ANCHORAGE (AP) -- An abandoned Cook Inlet pipeline sprung several leaks while it was being pressurized by cleanup crews.
The leaks Tuesday caused sheens as large as 200 yards and five miles long.
The mishap changed plans to scour residual crude oil from the 14-mile pipeline.
Cleanup crews spent the morning swabbing the Inlet's surface with plastic pompoms, according to Cook Inlet Regional Citizens Advisory Council.
Oil that wasn't picked up later evaporated or dissipated, according to BP Exploration (Alaska) Inc. The company is trying to clean the abandoned pipeline to stop it from leaking. It occasionally burped oil last summer.
Nobody knows how much oil lingers in the old line, so the oil company had hoped to push a train of nontoxic gel, called a pig, through the line to sponge it all up.
But for that to work, the line had to withstand about 2,000 pounds per square inch of air pressure.
BP forced air into the pipeline shortly after 7 a.m. Tuesday. It took 15 minutes for oil to bubble to the surface about two miles from shore, said BP spokesman Paul Laird.
Other sheens popped up a few minutes later.
Once BP stopped forcing air into the line, the leaking stopped.
The company called off its plans for the gel train, and has approval from the state Department of Environmental Conservation and U.S. Coast Guard to try something different, Laird told the Anchorage Daily News.
Starting next week, BP will tap into high points in the pipeline between Middle Ground Shoal and the Nikiski shore, he said. A pair of vacuum trucks aboard a landing craft will suck oil out of the high spots until they are getting nothing but water.
The company had success doing that in late July. It extracted about 1,000 gallons of oil and 7,800 gallons of oily water by tapping another high point in the same line, Laird said.
Cleanup costs are expected to reach up to $4 million, he said.
The pipeline connects the Anna drilling platform in Trading Bay to oil facilities in Nikiski. The pipeline failed repeatedly in the early 1970s and was abandoned by Amoco in 1974.
BP assumed responsibility for the line when the companies merged in 1998.
A first attempt to send a gel train, or pig, through the line was scrapped in late June after BP was unable to pressurize the line.
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