WIUM Tristates Public Radio

Dakota Access Pipeline: Risk of Explosion

Mar 14, 2015

The Bakken crude oil that Dakota Access plans to pump through its pipeline is more prone to explosion, according to the Pipeline and Hazardous Materials Safety Administration (PHMSA).

PHMSA was prompted to investigate the volatility of Bakken crude oil, which comes from the Bakken formation in North Dakota, after three separate railroad accidents in Alabama, North Dakota, and Quebec led to explosions and dozens of fatalities.

A 2014 report [.pdf] concluded that, “It is more volatile than most other types of crude – which correlates to increased ignitability and flammability."

Frits Wybenga, former deputy associate administrator for hazardous materials at PHMSA, said that doesn’t make the proposed pipeline more dangerous.

“I don’t see movement of crude oil through a pipeline as an unusual risk that’s unacceptable from an overall safety perspective,” Wybenga said.

Pipelines are safer than other modes of transportation, according to the Congressional Research Service [.pdf], with railroads being responsible for 2.7 times more hazardous-material spills.

Bakken crude oil’s volatility is linked to the geology of the Bakken formation where it’s trapped in between layers of shale rock. Tests have shown that elements of the crude oil include flammable gasses that cannot escape the compact layers of rock. These gases are called Volatile Organic Compounds (VOCs) and include Toluene, Xylene, Benzene, and Hexane.

VOCs mix in with the crude oil and give it a comparatively lower flash point, the lowest temperature at which a substance can still ignite, of negative 74.2 degrees Fahrenheit. That makes it more flammable than gasoline.

Wybenga said for these VOCs to be a problem, a pipeline would first need to leak.

“The only way you're going to get an explosion of a pipeline is if it's released into the atmosphere,” he said. “The material doesn’t explode in the pipeline itself.”

While PHMSA reports that the vast majority of pipeline leaks result in less than a gallon of oil spilled, about 280 significant spills happen every year. There have been four major pipeline incidents recently, including a gas pipeline in West Virginia exploding into a ball of flames and a leak in Montana spilling up to 50,000 gallons of crude oil into the Yellowstone River.  

If the Dakota Access pipeline does leak, Wybenga said only 5% of all the materials that make up Bakken crude have that low, volatile flash point.

“The rest of it, it’s kind of gunky material characterized as waxes,” he said.

Wybenga considers pipelines carrying gasoline and refined petroleum products to be more explosive because even though their flash point is less volatile, they have higher percentages of flammable material.

“From a flammability standpoint, gasoline transmission lines could be regarded as more dangerous than crude oil pipelines,” he said.

These pipelines, along with crude oil lines, already spread like a spider web underground, stretching from Texas to North Dakota and from Washington state to Washington, D.C. The Fraser Institute [.pdf] reports that pipelines carry more crude oil, petroleum products, and natural gas than all other modes of transportation combined.