Report by Ken Goodwin
A clean rivers campaigner has discovered what looks like a giant fatberg in the River Coln at Fairford in Gloucestershire.
It was hanging from an unidentified pipe next to a sewage outlet, which it is claimed has been dumping untreated effluent into the waterway during heavy rain. Thames Water says it is investigating the pollution.
The River Coln takes its water from the limestone uplands of the Cotswolds and the stream should be sparkling and clear but - by the sewage outlet pipe - it is anything but.
The pipe comes from the nearby sewage works at Fairford. The water is supposed to be treated but heavy rain turns the clear waters of the River Coln grey, and carries with it particles of foul-smelling effluent and bits of debris which look like toilet paper.
Ashley Smith of Windrush Against Sewage Pollution has been monitoring the water pipe and what it is releasing into the river.
We're ruining the environment for the next generation. We're ruining it for ourselves. There has to be a better way. It's far too cheap to pollute.
Ashley has discovered a second pipe beside the outlet, with what looked like a giant fatberg hanging from it.
He said: "I thought it was a fatberg. It was certainly stuck together, and Thames Water has been and taken it off."
In a statement, Thames Water says following reports of pollution from the sewage works, it inspected the two pipes.
It said: "One is connected to the sewage works and its role includes allowing treated wastewater to return to the environment.
"We found the second, the pipe in question here, is not shown on our maps as being the responsibility of Thames Water.
"We need to understand where this pollution has come from and have reported this to the local authority and the Environment Agency."
The agency added it has removed the build-up, which appeared to be mostly limescale.
Thames Water said the Fairford sewage works will undergo improvement in the next five years.