Yorkshire Water has been fined £6,000 after pleading guilty to polluting Clifton Beck in Brighouse.

The water utility company of Halifax Road, Bradford, was also ordered to pay full costs of £1,827 to the Environment Agency, which brought the case.

Ben Reid, prosecuting for the Environment Agency, told Halifax Magistrates’ Court that a combined sewer overflow (CSO) at Wyke Old Lane has blocked a number of times in recent years and has repeatedly sent sewerage into Clifton Beck. This has had a serious impact on the aquatic life that lives there.

The CSO blocked on May 2003, October 2003, November 2004 and September 2005. Yorkshire Water were cautioned and fined in 2003 after the blockages caused sewerage to enter the beck.

It took Yorkshire Water until 2006 to install a warning system. Even after the warning system was installed, the CSO again blocked and sent sewerage into Clifton Beck. A biological survey found that the pollution was chronic and had a significant impact on aquatic life. It was estimated that the June 2006 event killed 33 per cent of the animal life assessed.

The court heard how the Environment Agency took samples of the water upstream and downstream of the CSO and these were tested for the Biological Oxygen Demand (BOD), which is the rate at which biological elements remove oxygen from the water.

The samples were also tested for Chemical Oxygen Demand (COD), the rate at which inorganic elements remove oxygen from the water. The higher those levels, the lower the water quality. Above the CSO, the BOD level was just 1.3mg/l and the COD level 13.1mg/l. Below the CSO, the BOD level had jumped to 55.3mg/l and the COD level to 96mg/l.

The telemetry system at this site failed, so Yorkshire Water were not notified when there was a problem with the CSO. It appeared that the system had stopped working on 14 April 2006, unbeknown to Yorkshire Water.

However, a sensor was still working, and data from this showed that records during 20 April 2006 to 20 June 2006, this CSO sent nine illegal discharges into Clifton Beck.

In mitigation, Yorkshire Water Services Ltd said that the blockage was caused by an object put in the system by a third party. They entered an early guilty plea and co-operated fully with the Environment Agency.

The magistrates’ said that Yorkshire Water had failed to listen to warnings and did not

appreciate the pollution history at this site. They had failed to take appropriate immediate action.

Speaking after the case, an Environment Agency officer said: “This case had a significant impact on aquatic life in Clifton Beck. Yorkshire Water have a duty to maintain their monitoring equipment and we will prosecute any company that fails to take its responsibility seriously.”

Yorkshire Water Services Ltd were charged that:

In the district of Halifax on 19 June 2006, caused polluting matter, namely sewage, to enter controlled water, namely Clifton Beck.

Contrary to section 85(1) of the Water Resources Act 1991.