One in 20 private supplies may be unfit for human consumption

“The quality of private supplies in 2023 remains a concern with 4.93% of samples found to contain E. coli and 5.98% with enterococci, both of which are indicators of faecal contamination. This means that about one in 20 supplies are unsuitable to be used for drinking water and may be unfit for human consumption.”

That was according to chief drinking water inspector Marcus Rink, in a letter to water minister Robbie Moore to accompany the Drinking Water Inspectorate’s 2023 report on private water supplies in England.

Rink said the quality of private supplies tested deteriorated last year, and that 53% of large supplies (for more than 50 consumers), commercial supplies and supplies being used by the public, had not received a single test for E. coli in 2023, “leaving a significant and unknown risk for those consumers”.

The letter also flagged up chemical risks: “For instance, looking at the percentages of samples which fail to meet the standards, lead (2.69%), and nickel (3.73%) represent risks associated with the plumbing of these systems, and manganese (4.42%), natural fluoride (1.01%), and pesticides (0.17%), represent risks from the catchment, all of which can have an impact on health, children again being the most vulnerable.”

Rink concluded by highlighting other issues for those who use and regulate (local authorities) private supplies, including the prohibitive cost of a mains water connection for some rural communities faced with an unfit supply; planning processes for new housing developments which currently do not consider the availability of water supplies; and inadequate conveyancing processes resulting in properties and land being sold for development without proper consideration of an appropriate water supply.

At least 1.5% of England’s population, over 830,000 consumers, are on private supplies.