The District Council arranged testing of a total of 20 private water supplies. The results from all 20 private water supplies sampled have shown very low levels of a PFAS chemical.
Each private water supply generally provides water to between one and four homes, and residents linked to the 20 private water supplies sampled have all been visited or contacted by the Council’s Environmental Health officers to discuss these first results.
Following confirmation from Cambridge Water a fortnight ago that a local borehole had previously recorded higher levels of the chemicals, which resulted in them removing the borehole from the mains water supply, the Council immediately put plans in place to test the small number of private water supplies that are in the area.
In all instances, the concentration of PFAS monitored was below 0.1 microgram per litre, meaning the water is considered by the water industry to be ‘wholesome’. The rating means that the water industry would consider the levels of PFAS in the sample to be within acceptable levels, and suggests the water can continue to be used as normal, albeit with further monitoring.
Formal, written notification from the specialist testing lab has been received regarding the first 16 results and a verbal update has been received about the final four test results, with the formal written notification to follow within the next 24 hours as a matter of course.
Most homes get their water supply from ‘mains water’, provided by water companies such as Cambridge Water, with the supplies regulated by the Drinking Water Inspectorate (not the Council). The majority of residents in South Cambridgeshire are connected to the mains water supply and therefore not be affected by the testing results received by the Council. During the weekend and through the course of today (Monday 21 February) Council officers have made contact with all residents where private water supplies have been tested, to inform them about their results.
The Council is responsible for testing only the ‘private water’ supplies, which supply a small number of homes across South Cambridgeshire, for instance from local boreholes or wells.
PFAS group chemicals are not something that the Drinking Water Inspectorate mandates those monitoring private water supplies (like the Council) to test for. However, in light of the recent concerns about PFAS levels in the mains water supply, the Council implemented additional testing for the chemicals in the private water supplies in the area around Duxford on Wednesday 9, Thursday 10 and Monday 14 February. These samples can only be tested by being sent to specialist labs for analysis, which the Council had needed to arrange before sampling could begin.
The guidance on responding to high levels of PFAS in water supplies is still emerging from the UK Health Security Agency and the Drinking Water Inspectorate. The Council will continue to risk-assess and monitor the quality of bore hole water in light of recent findings.
Cllr Brian Milnes, Lead Cabinet Member for Environmental Services and Licensing and South Cambridgeshire District Council, 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.”