Contrary to reports from national news outlets and a congressional subcommittee, the trans-Alaska oil pipeline did not spill 5,000 barrels of oil onto the ground near Delta Junction, but rather into a lined pit designed as a back-up system for overflows.
Such an overflow occurred on May 25, as crews from Alyeska Pipeline Service Co., the consortium that runs the 800-mile pipeline, performed scheduled maintenance at Pump Station 9. During a test of the fire systems, the power went out, triggering a relief valve that sent oil into an overflow tank. Because power was out at the pump station, the command center in Anchorage couldn’t see the tank filling up, and the tank eventually overflowed.
As CNN reported today, “about 5,000 barrels then leaked onto the ground nearby.” The House Subcommittee on Railroads, Pipelines and Hazardous Materials, under the Transportation and Infrastructure Committee, made similar claims at a July 15 hearing.
However, the oil didn’t overflow onto unprotected ground, but rather into “secondary containment,” a lined pit designed for such an event, filled with gravel and surrounded by berms, according to Tom DeRuyter, of the Department of Environmental Conservation, and a member of the state response team that filed five situation reports on the incident.
After excavating the gravel, DEC and Alyeska found rips in the lining, but DeRuyter said their investigation hasn’t yet determine whether those rips existed before the oil overflowed into the pit, or were caused by the excavating equipment removing the gravel.
The oil that overflowed into the pit was recovered within a week, but recovering the oil entrained in the gravel took longer, requiring a sump pump and a drainage system. “We’ll put out a final sit rep once we have a good volume estimation on the amount released,” DeRuyter said. That report should tell how much oil got through the holes into the soil.
See story in Aug. 1 issue, available to subscribers online at noon, Friday, July 30, at www.PetroleumNews.com