BBC probes three water firms on dry spills

A BBC investigation broadcast and published last week accused Wessex Water, Thames Water and Southern Water of collectively releasing sewage when it was not raining for 3,572 hours in 2022. Discharging in dry conditions is illegal.

The three were highlighted because all other English water and sewerage companies declined to release data. The investigation team cross-referenced water company event duration monitoring data with Met Office rainfall data to identify dry spills. They found there were 388, including from all three firms on 19 July, during the peak of the summer heatwave. It found Wessex to be the worst performer, followed by Thames and then Southern, though it pointed out Thames only had 62% of overflows monitored compared to over 90% at the other two companies.

Wessex disputed the findings. It said there were no spills at five of its eight sites identified by the BBC and explained the remaining three discharged because of groundwater inundation which entered its network largely through private pipes. Unlike rainfall that stops relatively quickly, the groundwater can continue for days or even months. Wessex said the resulting discharge is groundwater with a small amount of sewage, and none of these overflows caused rivers to fail to meet ecological standards. Increasingly the company is also using wetlands to treat these discharges.

Labour and the Liberal Democrats called for an investigation. Labour's new shadow environment secretary Steve Reed blamed government underfunding of the Environment Agency. The BBC reported he said: ”They cut back enforcement and monitoring against water companies releasing this filth and are now failing to prosecute them when they are blatantly breaking the law.”

• Southern Water was criticised by TV naturalist, Chris Packham, last week for failing to report a sewage leak in the New Forest. According to a BBC report, sewage spilled from a burst pipe into a stream near Lyndhurst which flows into the Beaulieu River in August. The New Forest National Park Authority said it was not told about the incident, in a Site of Special Scientific Interest, until a week later. Packham called this “an absolute disgrace”.