There were more than 3,000 “monster” sewage dumps into England’s rivers and seas last year, up 63% from the year before, according to the Liberal Democrats.
The party’s analysis of Environment Agency data found that 3,276 storm overflows were classed as having a “high spill frequency” in 2022, meaning they dump sewage so frequently into a single area that water firms are obliged to investigate the cause within three months.
It marked a steep increase from 2021, when there were 2,008.
The Department for Environment, Food and Rural Affairs (Defra) said the figures do not align with its data.
The Liberal Democrats are calling for water companies to be forced to upgrade their infrastructure to fix the leakiest pipes and stop polluting waterways.
Lib Dem environment spokesperson Tim Farron said: “These monster sewage dumps cause devastation, flooding swimming spots with foul water and destroying animal habitats. The rise in these spills truly is a national scandal.
“Water company execs are raking in millions in bonuses whilst their pipes leak sewage into our lakes and rivers. The whole thing stinks. These polluting firms are obligated to investigate, yet still no action is taken. You would think after a historic drought these figures would drop. It seems there is no end in sight for the sewage scandal.
“Ministers need to get a grip of this. Their half-baked plans announced recently just let water companies get away with it. The public won’t stand for this any longer.
“Water companies need to be forced to fix the leakiest pipes responsible for these monster sewage dumps.”
The analysis found that United Utilities, the Lake District’s water company, and Devon and Cornwall’s South West Water were the worst offenders with almost 40% and 30% of their storm overflows, respectively, having a high spill frequency.
United Utilities’ Plumbland wastewater treatment works in Cumbria dumped sewage 339 times into the River Ellen for an alarming 6,896 hours last year.
Severn Trent Water spilled sewage into Whissendine Brook in Rutland from a wastewater treatment works 318 times for 6,646 hours.
Environment Agency figures published last month showed there were 301,091 spills overall in England in 2022, a 19% decrease from the previous year, but executive director John Leyland has said this was “down to dry weather, not water company action”.
Lib Dem leader Ed Davey has called for Environment Secretary Therese Coffey to resign over the issue.
As well as poisoning swimmers, sewage damages river ecosystems through chemical and microplastic pollution and algal blooms, which feed on the phosphates in faeces and explode in size, consuming the water’s oxygen and suffocating other forms of life.
A Defra spokesperson said: “We do not recognise these figures. High-frequency spills are defined as those spilling in excess of 60 times per year – the numbers here do not align with the official data.
“This government is the first to take such comprehensive action on storm overflows – and our new Plan for Water sets out the increased investment, tougher enforcement and tighter regulation to tackle this issue.
“We have recently announced £1.6 billion in new, accelerated investment to tackle storm overflows, including £700 million from United Utilities to reduce spills by 7,800 annually.
“The Environment Secretary has demanded an action plan on every storm overflow from every company in England, prioritising those near bathing waters. We are also consulting to give regulators more powers to impose much larger penalties for polluters without needing to go to court.”