Potentially toxic ‘forever chemicals’ have been detected in drinking water sources at 17 of England’s 18 water companies, with 11,853 samples testing positive, according to data from the Drinking Water Inspectorate (DWI). Experts say they are ‘extremely alarmed’ by the findings.
Per- and polyfluoroalkyl substances (PFAS), a group of around 10,000 human-made chemicals used in industrial processes, firefighting foams and consumer products, were found in raw and treated water samples tested last year. Some PFAS, including PFOS and PFOA, which are now mostly banned, have been linked to cancers, thyroid disease, immune system and fertility problems, as well as developmental defects in unborn children.
The DWI categorises PFOS and PFOA contamination in three tiers, with tier 3 (100 nanograms per litre or more) being high risk and requiring action to dilute or remove the source. PFOS was found in raw untreated water at 18 times the 100ng/l limit, and PFOA at 1.5 times the limit. Of the 47 PFAS that water companies have been told to look for, 35 were detected, along with an additional PFAS compound.
Affinity Water appears to have the biggest PFAS problem, with 73 raw water samples above the maximum DWI limits at five sites, followed by Anglian Water with 22 samples above the limit from two groundwater sources, according to a DWI report. Southern Water found two samples at or above the top limit in its treated water. The DWI says these high concentrations never reached taps because contaminated water was blended with other sources, but experts warn that some people may have consumed high levels due to a lag in testing.
Of the 12 water companies that provided data for PFAS in treated water, eight had 398 samples with PFAS above 10ng/l, putting them in the DWI’s medium-risk category. The Royal Society of Chemistry (RSC) is pushing for a tenfold reduction of the limit for individual PFAS types, from 100ng/l to 10ng/l, and an overall limit of 100ng/l for total PFAS. This would bring England and Wales closer to EU and Scottish standards, and far from stricter limits such as Denmark’s 2ng/l for four individual PFAS.
Dr David Megson, a forensic environmental scientist from Manchester Metropolitan University, said: ‘Our guideline values for PFAS in drinking water are not as stringent as other countries, yet it is still a challenge for water companies to provide water with PFAS levels below these limits. Ultimately it is water companies and consumers who are picking up the bill to try to manage these contaminated supplies, not the polluters.’ The RSC is calling for more regular monitoring and the creation of a chemicals agency to deal with PFAS and other contaminants.
