Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, what assessment he has made of the adequacy of the condition of water supplied by Thames Water.

Drinking Water quality in England is regulated through the Water Supply (Water Quality) Regulations. The Drinking Water Inspectorate is the enforcing regulator. The Regulations require a programme of random samples to be taken from consumers’ taps, and the results are reported to the Inspectorate. Any breaches are investigated by the company and assessed by the Inspectorate and enforcement action taken as appropriate.

Thames is required to notify the Inspectorate of any unusual event which could be a risk to consumers - each event is investigated by the Inspectorate, and enforcement action taken as required. The Inspectorate assessed 61 events reported by Thames Water in 2024.

Thames Water adopts a water safety planning approach to drinking water, in line with the WHO recommendations. This ensures risks are identified and mitigated before there is any impact on consumers.

In 2024, the Inspectorate completed technical audits at seven sites and conducted a further desktop audit of bespoke network assets. There are currently 26 improvement notices issued by the Inspectorate to improve water quality across Thames’ asset base.