Last reviewed 14 April 2021

Water companies are illegally dumping untreated raw sewage into rivers in England and Wales, according to data released by the regulators.

Discharge permits issued by the Environment Agency (EA) specify the level of sewage each treatment works must treat before it can dump untreated sewage. But according to a BBC Panorama programme, 7 of the 10 major water companies had treatment works that were breaching their permits by dumping sewage before they were treating the permitted volumes.

Treatment works are allowed to discharge excess sewage into waterways but only after extreme wet weather events, such as torrential rain or when operating conditions reach treatment capacity. This helps protect low-lying properties from flooding, and prevents sewage from backing up and spilling into streets and properties.

But new data released by the Environment Agency shows Water companies discharged raw sewage into rivers in England more than 400,000 times in 2020, a 27% increase on the previous year.

The data shows United Utilities was the worst offender for exceeding sewage discharge consents, recording over 113,000 incidents. Yorkshire and Severn Trent each recorded over 60,000 storm overflow events. In all, 10 major water companies in England and Wales discharged sewage during storm overflow events. An ENDS data map shows 100 sites in England that discharged the most raw sewage in 2020.

Sir James Bevan, Chief Executive of the Environment Agency, told the BBC that his organisation was "working actively with the water companies to ensure overflows are properly controlled".

The Rivers Trust, which campaigns to protect river environments in England and Wales, said: "This is a shocking volume of untreated contaminated wastewater reaching our rivers and shows that our current approach and infrastructure, managing storm water in particular, needs a radical overhaul."

A joint Storm Overflows Taskforce, made up of Defra, the Environment Agency, Ofwat, Consumer Council for Water, Blueprint for Water and Water UK, was set up last year to work with water companies on ways to eliminate pollution from storm overflows. Water companies also agreed to increase transparency about the release of sewage into rivers and inland waterways.