As cleanup continues on one of the biggest oil spills ever on Alaska's North Slope, criminal and civil investigations are under way into the circumstances of the pipeline's rupture.
The criminal investigatory arm of the U.S. Environmental Protection Agency joined with the FBI and others to examine what led the pipeline to split open in late November, officials said. An estimated 46,000 gallons of crude oil and water poured from a 2-foot-long gash onto the snowy tundra, cleanup officials say.
"The (EPA) Criminal Investigation Division is continuing to work in concert with our federal and state partners, and British Petroleum, to assess the situation associated with the Nov. 29 rupture," said Tyler Amon, the division's acting special agent in charge for the Northwest. "This matter is under investigation."
BP Exploration (Alaska) Inc. runs most of the North Slope's oil fields on behalf of itself and other oil companies and it operated the 18-inch flow line that ruptured.
"We always cooperate with regulatory agencies," BP spokesman Steve Rinehart said. "We have no comment on specific legal questions or specific investigations."
The EPA is working alongside the FBI in the investigation, Amon said. It's not yet clear where the federal investigation is headed, he said. FBI spokesman Eric Gonzalez, the chief division counsel for Alaska, declined to comment.
Meanwhile, the state Department of Environmental Conservation is conducting a civil investigation to determine what happened and if BP violated any state rules or laws.
This spill comes at a difficult time for BP, which is on probation after pleading guilty in 2007 to a misdemeanor violation of the federal Clean Water Act. That charge stemmed from a spill of more than 200,000 gallons of oil in 2006 from a corroded pipe that BP had failed to maintain. The corporation paid $20 million in fines and restitution and is in its third and final year of probation under a plea deal.
That was BP's second criminal conviction in Alaska for an environmental crime. In 1999, BP pleaded guilty to a single felony count of failing to immediately report hazardous materials dumping by a contractor at the Beaufort Sea's Endicott field. BP eventually agreed to pay $15.5 million and serve five years of probation to resolve that case.
Whether the circumstances of the new spill amount to a violation of its current probation hasn't been determined.
"Everyone is in a holding pattern right now," said Mary Frances Barnes, BP's federal probation officer. "We're waiting until all the players have conducted their investigation. That would be state, BP, EPA, FBI -- everybody who's investigating."
The pipeline that ruptured hadn't been in use for a few weeks before the spill because of ice plugs, though a companion flow line cross-connected to it continued to operate.
The breach at the bottom of the pipe was jagged and about two feet long, bigger than a state regulator said he had ever seen. Ice plugs had formed on either side of the leak site, and officials believe the area between the plugs became overpressured before the pipe split. The oil spilled over about three-quarters of an acre. The wind carried an oily mist over much of that area, with a smaller area of snow-covered tundra more heavily contaminated.
The line carried a mix of oil, water and natural gas from the wells to the Lisburne Production Center, where the materials were separated. About 25 percent of the substance was oil, according to BP.
The mix comes out of the ground hot and the pipeline is insulated. Usually North Slope pipes don't freeze. So what went wrong? That's what investigators are trying to find out.
"It's obviously a highly technical process to assess this specific rupture and do it appropriately in light of the evidence that might be present," Amon said by phone from Seattle.
CLEANUP WINDS DOWN
The cleanup now is in its third phase, with 95 percent of the work complete, according to a DEC report last week. The unified command of BP, the DEC, the EPA and the North Slope Borough has dissolved. State and federal officials say they are continuing to monitor the cleanup.
"They were essentially jack hammering the ice out and taking it over to the snow melter," Matt Carr, EPA on-scene coordinator for cleanup response, said after visiting the site again last week.
Contaminated snow and ice has been hauled to a processing area where the material will be melted and measured. The oil will eventually be reintroduced into the pipeline system for sale. Crews also flushed out the area with water and vacuumed up what was released. They recovered about 58,000 gallons of oily liquid, but that includes the water used for flushing as well as melted snow.
Mechanical problems with the snow melter have slowed the work but cleanup will continue until all the contaminated snow and ice is liquefied, according to the DEC.
Crews used a mechanical trimmer to scrape away ice and embedded oil from the tundra.
"You get bits of organic material, plants essentially, and a lot of ice as well," Carr said. That material will be ground up and injected under the surface, he said. Samples of soil scraped up are being tested for oil, DEC spokeswoman Weld Royal said.
Crews had been working 24-7 hauling away contaminated snow and ice. The last overnight crews worked Wednesday as the cleanup winds down.
"We will probably go up there again in the spring when things start to break up to see if there's any residual that's being released from melting snow or ice or the tundra," Carr said.
Find Lisa Demer online at adn.com/contact/ldemer or call 257-4390.
By LISA DEMER