A RIVER near sewage treatment works in Buckinghamshire has been covered in white foam since the weekend.  

Anger is mounting after layers of white foam was seen floating in River Chess and further.

Foaming was first spotted by River Chess Association volunteers on the morning of Saturday January 4 near Thames Water’s Chesham Sewage Treatment Works.

Chair of the River Chess Association Paul Jennings said today: “I’ve never seen anything like this in my 25 years of involvement with the river.”

“Over the weekend it has continued to develop. They haven’t given as any answers as to what’s causing it.

“We do know it’s on-going, and it has spread all over to River Colne and the Union Canal in Rickmansworth.

“This is not a small issue.”

Mr Jennings said he traced the foaming back to the sewage treatment works “without a doubt". 

“When you’ve got a non-turbulent stretch of the river, there’s no foam, but as soon as it hits a mill with a mill race and a waterfall, it foams up incredibly – to the point you can see 100 metres of the downstream from Bois Mill completely white.”

However, there appeared to be no sewage in the water underneath the foam layer, he pointed out.

He said: “There’s some chemical in the effluent that’s causing the foaming.

“That’s either something that’s come into the sewage treatment works which the sewage treatment works hasn’t been able to process. Or it’s something is happening in their process, and their process has gone wrong for some reason.

“Sewage discharges are quite normal, sadly.

“We can go for months at a time when they’re discharging sewage. That’s normal, we recognised that. This is very unusual. I’ve never seen anything like this.”

Thames Water confirmed it was investigating a foam discharge from Chesham Sewage Treatment Works into River Chess.

The company said in a statement: “We'd like to reassure you that this is not a storm overflow issue - that would be where the sewers cannot cope after excess rain, and so a mixture of rainwater and dilute untreated sewage gets discharged to the river to prevent sewer flooding.

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“This is instead a potential issue with the clean, treated water that flows out of our works and returns back to the environment.”

Thames Water’s water quality specialists were analysing samples to “understand what might be causing the white foam,” while engineers put absorbent booms used for oil spills on the outfall to stop foam entering the river.

“We've sent a clean-up team to site to skim away the foam that’s gathered behind the booms, and we’ll continue to monitor the situation while investigations continue,” the company said.