BISMARCK, N.D. (AP) — Nearly 41,000 gallons of oilfield wastewater has spilled from a broken pipeline in western North Dakota, impacting an unknown amount of land, state regulators said Wednesday.
The North Dakota Department of Environmental quality said Kansas-based Tallgrass Energy reported the produced water spill on Monday. The break occured about 6 1/2 miles south of Watford City.
It was not immediately known what caused the leak to the 4-inch plastic composite pipeline. Agency officials were on scene Wednesday to oversee the cleanup and investigate the spill, said Karl Rockman, director of the department’s division of water quality.
Rockman said the wastewater migrated at least a half-mile from the break in the pipeline and “varied in width along its path." Some of the water spilled in a dry drainage ditch that connects to Spring Creek, a tributary to the Little Missouri River.
“There is no indication that drinking water sources were threatened,” Rockman said. “There are still questions about the full extent of (the spill).”
Rockman said cleanup will involve excavating contaminated soil.
Produced water is a mixture of saltwater and oil that can contain drilling chemicals. It’s a byproduct of oil and gas development. Brine is an unwanted byproduct of oil production and is considered an environmental hazard by the state. It is many times saltier than sea water and can easily kill vegetation exposed to it.
The wastewater is typically carried from a well by pipeline or truck to a disposal site, where it is injected back in the ground for permanent storage.