East Lancs magistrates on Monday this week ordered North West Water to pay a fine of £ 12,000 with £ 2,188.17 costs to the Environment Agency who brought the prosecution.
NWW pleaded guilty to one charge that on or about 16 May 1999 at Wilpshire, it caused polluting matter to enter controlled waters, namely Showley Brook, contrary to section 85(1) and section 85(6) of the Water Resources Act 1991.
Sue Tysoe, prosecuting for the Agency, told the court how the incident, which led to the death of brown trout and bullhead fish in Showley Brook, on Knowsley Road, Wilpshire, near Blackburn, was both foreseeable and preventable.
The court heard how the failure of a chemical containment facility at Ramsgreave Water Treatment Plant, which is owned and operated by North West Water Limited, allowed sodium hypochlorite – which is used to chlorinate water – to enter the brook via a drainage system.
Miss Tysoe told magistrates how an Agency fisheries officer attended Showley Brook on 17 May 1999, following reports of dead fish. Over 100 dead brown trout and bullheads could be seen in the brook downstream of the culvert under Whalley New Road.
The level of chlorine in the brook was more than 100 times greater than the concentration at which harm to acquatic life would be expected.
North West Water’s senior process staff confirmed that there had been a problem on 15 May with the site’s sodium hypochlorite feed. An operative had been called to an alarm at the plant on 15 May, but had not found a spillage from a faulty valve until Sunday 16 May.
John Barnes, Water Services Director for North West Water, later stated in an interview that the spillage had occurred because of faulty equipment installed by a contractor which allowed the sodium hypochlorite to escape from the containment facility. The process controller who attended was not aware of the connection to the drainage system.
Mr Barnes added that lessons had been learnt from the incident, and all sites with similar equipment, had been reviewed to ensure the problem does not occur again.
The Agency contended that the siting of the sump with a direct drainage connection to the brook was wholly inappropriate, and that the operative should have taken proper steps to check for spillages when he attended the alarm call at the plant. He failed to take any action which may have prevented, or mitigated the incident.