Posted 6/02/15 (Tue)
By Kevin Killough
On the Jensen farm, mounds of dirt loom over the site of the country’s largest land-based oil spill.
It was April of last year when the Department of Health approved a remediation plan to clean up the site, which was expected to take a couple years when it began.
With excavation more than a year under way, the state is now estimating it could take a couple more years to complete.
“We’ve given them more time, because it’s going to take more time,” said Bill Suess with the Division of Water Quality.
The spill occurred in the fall of 2013, when a pipeline owned by Tesoro sprung a leak that contaminated soil beneath the farm owned by Patricia and Steven Jensen.
The following April the state approved a remediation process utilizing thermal desorption to clean the soil. The process involves digging up the contaminated soil and burning off the hydrocarbons. The contractors then put moisture back in the cleaned soil and return it to the site.
The excavation has brought the contractors face-to-face with the extent of the contamination. And as they dug up contaminated soil, piles of dirt have risen 30 feet off the farmland, rivaling the height of many natural hills surrounding it.
“The big problem is area,” said Suess. “That’s what is slowing them down is where to put it all.”
Suess also said the extent of the contamination turned out to be larger in terms of how far it spread from the pipeline break, which has meant more soil to clean.
According to a statement released by Tesoro spokesperson Tina Barbee, more than 6,000 of the estimated 20,000 barrels released have been recovered from the site.
Meanwhile, the project has become a part of daily life for the Jensens.
“Everyone asks me if they’re done up there yet, and I tell them, ‘You don’t even know,’” said Patricia Jensen.
Despite the extended timeline pushing completion into the summer of 2017, Jensen said she understands there are so many unknowns with a project of this size that it would be difficult to estimate a timeline accurately.
She also praised Tesoro’s response and the diligence of the contractors. The main concern Jensen and her husband have, she said, is this incident leads the industry to adopt practices that prevent anything like this from ever happening again.
“That’s what we’re hoping for,” Jensen said.
Metallurgical studies of the leaking pipeline have identified lightning as the most likely cause of the break, Barbee said in the statement.
Despite the challenges that have arisen in the course of excavation, Suess said the process is proving effective according to tests done on the soil, and so far, monitoring wells have detected no contamination of the groundwater below the spill.
“It’s a big site, obviously, but it’s running smoothly. It’s probably one of the smoothest sites I deal with,” Suess said.
Barbee said the company had no estimates as to when the project would be complete.
“Tesoro Logistics continues to work closely with the landowner, PHMSA, the North Dakota Department of Health, Environmental Section, and public safety and regulatory authorities. Our primary goal of remediation continues to be to restore the property to agricultural use, and protect groundwater,” Barbee said in the statement.