Pipe Corrosion Biggest Threat as Alaska Marks Exxon Valdez Spill

Since the Exxon Valdez caused the worst oil spill in the nation’s history, tankers that ship Alaska’s crude oil to the West Coast have become stronger, with double hulls and redundant operating systems for safety.

Two escort vessels guide the tankers out of Prince William Sound. And more equipment is housed nearby to respond if a spill happens again.

With the 17th anniversary of the 11 million-gallon (41.8 million-liter) spill on Friday, some say the potential for oil spill disasters has shifted onshore. Corrosion in the aging oil supply system is seen by some as a growing threat to the state’s pipeline system, as evidenced by a leak on the North Slope this month.

“I think many of us are seriously concerned about the aging and the deterioration of the pipeline and the facilities,” said John Devens, executive director of the Prince William Sound Regional Citizens’ Advisory Council.

For five days or more, a transit line operated by BP Exploration (Alaska) Inc. upstream of the 800-mile (1,290-kilometer) long main pipeline leaked up to 267,000 gallons (1.01 million liters) of crude from a small hole onto the frozen tundra.

Transit lines generally have not been subjected to regulations as rigorous as the main line, although state regulatory officials say that could change because of the spill. State environmental regulators said the spill will likely lead to fines.

The oil business has been lucrative in Alaska since crude began flowing from the North Slope via the pipeline in the 1970s. But the leak in the transit line has caused some observers to worry about the condition of the entire pipeline system.

The main pipeline, which stretches from Prudhoe Bay in the North Slope to Valdez in Prince William Sound, will be 30 years old in 2007. Less than half the oil is flowing now than at peak production, but the oil industry and state officials figure on at least another 30 years of life out of the pipeline.

Mike Heatwole, spokesman for Alyeska Pipeline Service Co., which operates and maintains the Trans-Alaska Pipeline System, said the company has enough funds to keep the pipeline running safely, with an annual budget of US$350 million (euro290 million) for operations and maintenance and another US$100 million (euro82.86 million) for capital projects.

But he said he does not know specifically whether the age of the pipeline was causing corrosion. “Probably the best way to describe it is that we’ve never had a leak in the main pipe due to corrosion,” he said.

However, as the oil fields of the North Slope decline, the quality of oil is also declining, meaning coarser and heavier crude is flowing down the pipe, causing stress on it. That is what happened in the North Slope spill, BP officials said.

The corrosion may have been due to water and sediment that are carried with viscous, or thick, oil, said company spokesman Daren Beaudo.

Heatwole said Alyeska was waiting for a detailed report on the leak and could not comment on heavy oil possibly causing the corrosion.

The 1989 spill created a slick that fouled shoreline, killing unknown quantities of animals and plants. The Exxon Valdez skipper, Joseph Hazlewood, later admitted having downed several drinks but said he was not to blame for the accident.

After a 1991 civil settlement, the company paid $900 million in damages. While some lawmakers and interest groups are calling for Exxon Mobil to pay $100 million more, spokesman Mark Boudreaux said the company had cleaned up the spill and provided compensation. He said studies show no new damage, and Prince William Sound is “healthy, robust and thriving.”

“It was a tragic accident that Exxon Mobil deeply regrets,” Boudreaux said Wednesday.

But Devens said the effects do linger. “You can still go and pick up a rock and find what looks like fresh oil,” he said.