Environment Agency inspectors found “odorous and black” effluent and copious amounts of sewage fungus polluting a stream at Treskinnick, Cornwall, in May 2011 due to a malfunctioning filter bed.
The agency told Bodmin magistrates the pollution killed most aquatic life in the stream for 600 metres and followed breaches found in 2009 and 2010.
Repeat breaches of environmental regulations were also identified at Black Dog sewage works, Devon and Holcombe Rogus, Somerset.
“These pollution incidents were avoidable and resulted from a failure on the part of South West Water to maintain these sites in accordance with their Environmental Permits. Even small sewage treatment works’ require maintenance and investment and should not be neglected by site operators,” said Louise Weller for the Environment Agency.
South West Water pleaded guilty to five charges and was fined £7,000 for each sewage works and ordered to pay £12,000 in costs.