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Anglian Water chief executive loses £1m bonus after raw sewage spill in Essex river
Overview
Anglian Water's chief executive, Mark Thurston, has had his £1.05m annual bonus withheld for the 2025-26 financial year following a Category 1 pollution incident in which nearly 3,500 tonnes of raw sewage entered the River Mardyke in Grays, Essex. The spill, which occurred on 25 August 2025, killed at least 4,723 fish across multiple species—including the critically endangered European eel—and severely impacted water quality over several kilometres. Investigators found that an alarm from a pumping station was ignored due to an oversight. The bonus was blocked under new government legislation via the Water (Special Measures) Act 2025, though Thurston still received other retention and alignment payments that were not tied to performance.
Key points
- Nearly 3,500 tonnes of untreated sewage entered the River Mardyke in Grays, Essex, on 25 August 2025.
- The pollution incident killed at least 4,723 fish, including the critically endangered European eel.
- Anglian Water CEO Mark Thurston was denied his £1.05m annual bonus for the 2025-26 financial year.
- The Environment Agency classified the event as a Category 1 incident, indicating major environmental harm.
- An investigation revealed that an alarm at the Corran Way pumping station was ignored after operators were mistakenly instructed to disregard alerts.
- The Environment Agency is prosecuting Anglian Water over the incident, and its investigation remains ongoing.