Water regulator Ofwat said it has proposed £168 million of fines for three of England’s biggest water companies.
The fine follows an investigation of the water companies wastewater treatment works.
In an announcement today, Ofwat said it had “uncovered a catalogue of failure”, resulting in “excessive spills from storm overflows”.
It added that there was a “strong correlation” between high spill levels and operational issues at their wastewater treatment sites, “which points to these companies not having properly operated and maintained their wastewater treatment works”.
Thames Water, Yorkshire Water and Northumbrian Water face £168 million fines after these historic sewage spills.
The regulator's Chief Executive, David Black, said: “Ofwat has uncovered a catalogue of failure by Thames Water, Yorkshire Water and Northumbrian Water in how they ran their sewage works and this resulted in excessive spills from storm overflows.
The proposed fine for Thames Water is £104 million
PA"Our investigation has shown how they routinely released sewage into our rivers and seas, rather than ensuring that this only happens in exceptional circumstances as the law intends."
Sewage spills into England's rivers and seas more than doubled last year.
Releasing raw sewage has the potential to significantly damage the environment and poses a risk to human health for those swimming in a river or sea where sewage is being discharged.
In December 2023 Ofwat notified the three companies of its provisional findings and they had the opportunity to provide any further evidence for consideration.
Ofwat explained the firms had failed to upgrade their assets where necessary, and had been slow to grasp their obligations to limit pollution from storm overflows.
Steve Reed, the Secretary of State for Environment, Food and Rural Affairs, said he welcomes the action from Ofwat to impose fines on Thames Water, Northumbrian Water and Yorkshire Water.
“The unacceptable destruction of our waterways should never have been allowed – and it is right that those responsible for illegally polluting our rivers, lakes and seas face the consequences,” he said.
“This Government will fundamentally reform the water sector.
“We have announced our first steps to clean up the water industry in our Water (Special Measures) Bill, to cut sewage pollution, protect customers and attract investment to upgrade its crumbling infrastructure.
“We will outline further legislation to transform and reset our water industry and restore our rivers, lakes and seas to good health.”
Water bills rose on April 1, with the average price rise will see £28 a year added to a water billPAThames Water has been struggling with debts of £14.7billion.
It announced last month it only had enough cash to fund operations until the end of May 2025 - and was already at risk of having the credit rating of its debts downgraded.