Environment Agency officers have been investigating the Shutterton Brook in Dawlish after reports of the river turning various shades of blue, red, white and green.
The Agency had received reports about pollution on the Brook since 2012, but visits to a nearby business park had failed to identify the source.
One local resident spotted the pollution and called the Agency immediately which allowed officers to witness the problem for themselves. It was decided to put CCTV cameras into the drainage system to find out where the mysterious coloured liquid was coming from.
The tiny camera found a misconnection from a building on the business park, which should have been connected to the sewer, but instead was flowing into the surface water drain, and from there out into the river.
The building in question is now occupied by a company manufacturing water-based paints.
‘It would appear that the misconnection mistake occurred when the building was converted by the previous owner more than ten years ago,’ said Nigel Thomas-Childs for the Environment Agency.
‘It is fortunate that the vibrant-coloured paint drew attention to this problem and that a local resident, who is passionate about their local river helped us by reporting the pollution. Once we made the landlord aware of the problem he acted quickly to address it, restoring the flow to the South West Water sewer which goes to the treatment works at Dawlish Warren.’