The sewage spill in Essex that cost a water company boss £1m

A water company boss was denied his annual bonus worth more than a million pounds after thousands of tonnes of raw sewage ended up in a river.

The BBC can reveal that almost 3,500 tonnes of untreated sewage entered the River Mardyke in Grays, Essex, on 25 August 2025, killing at least 4,723 fish.

Anglian Water confirmed its chief executive Mark Thurston’s £1.05m bonus was withheld for the 2025-26 financial year over the spill, external, following new government legislation designed to improve accountability and the performance of water companies.

Anglian Water said it could not comment on the pollution incident itself due to an ongoing investigation.

The spill was deemed a Category 1 incident, external by the Environment Agency, which is its highest classification for pollution events and indicates major environmental harm.

Investigation reports and correspondence obtained under the Environmental Information Regulations revealed the alarm sounding from the Corran Way pumping station in Stifford, Thurrock, was ignored after an oversight meant that operators were instructed to disregard alerts from the site.

The alarm was triggered when a valve controlling the flow of sewage automatically shut when it should not have, which sent the untreated sewage into the river.

Investigators noted that the total number of fish deaths was likely to be higher than 4,723, because parts of the watercourse could not be searched effectively due to vegetation and access constraints.

Among the aquatic life killed were European eel, a critically endangered, external species, pike, perch, roach, gudgeon, three spined sticklebacks and carp.