On March 16, 2015, about 400,000 litres of sewage was discharged from the Calenick Pumping Station into the Truro River via Calenick Creek. Located south of Truro at the head of an estuary, the site receives sewage from surrounding villages and pumps it to Truro (Newham) Sewage Treatment Works for full treatment, including disinfection.
An investigation by the Environment Agency (EA) revealed two factors contributed to the illegal discharge. In 2015, a contractor working on electrical panels at the pumping station forgot to restart the pumps, which meant sewage arriving in the wet well, a storage area within the site, was not pumped out.
Shortly before the spill, SSW received three urgent alarms via telemetry warning that sewage had reached a high level in the sump, yet no pumps were running. The team responsible for sending a crew to the pumping station failed to telephone them with a ‘high priority’ request to attend the site. Instead, they messaged them electronically, forgetting the crew was at a meeting and would not be able get to Calenick for some time.
A short while later, further alarms were triggered warning the water company that sewage was now spilling from the pumping station outfall into Calenick Creek. The discharge continued for more than four hours.
The pumping station lies within a Site of Special Scientific Interest (SSSI) and Special Area of Conservation close to commercial mussel and oyster beds at Grimes Bar and Malpas. Fortunately, the sewage spill occurred during the closed season for shellfish, although there was a risk of possible contamination of shellfish beds.
Mark Pilcher, of the EA, said: “It is vitally important water companies have robust procedures in place to ensure their sewage infrastructure assets perform appropriately.”
Calenick Sewage Pumping Station is situated at the head of a very sensitive estuary containing important intertidal habitats and commercial shellfish beds. The unpermitted discharge of crude sewage to the estuary because the pump station was not switched on following a site inspection is unacceptable.
SWW had earlier pleaded guilty to discharging crude sewage from Calenick Sewage Pumping Station contrary to Regulations 12(1)(a) and 38(2) of the Environmental Permitting Regulations 2010.
At a sentencing hearing at Truro Crown Court last week, SWW was fined £50,000 and ordered to pay £4,000 costs.