Tests confirm private water supplies and mains water in South Cambridgeshire villages are ‘safe to drink’
Private water supplies in the Duxford area are safe to drink, residents have been told, after tests detected “very low levels” of a PFAS chemical.
Meanwhile, tests at 40 homes using mains supplies in and around Stapleford and Great Shelford have also shown the tap water is safe.
The testing comes after a Guardian story revealed that Cambridge Water had found higher than expected levels of the so-called ‘forever chemical’ in June 2021 at the Duxford Airfield aquifer. The company took the aquifer out of commission at the time and, since the discovery was reported, has told the 6,500 households in the Stapleford and Great Shelford area that it supplied that their water was always blended with other sources and was safe to drink. Tests at the time showed it contained “at, or around, the tier 1 (lowest risk) level” of the chemical.
The Drinking Water Inspectorate is investigating Cambridge Water’s response.
Now Cambridge Water has confirmed the results of its home testing, carried out as part of its reporting to the inspectorate. It said the drinking water meets the highest possible quality category for the compound perfluorooctane sulfonate (PFOS), which is part of a group of perfluoroalkyl and polyfluoroalkyl (PFAS) chemicals.
Elinor Cordiner, Cambridge Water’s head of water quality and compliance, said: “The findings clearly demonstrate that the drinking water we supply to homes across the network is safe. The water quality standards in the UK are among the most stringent in the world. Last year we completed almost half a million tests and achieved 99.9 per cent compliance rate across all parameters.
“We can understand that residents want the objective reassurance that these new tests provide and would like to stress that the quality of drinking water we supply and the safety of our customers is our paramount concern.”
Meanwhile, South Cambridgeshire District Council has confirmed the results of lab tests carried out on 20 private water supplies since the story emerged.
The council, which is responsible for testing supplies not connected to the mains, had not previously been notified of the discovery last June by Cambridge Water.
A specialist testing lab has confirmed the concentration of the compound was below 0.1 micrograms per litre, which is within acceptable levels and considered by the water industry to be ‘wholesome’.
The council said the finding means the water can continue to be used as normal, but further monitoring will be required.
The chemical found at the Duxford Airfield aquifer was used in firefighting foams from the late 1960s until the early 2000s at airfields and firefighting training centres.
These chemicals are linked with increased cholesterol, low birthweight and suppressed immune response.
The Drinking Water Inspectorate, which deals with issues concerning water quality, does not currently mandate that private supplies are tested for such chemicals. Guidance on it for water companies was updated in January 2021 and continues to evolve, with the UK Health Security Agency also involved.
The council said it will continue to risk assess and monitor the quality of borehole water following the findings.
Cllr Brian Milnes, lead cabinet member for environmental services and licensing, said: “We responded immediately by sampling private water supplies and sending for independent testing, after Cambridge Water confirmed the details of the higher levels of PFAS in a local Duxford borehole, which they had later taken out of use.
“As soon as we received the test results, our officers quickly made contact with the people connected to these private water supplies, so they have all the necessary information.
“This is an emerging area of water testing and regulation and we anticipate further guidance being provided by the UK Health Security Agency and Drinking Water Inspectorate for owners of private water supplies, as well as for organisations like ours with responsibility for monitoring those water supplies.
“While we are not responsible for maintaining private water supplies, we will be implementing any new guidance as it is published on the safety of those private water supplies.”
The council’s environmental health officers have discussed the first results with the households affected.
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