5 years, $93 million to clean up massive North Dakota spill

BISMARCK, N.D. - It's taken nearly five years of cleanup work, but a farm family in northwestern North Dakota is hoping to plant for the first time since a pipeline break sent some 840,000 gallons of oil oozing across their wheat field.

The spill by Tesoro, now known as Andeavor, was discovered by a Tioga farmer in September 2013. As the end of the cleanup draws near, here's a look at the status of the pipeline break that has been called one of the largest onshore spills in U.S. history:

What happened?

Steve Jensen said he smelled the crude oil for days before discovering that his combines' tires were covered in it. The Texas-based company and federal regulators have said a lightning strike may have caused the rupture in the pipeline, which runs from Tioga to a rail facility outside of Columbus, near the Canadian border. Coincidentally, the spill was not far from where oil was first discovered in North Dakota in 1951.

How big is it?

North Dakota regulators initially thought just 31,500 gallons of oil was involved in the spill, but later updated the amount exponentially. They also expanded the affected acreage from about 7 — the size of seven football fields — to about 14 acres. North Dakota Health Department environmental scientist Bill Suess said a total of about 48 acres were affected by cleanup equipment and stockpiles of excavated and treated soils.

Cleanup

Though crews have been working around the clock to deal with the spill since it occurred, less than a third of the 840,000 gallons was recovered. The remaining oil has been cooked from the soil in a process called thermal desorption. Company spokeswoman Destin Singleton said the two thermal desorption units at the site should be shut down within a month. Additional work, including packing up equipment, will continue through the summer.

Deep holes and dirt

Suess said about 1.2 million tons has been excavated from the site and treated. Crews have had to dig as deep as 60 feet to remove oil-tainted soil. No water sources or wildlife was affected, he said.

Cost

The company originally thought it could clean up the site in two years for about $4 million. It now estimates the costs at $93 million. The state fined the company $454,000 for the spill.

Finally, fertile farmland?

Patty Jensen, Steve's wife, hopes so. They intend to plant a cover crop this year on the spill-affected area to put nutrients in the soil, with hopes of a cash crop next year.

Patty Jensen said she won't miss the sounds of construction equipment running constantly near the couple's home. And she's hopeful the land will once again be productive.

Yet she says she will miss the cleanup workers, who routinely are treated to her homemade pies.

"They've almost become family," she said.