Borough mayor questions oil leak detection

Itta says clean-up effort first rate as crews pick up 60,000 gal. of an estimated 201,000 gal.; crews also working Kuparuk spill

Wesley Loy

Anchorage Daily News

The ongoing effort to clean up the North Slope’s largest oil spill ever is “first-rate,” but pipeline leak-detection equipment to prevent such spills is lacking, the region’s mayor said March 13.

A major pipeline carrying crude oil away from a processing plant known as Gathering Center 2 sprang a leak, sending an estimated 201,000 gallons, or 4,790 barrels, of crude oozing over nearly 2 acres of tundra. That’s enough oil to fill 25 tractor-trailer tank trucks.

Officials with the state Department of Environmental Conservation said clean-up workers have recovered about 60,000 gallons of the spilled oil using vacuum trucks and other methods while working in subzero temperatures.

The spill is near the heart of pipeline-laced Prudhoe Bay, the nation’s largest oil field. BP Exploration (Alaska) Inc. runs the field on behalf of itself and other owners, including ExxonMobil and ConocoPhillips.

“BP’s response to this spill has been first-rate,” North Slope Mayor Edward Itta said March 13. “I’m very pleased with the speed of their response, the amount of resources they have mobilized, and the degree of communication they have maintained.”

Mayor calls for better technology

Itta sent a letter to DEC Commissioner Kurt Fredriksson, the state’s top pollution control official, endorsing a joint BP-state investigation into the leak-detection system on the 34-inch pipeline. The borough also wants “an audit of other pipelines with similar leak-detection systems.”

The North Slope Borough is the local government for the Minnesota-sized territory across the top of Alaska, including the slope’s many oil fields.

Over the past year, the borough twice urged DEC to require better leak-detection equipment than that used on the failed Prudhoe Bay pipeline, Itta’s letter adds. The borough said currently available leak detectors are capable of performing more than twice as well as those the state now requires.

Fredriksson could not be reached for comment. DEC spokeswoman Lynda Giguere said the agency had not yet seen Itta’s letter.

Line remains shut down

Now patched and no longer leaking, the line remains shut down and North Slope oil production is down by 95,000 barrels a day, or 12 percent of total Slope production. A BP spokesman has said it could be weeks before the pipeline is fixed or engineers figure out a way to reroute oil to bring production back to normal.

BP and DEC officials who are investigating the spill have said they’re not yet sure whether the leak-detection system failed to work as designed.

It’s possible, they said, that the leak was small and slow enough to escape detection. Under state regulations, the system is required to sound an alarm only if the flow through the pipeline drops by 1 percent or more over a 24-hour period. A DEC official said earlier that the agency recently considered tightening that standard but decided not to.

Company spokesman Daren Beaudo said the leak-detection system was tested and “it complies with regulations.”

Spill discovered March 2

Beaudo said investigators looked into a “rumor” that workers had first smelled oil many hours before that time.

“We have not been able to substantiate it as a fact,” he said. “If someone knows something differently we would welcome that input, but we have not confirmed it to date. Everything we’ve found suggests it was discovered the morning of March 2.”

The spill, though the largest on the North Slope, ranks fourth in terms of all spills involving ANS crude. The biggest came in 1989, when nearly 11 million gallons of oil spilled into Prince William Sound after the tanker Exxon Valdez ran aground. In 1978 nearly 672,000 gallons spilled near Fairbanks after saboteurs damaged the 800-mile trans-Alaska oil pipeline, which carries oil from Prudhoe Bay to the tanker port at Valdez.

Five years ago 286,000 gallons sprayed out of a bullet hole in the trans-Alaska pipeline.

Clean-up workers continued work March 13 on a second but far smaller spill in the Conoco-run Kuparuk oil field west of Prudhoe Bay. An inspection has turned up three breaches in a 24-inch line that carries water mixed with a trace of oil, DEC officials reported. Cleanup workers are still calculating the leak size, but DEC officials believe it’s likely less than 500 gallons.

Slope slowdown costs state $1M per day

The slowdown in production is costing the state nearly $1 million a day in revenue.

The BP managers also said they figure the pipeline leaked for at least five days before the snow-covered spill was discovered.

And they said corrosion that ate a small hole in the steel pipe might have been caused by peculiar chemical factors in the pipeline.

Production down by 12 percent

The 95,000 barrels, plus an additional 4,000 barrels of idled production because of another pipeline leak in the neighboring Kuparuk field, is trimming state oil revenue by about $960,000 a day at current oil prices of around $60 a barrel, said Michael Williams, chief economist with the Alaska Department of Revenue.

If the production cut lasts two more weeks, it’ll mean some $26 million less into state coffers this budget year.

Kemp Copeland, BP’s Prudhoe Bay field manager, said company engineers are working to restore at least some Prudhoe production by diverting oil that normally flows through the damaged 34-inch pipeline into a nearby 24-inch line. To do that, workers must link the two pipelines by laying a 10-inch “jumper” pipeline about the length of a football field.

The bypass could start up in two weeks but would restore only 50 percent to 75 percent of the idled production, said Maureen Johnson, a BP senior vice president.

Meanwhile, the 34-inch pipeline will be out of service for up to six weeks while it is repaired and tested to make sure it doesn’t have any other serious corrosion problems, she said.

Officials believe detection system working

By regulation, the system must detect leaks involving 1 percent or more of a pipeline’s daily oil flow. In this case, 1 percent would equal about 1,000 barrels, leading Johnson to figure the leak must have persisted for at least five days given the spill’s estimated size of nearly 5,000 barrels. Otherwise, the leak volume would have been large enough to set off an alert.

“We believe the leak probably started as a pinhole and grew over time and was too small to be detected by our system,” Johnson said.

Johnson said BP and DEC investigators are looking into whether too little anti-corrosion chemicals were flowing down the pipeline from Gathering Center 2, a plant that separates water from oil. That or other chemical factors might have caused the increased corrosion seen in the pipe over the last six months, eventually leading to a hole about a quarter-inch wide and a half-inch long, she said.

A different section of the same pipeline didn’t show the same corrosion problem, Johnson said.

BP plans to work with DEC on ways to detect smaller spills that might evade leak detectors, Johnson said. One idea might be to increase the use of aerial infrared surveys, which can spot warm oil obscured by snow.

—Wesley Loy, Anchorage Daily News