More than 3,000 “monster” sewage dumps into rivers and coastlines took place last year, analysis suggests.
The number of “high spill frequency” discharges, when raw sewage is dumped frequently in one area, rose 63% on the year before.
There were 3,275 spills recorded in 2022, up from 2,008 the previous year.
The Liberal Democrats probe found the Lake District water company United Utilities is the worst offender, with nearly 40% of storm overflows being identified as having a “high spill frequency”.
The longest dump was from its Plumbland works in Cumbria, which pumped sewage 339 times into the River Ellen for 6,896 hours. The Lib Dems are calling for water firms to be forced to upgrade their infrastructure.
Environment spokesman Tim Farron said: “The rise in these spills truly is a national scandal.”
United Utilities said: “We have ambitious plans to deliver one of the largest environmental improvement programmes in the country.”
Industry body Water UK said: “Every company is firmly of the view urgent action is needed to tackle the harm caused by storm overflows.” Defra said: “We do not recognise these figures. This Government is the first to take such comprehensive action on overflows.”
