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

To ask the Secretary of State for Environment, Food and Rural Affairs, what data his Department holds on levels on lead in tap water exceeding safe limits in (a) England, (b) Norfolk and (c) South West Norfolk constituency.

The Drinking Water Inspectorate (DWI) holds data on lead in drinking water based on compliance samples taken by water companies. These tests assess whether lead levels meet the regulatory standard of 10 micrograms per litre under the Water Supply (Water Quality) Regulations 2016.

Where a sample exceeds this limit, it is recorded as a failure and triggers an investigation. Each failure is followed up to a satisfactory resolution. Most failures are linked to lead pipework, often in the final sections of pipework in private ownership. In such cases, customers may need to replace their section of pipe, with support from the water company. In the meantime, companies mitigate risk by adding orthophosphate to reduce lead solubility.

To support long-term improvements, companies are delivering lead reduction strategies under the current Asset Management Period (AMP8), which began in 2024. Anglian Water, which supplies South West Norfolk, reported 16 exceedances across its entire supply area - serving 5 million consumers - over the past five years. Its AMP8 lead strategy is being closely monitored.

National compliance with the lead standard was 99.60% in 2020–2022. More detail is available in DWI’s triennial report.