Peter Hammond, a retired professor of computational biology and campaigner with Windrush Against Sewage Pollution, criticized the water industry for flouting poor regulation by the Environment Agency
Seven companies - Southern Water, South West Water, Thames Water, United Utilities, Wessex Water, Yorkshire Water, and Welsh Water - discharged untreated sewage from 59 treatment works that treat 4.5 million people's wastewater
Water companies can be acting illegally if they discharge untreated sewage when conditions are dry (dry spill) or if they do not treat enough of the sewage before discharging it (early spill)
United Utilities, Southern Water, and Welsh Water questioned the accuracy of some data, while Yorkshire Water disputed Prof Hammond's understanding of the data
The sewage treatment works at Dorking run by Thames Water had the highest number of unpermitted spills, discharging untreated sewage into the River Mole on 223 days over the last four years
Thames Water stated that all discharges of untreated sewage are unacceptable and they are determined to work with authorities to stop them from being necessary
1,300 storm overflows and storm tanks at waste water treatment works have been identified as "spilling frequently," and a major investigation into possible unauthorised spills at thousands of sewage treatment works is ongoing