"Why wasn"t pipeline pigged?"
Anchorage Daily News, 14 Oct. 2006

Alaska"s congressional delegation on Friday grilled BP executives and government regulators about Prudhoe Bay oil leaks and, in particular, this week"s revelation that state officials had ordered BP to clean sludge out of key pipelines in 2002 but let the company off the hook three months later.
Federal pipeline regulators believe the sludge that BP allowed to accumulate inside the pipes for many years might have harbored corrosives that ate holes through the steel, leading to a 201,000-gallon oil spill last winter and a second leak in early August that forced an emergency partial shutdown of the nation"s largest oil field.