Thames Water has been fined £2 million and ordered to pay costs of £79,991.57 after raw sewage polluted two Oxfordshire streams, killing almost 150 fish.

Judge Peter Ross, at Oxford Crown Court on 21 December, ruled the incident was a high-end, category three harm offence and found Thames Water were “reckless” in polluting Idbury and Littlestock brooks at Milton-under-Wychwood, near Chipping Norton, on 8 and 9 August 2015. However, in the three-and-a half-years since the pollution took place, Thames has not had a serious incident at any of its 4,700 pumping stations.

According to the Environment Agency, who led the investigation, said that numerous failures in the management of a sewage pumping station operated by the company resulted in sewage created by two villages emptying into two brooks leading to the River Evenlode, a tributary of the River Thames, for up to 24 hours.

Environment Agency officers were quickly on site, discovering the entire local population of almost 150 bullhead fish had been killed by the toxic waste along a 50-metre stretch of water.

A member of the public reported dead fish in Idbury brook to the Environment Agency. A backlog of raw sewage was forced into the water from a sewer pipe that couldn’t hold it. Sewage also escaped from a manhole and onto a residential front garden.

More than 800 high-priority alarms needing attention “disregarded”

The court heard Thames Water disregarded more than 800 high-priority alarms needing attention within four hours in the six weeks before the incident. Another 300 alarms were not properly investigated, all of which would have pointed out failures with the pumping station. One alarm was deliberately deactivated during a night shift.

Investigations by the Environment Agency revealed Thames Water was aware the pumping station failed several times in the 12 months up to and including the incident in August 2015.

Robert Davis, who led the investigation for the Environment Agency, said:

“This incident was foreseeable and avoidable. Thames Water didn’t recognise the increased risk to the environment, ignoring or failing to respond adequately to more than 1,000 alarms.

“These streams are normally a haven for kingfishers, grey herons, brown trout and other fish and invertebrates. Sewage poured into the water for 24 hours, having a terrible impact, killing fish and other water life.

“We hope this prosecution sends a loud and clear message that the Environment Agency will not accept poor operation, management and maintenance of sewage pumping stations. Where we have evidence of offending and serious pollution incidents like here, we will take appropriate action to bring polluters to justice.”

Judge Ross said Thames Water was ‘reckless’ by taking an unacceptable level of risk with the environment. It allowed the sewage pumping station to operate with no automatically available standby pump for around 10 months in the year prior to the pollution.

Environment Agency officers discovered other information and data highlighting repeated problems with the pumping station in the year before the pollution, which Thames Water failed to report to the Environment Agency.

Judge Ross ordered Thames Water to pay full costs of £79,991.57. The company pleaded guilty at an earlier hearing to two charges of breaching environmental law.

Thames Water - we take our role of protecting and enhancing the environment extremely seriously

Commenting on the fine, Thames said it takes its role of protecting and enhancing the environment extremely seriously, describing the fine as “deeply disappointing”.

Richard Aylard, External Affairs and Sustainability Director, said:

“We take our role in protecting the environment extremely seriously and are really sorry for what happened here in 2015.

“We have made a series of improvements since this regrettable incident, including bringing in more people, more maintenance, more training and better systems. In the three-and-a half-years since, we have not had a serious incident at any of our 4,700 pumping stations.

“We would like to re-assure our customers that we continue to innovate and drive further improved performance right across the business, to help us achieve our ambition of zero pollutions.”

The judge acknowledged that changes have been made, commenting that, “technology is now being used effectively and this should give the public reassurance. Thames Water has put in place more staff, more training, better systems and better management of data.”

The water company said it welcomed the suggestion that £200,000 of the fine should go to three environmental charities in the Oxfordshire area.

Thames Water has reduced pollution by 69 per cent since 2013 and, as part of the company’s record £11.7 billion business plan, it is investing record amounts on improving resilience, service and efficiency.

The plan also includes a commitment to reduce pollutions by a further 18 per cent.