Anglian Water could be prosecuted over a sewage leak from its Braintree treatment works which polluted the rivers Brain and Blackwater last week, the Environment Agency has announced.

If a case is brought before magistrates the company could face penalties of up to £20,000, or unlimited fines at a crown court.

Over 1,000 fish died in the River Brain as sewage poured from a faulty pipe at the company's Skitts Hill works almost two weeks ago.

Staff from the Environment Agency and Essex Fire and Rescue Services mounted a round-the-clock attempt to protect the habitats of the two rivers.

Agency environment protection officer, Mike Webley, said this week that the disaster was being classified as Grade 1, signifying a major ecological disaster.

Remedial work was complete and monitoring showed fish in the Blackwater were not affected. "We regard this as a very serious incident," he said. "At the very least Anglian Water will be cautioned, but it seems likely at this stage that there will be a prosecution."

A decision is expected in about four weeks.

Braintree's Green Party has called for tough action to be taken.

Green Party district councillor, James Abbott, said: ''If the principle that the polluter pays means anything, Anglian Water should be heavily penalised, be made to review and upgrade their facilities to ensure this never happens again and repair the ecological damage as far as it is possible to do so."

A spokeswoman for Anglian Water said this week that the company had already agreed to pay for the river to be restocked and is working closely with the Environment Agency.

"We can only say this was a deeply regrettable, but isolated incident. It seems there has been no long-term environmental damage to the river."

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