2015). The manufacture of stain-resistant finishes releases PFAS into the environment, both by air and water emissions. PFAS are very hard to remove during water treatment. Industrial emissions are estimated to be the biggest source of these chemicals to the environment.

PFAS: The Unwelcome Guests in Our Water Sources

For decades, the invisible threat of ‘forever chemicals’ has been creeping into our daily lives through our clothes, cookware, furniture and even our food packaging. Now growing evidence demonstrates PFAS are also contaminating our water sources. All around the world PFAS are increasingly found in groundwater, rivers and even our drinking water. With mounting evidence of the health and environmental impacts associated with these persistent chemicals, more and more countries are taking action to turn off the tap of PFAS pollution, but will the UK do the same?

How is PFAS getting into our water supplies?

PFAS can contaminate groundwater from a multitude of sources. Scotland’s Centre of Expertise for Waters (CREW) estimate the biggest sources of direct PFAS contamination of groundwater to be from: wastewater discharges, land treated with PFAS-contaminated sewage sludge, land contaminated from PFAS-containing firefighting foams (e.g. military bases), chemical, oil, gas and mining production sites, and landfills[1]. Recently, the highest PFAS concentration ever recorded in UK groundwater was detected near a firefighting foam testing facility in Bentham, North Yorkshire. The groundwater PFAS concentration was measured at 1,199,000 ng/l[2]. This level is nearly 12,000 times higher than the drinking water limits for England and Wales of 100 ng/l for PFAS.

Another direct source of groundwater PFAS contamination receiving increasing attention is PFAS containing pesticides. Once in the environment, PFAS pesticides have been found to degrade into a short chain PFAS called Trifluoroacetic acid (TFA), which is more mobile, meaning it moves through soil to groundwater more easily and spreads rapidly throughout water sources[3].  In fact, according to a recent study carried out by the German Federal Environment Agency, pesticides were identified as the main source of TFA pollution in rural areas[4].

Studies have even found PFAS falling in rainwater around the world. So much so, scientists claim atmospheric deposition of PFAS chemicals has led to the ‘planetary boundary’ for chemical pollution to be exceeded[5]. This is the point at which the levels of chemicals in our environment are so great, they exceed what scientists define as the ‘safe’ limit which pushes our planet outside a stable environment.

PFAS contaminated groundwater is then pumped to water treatment facilities which produce our drinking water.  As traditional water treatment methods cannot completely remove PFAS contamination, water companies combine different water sources together to dilute PFAS concentration levels[6]. Research into innovative technologies, such as high pressure membranes and ultrasonic waves, to improve the removal of PFAS from water sources are on-going but are not yet widely available[7], [8].

how pfas spread illustration

How PFAS spread and accumulate in the environment, credit: Fidra

How much PFAS could I be consuming from drinking water in the UK?

England and Wales

From 2021, water companies in England and Wales are required to test and monitor 47 different PFAS but are only required to act should concentrations exceed ‘high risk’ levels[9]. The high risk level is 100ng/L per PFAS compound, this is approximately one drop in an Olympic sized swimming pool. Although this doesn’t sound like a lot, this standard falls short of more protective approaches taken by other countries. For example, Scotland and the EU stipulate that the combined total of 20 widespread PFAS must not exceed 100ng/L[10], [11] and the US has recently proposed a new limit of just 4ng/L for both PFOA and PFOS separately[12] (two internationally restricted and highly toxic PFAS). Furthermore, when it comes to some types of PFAS, scientists claim there is no safe level of exposure, for example, even very small exposure amounts to PFOA can cause adverse health effects [11].

Additionally, England and Wales’s approach for PFAS in drinking water doesn’t take into account the chemical ‘cocktail effect’. This is where chemicals can be more harmful when combined with others[13]. The current regulations mean that multiple PFAS could be present in drinking water, however, because all of the individual PFAS are below 100ng/l there is no reason to act. In reality a collective mixture of harmful PFAS, amongst other chemicals of concern, could propose a significant risk to health and the environment, and yet are slipping under the radar of current regulatory standards.


Scotland follow the same approach as the EU, so a combined total of 20 PFAS must not exceed 100ng/l[10]. However, PFAS is still commonly found in Scotland’s drinking water. In 2023, PFAS was found in more than half of all drinking water samples taken by Scottish Water[14], including  PFOS and PFOA – two restricted substances, which were found in 69 and 217 of the samples respectively.

The rise of TFA in drinking water

Trifluoroacetic acid (TFA) is a short chained PFAS that is a common breakdown product of other PFAS used in products such as F-gases (gases commonly used in refrigeration and air conditioning units) and pesticides. The scientific community are becoming increasingly concerned about the potentially harmful properties of TFA and increasing levels in the environment, particularly in water sources[15].

TFA is highly mobile and persistent in the environment. It has been found far away from known industrial sources (e.g. TFA from F-gases have been found in the Arctic[16]) and is appearing to rapidly accumulate in our environment. It has also been shown to cause serious health concerns in animal studies; a two-generation study found exposure to TFA can cause birth defects in rabbits[17].

A recent study in Germany highlighted the extent of TFA accumulation in drinking water. The organisation, BUND, tested and evaluated five mineral waters and ten tap waters from ten major cities in Germany. TFA was the most frequently detected chemical with concentrations ranging from 50 to 100 ng/L in tap water and between 50 and 200 ng/L in mineral water[18],  exceeding the EU PFAS drinking water limit (100ng/l) by almost double. TFA is not currently monitored in drinking water, however this evidence strongly supports calls for urgent intervention.

Shouldn’t something be done about PFAS in our water sources?

Short answer – yes! Considering access to safely managed water is recognised by the United Nations as a basic human right[19], Governments have a duty to safeguard our drinking water sources from harmful chemicals.

Fidra and other NGOs are calling on the UK government to restrict all avoidable uses of PFAS, preventing further PFAS pollution at source and transitioning the UK towards a PFAS-free economy. Strict standards for PFAS in drinking water should also be set. The limits for individual PFAS in drinking water should be significantly lowered and a combined PFAS limit should be established to protect against exposure to PFAS mixtures.

The UK Government is currently calling for evidence to restrict PFAS use in firefighting foams. This is an important first step in preventing further widespread PFAS pollution in water sources and the wider environment, which Fidra strongly supports. The deadline for submission is June 24th, 2024. To find out more, visit:

Restrictions on PFAS in firefighting foams must form part of wider plans to address PFAS pollution in the UK. Read our NGO Action Plan to find out how the UK can achieve a PFAS-free economy.


[1]  Akoumianaki, I. and Coull, M., 2018. Scoping study for addressing risks to private water supplies from the presence of per- and polyfluoroalkyl substances (PFAS). Available online with supporting documents (CRW2017_12) at:

[2] Pippa Neill and Tess Colley, ENDS Report 2024. ‘God’s own Dark Waters? Exposing how a Yorkshire town became the most PFAS polluted place in the UK – and how the regulator let it happen’. Accessed: Jun. 18, 2024. [Online]. Available online.

[3] Brunn, H., Arnold, G., Körner, W. et al, 2023. PFAS: forever chemicals—persistent, bioaccumulative and mobile. Reviewing the status and the need for their phase out and remediation of contaminated sites. Environ Sci Eur 35, 20.

[4] Global 2000 – Friends of the Earth Australia, Pesticide Action Network Europe (PAN Europe), and Générations Futures, 2024. TFA in Water Dirty PFAS Legacy Under the Radar. Available online.

[5] Cousins, I, T., Johansson, J, H., Salter, M, et al, 2022. Outside the Safe Operating Space of a New Planetary Boundary for Per- and Polyfluoroalkyl Substances (PFAS). Environ. Sci. Technol. 56, 16, 11172–11179.

[6] Royal Society of Chemistry, 2023. Evidence Report: PFAS in UK waters – presence, detection, and remediation. Available online.

[7] University of Surrey, funded PhD project (s) focusing on remediation of per- and poly-fluoroalkyl substances (PFAS) using new technologies. Information available online.

[8] Das, S. & Ronen, A. 2022. A review on removal and destruction of per-and polyfluoroalkyl substances (PFAS) by novel membranes. Membranes 12, 662. DOI: 10.3390/membranes12070662

[9] Drinking Water Inspectorate, 2022, Letter to Board Level and Day to Day Contacts of Water and Sewerage Companies and Water Companies in England and Wales. Available online.

[10] European Chemicals Agency (ECHA), Per- and polyfluoroalkyl substances.

[11] Scottish Government, 2022. Protecting Scotland’s water.

[12] United States Environmental Protection Agency (EPA), 2024. Biden-Harris Administration Finalizes First-Ever National Drinking Water Standard to Protect 100M People from PFAS Pollution.

[13] CHEM Trust, 2022. Chemical cocktails: The neglected threat of toxic mixtures and how to fix it. Available online.

[14] Paul Dobson, The Ferret, 2024. Forever chemicals found in 55 per cent of Scottish drinking water. Available online.

[15] Freeling, F., Björnsdotter, M. K. 2023. Assessing the environmental occurrence of the anthropogenic contaminant trifluoroacetic acid (TFA). Current Opinion in Green and Sustainable Chemistry.

[16] Hartz, W. F, Björnsdotter, M. K., Yeung, L. W. Y et al.   Leo W.Y. 2023. Levels and distribution profiles of Per- and Polyfluoroalkyl Substances (PFAS) in a high Arctic Svalbard ice core, Science of The Total Environment,

[17] European Chemicals Agency (ECHA), 2021. Developmental Toxicity, Available online: Registration Dossier – ECHA (

[18] BUND Friends of the Earth Germany, 2024. BUND and BDEW: PFAS pollution – manufacturers should pay. Available online.

[19] United Nations Department of Economic and Social Affairs, available online:


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