Thames Water is handing over £80,000 to an environmental charity after a pollution incident in south east London.
According to the Environment Agency, the money will be given to the South East Rivers Trust to make improvements to the River Shuttle after the water company allowed sewage to escape from a blocked sewer in October 2013.
An underground sewer pipe in Chislehurst became lodged with tree roots, fat, oil, grease and other debris and the build up forced sewage above ground, flooding a field and two streams, before entering the river.
Environment Agency officers believe the sewage, which killed as many as 20 stickleback fish and hundreds of invertebrates, could have been flowing for several days, with the effect of the pollution on water quality and river habitats seen over several miles.
Thames Water will also pay the Agency’s full investigation costs of almost £20,000.
Jamie Lloyd, a land and water officer for the Environment Agency in south east London said: “A lack of maintenance by Thames Water over an extended period of time was to blame for this incident.
“Tree roots were allowed to grow into the sewer unchecked, resulting in fat and sewage solids causing a complete blockage. Sewage backed-up and was sent with some force through two manholes, triggering significant pollution. Water compounded the pollution by failing to clear the sewer quickly after the Environment Agency reported the incident to them.”
The water company has since installed equipment to monitor sewage levels in its sewer network, near where the blockage occurred – this will help inform about any developing problems and allow obstructions to be cleared as soon as possible.
It has also relined the sewer to help prevent roots from entering the pipes again.
Thames Water said in a statement: “We’re sorry for what happened in Chislehurst in 2013 as we take our role in protecting the environment very seriously. Since then we’ve introduced major changes to how we manage our sewer network and treatment sites. This work has reduced pollution incidents by 69%.
“We are pleased the Environment Agency decided to accept our Enforcement Undertaking to fund work by the South East Rivers Trust which will benefit river wildlife.”