BILLINGS — The company responsible for a 30,000-gallon oil spill into Montana’s Yellowstone River will try to remove its breached pipeline Wednesday as regulators investigate the cause of the accident that contaminated downstream water supplies.
The broken section of pipeline will be sent to a laboratory for a metallurgical analysis as required under a federal order, Bridger Pipeline spokesman Bill Salvin said.
The January 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 were recovered from the river.
It was the second large spill into the Yellowstone since 2011, renewing calls for pipelines to be buried more deeply at river crossings.
Bridger’s Poplar Line carries oil from the Bakken region of Montana and North Dakota. The damaged section was installed in 1967, in an 8-foot-deep trench dug into the river bottom, according to documents submitted to regulators.
Officials are investigating whether high waters or an ice jam on the river near the spill last year 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 pipelines to be buried just 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 those river crossings that pose a risk.
Near Billings, Phillips 66 on Tuesday was to begin 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 2-½ feet beneath the Yellowstone’s shifting riverbed.
It will be at least the 10th pipeline crossing that 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.
Yet protecting pipelines beneath rivers presents challenges even with drilling technologies that bury them dozens of feet.
In 2011, days after flooding across the Northern Plains broke the Exxon pipe, U.S. Geological Survey researchers found “scour holes” as deep as 53 feet along the Missouri River.