BISMARCK, N.D., Feb. 18 (UPI) -- Slightly less than 1,000 barrels of oil spilled in incidents involving road transportation and operational issues, North Dakota's government said.
The North Dakota Department of Health said it was notified by Hess. Corp. of two spills from wells located three miles apart in the northwest city of Tioga. The department estimated the total spill volume at 960 barrels of oil, attributing both incidents to an open valve at the well sites.
"Some of the spilled fluid escaped the site and may be impacting a nearby wetland," the department said in a Tuesday statement. "The company is evaluating that site."
There was no statement on the incident from Hess Corp. and the state government made no indication public health was at risk.
A total of 30 barrels of oil spilled from an overflow vent of a truck carrying residual oil in western North Dakota. Some of the oil made its way to a small isolated body of water, though the nearby Charbonneau Creek was spared.
The Health Department said cleanup of that release is under way.
North Dakota's oil production is in part behind the steady rise in overall crude oil output from the United States. State data released last week show oil production in December, the last full month for which data are available, was 1.2 million barrels per day, an all-time high.
More than 90 percent of the production comes from the Bakken and Three Forks shale region of the state.
