Illegal discharges at sewage treatment works in Denbury and Praze an Beeble broke permit conditions.
South West Water Ltd has been ordered to pay more than £142,000 in fines and costs for discharging poor quality effluent from two of its sewage treatment plants. The prosecutions were brought by the Environment Agency.
The offences were committed in Denbury, Devon and Praze an Beeble near Camborne, Cornwall where the company breached permit conditions by allowing inadequately treated effluent to enter nearby watercourses.
Strict limits are set on effluent discharged from sewage treatment works to ensure they don’t adversely affect receiving watercourses. It is the responsibility of the site operator to ensure a treatment works operates in accordance with its permit. They must carry out regular maintenance and repairs.
At Denbury, treated effluent is discharged into the Halwell Stream. Between September 2015 and June 2016, four samples tested for ammonia, suspended solids and Biochemical Oxygen Demand (BOD) exceeded the quality standards laid down in the site’s permit. The treatment works is only permitted two exceedances in any 12 months so the additional discharges made in March and June 2016 were offences.
The court was told the filter bed rotating arms at the site failed to operate effectively over a number of months. This coincided with a time when the site was not visited every day and alarms were not working reliably.
The sewage treatment works at Praze an Beeble requires a lot of maintenance and is permitted to discharge only a very limited amount of ammonia. Every month South West Water must take a sample of the discharge and notify the Environment Agency of the result.
In May and August 2016 the amount of ammonia discharged exceeded the amount allowed by the permit.
When further inquiries were made by the Environment Agency, it transpired that the site’s online ammonia monitor had recorded that too much ammonia had been discharged from the treatment works for some 15 days in April 2016 as well.
In May, part of the site was not being cleaned often enough and equipment needed repairing. In August, part of the site had been blocked by moss, blanket weed and sludge. South West Water said the monitoring equipment had not always worked accurately in April.
Mark Pilcher of the Environment Agency said:
Water companies must ensure effluent is treated to a sufficiently high standard to protect the environment. Regular maintenance of sewage treatment works helps with the early detection of faults and allows repairs to be made in good time before treatment deteriorates to the point where a site breaches its permit.
Appearing before a district judge at Bodmin Magistrates’ Court, South West Water Ltd was ordered to pay a total of £142,524. The company had earlier pleaded guilty to three charges (two for Denbury and one for Praze an Beeble) of breaching Regulation 38(2) of the Environmental Permitting (England and Wales) Regulations 2010.
The fine for Denbury was £80,000 with £4,993 costs plus a £120 victim surcharge. The fine for Praze an Beeble was £53,334 with £3,957 costs plus a £120 victim surcharge. The case was heard on 3 August, 2017.