READ MOREJudge Peter Ross, at Oxford Crown Court on 21 December, ruled the incident in 2015 as a high-end, category three harm offence.
Numerous failures in the management of a sewage pumping station operated by the company led to 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.
Judge Ross found Thames Water were “reckless” in polluting Idbury and Littlestock brooks at Milton-under-Wychwood, near Chipping Norton, on 8 and 9 August 2015.
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.
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. ■