Thames Water fined £4m for 2016 sewage deluge in London park

Thames Water has been fined £4m with £85,000 in costs after pleading guilty to depositing some 79Ml of sewage waste across 6,500 square metres of a London park and the Hogsmill chalk stream in February 2016.

The court took into consideration a breach of a permit relating to the incident, and subsequent discharges into the Hogsmill in January and October 2018 as well as an incident in September 2019, when sewage sludge was released from Hogsmill sewage treatment works in error.

This latest conviction brings the total amount of fines on Thames Water since 2017 to £28.4 million for ten cases of water pollution.

A hearing in Aylesbury Crown Court on 26 May head that the Hogsmill sewage treatment works at Surbiton was unable to handle the amount of sewage produced by Storm Imogen in the winter of 2016.

Environment Agency land and water officer, Gary Waddup, told the court that “like similar incidents in the past few years for which they have been prosecuted, better management overall and on the night by Thames Water could have prevented this catastrophic incident.”

The judge noted Thames Water’s new commitment to improving compliance, but said that the commitment must be the norm, and the company will be held to it in future cases.

The Environment Agency reported that just after midnight on 8 February 2016 the failure of sewage pumps at the unmanned treatment works triggered some 50 alarms over the following five hours but each one was unchecked. It said the malfunction should have been received remotely by Thames Water staff, and an engineer despatched immediately but a Thames engineer did not arrive until dawn.

The Environment Agency said that Thames Water took 15 hours to report the incident to the agency and another 12 hours to have “any sizeable presence at the scene.”