Three major water companies are being accused of illegally discharged sewage hundreds of times last year on days when it was not raining. This practice is known as “dry spilling” and is banned because it can lead to higher concentrations of sewage in waterways.
Dry spilling
Releasing sewage into rivers and seas is allowed in the UK to prevent pipe systems becoming overwhelmed, but only if it has been raining. Without rainwater the sewage is likely to be less diluted, leading to build-ups of algae which produce toxins. According to Dr Linda May, a water ecologist at the UK Centre for Ecology and Hydrology, these toxins can be fatal to pets and pose a health risk to swimmers. Discharging in dry conditions is therefore illegal under environmental law.
All nine English water companies were sent environmental information requests for data on when their spills started and stopped. Only Thames, Southern and Wessex provided details and based on this, appear to have collectively released sewage in dry spills 338 times totaling 3,500 hours in 2022. This breaches their permits so Water UK, the industry body, has called for an investigation.
There even appears to have been spills by all three companies on 19 July 2022, the hottest day on record, when temperatures topped 40C in some places and many people tried to cool off in rivers. Environment Secretary Therese Coffey said ‘It does seem extraordinary on the hottest day of the year that there may be releases. The Environment Agency is the regulator; they are the people who do the detailed investigation of why that has happened.”
The remaining six water companies in England said they could not provide information because they were already being investigated for potential illegal spilling by industry regulator Ofwat and the Environment Agency. If the companies shared data, they claimed that analysis could be carried out which could sway public opinion.
Frequent sites
Across the Wessex Water region, from the Dorset coast to the Bristol area, there are 68 sites where sewage may have been discharged illegally last year. The spills that started on dry days appear to have lasted for more than 1,500 hours. In one case, analysis suggested that sewage was discharged into the River Chew in north Somerset from a nearby wastewater treatment works for nearly 50 hours during dry periods.
Wessex Water said the spills into River Chew were caused by groundwater coming up into pipes and forcing it to spill. It said this dilutes the sewage and “the storm overflow is not identified as one of the factors affecting the ecological condition of the river”. However, the Environment Agency said that any dry spills due to groundwater are a breach of permit and illegal.
Another frequent spiller appears to be Thames Water’s Longbridge Road overflow site in east London, which releases sewage directly into Mayes Brook. The river is located in the UK’s first “climate” park in Dagenham – constructed at a cost of £3.8m to provide a green haven for the local community and wildlife. However, last year, the overflow spilled for nearly 200 hours, leaving excrement-soaked wet wipes on the riverbanks. Research estimates that about a quarter of those hours were from dry spills.
“You’ve got this contrast of an improved park costing millions of pounds, getting polluted every four days on average by sewage and that’s a scandal,” says Theo Thomas, chief executive at water charity London Waterkeepers, who has been lobbying Thames Water and the local authority to resolve the issue.
Criticism of the Environment Agency
Technically, any illegal spills should be investigated by the Environment Agency. Enforcement action can be taken, ranging from a warning to an unlimited fine. The Government has revealed that the Environment Agency recorded 115 cases of illegal operation in 2022 for the three water companies but this is less than a third of what recent data has found. One of the agency’s officers, who works in environmental regulation, has pointed to a “firm link” between the Environment Agency’s failure to identify and investigate dry spills, and budget cuts and staff losses.
Crucially, the Environment Agency’s environmental protection budget, funded by the government’s Department for Environment, Food and Rural Affairs (Defra), was halved between 2010-20 so the agency is increasingly relying on companies to report their own dry spill incidents.
Final thought
Water firms should be effectively held accountable for dry spilling. The data revealed today is damning and more needs to be done to ensure firms are following regulations. Based on revelations concerning cuts to the Environment Agency, it is clear that the Government needs to re-think its priorities concerning environmental protections.
As Tessa Wardley, Director of Communications and Advocacy at The Rivers Trust, discussed in the latest edition of our journal, long-term thinking is needed for an integrated approach to water management, underpinned by nature-based solutions such as tree and hedge planting, buffer strips alongside rivers, and restoring wetlands.