Energy company Chevron has been ordered to pay more than £11,500 in fines and costs for allowing diesel oil to escape from its terminal in Poole, Dorset, and putting an important nature reserve at risk of pollution.
On 30 October 2006, the Environment Agency was alerted to a fuel spill at the site. An agency officer saw liquid escaping from a diesel storage tank. The fuel was flowing down a crack in a concrete floor, surrounding the tank that formed part of a ‘bund’, which should have contained any spills.
Further checks with Chevron revealed that approximately 29,000 litres of diesel had been lost from the tank and escaped to the ground beneath the bund floor. Surface water drains close to the terminal and the nearby Poole Harbour were checked for pollution and were found to be clear.
However, on 1 November 2006, Wessex Water reported that fuel was contaminating Poole sewage treatment works and a nearby sewage pumping station. An investigation showed that most of the spilled diesel from the terminal had entered a foul sewer, resulting in a reduction in the quality of effluent at the sewage works, causing it to breach its discharge consent for 12 hours.
The leak was traced to a small hole in the metal base of the storage tank. The bund that should have contained the spillage was cracked and the joint between the tank and bund base had not been sealed properly.
All tanks at the Poole terminal were checked once a year. Agency officers discovered that Chevron had been advised on a number of occasions to replace the sealant between the leaking tank and the bund base, but the company had failed to carry out the work. When inspected, there was also no sign of anti-cracking reinforcement or waterstop barriers at construction joints on the bund floor.
‘This was a major fuel spill that could have resulted in the serious pollution of Poole Harbour, an internationally important wildlife site,’ said Julian Wardlaw for the Environment Agency. ‘The majority of the diesel entered Wessex Water’s foul sewer network where it caused serious operational problems, but the water company prevented major pollution of the harbour by intercepting and containing the spilled fuel. Had there been heavy rainfall at the time, diesel would have escaped from the sewer network into Poole Harbour.
‘This incident could have been avoided if Chevron had acted on a consultant’s advice and carried out repairs and improvements to the tank and the surrounding concrete bund,’ he added.
Appearing before a district judge at Bournemouth Magistrates’ Court on 26 October, Chevron was fined £6,000 and ordered to pay £5,511 in costs after pleading guilty to causing poisonous, noxious or polluting matter to enter controlled waters.