INVESTIGATION: Pipeline's leak detection system is under scrutiny after 200,000 gallons were lost.
By WESLEY LOY, Anchorage Daily News
State pollution regulators are focusing on a pipeline leak-detection system as they investigate what led to a 201,000-gallon oil spill, the largest by far in the 29-year history of oil production on Alaska's North Slope.
The regulators and field operator BP on Friday said the spill, discovered last week along a major, 34-inch pipeline near the heart of the country's largest oil field, was more than five times the size of the next largest oil spill.
The discharge, however, is small compared to the nearly 11 million gallons spilled from the tanker Exxon Valdez in 1989.
The pipeline and wells capable of producing about 95,000 barrels of crude oil, or 12 percent of total North Slope output, remained shut down Friday as BP workers tried to clean up the spill and figure out a way to restore oil production. The stalled oil flow is worth close to $6 million a day.
Vicious cold, with wind chill as low as 64 below, hampered all efforts.
Bill Hutmacher, a state Department of Environmental Conservation official who enforces industry spill-prevention regulations, said a joint government-industry team will investigate whether the pipeline's leak-detection system performed as required.
Under state law, the system must sound an alarm for field workers if the pipeline's oil flow dips by 1 percent or more in a 24-hour period.
If oil leaked over a period of days or weeks at a rate too low to trigger the alarm, BP and its leak-detection system might have met the legal standard, Hutmacher said, even though oil reached the tundra. Determining the rate of the leak is key, he said.
"That's part of what we have to determine," said Hutmacher. "Were they in compliance with the regulations? Was the system functioning?"
Beyond that, state officials will consider whether spill-prevention regulations are stringent enough, he said.
Daren Beaudo, spokesman for BP Exploration (Alaska) Inc., which runs Prudhoe, said his company remains unsure how it could have missed 201,000 gallons of oil, or 4,790 barrels, that leaked from the pipeline.
That's enough oil to fill 25 tractor-trailer tank trucks commonly seen on U.S. highways.
"We hope to have some preliminary results by early next week," Beaudo said of the investigation.
Asked whether the pipeline's leak-detection system sounded an alarm, he said: "I don't know."
A BP field worker who happened to be driving on a gravel road alongside the pipeline discovered the leak early on the morning of March 2. The smell tipped him off.
"Even when we went looking for the source of the oil smell, responders had trouble finding the oil due to snow," Beaudo said.
Workers this week pinpointed the source of the leak: a quarter-inch hole, likely caused by internal corrosion, at a point where the steel pipe crosses under a gravel caribou crossing. A caribou crossing is a mound of gravel placed over elevated, above-ground North Slope pipelines to allow the animals to walk over.
The spill size estimate DEC and BP announced jointly Friday is subject to change. The spilled oil, which covered just shy of 2 acres including the edge of a frozen lake, could range from 135,000 to 268,000 gallons, they said. Cleanup workers had recovered 53,000 gallons as of Friday morning.
BP is studying alternatives for restoring oil production, Beaudo said. One is restarting the pipeline once the now-patched 3-mile line is permanently fixed. Another is rerouting oil production through another, smaller pipeline.
Either way, it "will be a couple of weeks before we have a solution," he said.
The frozen ground will make the cleanup easier and more effective, BP and state officials said.
Hutmacher added: "This is the last thing that any oil company wants to have happen. Just think of the extreme costs involved in dealing with the incident."
BP runs Prudhoe and owns 26 percent of the production. The biggest Prudhoe owners are Exxon Mobil and Conoco Phillips, each with about 36 percent. See the Anchorage Daily News story here, and comment below
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