CARELESS businesses have been accused of polluting a stream at a nature reserve - turning its water blue and green.
Bosses at the Environment Agency say that firms in Washington need to “improve their performance” after a string of incidents at Barmston Burn.
In the past two years, the stream, which runs through the Washington Wetlands Centre, has been polluted with paints, oils and solvents.
Experts at the agency believe they are coming from industrial estates, where surface water drains are connected to the burn.
More than 170 firms were visited in May to identify the source of the problem.
Oil was discovered being incorrectly stored and workers washing vehicles in the road led to detergents running into the burn through drains.
Rob Carr, environment officer for the agency, has now written to businesses informing them of the measures they need to take to stop the problem.
He warned they could be hit with further action if they fail to heed the advice.
“We are really pleased with the number of businesses we managed to visit and also with the way we have raised awareness about how the drainage system works,” said Mr Carr.
“We also spoke to businesses about the potential impacts on both the wetland centre and the River Wear.
“We will continue monitoring incidents on the Barmston Burn to see whether we need to take any further action.”
Leanne McCormella, from Washington Wetland Centre, said it was vital local wildlife was protected.
“Our centre is home to rare and endangered water-bird species from around the world, as well as a diverse range of insects, amphibians, flora and unique habitats,” she said.
“The quality of the water filtering through our ponds, streams and reed beds is obviously crucial to everything that depends on it for survival, and we hope that this work will help to tackle the ongoing issues that we’re having.”
The Wildfowl and Wetlands Trust is also looking to invite businesses from the nearby industrial estates to Washington Wetland Centre to increase awareness about the problem.
Anyone who notices pollution in Barmston Burn should call the free, 24-hour Environment Agency hotline on 0800 807060.