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

To ask the Secretary of State for Environment, Food and Rural Affairs, whether her Department is taking steps to ensure that water companies (a) sample water entering their water treatment plants and (b) publish data on this.

There is no requirement currently for water companies to sample and publish data on the quality of water entering their waste water treatment plants. However, they are required to sample treated effluents from their plants which are discharged to the environment. These samples are analysed and assessed for compliance against protective environmental permit requirements. This information is reported to the Environment Agency and published on GOV.UK.

However, a new requirement in S. 82 of the Environment Act 2021 requires sewerage undertakers to continuously monitor the quality of the receiving water upstream and downstream of their assets. This will allow sewerage undertakers to assess the impact of discharges from their assets on the receiving watercourse. The requirement covers both storm overflows and the treatment works discharges and is being introduced in 2025.

Continuous Water Quality Monitoring Programme - provisional technical guidance for sewerage undertakers (publishing.service.gov.uk).