BISMARCK, N.D. (AP) — A company with a history of oil field-related spills in North Dakota and Montana is being hampered by winter weather in its cleanup of a "significant" pipeline break that leaked crude oil into a tributary of the Little Missouri River in western North Dakota, a regulator said Thursday.
Bill Suess, an environmental scientist with the North Dakota Health Department, said the Belle Fourche Pipeline Co. spill was discovered Monday by a landowner near Belfield. The cause of the leak is under investigation and the amount of the spill is unknown, in part because of recent blizzards and subzero temperatures throughout North Dakota, he said.
"Anytime you have cold temperatures, it's going to hinder cleanup and the investigation," Suess said.
He said the spill migrated about 2½ miles from the spill site along Ash Coulee Creek, and it fouled an unknown amount of private and U.S. Forest Service land along the waterway. He said state and federal inspectors have been monitoring the spill and that it appeared to be contained. The creek was free-flowing when the spill occurred but has since frozen over.
The spill in the creek is about 20 miles upstream of the Little Missouri River. Suess said it did not appear that any of the oil reached the river and no drinking water sources were affected.
The 6-inch steel pipeline is mostly underground but was built above ground as it crossed the creek, Suess said. The pipeline is used to gather oil from nearby oil wells to a collection point.
"It is not a transmission line so overall it won't have a major impact on oil movement," Suess said.
Belle Fourche Pipeline is part of Casper, Wyoming-based True Cos. A spokeswoman for True, Wendy Owen, said the pipeline was shut down immediately after the leak was discovered and crews had been cleaning it up since. She said it was not known how much oil leaked due to the pipeline breach.
Owen said she "couldn't even begin to speculate" what caused the breach and that the company was doing its "best to assess the entire situation and what the next step will be."
True Cos. operates at least three pipeline companies with a combined 1,648 miles of line in Montana, North Dakota and Wyoming, according to information the companies submitted to federal regulators.
Since 2006 the companies have reported 36 spills totaling 320,000 gallons of petroleum products. Most of the product spilled was never recovered, including after a January 2015 pipeline break into the Yellowstone River. The 32,000-gallon spill temporarily shut down water supplies in the downstream community of Glendive, Montana, after oil was detected in the city's water treatment system.
The companies' spills caused combined damage of almost $11 million, with most of that attributed to the Glendive spill, records show. A federal investigation into that spill is pending.
Kevin Pranis, a spokesman for the Laborers District Council of Minnesota and North Dakota, which represents some workers building the disputed four-state, $3.8 billion Dakota Access Pipeline, said Thursday that regulators need to provide better oversight of the True Cos.
True Cos. also owns Black Hills Trucking Inc., which is accused of illegally dumping saltwater, a byproduct of oil production, in 2014 on a road in northwestern North Dakota. The three-member North Dakota Industrial Commission that includes Gov. Jack Dalrymple is pursuing $950,000 in fines against Black Hills Trucking, but there has been a dispute over whether the commission has jurisdiction.
Associated Press writer Matthew Brown in Billings, Montana, contributed to this report.