R. Soper Ltd, trading as Albert Hartley, was also ordered to pay costs of £1,489.29.

The pollution occurred last September when a storage container collapsed while it was being dismantled for removal.

The container had been empty, but some liquid waste remained in the bottom and while the exact quantity of effluent that entered the watercourse was unknown, the court heard there had been a significant impact on a 100m stretch of the beck.

This discharge, thought to have contained chemicals used in a finishing process at the site to apply a special coating to fabrics, coated algae on the stream bed with a grey silty deposit which killed beetles, worms and freshwater limpets in the beck.

A member of Ribble Catchment Conservation Trust had reported the pollution behind Soper's Crow Nest Mill to the Environment Agency, the court heard.

The Environment Agency had visited the firm in April, 2007, as part of a pollution prevention campaign during which officers had advised the company on how to minimise the environmental risk to nearby Stock Beck and detailed a number of measures that should be taken to achieve this.

The court was told while the company had taken steps to comply with the Environment Agency's requests, the required measures had not been fully implemented when this incident occurred.

Helen Nightingale, environment management team leader said: "This was a serious pollution incident which had a significant impact on wildlife in Stock Beck."

R. Soper's managing director, Mr Sinclair Finlay, said it was unfortunate that one of the containers had collapsed during the move as the firms took environmental matters very seriously. "We do all we can environmentally and we are currently converting machinery from oil to gas, which will reduce the firm's carbon footprint by half," he said.