Small Pipeline Leaks May Go Undetected

State regulators aren’t alone in their scrutiny of the Yellowstone Pipe Line Co. Federal officials also wonder if the company is going far enough to guard against spills.

Yellowstone’s proposed leak detection system cannot detect pipeline leaks smaller than 840 gallons an hour, according to a final environmental impact statement compiled for the Lolo National Forest. The company can detect much smaller leaks, but only if it shuts down for testing.

Yellowstone’s track record isn’t encouraging, said Stephen Potts, with the U.S. Environmental Protection Agency in Helena.

The company spilled about 300,000 gallons of gasoline near Kingston in 1967. Decades of fuel spills led tribal officials to yank a permit for the pipeline to cross the Flathead Indian Reservation in 1995.

“Some of the greatest threats occur from small leaks you don’t detect … they go on for long periods of time,” Potts said. “you can have significant amounts of petroleum leaking into the ground or the groundwater.”

The Lolo National Forest will issue a decision on a permit renewal for the pipeline some time next year. The EPA is providing input.