A broken pipeline that leaked 30,000 gallons of oil into the Yellowstone River in Montana will end up removed so investigators can determine the cause of the spill that contaminated downstream water supplies.
Divers will pull up the broken section of pipeline and then send it to a laboratory for a metallurgical analysis as required under a federal order, Bridger Pipeline LLC spokesman Bill Salvin said.
January’s breach in the Casper, Wyoming company’s pipeline temporarily fouled water supplies for thousands of people downstream in Glendive.
Only about 2,500 gallons of crude ended up recovered from the river. It was the second major spill into the Yellowstone since 2011, renewing calls for pipelines to end up buried deeper at river crossings.
Bridger’s Poplar pipeline carries oil from the Bakken region of Montana and North Dakota. The damaged section ended up installed in 1967, in an 8-foot-deep trench dug into the river bottom, according to documents submitted to regulators.
A closer examination of the damaged section could help explain why it failed.
“It will tell you whether or not there were any defects in the metal, or was it exposed and hit by something,” Salvin said.
Officials are investigating whether high waters or an ice jam on the river last year near the spill site played a role in the breach. A large enough ice jam can scour a river bottom and scrape away the cover over a pipeline.
Federal law requires companies bury pipelines at least 4 feet beneath major water bodies. Despite criticism those rules were inadequate, the U.S. Transportation Department determined in 2014 that 4 feet was sufficient.
Spokesman Damon Hill said the agency has worked closely with pipeline companies in Montana and elsewhere to identify and replace river crossings that pose a risk.
Near Billings, Phillips 66 started drilling a new line for its Seminoe petroleum products pipeline to put it approximately 40 feet beneath the river. The line at times has been just 2½ feet beneath the Yellowstone’s shifting riverbed, according to the Montana Department of Natural Resources and Conservation.
The 8-inch Seminoe line spilled 25,000 gallons of gasoline in 2013 beneath land on the Crow Reservation west of Lodge Grass. Two earlier breaks along the same line in 1997 spilled a combined 97,000 gallons. It was owned then by Conoco Pipe Line Co.
The work that began Tuesday marks at least the 10th pipeline crossing that Texas-based Phillips 66 has replaced since 2011, when an ExxonMobil pipeline broke and released 63,000 gallons of crude into the Yellowstone near Laurel, Hill said.
“We continuously remind operators that they are responsible for knowing the conditions of their pipelines,” Hill said. “They are responsible for evaluating the water body crossings during flooding.”
Bridger Pipeline plans similar work before it restarts the line that breached near Glendive. Salvin said a permit for the drilling work is pending before the U.S. Army Corps of Engineers.