The U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) Thursday issued a safety order to the Tesoro High Plains Pipeline in response to a recent rupture that resulted in a spill of Bakken crude oil in North Dakota.

PHMSA has required the company to complete a number of short- and long-term system-wide improvements to protect people and the environment. The pipeline regulator said it will not allow the Tesoro Logistics LP pipeline to restart its system unless the operator accepts the corrective measures outlined in the order, including performing frequent aerial and ground inspections, installing additional leak detection equipment, updating maps of the entire High Plains Pipeline system and evaluating the pipeline to identify further preventative measures.

The rupture in late September resulted in the spill of approximately 20,600 bbl of crude oil in a wheat field northeast of Tioga, ND (see Shale Daily, Oct. 11). The pipeline was carrying crude oil from the Bakken shale region to a rail facility outside of Columbus, ND, when the rupture occurred. It was the largest oil spill in the U.S. this year, even exceeding the ExxonMobil pipeline spill in Mayflower, AR (see Shale Daily, April 3).

PHMSA said it is continuing its investigation into the circumstances leading to the Sept. 29 failure of the pipeline.

In addition to the corrective measures in the safety order, PHMSA required Tesoro to submit a restart plan for the entire pipeline segment to the agency for approval, conduct mechanical and metallurgical testing and failure analysis of the failed pipe, and evaluate previous inspection results. It noted that the failed pipe segment has been removed and sent to a lab for analysis. New pipe has since been installed and tested, and pressure and flow-detection systems have been installed.

The 700-mile High Plains Pipeline system stretches from Montana to North Dakota.