By Randy Sargent, Carnegie Mellon CREATE Lab and Samantha Malone, FracTracker Alliance
In the past two years, crude oil trains have exploded 10 times, killing 47 people.
It could have been much worse. Eight of the ten trains exploded in rural areas. The train that flattened half the business district of the small town of Lac-Mégantic might have killed hundreds of people if it had exploded during business hours. Residents in Philadelphia have dodged a bullet several times already; they’ve seen two oil train derailments there that fortunately did not explode. And last week’s Amtrak train derailment in Philadelphia that killed 8 people and injured more than 200 could have been much worse, had it impacted an oil train in that area.
Today we ship 17 times as much oil by rail as we did in 2010. This past year we shipped 14.5 billion gallons of oil — that’s 6,700 oil trains the size that destroyed Lac-Mégantic:
This chart above and the ones that follow are derived from the U.S. Energy Information Administration’s recently provided data tracking crude oil movements by rail.
Why do oil trains explode so easily?
Like a carbonated beverage with dissolved CO2, oil extracted from Bakken wells naturally has lighter hydrocarbons in it, such as methane, ethane, propane, and butane. Methane — natural gas — is the lightest of the gases and boils out quickly at surface pressure. But ethane, propane, and butanes, known as light ends or natural gas liquids in the oil industry, take time and/or heat to boil out.
In the most prolific oilfield in the U.S. today, North Dakota’s Bakken formation, most of light ends are left in the oil before loading on the train, to maximize value of what is sent to the refinery. But much like a soda bottle, the pressure increases with temperature and motion, with pressurized ethane, propane, and butane at the top. With those highly volatile gases under pressure, all it takes to create an explosion is a leak and a spark, and both commonly happen in a derailment or collision.
All ten exploding crude trains carried oil from the Bakken.
In contrast, shale oilfields in Texas do stabilize crude by removing light ends prior to shipment by rail.
Where are the exploding Bakken oil trains going?
Bakken trains travel through much of the US and Canada, heading to refineries on the coasts. Increasingly, they are traveling to East coast refineries, which now handle over half of Bakken crude oil production.
Closer to home for the authors, Pittsburgh is a popular waypoint for Bakken oil trains. Known for its steel industry in the 20th century, Pittsburgh continues to sport a large rail infrastructure. Its rails go through very densely populated areas, a good thing when the rails carried ore and steel and coal for the mills. But it’s a disaster waiting to happen now that the rails are bringing explosive oil trains through the city.
A significant and growing fraction of Bakken oil trains carrying 1 million gallons or more transit Pittsburgh, with ~30 a week based on Pennsylvania Emergency Management Agency data released for five days in October 2014. Prior to the disclosure, volunteers spent a day with us in 2014 recording traffic along one of several routes into the city to learn more about whether / how the trains might pose a risk to city residents and workers. Learn more about what we found here.
Why does this matter?
As crude-by-rail traffic continues to increase, it is only a matter of time before an oil train explodes in a populated area again. Imagine any of the 10 explosions so far taking place instead in downtown Philadelphia or Pittsburgh, or flattening a school in suburban Chicago, for example.
Learn more about the Lac-Megantic disaster through the eyes of those who lived through it.
What can be done
One attempt to make these trains safer, by requiring new tanker cars be built to a safer standard, does not appear to have helped; the most recent 5 exploding trains used the newest, “safer” tanker cars.
But there are effective measures that are in our power to take:
- Stabilize Bakken oil before shipment, by removing the light ends (a.k.a. natural gas liquids), as is currently done in Texas.
- Reroute trains around densely populated areas. St Louis has been successful in this.
- If you are concerned about these oil trains, please engage in the democratic process and tell your representatives and friends what you think. The Department of Transportation regulates interstate rail traffic. And local governments can be effective in rerouting traffic, as we’ve seen in St. Louis.
- More ways to engage, at Forest Ethics
Photo and Video Credits
- Lac Mégantic: video by Jimmy Charbonneau, map by the Toronto Star
- Outside Aliceville, AL image from WBRC Fox 6
- Outside Casselton, ND video from CCTV News 24/7
- Outside Plaster Rock, New Brunswick video from Global News
- Outside Lynchburg, VA image by Paula Mays via Richmond Times-Dispatch
- Outside Mount Carbon, WV video via Guardian Wires
- Outside Galena, IL image via WKOW ABC 27
- Outside Gogama, Ontario image by Steve Patriquin via BayToday.ca
- Outside Heimdal, ND image by Jennifer Willis
- The direction that the ignited oil flowed after the incident also played a significant role in the path of the damage and fatalities.
- Light Ends information