Tesoro’s oil pipeline responsible for North Dakota oil spill

US-based Tesoro’s oil pipeline has broken in northwestern North Dakota, US, and spewed out more than 20,000 barrels of crude over 7.3 acres, according to the state Health Department.

The pipeline runs underground around 35 miles from Tioga to a rail facility outside of Columbus, near the Canadian border.

State environmental geologist Kris Roberts told The Huffington Post that the spill was discovered on 29 September by a farmer harvesting wheat around nine miles north of Tioga. He found oil bubbling six inches high due to a break in the underground pipeline.

North Dakota Governor Jack Dalrymple said that the state government has started contacting other agencies, as it is a fairly sizable spill.

"There are many questions to be answered on how it occurred and how it was detected and if there was anything that could have been done that could have made a difference," Dalrymple added.

Tesoro Logistics contingency planning and emergency response director Eric Haugstad said that the hole in the 20-year-old pipeline was a quarter-inch in diameter. The hole is expected to be caused by corrosion.

The cleanup cost is expected to be approximately $4m. State and federal regulators are initiating the cleanup process, where crews have recovered around 1,285 barrels of oil.

Tesoro has shut down the damaged portion of the pipeline. The company reported that no water sources were contaminated and no wildlife was affected by the spill.

The Tesoro spill is expected to be more four times larger than the pipeline rupture in March that occurred north of Little Rock, Arkansas.