ANCHORAGE - Alyeska Pipeline Service Co. is reviewing whether it needs to modify clamps used to control potential pipe leaks.
Alyeska, which operates the 800-mile pipeline, faced scrutiny from some industry watchdogs for not clamping the spraying leak sooner after Daniel Carson Lewis allegedly shot the pipeline about 75 miles north of Fairbanks on Oct. 4.
The shooting caused a spill of more than 285,000 gallons of crude oil.
About 36 hours after the shooting, Alyeska stopped the leak using a hydraulic clamp.
One reason workers waited was that pressure in the line immediately after the leak was more than 500 pounds per square inch - roughly double the tested strength of the clamp.
Once dangerous fumes from the leak eased and pipeline pressure neared 250 psi, workers clamped the hole, Alyeska president David Wight said last fall.
Now Alyeska is reviewing whether it should modify the clamp or replace it, perhaps with one that can handle higher pressures. Alyeska is also looking at whether to buy additional clamps, spokesman Mike Heatwole said.
He was vague on why Alyeska might modify or buy new clamps, saying an evaluation of Alyeska's response due at the end of the month will provide more direction on how the consortium should proceed. The review is being done by Alyeska, the Alaska Department of Environmental Conservation and the Environmental Protection Agency, he said.
About three dozen workers have begun the second cleanup phase at the spill site.
Crews have recovered about 170,750 gallons of crude and reinjected it into the pipeline. They have also cleared dozens of trees soaked from the streaming leak, said Wes Willson, an Alyeska environmental team leader.
The trees and contaminated soil will be trucked to North Pole, where the trees will be chipped and the chips and soil will be sent through a thermal incinerator.
Oil-drenched moss that covers much of the site also will be removed and trucked to North Pole. It will undergo a different process from that used to treat the trees and soil, one that Alyeska hopes will recover usable oil.
"The vegetative matter worked like a sponge and soaked up a considerable amount of oil, so there is an opportunity to recover some of that," Willson said.
Alyeska will use an oil recovery unit shipped from California, a machine so big that it takes three or four semi trailers to move, he said. The unit uses heat and condensation to separate oil from plants. Testing shows that out of three barrels of vegetative matter, the machine can recover about 40 gallons of oil, Willson said.
The current cleanup phase could take up to 90 days, depending on weather, he said.
"The cleanup is moving along quite nicely," said Ed Meggert of the Department of Environmental Conservation.
Cleanup so far has cost about $7 million. It could cost several million more before the cleanup and restoration are completed, Alyeska said.