Thames Water has been discharging sewage into rivers in more than 50 locations around the county while water has gone into some people's homes during Storm Bert.

Some of the discharges, tracked on the water company's Event Duration Monitoring (EDM) storm discharge map, went on for days amounting to hundreds of hours of non-stop discharge. 

Witney Sewage Treatment Works began discharging at 2am on Sunday (November 24) and continued for over five full days.

In the past 12 months it has dumped 2,747 hours - or almost four months - according to clean rivers campaigners Windrush Against Sewage Pollution (WASP).

WASP Chair Ash Smith believes he became ill after going out sampling river water.

He said: "I was out in the rain at the outfall testing for ammonia on the Sunday morning and found readings of over 6mg/l of ammonia in the untreated outfall, which was discharging a high flow into the brook.

More than 50 treatment works were discharging on Thursday (November 28) long after the heavy rain (Image: Windrush Against Sewage Pollution)

"So much for water company bosses claiming that storm sewage is just highly diluted contaminated rainwater - the smell was disgusting."

He said the 'under-capacity site' was actually performing well "but only doing so by dumping what could not be treated - the highly polluting discharge".

"Of course the wildlife in the river can't tell the difference. There had been fish in the brook that had come up to feed on undigested food and who knows what.

"That sewage then runs down past the highly popular walking path at Duck Lake, and we worry that the dogs that get into it and people inadvertently making contact are at a high risk from the bacteria in the sewage, even the treated effluent."

Mr Smith added: "While sampling, and I am very careful with gloves and such, I pricked my wrist on a thorn, a very minor scratch without any sign of blood, but two days later I was at Burford Surgery getting an antibiotic for a skin infection that was heading up my arm."

WASP first reported Witney for 'dry' - when it was not raining and therefore illegal -  discharging in 2019. The Environment Agency has still not reported on that criminal investigation.

Lib Dem MP for Witney Charlie Maynard said: "Almost every sewage treatment works in western Oxfordshire is currently dumping sewage into our rivers.

"Thames Water is swamped in debt. The Labour government is hoping the problem will be solved by bankers and the markets. It won't be.

"They need to step up, put the company into special administration, cut the company's debt and put it on a stable footing so that it can make the major investment required to fix our pipe network and sewage treatment works."

Reading of over 6mg/1 of ammonia in the untreated outfall (Image: Windrush Against Sewage Pollution) A Thames Water spokesperson said: “While all storm discharges are unacceptable, the sewage system was historically designed to work in this way, to prevent sewage backing up into people’s homes.   

“We know how much people enjoy and appreciate rivers, and we are committed to seeing waterways thrive, but we can’t do it alone. Farming, industry, road runoff, wildlife and increasingly extreme weather also play a role in river health. 

"We have clear and deliverable plans to upgrade 250 of our sites across the region, to increase treatment capacity and reduce the number of storm discharges.

"This includes our Witney sewage treatment works, which is being upgraded at a cost of £17million and is scheduled to be completed in 2025.

 “As infrastructure ages and demand on it increases, more investment is needed across the entire sector. That’s why we’ve asked for increased investment in the next regulatory cycle between 2025-2030. 

"We’ve put transparency at the heart of what we do, and we were the first water company to publish a real time data map on our website, which in its first year has been viewed over 350,000 times.”