Dec 8 (Reuters) - Water company Severn Trent (SVT.L) has been fined 1.5 million pounds ($2 million) for illegal sewage discharges, Britain"s Environment Agency said on Wednesday, after the country launched a major investigation into sewage treatment in November. The agency and water regulator Ofwat last month launched an investigation into sewage treatment after water companies admitted they could be releasing unpermitted sewage discharges into rivers and watercourses. read more Severn Trent, one of the largest listed water firms in Britain, has been fined for discharges from four sewage treatment works in Worcestershire between February and August 2018, the Environment Agency said. "The court heard how the company failed to respond to alarms warning of a blockage, failed to adequately manage sewage sludge, and failed to adequately manage a situation when a piece of equipment failed," the environment watchdog said in a statement.Severn Trent, which brought forward its time target of implementing actions to improve river quality by 16 years following the investigation, said it accepted the court"s findings. "These were historic issues that occurred in 2018 and we self-reported them to the Environment Agency at the time," the company said. Thames Water (KMBWTU.UL) was fined 4 million pounds last month for discharging an estimated half a million litres of raw sewage. ($1 = 0.7571 pounds)