EXCREMENT surged on to a primary school's playing field and killed wildlife after a severe sewer blockage. Thames Water Utilities was ordered by a court on Friday to pay more than �13,200, after bosses admitted causing raw sewage to run into

EXCREMENT surged on to a primary school's playing field and killed wildlife after a severe sewer blockage.

Thames Water Utilities was ordered by a court on Friday to pay more than �13,200, after bosses admitted causing raw sewage to run into Hatfield Hyde Brook, at Commonswood School, in WGC.

The effluent killed freshwater shrimps and worms.

Debbie Dolan, head of the Friends of Commonswood School, told the WHT she was "very angry" with Thames Water for putting her daughter's and other pupils' health at risk.

"It could have been very dangerous. We take our children to school and we expect them to be safe.

"It's an area where children go to eat and play. Children could have been made seriously ill."

The first occurrence happened in October 2007 and, despite assurances by Thames Water the problem had been fixed, Environment Agency officers were called out repeatedly until July the following year.

The school reacted quickly and fenced off the area so pupils could not get near. Site manager Rod Anstey said school life had not been affected and the muck was out of the reach of pupils.

The problem was caused by rag - the generic term for what is flushed down toilets - roots and once by a piece of concrete.

Thames Water Utilities was fined �8,500 and ordered to pay �4,764 costs by Watford magistrates.

After the hearing, Environment Agency officer Peter Kirton said maintenance of sewers should be the statutory duty of water companies.

He said: "In this case they clearly failed to do that, having already been warned for previous failures in 2007, putting local wildlife and flooding a school playground with raw sewage.

"This is simply unacceptable, and we are pleased the court has made a strong statement by fining the company for its consistent failures to protect the environment."

A spokesman for Thames Water told the WHT �70,000 has been spent replacing and relining the sewer line after someone blocked the sewer with a lump of concrete.

He said: "Fortunately no fish died as a result of this irresponsible act and it did not affect services for customers.

"If people put things down the sewer which they shouldn't, then we are in a difficult position.