BISMARCK, N.D. -- More than 20,000 barrels of crude oil have spewed out of a Tesoro Corp. oil pipeline in a wheat field in northwestern North Dakota, the state Health Department said Thursday.
State environmental geologist Kris Roberts said the 20,600-barrel spill, among the largest recorded in the state, was discovered on Sept. 29 by a farmer harvesting wheat about nine miles north of Tioga.
'The farmer was harvesting his wheat and started smelling oil,' Roberts said. 'It went from there.'
The release of oil has been stopped, Roberts said. Spread out over 7.3 acres, or about the size of seven football fields, the spill has been contained. Tesoro said no water sources were contaminated, no wildlife was hurt and there weren't any injuries.
Gov. Jack Dalrymple said he wasn't told of the spill until Wednesday night.
'Initially, it was felt that the spill was not overly large,' Dalrymple said, when questioned at a news conference on a separate topic. 'When they realized it was a fairly sizable spill, they began to contact more people about it.'
The governor said North Dakota is investigating its procedures for reporting spills, saying, 'There are many questions to be answered on how it occurred and how it was detected and if there was anything that could have been done that could have made a difference.'
Tesoro Logistics, a subsidiary of the San Antonio, Texas-based company that owns and operates parts of Tesoro's oil infrastructure, said in a statement that the affected portion of the pipeline has been shut down.
'Protection and care of the environment are fundamental to our core values, and we deeply regret any impact to the landowner,' Tesoro CEO Greg Goff said in a statement. 'We will continue to work tirelessly to fully remediate the release area.'
Wayde Schafer, a North Dakota spokesman for the Sierra Club, said the spill is an example of the lack of oversight in a state that has exploded with oil development in recent years.
'We need more inspectors and more transparency,' Schafer said. 'Not only is the public not informed, but agencies don't appear to be aware of what's going on and that's not good.'
Roberts said the farmer who discovered the leak had harvested most of his wheat prior to the spill. The wheat is being tested for contamination at a local grain elevator.
An oil pipeline breach in the late 1980s in the northeast corner of the state was larger than this spill, Roberts said.
The Tesoro spill is four times the size of a pipeline rupture in late March that happened north of Little Rock, Ark. An ExxonMobile pipeline burst March 29 and spilled 5,000 barrels of oil in a Mayflower, Ark., neighborhood, forcing the evacuation of more than 20 homes.
Eric Haugstad, Tesoro's director of contingency planning and emergency response, said the hole in the 20-year-old pipeline was a quarter-inch in diameter. Tesoro officials were investigating what caused the hole in the 6-inch-diameter steel pipeline that runs underground about 35 miles from Tioga to a rail facility outside of Columbus, near the Canadian border. Roberts said the hole may have been caused by corrosion.
Tesoro owns North Dakota's only oil refinery, which occupies about 1 1/2 square miles of land overlooking the Missouri River in Mandan. The facility was built in 1954, three years after drillers began pumping oil in North Dakota. Tesoro acquired the refinery from BP in 2001.
Tesoro said that the cleanup cost is estimated at $4 million, and Roberts said state and federal regulators are monitoring the cleanup, the completion of which is not known. Cleanup crews have recovered about 1,285 barrels of oil, officials said. A barrel is 42 gallons.
Crews initially burned oil from the surface but have since dug ditches and recovery wells, Roberts said. Several vacuum trucks have sucked oil from the ditches and wells on the site, he said.
A natural layer of clay more than 40 feet thick underlies the spill site and has 'held the oil up' so that it does not spread to underground water sources, Roberts said. The nearest home is about a half-mile from the spill site, he said.
'It is completely contained and under control,' Roberts said Thursday. 'They got very lucky.'