BISMARCK, N.D. (AP) — One year after a pipeline rupture flooded a wheat field in northwestern North Dakota with more than 20,000 barrels of crude, Tesoro Corp. is still working around the clock cleaning up the oil spill — one of the largest to happen onshore in U.S. history.
Cleanup costs have soared from the company's original estimate of $4 million to a forecast of more than $20 million, and it may be at least another year before work is completed, the company and state officials said. The oil-sopped parcel of land, about the size of seven football fields, is no longer usable for planting at present.
"It's a big cleanup and it's become part of our life," farmer Steve Jensen said Monday. "The ground is still saturated with oil. And they're out there seven days a week, 24 hours a day."
Jensen discovered the spill while harvesting wheat on Sept. 29, 2013, on his farm near Tioga. It was almost two weeks after Jensen reported the spill that state officials told the public what had happened, and only after The Associated Press asked about it.
Tesoro blames a lightning strike for causing the rupture.
"We are committed to making this situation right," said Tina Barbee, a spokeswomen at the company's headquarters in San Antonio, Texas.
The 35-mile long pipeline was restarted last November. The pipeline now has leak-detection equipment installed, and frequent aerial and ground inspections are being done.
Jensen blames the company for not detecting the leak. Some 20,600 barrels of oil were determined to have spilled. A barrel is 42 gallons.
"It was definitely negligence," he said. "Negligence is to lose a million gallons of oil and not know about it."
The state Health Department, which is monitoring the cleanup, said no water sources were contaminated and no wildlife was hurt from the spill.
Dave Glatt, chief of the agency's environmental health section, said Tesoro has not been sanctioned for the incident.
"A fine is still on the table, but it depends on the level of cooperation and how quickly they can get it cleaned up," Glatt said.
Cleanup crews have recovered about 6,000 barrels of oil, though more than 14,000 barrels are lost, officials said.
"The rest is pretty much stranded in the soil," said Eric Haugstad, Tesoro's director of contingency planning and emergency response.
Crews initially burned oil from the surface and later used vacuums to recover it. That proved ineffective after the oil seeped far underground, officials said. Tesoro now is using a thermal desorption process that involves excavating contaminated soil and heating it before being replaced.
University scientists from North Dakota are studying the soil and plan to plant a test crop there next year, state and company officials said.
Jensen is optimistic that he'll be able to farm the land someday.
"This land is going back in production — there is no doubt in my mind," he said. "I think this company is going to do the right thing. They can afford to."