The Environment Agency report that:

Thames Water Utilities Limited, of Clearwater Court in Reading, pleaded guilty to an offence under the Environmental Permitting (England & Wales) Regulations 2010. The company was fined £18,000, ordered to pay costs of £9,764.15 and a victim surcharge of £15. (A total of £27,779.15)

The court heard that on the 7 November 2011 sewage burst from a Thames Water rising main in a field behind Walton Lane sewage pumping station and flooded the field with sewage, which then entered the Engine River. Thames Water reported the incident to the Environment Agency and said that they had shut off the flow and that the spill was only affecting the top part of the river.

An Environment Agency officer visited the site the following day and observed a ‘volcano’ of sewage erupting from a hole in the field behind the pumping station. Thames Water stated later that there had been a leak on the valve. Samples were taken and results indicated a high concentration level of raw sewage.

Thames Water was advised to contain the spilt sewage with sandbags and to remove the sewage from the top section of the river. However, Thames Water did not make sufficient efforts to contain the pollution resulting in sewage water seeping further downstream, eventually affecting over 1.2 km of the Engine River.

The Environment Agency received a report from a member of the public on the 10 November about sewage pollution in fields where horses were kept. On 14 November, Environment Agency officers visited the site after a report of dead fish and checked the river, where 480 dead fish were found. An Environment Agency fisheries officer estimated that a minimum 1550 fish had died, including perch, roach and carp.

Thames Water were interviewed under caution on 27 March 2012 and were not clear why they did not make sufficient efforts to contain the pollution in the days immediately following the pipe burst. Subsequently they have stated that they did not want to take heavy machinery onto the field.

Environment Agency Solicitor Marie De Viell said:

“Rivers and water courses are an important part of the environment; they offer an essential resource for wildlife, fisheries and recreation. It is distressing when incidents such as this one occur and cause fairly significant environmental damage, with several hundred fish killed by this sewage spill.

The prosecution and fining of Thames Water sends a clear message to other companies that if you fail in your environmental responsibilities you may be prosecuted.

The Environment Agency will continue to work within local areas and with companies to protect river wildlife. If you see a pollution incident please immediately call our pollution hotline 0800 807060 open 24 hours a day.”

The River Engine was a very healthy watercourse prior to this pollution incident, at the time the deeper section contained a significant number of fish and was used as an amenity by the landowners, and was occasionally fished. The incident also caused significant disruption to local landowners.