Serious pollution incidents at Anglian Water rise by 71% as company retains two-star environmental rating
Anglian Water recorded 12 serious pollution incidents in 2025, up from seven the previous year, as the company remained on a two-star environmental rating for the fifth consecutive year.
The Environment Agency's annual assessment published last week found that the water company, which serves Northamptonshire and much of eastern England, continued to fall short on pollution performance despite improvements in other areas.
Across its operating region, Anglian Water recorded 433 pollution incidents during 2025, including incidents linked to sewerage and water supply operations.
The 12 serious incidents represented an increase of around 71% compared with 2024, although the overall number of pollution events fell.
The Environment Agency awarded the company two stars out of four, a rating indicating that improvement is required.
Anglian Water acknowledged that serious pollution incidents remained a concern but highlighted reductions in storm overflow spills and investment in environmental improvements.
Dr Robin Price, the company's director of quality, environment and assurance, said it was undertaking its largest investment programme, with more than £2 billion earmarked for environmental improvements between 2025 and 2030.
The programme involves 2,611 individual schemes across the East of England.
According to the company, storm overflow spills fell by 62% compared with 2024, while pollution events decreased by 16%.
It also reported improvements in treatment works compliance and reductions in harmful nutrients entering waterways.
Dr Price said: "We know that there is more to be done, particularly on pollutions performance, especially those of a more serious nature, which is the main driver of the EPA star rating."
The company said sewer blockages, underground infrastructure failures and pumping station power supply failures accounted for 82% of its pollution incidents.
It attributed 37% of incidents to blockages and said campaigns targeting wipes and other materials flushed down toilets had reduced expected blockages in targeted areas.
Anglian Water also pointed to improvements in pollution self-reporting and said it was ahead of schedule with its environmental enhancement programme.
The assessment also recognises the company's delivery of environmental improvement schemes during 2025.
Dr Price argued that existing regulatory assessments did not fully reflect wider environmental outcomes, including river health, biodiversity improvements and nature-based solutions.
He called for a broader system of assessing water companies' long-term performance.
The company was separately categorised as 'on-track' in Ofwat's 2025-26 operational performance report.
The Environment Agency figures cover Anglian Water's entire operating region and do not establish how many of the incidents occurred in Northamptonshire.