Anglian has been ordered to pay £156,000 for polluting a brook in Northamptonshire with sewage after failing to maintain pumping station.
The Environment Agency prosecuted the company after finding failings at its Yardley Hastings sewage plant in August 2016.
Failures at the pumping station caused sewage to back up in the storage tank, which then discharged into the brook.
The brook was contaminated with sewage for two days and found to contain toxic levels of ammonia but did not kill fish or invertebrates.
An alert to indicate a problem was mistakenly closed down without resolution so the incident was not dealt with.
EA investigations found Anglian’s records were not up to date for cleaning and maintenance for the equipment that was at fault despite three maintenance visits in the year leading up to the incident.
The pollution was reported on 24 August but not acted on and the company had no record of the report being made. It was therefore left untreated for two days until it was noticed and stopped – by which time it had spread over a kilometre and a half.
Under the terms of its permit the company was required to maintain a 24-hour alarm system in case the pumping station broke down or failed and a separate alarm system should have notified staff when the tank overflowed to the brook.
Adam Glassford, senior environment officer with the EA said: “Earlier this year, we pledged a tougher approach towards water companies that don’t live up to their environmental responsibilities, and this case proves that we will hold them to account when they pollute the natural environment.”
The company, which self-reported the incident, has since fixed the fault and cleaned up the brook.