Tesoro Logistics officials said Wednesday they had not received preliminary results of a pipeline test before a major oil spill last month near Tioga.
Few new answers were available when a federal official updated the North Dakota Public Service Commission on the investigation into the estimated 20,600-barrel spill, which occurred Sept. 29.
An official with the federal Pipeline and Hazardous Materials Safety Administration said there were still unanswered questions, but she did say it was “completely unacceptable” and “unconscionable” that a company could lose so much oil from a pipeline and not realize it.
Linda Daugherty, an administrator with the Pipeline and Hazardous Materials Safety Administration, updated the commission by phone from a regional office in Kansas City, Mo. On Aug. 10, she said, the direction of the flow on the line was reversed, which can affect the integrity of a pipeline.
“This line was leaking for a while,” Daugherty said.
The Baker Hughes company had been contracted by Tesoro to use a small robotic device known as a “smart pig” to locate defects in pipelines. A test had been run on Sept. 10-11.
Preliminary results generally take one to two weeks to be available but compiling final results can take months.
Daugherty said contracts between companies typically have clauses to notify the owner of the pipeline if anything unusual is found in preliminary results.
John Berger with Tesoro Logistics was unable Wednesday to track down the specifics of the Baker Hughes contract for the smart pig test. He said he was unsure if there was a clause in the contract to be notified of preliminary results.
If there was one, he said, he also was unsure of the timeframe it would have specified for the information to be passed along to Tesoro.
Berger said as of the Sept. 29 spill, “we had no results back from Baker (Hughes).”
Daugherty said it still is unclear how long the oil was coming from the line. She said the Tesoro line has a maximum operating pressure of 1,112 pounds and at the time of the spill, it was running at about 350 pounds of pressure at the site.
Daugherty said the line also has intermittent flows and doesn’t run 24 hours a day.
The pipeline’s size, pipeline pressure and location put it beneath the minimum threshold for monitoring and testing requirements.
Commissioner Randy Christmann questioned Daugherty on how it went undetected for so long.
“We’re talking about days and days,” Christmann said. “How can we get to the point of 20,000 barrels missing?”
Christmann asked how a company didn’t know how much was going into one end of a pipeline and how much was showing up at the other end.
Daugherty’s reply was clear:
“It’s completely unacceptable that a company can lose that much ... and not know about it. It’s unconscionable,” she said.
Daugherty said flow records must be reviewed to determine what went in and what should have come out the other end.
While state and federal agencies were notified right away, the spill was not made public until Oct. 10 following media inquiries.
Two sets of trenches have been constructed around the site to contain the spill. Some oil already has been recovered and remediation efforts are ongoing. Daugherty said work at the site will continue until the winter, and will resume in the spring.
There is no set timetable as to when the line would be repaired and operating again.