Thames Water has pumped at least 72bn litres of sewage into the River Thames since 2020 – roughly equal to 29,000 Olympic swimming pools – new figures reveal.
Mogden near Twickenham was the worst affected site, where 17.1bn litres of sewage was discharged into the river.
The area contains a nature reserve, rare wildlife and areas where people swim and boat. This was closely followed by Crossness in east London where 15.8bn litres of sewage was spilled.
Local Liberal Democrat MP Munira Wilson, for Twickenham, is campaigning for Thames Water should be disbanded and replaced by a “public good company”, with a board populated by environmentalists, and that would not be allowed to prioritise profit over the environment.
She said: “These horrifying revelations are proof that Thames Water needs to be ripped up. It is outrageous that Conservative ministers continue to sit on their hands and let Thames Water get away with this.
“The government is standing idly by whilst our rivers are poisoned and water firm execs pocket millions. The era of water firms putting profit before the environment must come to an end.
These water firms are committing environmental crimes which are destroying our rivers and wildlife habitats, all whilst pocketing eye-watering sums of money.”
Water firms have no legal obligation to report the amount of sewage discharged, only the number of hours that it was released.
But campaigners argue this data is insufficient as this does not properly quantify how much sewage is in England’s rivers.
The data was revealed by an environmental information request submitted by the Liberal Democrats, who are calling for water companies to be more transparent with their data on sewage spills.
In most areas there are not volume measuring devices, but Thames Water use sewage monitors to measure volume in some locations.
The water company used them while making the Thames Tideway, and they are the only known monitors of the kind fitted in the country. Because they do not cover the entire network, it is likely far more sewage was released than that measured.
Last year, at least 14.3bn litres of sewage was discharged into the Thames, and the worst year was 2021 when at least 32bn litres was released.