An oil train south of St. Paul, Minnesota, in July 2014. Connor Lake/AP/The Star Tribune

After almost two years of deliberation, Barack Obama’s administration is expected to enact regulations next month that will attempt to protect trackside communities from exploding oil trains. However, the new rule won’t take the one step that could decrease the risk almost immediately — requiring North Dakota oil producers to either reduce their product’s explosiveness or ship it in pressurized cars. Officials say they can’t take that step because nobody really knows how to reduce or properly measure the oil’s volatility. Roughly a dozen oil trains have exploded in the United States and Canada in the past 21 months, including one in Quebec that left 47 people dead. The U.S. Department of Transportation has repeatedly warned of the unusual volatility of North Dakota’s oil. But the draft of the new rule that was released in July didn’t include anything to limit the oil’s volatility, and officials say the final rule won’t either. That falls in line with the urging of the American Petroleum Institute (API), the oil and gas industry’s largest trade group, but it’s likely to anger those residents and activists living near rail lines on which the oil trains travel. Nancy Casler, who lives near tracks in Menands, New York, says the DOT needs to address her concerns about both tanker standards and volatility before she and her family can feel safe again living next to what she considers an immense rolling pipeline. “I’m especially concerned that the [new tankers] that pass 30 feet from my house are … the same type that have exploded in recent derailments,” she said. “It perturbs me greatly that the API is aggressively lobbying against a national volatility standard, not missing a beat with recent derailments.” The White House supports the DOT’s decision, said a White House official who asked not to be identified, in part because the state of North Dakota recently enacted rules that require oil companies there to reduce the volatility of the oil before shipping it.

‘I’m especially concerned that the [new tankers] that pass 30 feet from my house are … the same type that have exploded in recent derailments.’ Nancy Casler resident, Menands, New York

But critics argue that the North Dakota restrictions don’t reduce volatility enough. The DOT requires flammable gases such as propane to be shipped in pressurized rail tankers. Oil, on the other hand, is transported in unpressurized cars. But North Dakota’s oil can fall into both categories. It starts its journey as a liquid that contains high amounts of propane, butane and other flammable gases. During the trip to the refinery those gases can separate and form a blanket of combustible gas on top of the oil. If one of the rail cars ruptures and the gas is ignited — perhaps by a spark thrown off in a crash — it can explode and cause adjacent cars to do the same. In an interview with Reuters last year, the DOT’s deputy associate administrator for hazardous materials safety, Bill Schoonover, suggested that under federal rules a mixture of flammable oil and flammable gas should be transported in a pressurized tanker. “A person must account for all hazards present if more than one hazardous material is being transported in a container,” Schoonover said. “If flammable gas like propane moves in the same shipment as flammable liquids like crude oil, the cargo should typically be treated as the more dangerous of the two substances.” DOT spokeswoman Susan Lagana said the federal agency needs more scientific understanding before it draws up volatility rules. She cited a recent U.S. Department of Energy survey of research literature which she said concluded “that while composition matters, no single chemical or physical variable has been proven to predict the likelihood or severity of an explosion.” Lagana said the DOT and other federal agencies will continue studying the volatility problem and still hope to come up with sampling and testing guidelines. “We also encourage the industry to do what they can to increase the safety of the product they are shipping,” she said. Experts acknowledge there is no proven way to link any specific chemical property of oil to the likelihood or severity of an explosion. But they also say the risk can be reduced by using a piece of equipment called a separator to boil off some of the combustible gases the oil contains when it comes out of the ground, including propane and butane. “The notion that this requires significant research and development is a bunch of BS,” said Ramanan Krishnamoorti, a professor of petroleum engineering at the University of Houston. “The science behind this has been revealed over 80 years ago, and developing a simple spreadsheet to calculate risk based on composition and vapor pressure is trivial. This can be done today.” he wrote in an email. The API has steadfastly maintained that North Dakota crude is no different from traditional crude oil in terms of volatility and argues that no federal restrictions should be placed on the volatility of oil transported by rail. “Multiple studies have shown that Bakken crude is similar to other crudes,” API president and CEO Jack Gerard said in July after the DOT released the proposed rule. “DOT needs to get this right and make sure that its regulations are grounded in facts and sound science, not speculation.” API did not respond to numerous requests for comment for this article.

If gases such as propane and butane remain in the oil until it gets to the refinery, they can be processed and sold separately for a profit. If they are boiled off at the wellhead their value is usually lost. Boiling off the gases at the wellhead can increase air quality problems in drilling areas, but transporting the oil without removing at least some of the gases increases the likelihood and severity of oil train explosions, according to many oil and gas experts. The DOT’s decision not to address volatility in the new rule leaves trackside communities in a bind because it will be years before the key safety measure in the draft rule — upgrading the fleet of roughly 100,000 rail cars that carry the oil — can be fully implemented. Under the proposed rule, some of the highly vulnerable tank cars could still be hauling volatile North Dakota oil until 2021 or later. And whether the new tanker standards will ensure safety is still a matter of heated debate. Under North Dakota’s regulations, which went into effect April 1, oil and gas developers must have separators or similar equipment at their wellheads to reduce the oil’s vapor pressure to no more than 13.7 pounds per square inch. But North Dakota’s cap is higher than 9.3 psi — the vapor pressure of the oil that blew up in Quebec in 2013. It’s also higher than the 10-psi vapor pressure cap for oil transported by pipelines, a cap enforced by the U.S. Environmental Protection Agency. Alison Ritter of the North Dakota Department of Mineral Services said the state’s decision to set the limit at 13.7 psi “is based on sound science … and represents an important step in our ongoing work to make sure that the transportation of oil is as safe as possible, as soon as possible.”

‘The notion that this requires significant research and development is a bunch of BS. The science behind this has been revealed over 80 years ago, and developing a simple spreadsheet to calculate risk based on composition and vapor pressure is trivial. This can be done today.’ Ramanan Krishnamoorti professor, University of Houston