Three months after a derelict deck barge began leaking oil in the Columbia River, efforts were continuing to clean up the pollution and remove the wreck.
Davy Crockett, a World War II Liberty ship cut down to a deck barge, began leaking oil into the Columbia River upstream from Vancouver, Wash., early in January. The U.S. Coast Guard sent the owner an order to remove the hazard, but on Jan. 27, a Washington state spill-response team traced an 11-mile-long sheen of oil back to the partially sunk derelict 431-foot vessel. The next day, Coast Guard Sector Columbia River established a unified command with the Washington State Department of Ecology and Oregon Department of Environmental Quality to respond to the pollution threat.
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Environmental response crews have completed construction of a cofferdam around the derelict barge Davy Crockett in the Columbia River. The Coast Guard is overseeing the dismantling of the converted former Liberty ship, which was identified as the source of oil spilling into the river. (Photo courtesy Washington State Department of Ecology) |
At a briefing on March 28, U.S. Coast Guard Capt. Daniel LeBlanc, the commanding officer of Coast Guard Marine Safety Unit Portland, the federal coordinator, announced that both local shipyards had refused to dry dock Davy Crockett and dismantle it because of the potential environmental liability. The command had therefore decided to build a cofferdam around the wreck, cut it up on site and haul the scrap by barge to Astoria, Ore., for recycling.
The inside of the dam was to be draped with a silt barrier, a water filtration system was to be set up to clean the oily bilge water and regulators would evaluate the sediment within the dam, both before and after the cleanup, to see if it needed to be removed. In addition, a 100-foot-long deflector wall was to be erected upstream to ensure that the strong current caused by spring runoff did not impact the site.
By mid-April, workers had completed the "deflection breakwater" just upstream of the wreck to protect the cofferdam and crews from any river debris. On April 18, Bergerson Construction completed the cofferdam.
LeBlanc stressed that the hull plating of Davy Crockett still appeared to be in reasonable condition, and that the train of events was set in motion by the removal of the aft deck, causing it to buckle amidships. According to LeBlanc, the removal of the steel was ordered by the owner, Bret Simpson of Ellensburg, Wash.
The projected costs of the cleanup have grown steadily. As of early April, the estimated cost was put at around $10 million. The money is to come from the Oil Spill Liability Trust Fund, which collects a five-cent tax on each barrel of oil produced in or imported into the United States.
In the initial response to the oil spill, Ballard Diving and Salvage and National Response Corp. Environmental Services were hired to conduct underwater surveys and determine the type and quantity of pollutants on the vessel. Approximately 18,000 feet of sorbent boom and 2,800 feet of hard boom were deployed. Oil samples taken from the engine room of the vessel detected 3.44 parts per million of PCBs. By Jan. 30, there were 134 people at the site, two spud barges, two dive-support vessels, a deck barge and a small tug.
As of Feb. 4, 25 tons of material and 3,500 gallons of oily water had been removed from the barge and the stern had been successfully ballasted down with about 600,000 gallons of water to allow divers access to underwater compartments. In mid-February, U.S. Coast Guard Commandant Adm. Robert Papp authorized Coast Guard Sector Columbia River to remove and destroy the barge. At this point, the estimated cost was put at over $1.5 million.
By the end of March, around 350 tons of debris had been re—moved by divers and loaded onto a deck barge, the response crew numbered 60; and the cost had risen to $7 million. Bunker oil sludge had been found in some of the vessel's double-bottom tanks, and a few tar balls showed up on a beach downstream.
