‘Forever chemicals’ found in drinking water sources across England

Potentially toxic “forever chemicals” have been detected in the drinking water sources at 17 of 18 England’s water companies, with 11,853 samples testing positive, something experts say they are “extremely alarmed” by.

Per- and polyfluoroalkyl substances (PFAS) – a group of 10,000 or so human-made chemicals widely used in industrial processes, firefighting foams and consumer products – were found in samples of raw and treated water tested by water companies last year, according to the Drinking Water Inspectorate (DWI), the Guardian and Watershed Investigations has found.

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 says the “dangers of PFAS have become a growing concern due to their persistence in the environment, ability to accumulate in the human body, and potential health effects”.

The DWI categorises PFOS and PFOA contamination risk in three tiers, with tier 3, equal to or more than 100 nanograms a litre, being high risk and the point at which action must be taken to dilute the PFAS or remove the water source from public supplies.

PFOS was found in raw untreated water at 18 times the tier 3 100ng/l limit for drinking water. PFOA was detected at 1.5 times the limit.

Despite growing concerns about the health impacts of other PFAS, there are no limits set for the rest of the 10,000 or so substances. Of the 47 PFAS which water companies have been told to look for, 35 were detected and an additional PFAS compound was also found.

The DWI says these high concentrations never made it to people’s taps because the contaminated water is blended with another source to bring the levels down.

“The report shows that there are people who are drinking medium-risk water,” said Stephanie Metzger, a policy adviser at the Royal Society of Chemistry (RSC).

Of the 12 water companies that provided data for PFAS in treated water, eight had a total of 398 samples with PFAS above 10ng/l, putting them in the DWI’s second tier category, also termed medium risk. Blending is not required at this level.

“We don’t think anyone should be drinking medium-risk water … the toxicology data shows the risk of health effects becoming more over time as PFAS builds up in our body,” said Metzger.

The RSC is pushing for a tenfold reduction of the limit for individual PFAS types – from 100ng/l to 10ng/l – as well as an overall limit of 100ng/l for the total amount of PFAS.

It would bring England and Wales closer to the EU and Scotland, which have a stricter limit of 100 ng/l for the sum of 20 specific PFAS in treated water. Some countries have stricter limits, with Denmark’s set at just 2ng/l for four individual PFAS, and the US Environmental Protection Agency has proposed dropping limits on some to just 4ng/l.