The full environmental impact of the spill, which contaminated two creeks, might not be clear for months. Some previous saltwater spills have taken years to clean up. A contractor hired by the pipeline operator will be on site Thursday, assessing the damage.
Operator Summit Midstream Partners LLC detected the pipeline spill on Jan. 6, about 15 miles north of Williston and informed North Dakota officials then. State health officials on Wednesday said they weren't given a full account of the size until Tuesday.
Inspectors have been monitoring the area near Williston, in the heart of North Dakota's oil country, but it will be difficult to assess the effects of the spill until the ice melts, said Dave Glatt, chief of the North Dakota Department of Health's environmental health section.
"This is not something we want to happen in North Dakota," Glatt said.
The spill presently doesn't threaten public drinking water or human health, Glatt said. He said a handful of farmers have been asked to keep their livestock away from the two creeks, the smaller of which will be drained.
Brine, also referred to as saltwater, is an unwanted byproduct of drilling that is much saltier than sea water and may also contain petroleum and residue from hydraulic fracturing operations.
The new spill is almost three times larger than one that fouled a portion of the Fort Berthold Indian Reservation in July. Another million-gallon saltwater spill in 2006, near Alexander, is still being cleaned up nearly a decade later.
Summit Midstream said in a statement Wednesday that about 65,000 barrels of a mix of freshwater and brine have been pumped out from Blacktail Creek. Brine also reached the bigger Little Muddy Creek and potentially the Missouri River.
Glatt said the Blacktail Creek will be completely drained as part of the initial cleanup, but the water and soil will have to be continuously tested until after the spring thaw because some of the contaminated water has frozen. The Little Muddy Creek will not be drained because it is bigger than the Blacktail Creek and the saltwater is being diluted.
"We will be monitoring to see how quickly it gets back to natural background water quality conditions, and we are already starting to see that," Glatt said of the Little Muddy Creek. "It's getting back pretty quickly."
Summit Midstream's chief operating officer, Rene Casadaban, said in a statement that the company's "full and undivided attention" is focused on cleaning up the spill and repairing any environmental damage.
Spokesman Jonathan Morgan did not immediately confirm exactly when the spill began. It also was not clear what caused the pipeline to rupture. Glatt said the company has found the damaged portion of pipeline and it was sent to a laboratory to determine what caused the hole.
North Dakota has suffered scores of saltwater spills since the state's oil boom began in earnest in 2006.
A network of saltwater pipelines extends to hundreds of disposal wells in the western part of the state, where the briny water is pumped underground for permanent storage. Legislation to mandate flow meters and cutoff switches on saltwater pipelines was overwhelmingly rejected in the Legislature in 2013.
Wayde Schafer, a North Dakota spokesman for the Sierra Club, called the brine "a real toxic mix" and "an extreme threat to the environment and people's health."
"Technology exists to prevent these spills and nothing is being done," said Schafer. "Better pipelines, flow meters, cutoff switches, more inspectors — something has got to be done."
Daryl Peterson, a grain farmer from Mohall who has had spills on his property, said the latest incident underscores the need for tougher regulation and enforcement.
"Until we start holding companies fully accountable with penalties, I don't think we're going to change this whole situation we have in North Dakota," said Peterson, a board member of the Northwest Landowners Association.
Associated Press writers James MacPherson in Bismarck, North Dakota, and John Flesher in Traverse City, Michigan, contributed to this report.
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