Water from a quarry was allowed to enter a Peterborough brook affecting tiny creatures living in the stream.
Staff from Mick George working at Cook’s Hole Quarry in Thornhaugh allowed the muddy water into Thornhaugh and Wittering Brook in May last year.
The flow or water, which was being re-circulated from the quarry, reduced water quality in Thornhaugh Brook by two levels, and was so dirty a passing member of the public reported the pollution to the Environment Agency.
On Friday, directors of the firm appeared at Peterborough Magistrates’ Court where they pleaded guilty to causing polluting matter to enter inland freshwaters.
Francis Aldson, representing the Environment Agency said: “The water was allowed to enter the brook through a drainage channel.
“The channel is about 400-500m long.
“On May 16 last year silty water entered the brook.
“This is water that was not filled with chemicals, but had suspended solids in.”
The court was told the water quality before the silty water entered the brook was ‘excellent,’ afterwards it was rated as ‘good.’
Mrs Aldson said: “Small invertebrates were affected. There were more creatures found upstream than downstream of the drainage channel.”
James Burton, defending Mick George said: “This company is as far from fly by night as you can find. They hold many environmental permits.”
Mr Burton said the firm had tested the channel to make sure water would not reach the brook, but conceded it had on May 15.
He added: “We say there was a minor change to the water quality.”
Deputy District Judge Dodd said the case was too serious to be heard at Peterborough Magistrates’ Court, and sent the sentencing hearing to the crown court where a judge will have greater sentencing powers.
The hearing will take place on a date to be confirmed.