HUNDREDS of fish were killed in a river near Bromsgrove after a sewerage works polluted it.

Seven Trent Water pleaded guilty at Redditch Magistrates Court after releasing poorly treated sewerage into the River Salwarpe from its Bromsgrove sewerage treatment works, in Aston Road.

Speaking after the case, Paul Williams, an Environment Agency officer involved in the investigation, said: "Companies treating potentially polluting material have a responsibility to ensure that there is as little risk as possible of them affecting the environment."

Seven Trent has permission to discharge treated sewerage into the river but the water has to be of a set condition when it is discharged.

An Environmental Agency officer inspecting the river just downstream of the sewerage treatment works found signs of serious organic pollution on October 20, 2003.

The problem, which killed around 400 fish, was caused when the treatment system failed to supply air to the treatment process.

Poorly treated sewerage was then discharged into the river reducing oxygen levels and killing the fish.

During the incident, the Environmental Agency undertook work to support and boost oxygen levels in the river with Seven Trent also adding clean water to dilute the pollutant. A spokesman for Seven Trent Water said: "Our record with pollution is excellent. We now need to look into the cause of the problem to make sure it does not happen again."

The company was fined £15,000 and ordered to pay costs of £3,364.67p.