UPDATE 2-Tesoro detected anomalies on N.Dakota line before spill
Oct 17 (Reuters) - Tesoro Logistics LP detected anomalies during an inspection of its 20-year-old North Dakota pipeline just days before the line ruptured and spilled 20,600 barrels of oil onto farmland, the company said on Thursday.
The six-inch pipeline was carrying Bakken oil to the Stampede rail facility outside Columbus, North Dakota, when it ruptured. A farmer harvesting wheat discovered oil spouting from the line on Sept. 29.
A robot, known as a "smart pig," detected anomalies during what Tesoro called routine internal inspections of the pipeline Sept. 10 and 11.
"We were awaiting results of the analysis of that inspection when the leak was reported," Tesoro spokeswoman Tina Barbee said.
North Dakota regulators said corrosion on the pipeline may have caused the spill.
The U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration was on site investigating the spill despite the government shutdown over the last few weeks.
The pipeline remains shut down while the federal regulator looks into how Tesoro responded to the spill, its control-room processes and records and whether non-compliance contributed to the pipeline's failure, said Jeannie Shiffer, PHMSA's director for Governmental, International, and Public Affairs.
The ruptured pipeline runs 35 miles from Tioga to Black Slough in North Dakota. It was built by BP Plc in 1993. Continued...