River Thames: More than 2bn litres of raw sewage discharged over two days

More than two billion litres of raw sewage were dumped in the River Thames over two days, a report has found.

Thames Water's Mogden wastewater treatment works in Isleworth, west London, discharged enough sewage to fill 400 Olympic-sized swimming pools on 3 and 4 October 2020.

The figures were in a report published by the Environmental Audit Committee (EAC) on UK rivers' water quality.

Thames Water said any discharges of untreated sewage were "unacceptable".

Mogden is the third largest sewage treatment works in the UK and one of the few that has a separate device to monitor the volume of untreated sewage discharged.

During the whole of 2020, 3.5 billion litres of untreated sewage entered the Thames from Mogden - seven times as much as was dumped in 2016.

Thames Water's chief executive Sarah Bentley admitted the company "struggled to treat the sewage", blaming the UK's wettest day on record.

In the report she said: "We would have needed either another treatment works the same size as Mogden treating another one billion litres or we would have needed 150 more storm tanks."

Figures published last year by the Environment Agency revealed untreated sewage, including human waste, wet wipes and condoms, was released into waterways for more than three million hours in 2020.

Spillages into rivers, otherwise known as overflows, are legal when sewage networks and sewers are likely to become overwhelmed.

Releasing the sewage into rivers prevents it from backing up into residential homes and potentially spilling out of toilets and bath plugholes, as well as manholes in gardens and streets.

Residents living close to Mogden have complained about the works for several years, citing problems with pungent smells and the fact it attracts mosquitoes to the area.

Councillor Salman Shaheen, who represents the ward of Isleworth for Hounslow Council, called on Thames Water to upgrade Mogden's infrastructure.

He told the Local Democracy Reporting Service: "People are very angry. They are outraged to hear about it because their kids are paddling in the Thames.

"It really is a treasured resource we have in our part of west London and it is being polluted by a water company."

A spokesperson for Thames Water said: "We regard all discharges of untreated sewage as unacceptable and will work with the government, Ofwat and the Environment Agency to accelerate work to stop them being necessary.

"Our aim will always be to try and do the right thing for our rivers and for the communities who love and value them. We have a long way to go - and we certainly can't do it on our own - but the ambition is clear."

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