ILLEGAL SEWAGE SPILLS EXPOSED

CAMPAIGNERS in Henley have condemned Thames Water after an investigation suggested it illegally discharged sewage on 110 days last year.

Data obtained by the BBC showed that the company was responsible for 1,253 hours of “dry spills”.

Water companies are legally allowed to spill untreated wastewater under certain conditions such as heavy rainfall to prevent the sewage system from being overwhelmed.

But dry spills, when untreated wastewater spills straight into rivers when there has been no rain, are illegal under environmental law as they can lead to higher concentrations of sewage.

The BBC used Environmental Information Regulation requests to source the 2022 dry spill data and cross-referenced it with rainfall data, which showed that Thames Water dry-spilled at 49 overflow sites last year.

Southern Water and Wessex Water were also responsible for hundreds of hours of dry spills over the same time period. None of the other six English water companies provided data.

Jo Robb, South Oxfordshire District Council’s “river champion”, said: “This data comes as no surprise to those who have been campaigning on this issue for some time.

“But it is shocking to see in black and white that Thames Water dumped untreated sewage for more than 1,000 hours on dry days last year.

“On July 19, 2022 — the hottest day on record, when hundreds of people were paddling in our rivers to escape the heat — Thames Water was releasing untreated sewage.

“Dry spilling is especially harmful to ecosystems and human health because, during dry weather when river levels are low, there is not the ‘benefit’ of dilution, So the impact of untreated sewage is more severe.”

Councillor Robb, who represents the Green party and is a member of the Henley Mermaids open water swimming group, said: “We have been told for years that sewage discharges were necessary to prevent sewage from flooding people’s homes but we know now that these discharges are happening in dry weather, all year round, because of the failure of Thames Water to invest in its sewage infrastructure.

“Water companies are permitted to discharge raw sewage only in ‘exceptional circumstances’ and these dry discharges are thus illegal.

“The Environment Agency should be investigating these spills and prosecuting Thames Water. And we need to see urgent investment in our crumbling sewerage network to ensure it is fit for purpose.

“The River Thames is the jewel in the crown of our beautiful local area and many people’s livelihoods and businesses depend on a clean river, not to mention the aquatic life that relies on a clean river to thrive and those of us who enjoy swimming, paddleboarding, rowing or just walking by the river.”

Dave Wallace, co-founder of the Henley and Marlow River Action Group, has been testing pollution levels in the River Thames at Fawley Meadows. He and other “citizen scientists” from the group have identified high levels of phosphates, nitrates and E. coli in the water this summer.

Mr Wallace said: “Sadly, it is not news to some of us who have been looking at what’s going on but all credit to the BBC.

“The scale of it is unbelievable and intolerable. For us in the Thames catchment area it is more evidence of how Thames Water is treating the river. It is not surprising but it is terrible.”

On Friday, the group installed an ammonia sensor to detect the presence of sewage in the river.

Mr Wallace said: “It can give a very good indication if there’s sewage in the river. We’ve got it attached to an app so we can see what’s going on in real time and monitor ammonia. This is moving us up a gear in terms of our testing.”

A spokeswoman for Thames Water said: “There is a number of methodologies for defining and calculating why and how dry day spills occur.

“The Environment Agency’s methodology for calculating dry day spills is still being determined and we will continue to work with our regulators as they define this.

“We regard all discharges of untreated sewage as unacceptable and we have planned investment in our sewage treatment works to reduce the need for untreated discharges including at Stewkley, Stone and Haddenham.

“We are the first water company to provide storm overflow alerts for inland waters and this ‘near real-time’ data is available to customers as a map on our website.

“We want to lead the way with this transparent approach to data and we have also published on our website our plans to upgrade more than 250 of our sewage treatment works and sites.

“Stopping discharges altogether will take time and sustained investment, however each step we take on this journey is a move in the right direction.”

An Environment Agency spokesman said: “We are conducting our largest ever criminal investigation into potential widespread non-compliance by water and sewerage companies at thousands of sewage treatment works. Our enforce-ment action has already led to more than £150 million in fines since 2015.

“We will always pursue and prosecute companies that are deliberately obstructive or misleading – and work constructively with those driving improvements.

“We are also improving how we regulate the sector, including expanding the number of officers focused solely on regulation, increasing compliance checks and recruiting more data specialists able to translate storm overflows monitoring data into stronger regulatory intelligence.”