Prudhoe workers recover 56,000 gallons after North Slope spill

JUNEAU, Alaska – Workers have recovered more than 56,000 gallons of crude oil and snowmelt after a leak was discovered on a transit line on Prudhoe Bay, officials said Tuesday.

It's still not known how much oil spilled from the 34-inch diameter transit line onto the North Slope's frozen tundra, but one oil company official said it will likely be mostly crude once water is separated out.

The total was based only on collection efforts in the first 36 hours after the discovery of the leak early Thursday morning. Officials said about 501 barrels — or more than 21,000 gallons — of crude had been separated from the melted snow.

The North Slope's largest spill in the last 20 years was 38,850 gallons spilled in 1989, said Linda Giguere with the state Department of Environmental Conservation.

Workers on Tuesday temporarily patched a quarter-inch hole in an oil transit line that is believed to be the source of the leak. It appears internal corrosion is the cause, although an investigation is underway, BP Exploration (Alaska) Inc. spokesman Daren Beaudo said.

Spill responders early Sunday morning located the rupture in the 34-inch pipeline that runs between two so-called gathering centers and ultimately into the Trans-Alaska Pipeline about 7 1/2 miles away.

Gathering centers are facilities where the product pumped out of the ground is separated into oil, gas and water. The pipe that ruptured was carrying oil.

Beaudo said the 60 spill responders expect to recover at least 90 percent of the spill. They are being helped by winter weather.

"When it interacts with the cold, the material gels up and thickens and it doesn't move very fast and very far. So we are hopeful there's enough of a natural barrier that we can get it all up," he said.

The spill covers almost two acres of tundra about 650 miles north of Anchorage, and has reached the edge of a frozen lake.