THAMES Water has been fined £6,000 for polluting a Tadley stream with sewage.

Basingstoke Magistrates’ Court heard how a blockage in a Thames Water public sewer in Tadley caused sewage to overflow from an adjacent abandoned sewer, which crosses under Huntsmoor Road, Whitedown Road and Bishops-wood Lane. It then spilled into an inland freshwater pond and overland into the Bishopswood Stream.

The sewage, which spread downstream for 250 metres, caused a dramatic deterioration in the water quality, and affected wildlife.

The court heard that the incident was reported to the Environment Agency on March 6, but it is not clear when the sewage was initially discharged.

An investigation by agency officers found Thames Water had failed to prevent future problems following a sewage discharge, due to a blocked public sewer, in the same location in September 2010.

On that occasion, sewage did not overflow into the stream, due to a lower water level in the pond, but the company did not find the blockage or source of the pollution. The court heard that the company put only temporary bungs in place and failed to investigate potential future problems.

Alison Love, the investigating Environment Agency officer, said: “Rivers and water courses are an important part of the environment. They offer an essential resource for wildlife, fisheries recreation and commercial activities.

“Thames Water jeopardised this when they failed to investigate the initial sewage spill properly. This incident caused fairly significant environmental damage which could have been prevented. We are pleased with the result of the court case.”

Thames Water Utilities Limited was fined £6,000 after admitting polluting the stream, and the company was also ordered to pay prosecution costs of £7,293 and a victim surcharge of £15.

Since the incident, Thames Water has introduced 19 changes to its business processes, improving the way it works and communicates internally and with the Environment Agency. The magistrates’ verdict took into account that the company has spent nearly £30,000 in remedial costs.

Craig Rance, press officer for Thames Water, said: “This pollution event was deeply regrettable, and although we could not have predicted the blockage of fats, oils and grease, or that it would have caused a spill from a pipe we did not know about, and that does not belong to Thames Water, we have accepted responsibility for the harm caused to the environment.

“We understand the seriousness of this case, which is reflected in our guilty plea, and have already addressed the way we work to try to prevent any similar pollution incidents in future.”