North Dakota suffers first big oil spill

A Tesoro Logistics LP pipeline has spilled more than 20,000 barrels of crude oil into a rural North Dakota field, the biggest leak in the state since it became a major U.S. producer.

The pipeline was carrying crude oil from the Bakken shale play, which has boosted North Dakota’s state production to the second-biggest in the country. The affected part of the line has been shut down, Tesoro said.

The leak, first discovered on September 29 in a low-lying hill 9 miles north east of Tioga, North Dakota, did not pose an immediate threat to groundwater sources, Kris Roberts, who leads the environmental response team at the state Department of Health, told Reuters.

At an estimated 20,600 barrels, the spill would rank among the country’s biggest in recent years, and comes amid heightened concern over the safety of the U.S. pipeline network which is pumping harder than ever to bring burgeoning shale oil and Canadian crude to refiners.

While authorities said there were no surface bodies of water like lakes, streams or rivers within a 5-mile radius of the site, the incident could add to a fractious political debate over the construction of more pipelines, such as the much larger Keystone XL from Canada to Oklahoma.

Roberts said it wasn’t clear what caused the spill or how long it lasted.

San Antonio, Texas-based Tesoro Logistics said in a statement the affected segment of pipeline was shut and repairs were underway, which, along with containment and remediation work, could cost the company $4 million.

Tesoro Logistics owns and operates a “High Plains” pipeline in North Dakota and Montana, which gathers oil from the Bakken shale and delivers it to another Enbridge pipeline and Tesoro’s 68,000 bpd Mandan refinery in North Dakota.

It was not immediately clear if this was the pipeline in question. Tesoro did not immediately respond to queries.

This is the biggest oil spill in North Dakota since 1 million barrels of salt water brine, a by-product of oil production, leaked from a well site in 2006, according to the state Department of Health. Another pipeline leak in 1989 also released large volumes of oil to the environment.

Tesoro said the U.S. Environmental Protection Agency and the Pipeline and Hazardous Materials Safety Administration (PHMSA) were at the site monitoring its response.

The regional EPA office could not be reached because of the government shutdown.

North Dakota produced more than 874,000 barrels per day in July.

Bloomberg