BBC News By Victoria Gill image captionEnvironmental campaigners are concerned about the impact of sewage on our rivers Hundreds of previously unreported releases of raw sewage into UK rivers have been detected thanks to artificial intelligence, researchers say. Scientists identified 926 "spill events" from two wastewater treatment plants over an 11-year period by employing machine learning. The UK Environment Agency said it was "impressed by the accuracy" of the approach. "We welcome any tool that prevents pollution," the agency said. The researchers, who published their study in the journal Clean Water, trained a computer algorithm to recognise, through the pattern of flow through a treatment plant, when a spill was happening.