Rise in sewage pollution from Thames Water’s ageing treatment works

The need for improvements at the treatment works at Mogden, south-west London, was among the reasons given for the rise in pollution incidents. Photograph: Toby Melville/Reuters

Sewage pollution from ageing Thames Water treatment works that have not been upgraded increased last year, causing the company to again fail to meet its legal targets, according to its financial report.

Across the Thames Water area, the number of incidents of pollution from treatment works and the pipe network increased to 350, compared with 331 in 2022. The rise was attributed to delays in investment to create more capacity at many of the company’s 400 ageing sewage treatment works. Chris Weston, Thames Water’s chief executive, said the works could not cope with a 40% increase in rainfall and exceptionally high levels of groundwater.