Water companies not monitoring most ‘emergency overflows’ of raw sewage

Emergency overflows are designed to be used as a very last resort in the event of a mechanical, technical or physical failure
Emergency overflows are designed to be used as a very last resort in the event of a mechanical, technical or physical failure

Water companies are failing to monitor 90 per cent of emergency overflows that release raw sewage into the environment, it has emerged.

A Freedom of Information (FOI) request from the Marine Conservation Society (MCS) found that 233 emergency overflows discharged effluent in 2022, around one in three of those monitored.

Yet fewer than 10 per cent of the 7,016 emergency overflows are actually monitored, meaning the true discharge figure could be ten times higher if those being checked are representative of the bigger picture.

Emergency overflows are designed to be used as a very last resort in the event of a mechanical, technical or physical failure in the network because they release raw, undiluted sewage into the environment.

The MCS found that nearly two-thirds of the overflows releasing sewage were doing so repeatedly.

Last year the Telegraph launched its Clean Rivers Campaign calling for action to stop water companies, industrial agriculture and urban waste from polluting England’s beauty spots.

Untreated sewage can contain harmful chemicals, bacteria and viruses as well as wet wipes and sanitary products - Maureen McLean/Shutterstock
Untreated sewage can contain harmful chemicals, bacteria and viruses as well as wet wipes and sanitary products - Maureen McLean/Shutterstock

Laura Foster, Head of Clean Seas at the Marine Conservation Society, said: “Emergency overflows are designed to be used as a last resort.

“Yet, from the tiny amount of data we do have, we can see that these discharges aren’t an uncommon occurrence, and there are repeat offences.

“It’s not clear why, after the first incident, measures aren’t being taken to prevent another emergency overflow discharge. Water companies are paid to treat our sewage and they need to be fulfilling this duty.

“The failure to put procedures in place, which they’re required to do, is putting marine life, and people, at risk.”

Water companies have been heavily criticised for sewage leaking from storm overflows, which are used when excess rainfall floods the system. But in that case, the sewage is diluted unlike the raw sewage that is released from emergency overflows.

The Environment Agency insists on a number of warning systems, standby pumps and emergency storage to ensure that they are rarely, if ever used. The highest requirements are in place for overflows which could flow into waters where shellfish are farmed.

But the FOI data shows that last year, there were 491 discharges into shellfish waters from 86 overflows, which the MCS said put businesses and people at risk.

Untreated sewage can contain harmful chemicals, bacteria and viruses as well as wet wipes and sanitary products.

Wild swimmers were appalled to see so much sewage on the Jubilee River in Dorney Reach - Maureen McLean/Alamy Live News
Wild swimmers were appalled to see so much sewage on the Jubilee River in Dorney Reach - Maureen McLean/Alamy Live News

Last year, Prof Sir Chris Whitty, the Chief Medical Officer for England and the Government’s Chief Medical Adviser, warned that sewage in waterways was putting people at risk of ingesting bacteria which could cause severe infections.

The MCS has joined forces with the Good Law Project to take legal action against the Department for Environment, Food and Rural Affairs (Defra) and is calling on the Government to rewrite its Storm Overflows Discharge Reduction Plan 2022, to impose tighter deadlines on water companies and redevelop the plan to effectively apply to coastal waters. A hearing is due to take place on July 4.

Emma Dearnaley, Legal Director at the Good Law Project, said, “These extraordinary figures suggest that the true scale of the sewage dumping crisis is even more shocking and devastating than we knew.

“Good Law Project is playing its part to end this environment scandal by supporting the Marine Conservation Society and others in a High Court challenge next month which seeks to compel the Government to impose much more robust and urgent targets upon water companies to clean up their act.”

Defra said it was considering the inclusion of “event duration monitoring” on all emergency overflows, with regulatory reporting requirements, but has not said when those requirements will be in place.