Quality watchdog warns of contamination risks for private customers in England and Wales

Almost two thirds of the 950,000 people In England who take their drinking water from private suppliers – those not directly connected to the national mains water system – are “potentially drinking contaminated supplies,” according to the Drinking Water Inspectorate (DWI). In Wales the risk applies to half of 75,000 people on private supplies. The main risk from contaminated supplies in both jurisdictions, is to children under ten years old the inspectorate warned.

The DWI concluded that data from the local authorities in England and Wales – who regulate the quality of drinking water provided by private suppliers – shows “an ongoing risk to consumers of private supplies.” It warned that while the current a “regulatory gap” remains, the risks persist and “the scope for significant improvement in the quality of private supplies is limited.”

The risk arises according to the inspectorate, from inadequate risk assessments by local authorities. Following its latest pair of annual reports on private water supplies in England and in Wales for 2022, the DWI warned that two thirds of private water supplies in England and half of those in Wales are lacking a current risk assessment. “The owners and/or consumers of these supplies are therefore unaware of the risks, and this ultimately results in people potentially drinking contaminated supplies unknowingly and for extended periods of time,” the DWI reported.

The inspectorate said an area of concern is privately supplied holiday accommodation where children visit. It highlighted a further risk to children from lead arising from plumbing. It found that more than, 3,000 consumers in England received a private supply with concentrations in breach of the lead standard in 2022 while the figure in Wales was 614 people.

In 2022, 3.8% of samples taken in England contained fecal indicators, affecting 5,577 consumers, and 2.3% of samples in Wales, affecting 1,739 consumers. DWI said analysis of the past five years’ data shows “little improvement in the percentage of samples failing to meet the standards for wholesomeness in these supplies.”

The inspectorate’s role in England and Wales, relating to private supplies, is to provide technical support to local authorities and report progress to Ministers in each jurisdiction.

The DWI flagged up research commissioned for 2024 into the private water supplies regulatory model and legislative framework in England and Wales. The study will “review the effectiveness of the current regulatory regime around private water supply. It will address issues arising from shortcomings reported in its current annual report including the deterioration by climate change in the sufficiency and quality of private supplies by reducing water availability and increasing pollutants. It said in the report: “The option of connection to public supplies can be geographically difficult and costly, and alternative supplies are not always available.”

Other issues included shortfalls in the planning process for new housing developments which “do not consider the availability of water supplies for drinking or sanitation, whereas they do consider drainage and wastewater removal. And conveyancing processes, the DWI reported, “do not consider the availability and type of water supplies, resulting in properties and land being sold for development without proper consideration of an appropriate water supply.”