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Evolving situation at Drift River terminal
Alan Bailey Petroleum News
Multiple explosive eruptions at Alaska’s Redoubt Volcano on the west side of Cook Inlet since March 22 have caused lahars, volcanic mudflows that is, on the flanks of the mountain, while melting of the Drift Glacier on the edge of the volcano’s crater has caused major flooding in the Drift River which flows past the Chevron-operated Drift River oil terminal at the base of the volcano.
And another major eruption on March 26 caused the National Weather Service to issue a new flood alert for the river.
According to the Anchorage Daily News, over flights of the terminal on March 24 revealed that muddy water from eruption-induced river flooding had lapped over a dike at the terminal — the river level had risen by 25 feet on the morning of March 23, the Daily News report said.
But massive protective dikes have prevented flood water from reaching the terminal’s tank farm. Nevertheless it appears that flooding has damaged parts of the facility outside the protected tank farm and has covered part of the terminal’s airstrip with mud, according to workers who visited the terminal on the day of the over flights.
“Initial indications are that the dikes performed as designed,” the U.S. Coast Guard said March 24. “… No (oil) release has been observed and no sheen was observed Monday afternoon by Coast Guard, ADEC and Alaska Volcano Observatory personnel on an over flight of the area.”
Evacuated Chevron had evacuated the terminal shortly after the initial eruptions of the volcano. “The facility was shut down and the 11 personnel evacuated by helicopter Monday (March 23),” the U.S. Coast Guard said.
Terminal owner Cook Inlet Pipe Line Co. built protective dikes around the tank farm after some minor flooding occurred at the terminal, when Redoubt eruptions in 1989 and 1990 diverted the Drift River. But the Chevron subsidiary that operates the terminal keeps a minimum quantity of oil in the two active tanks at the terminal, to ensure that the tanks are not floated from their foundations, were the protective dikes to be breached.
“Each tank contains about 74,000 barrels of crude oil,” the Coast Guard said.
And engineers are standing by to examine the continuing integrity of the protective dikes, with heavy equipment stationed inside the dikes to enable repair work if the flooding causes erosion of the dike structures.
—The Anchorage Daily News contributed to this story.
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