Philadelphia is at the center of a new industrial boom: trains are snaking through the city, bringing light, sweet crude oil from North Dakota to the city’s revived refineries. They’re the same type of train that derailed and exploded in the Canadian town of Lac-Megantic in July, leaving 47 people dead.
StateImpact has reported that the deadly accident hasn’t put the brakes on oil trains coming into Philadelphia. In fact, there are more coming than ever.
So, what exactly is this stuff and what are some of the risks involved?
StateImpact talked to oil spill expert Nancy Kinner, Director of the Coastal Response Research Center at the University of New Hampshire, who put this new boom in perspective.
The conversation has been edited for length and clarity:
Q: I’ve heard this Bakken crude described as “light and sweet.” What does that mean, Nancy?
A: When you characterize a crude oil, you’re looking at basically the types of compounds that are in that crude. Now remember, a crude oil is made up of hundreds of different organic molecules which means that it’s molecules that have lots of carbons in them and lots of hydrogens. The crude is formed when you have [plants that] fall to the bottom of a lake or an ocean and then over time, get compressed and bacteria break down those plants without oxygen. They start by eating the molecules that have the fewest number of carbons in them.
If you think of a dinner plate where you might have a nice piece of chicken, some brussels sprouts, some wood chips and a piece of rubber. I’m going to guess that you would prefer to eat that piece of chicken first because it’s easy to eat and it gives you lots of nutrition. [That represents] the lighter, shorter chains of these organic molecules for the bacteria when they’re degrading the plants. Then they move to the stuff that’s less easy to digest and break down and get energy from – that’s the brussels sprouts. Then they move to the things that are left which is the wood chips – they’re really not that great – and then finally, to the things that are really hard to degrade.
So in a light crude, it’s a younger crude in geologic time so that the microbes haven’t eaten that many light compounds. They’re still left along with the heavy ones.
Q: Where does the “sweet” come from?
A: The sweet comes from the sulfur. Think of going past a marsh. Lots of times you can smell the sulfury smell that comes off a marsh and that is what you’d smell in a sour crude. So a light crude and a sweet crude are ones that are younger geologically and have more of those shorter chains of carbon molecules and it doesn’t have much sulfur.
Q: And this light and sweet crude is very desirable for refineries in the Northeast.
A: You can make more of the compounds like gasoline or diesel fuel from a lighter crude. The reason for that is in the refining process, what the refinery does is it concentrates all of the light fractions and then each of the fractions is taken off. The lightest fractions form things like gasoline and then a little bit heavier form diesel and then home heating oil and those are the big drivers in the east for what we want for products.
Q: We don’t have a very extensive pipeline network on the east coast, so we’re getting a lot of this light, sweet crude by rail to refineries here in Philadelphia. What’s the difference in safety between these two modes of shipping hazardous materials like crude oil?
A: From a spill perspective, with a pipeline, you tend to have the spills be a lot larger because the flow in the pipeline of the oil is so much higher that when there is a leak, typically you lose a lot. Obviously with a train, the maximum you can lose is what’s on the train itself. Typically during a derailment, if one occurs, a. not all the cars leak and b. you can only have as much as is in that car leak out of it.
Q: So does rail have a better track record?
A: Well, the track records of pipelines and rail are fairly similar when you look at an annual basis at the number of incidents. But where the big difference comes in is the volume spilled. So the volume spilled in pipeline incidents annually is at least an order of magnitude greater than what you would see in rail cars.
Q: What causes a lot of these accidents?
A: One of the biggest factors is human error where humans override a system that is designed for protection or don’t believe the data that’s being given to them or simply make a bad judgement.
Q: The number of trains bringing crude oil to Philadelphia and around the country is on the rise. Does that increase the chances of accidents?
A: Of course, that’s going to happen. The more movement you have of any kind of trains or any kind of transportation, the higher the risk goes. However, relatively speaking, rail is a much, much safer mode of transport than say, trucking is. So yes, the risk goes up, but it’s still a relatively small risk. What people don’t realize or maybe don’t think about is the fact that every day on rail lines all across the country we move lots of chemicals and materials around and it’s moved mile after mile after mile with relatively few accidents. But of course, like anything else, accidents do occur and when they occur, they can be quite costly in terms of human lives and environmental damage.
Q: In other words, we need to keep the increased movement of Bakken crude by rail in context?
A: Absolutely. It has to be kept in the context of our demands for fossil fuels and I think that we need our communities to be aware of what preparations and what preventive measures are going on. Being prepared is three-quarters of the battle so I think that we are going to see some changes and at least some reevaluation in light of the Lac-Megantic even. That’s what always happens. That’s a good thing that it happens, but unfortunately, it takes something like that to put things on our radar screen.