An investigation is being carried out to try and determine what caused the Stour Brook in Haverhill’s East Town Park to turn a strange shade of pink last week.
The odd hue is thought to have been caused by a mystery substance being disposed of down a rain drain, which leads directly into the brook.
A spokesman for the Environment Agency said of Wednesday’s incident: “There were no signs of dead or distressed fish. We contacted Anglian Water who are currently investigating the source of the discolouration.”
Emma Staples from Anglian Water said: “We are currently working to trace the source of a pink/purple liquid substance that was found coming from a surface water drainage pipe on the river in Haverhill.
“The bright substance is not a product of the sewage or surface water drainage network, and all of our equipment is working correctly. It may be from a spillage or someone who has wrongly disposed of the substance using the rainwater sewer network.
“We have boots on the ground and we are working with the Environment Agency to trace the source.
“Protecting our beautiful waterways that sit at the heart of our communities is a main priority for us, and we’ll be doing what we can to prevent a repeat in future including tracing the source, speaking to the party responsible, and writing to local businesses and the community who can help.
“Surface water – or rain drains – flow directly to rivers and the sea without treatment. Anything wrongly tipped down these drain them can pollute the environment. Earlier last year (in October) there was another instance of pollution caused by a third party, so we’ll be working hard to share this message around Haverhill and the wider area.
“If everyone can remember the phrase ‘only rain down the drain’ we’ll be a step closer, and if members of the public spot anything unusual, they can report it to us on our Pollution Watch hotline number 03457 145 145 and we will investigate to help protects our waterways - even if it’s nothing to do with Anglian Water.”