Discharging poorly treated effluent from a sewage treatment works in Cornwall has cost South West Water £150,000 in fines and £3,600 in costs.
The Environment Agency estimates that 1.8 million tonnes of sewage effluent above the permitted level of biochemical oxygen demand (BOD) were released into the River Par in July 2013.
Truro crown court was told that between 9 and 23 July last year, the firm’s Luxulyan treatment plant near St Austell was not operating properly. An effluent sample taken by agency officers revealed a BOD of 66.4mg per litre (mgl), exceeding the maximum permitted level of 56mgl and well above the BOD for normal conditions, which is 20mgl. The investigation found that a surface aerator taken out of service in March 2013 was still not working in July when a second aerator failed. The agency said the plant, which has five aerators, could function effectively when one was out of action, but not more. “South West Water took an unreasonably long time to repair a broken aerator and this meant the works were running at a significantly reduced efficiency,” said Phil Christie for the agency.
Sentencing the company, Judge Christopher Harvey Clark said he had the strong impression that the plant operatives had lacked proper vigilance. “They were treating their responsibilities with a slackness amounting to complacency,” said the judge. He also described the area surrounding the treatment plant as “environmentally sensitive” and noted that Cornwall council had erected warning signs at Par and Polkerris beaches informing their users of the potential contamination.
Under the terms of its permit for the plant, South West Water is required to notify the agency of anything that might affect effluent quality. The company failed to do so, however, and the problem was discovered only when an agency officer noticed a bad smell and traced it back to the Luxulyan works.
South West Water was fined £50,000 under the Environmental Permitting (England and Wales) Regulations 2010 for each of these offences: failing to return the Luxulyan sewage treatment works to normal operation as soon as practicable; exceeding the BOD discharge limit of 56mgl; and failing to inform the agency of any failure that may adversely affect effluent quality.
The agency has warned utility providers and other large companies that they face higher penalties in future for breaches of environmental legislation after recent judgments in the Court of Appeal and the new sentencing guidelines.
