Thames Water treatment facility leaves entire town reeking of sewage

A riverside town located downstream of a Thames Water treatment facility town has been left reeking of sewage with residents claiming they “effectively have an open sewer running down their back garden” due to the outflows.

Eton Wick in Berkshire, south-east England is connected to Thames Water’s sewage treatment facility in Slough through the Roundmoor stream.

The discharges from the Slough facility account for 95 per cent of Roundmoor’s source of water, meaning that the stream is mainly comprised of treated effluent.

Eton and Castle councillor Mark Wilson told i that when untreated sewage is discharged into Roundmoor during storm overflows, Eton Wick is permeated with an “unbearable” stench of sewage.

“The stream has no other source of water,” Mr Wilson said. “Because of heavy rainfall, you get storm overflows and untreated sewage is pumped straight out. The water has a very unpleasant blue-grey colour and becomes very thick.

“Residents effectively have an open sewer running through their back garden.”

He added: “A smell of sewage and wastewater blows across the entire village and thousands of residents are impacted by this.”

Eton Wick’s wildlife has also been affected by the discharges, with residents often spotting dead fish floating in the stream after sewage outpours.

The Roundmoor stream is maintained by residents who enter the water and manually pull weeds out that may block the flow of water, causing flooding.

“It is something that needs to happen,” Mr Wilson said. “Otherwise you get flooding on fields and footpaths around the stream. But with the current state of the water, it would be extremely unsafe to do that.

“The impact of the sewage coming out of this stream has a real negative impact on the community.”

While Mr Wilson intends to take part in the Royal Windsor Triathlon in June, he expressed concerns about swimming in the Thames downstream of Roundmoor because of the pollution.

“This is a concern expressed by many local river users I’ve spoken to – swimmers, paddle boarders and rowers in particular,” Mr Wilson said.

Data by the Environment Agency shows that untreated waste was discharged into waterways in England 464,056 times last year. The duration of these overflows in 2023 amounted to a total of 3,606,170 hours, up from 1,754,921 hours in 2022.

While wastewater companies are permitted to discharge untreated sewage into waterways to prevent their infrastructure from becoming overwhelmed, they are only allowed to do so during exceptional periods of heavy rainfall.

A Thames Water spokesperson said: “We regard any untreated discharges as unacceptable, and we’re committed to stopping them from being necessary.

“Storm discharges are closely linked to rainfall and our region experienced above average rainfall for most of 2023. The overflows are designed to discharge automatically when the sewer network is about to be overwhelmed, by releasing diluted wastewater into rivers, rather than letting it back up into people’s homes.

“We have published plans to upgrade over 250 of our sewage treatment works, including at our site in Slough. This project will increase treatment capacity, from 1150 to 1416 litres a second and reduce the need for untreated discharges in wet weather.”

Thames Water announced earlier this month that it was denied £500m in funding from its shareholders, which was the first part of a £750m funding package, after the regulatory body Ofwat deemed it’s business plan “uninvestible.”

Shareholders in Thames Water, which serves 16 million customers in London and south-east England, are asking the firm to increase its water bills amid fears the firm’s £18bn debt will lead to its collapse.

As a result of the lack of investment, the company could face temporary nationalisation next year if it cannot strike a deal between its shareholders and Ofwat.

This week it emerged that the firm’s parent company has defaulted on a £400 million loan – creating further uncertainty about the future of the supplier.

Kemble informed bondholders in a formal notice interest payments due this week “have not been paid”.