In Valdez, Alaska, Alyeska Pipeline Service Co. is working to reinstate a waiver originally issued by the Department of Environmental Conservation (DEC) that would delay an inspection of one of its crude oil storage tanks.
Following a request submission, DEC awarded Alyeska a two-year waiver in February that would postpone an internal inspection of Valdez Marine Terminal’s Tank 5 until mid-2014 – and increase the time between such inspections from 10 to 12 years.
However in May the DEC withdrew the waiver, which was granted subject to Alyeska agreeing to six conditions, claiming the company failed to comply with conditions relating to corrosion control. Under the agreement, Alyeska agreed to provide regular ‘rectifier logs’ to DEC as proof of the continuous operation the cathodic protection (CP) system.
According to the letter issued by DEC on 23 May, while Alyeska did provide the logs as required, data revealed the CP system was operating correctly just 26% of the time during a six-month period ending mid-April.
‘Stated differently, the cathodic protection system was not operated correctly 74% of that time,’ the letter said. The letter went on to say that Alyeska failed to explain ‘why technicians failed to recognise, investigate or correct’ the faulty system.
‘There is no indication that Alyeska personnel recognised the significance of the problem until contacted by the department engineering staff about the rectifier logs,’ the DEC was reported to have said.
As a result, the department has ordered Alyeska to take Tank 5 out of service and have it internally inspected before 31 December 2012.
Since its revocation, Alyeska is pursuing the reinstatement of the waiver. In a letter sent to DEC on 7 June, Alyeska’s operational director of the Valdez terminal Scott Hicks wrote: ‘Alyeska acknowledges that some deficiencies occurred in the Tank 5 rectifier monitoring and CP maintenance programmes between October 2011 and April 2012, and we take these deficiencies very seriously.’
Alyeska operates the Trans-Alaska Pipeline System and the Valdez Marine Terminal, which comprises 18 510,000-barrel storage tanks measuring 250ft wide and 63ft high. Not all the tanks are operational today as oil flow via its pipeline has fallen by more than two-thirds from the 2.1 million barrels a day in 1988.