Maintenance and cleaning issues led to effluent quality breeches in Cornwall

South West Water 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 fines were issued by the Environment Agency after SWW’s sewage treatment plants at Denbury and Praze-an-Beeble were found to have exceeded the permitted discharge of ammonia into local watercourses in May and August 2016.

The company pleaded guilty to three charges of breaching regulation 38(2) of the Environmental Permitting Regulations 2010: two for Denbury and one for Praze-an-Beeble

Bodmin magistrates court heard how filter bed rotating arms at the Denbury site failed to operate efficiently over a number of months. This coincided with a time when fewer site visits were being made and there were issues with alarm systems, which in turn led to breaches in quality standards.

The breaches at Praze-an-Beeble were due to the site not being cleaned often enough and equipment being in need of repair. SWW also said that monitoring had not been functioning as it should have.

The company “accepted and apologised for the temporary drop in final effluent quality”  at both sites and insisted that no environmental damage occurred.

Maintenance at the Denbury site has since been improved, with £41,800 having been invested since the incident occurred and another £44,300 earmarked for further refurbishments.

SWW added that it has improved the monitoring and performance of the Praze-an-Beeble works, which has remained fully compliant with its permit since August 2016.

“Water companies must ensure effluent is treated to a sufficiently high standard to protect the environment,” said the Environment Agency’s West Cornwall team leader Mark Pilcher.

“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.”

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