The fine – the largest penalty so far given to a water company following an Environment Agency prosecution – was handed down on Friday by Leeds Crown Court. Yorkshire Water had previously admitted three environmental offences relating to pollution coming from Naburn Sewage Treatment Works, near Fulford.
The EA prosecuted the company after its officers spotted the pollution while carrying out a monitoring survey on the River Ouse in August 2013.
Environmental officers saw a large volume of sewage effluent discharging from the works into the Ouse. It smelled like sewage and could be seen in the water for about 200 metres to Naburn Marina. Water quality in the river was affected for up to a kilometre.
The sewage had overflowed into the river because of a pump failure at the treatment works. Three pumps are needed to cope with the volume of sewage, and the company is legally required to have at least one backup pump available in case any of the others fail.
But at the time of the incident, when one of the pumps failed, the backup was not operational. It has been out of use for five months – a breach of the firm’s environmental permit.
With only two pumps working, sewage flowed into emergency storage tanks, filled them up, and approximately 6,000 cubic metres of sewage overflowed through an old outfall into the river, at a location where discharges are not permitted.
Had the backup pump been operational, the pollution incident would have been avoided.
Despite this incident, the backup pump was found to be out of operation again just over a year later, during a site inspection by the Environment Agency in September 2014. The pump had been taken away for repair, but had not been replaced.
Environment Agency environment management team leader Mike Riby said, after the case: “Water companies have a legal duty to ensure that their operations do not pose a threat to the environment. In this case, Yorkshire Water failed to have in place appropriate pumping equipment needed to process sewage at its Naburn treatment works. The resulting pollution had an impact on the quality of the water in the Ouse, affecting up to a kilometre of the river.
“We hope the court’s sentencing decision demonstrates the importance of companies adhering to environmental permitting rules.”
In mitigation, the company said that since April 2015 it has been running a distribution centre that supplies spare pumps and parts to enable it to replace and repair broken pumps.
The fine exceeds the £1 million penalty given to Thames Water in January for polluting the Grand Union Canal in Hertfordshire, which was the first million-pound fine of this nature given to a water company.
Yorkshire Water was also ordered to pay £27,073.69 costs.