Data: Oil Trains Spill More Often, But Pipelines Spill Bigger

CREDIT: AP Photos/Graphic by Andrew Breiner

Which is safer: pipeline or rail?

The question’s been hot on bloggers’ minds since Monday, when a train carrying 3 million gallons of crude oil derailed and exploded in West Virginia. And it’s not a bad one to ask, considering recent political discussion has been dominated by a debate over whether a certain pipeline is in the national interest.

Many blogs, this one included, have pointed out that oil train disasters are on the rise. In 2014, oil trains in the U.S. spilled more often than any other recorded year. These accidents have happened as crude-by-rail shipments are soaring, increasing 40-fold since 2008. And compared to pipelines, rail incidents are occurring more frequently — according to U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA) data, rail incidents outnumbered pipelines two to one over the period of 2004 to 2012.

A lot of people have used this data to argue that transporting oil via pipelines is safer than rail. And that’s true, if your idea of safety is defined by the frequency of accidents, regardless of how large the accidents are. If, however, you think massive releases of oil into the environment pose a greater risk to human health, than pipelines are the greater evil.

According to the same PHMSA dataset, compiled and analysed by the International Energy Agency, U.S. pipelines spilled three times as much crude oil as trains over that eight-year period, even though incidents happened much less frequently. And that eight-year period was dominated by large pipeline spill events, including one that saw 800,000 gallons of Canadian tar sands crude spill in and around the Kalamazoo River, and another 63,000 gallon pipeline spill into the Yellowstone River.

There are numerous other factors at play. When a pipeline bursts, it can be harder to contain than a leaking oil tanker — only a certain, contained amount can spill out of a single punctured rail car. A pipeline can just keep spilling until the operator shuts down the flow, and will usually continue to gush until it’s empty. Large oil spills pose major, long-term risks to human health and the environment. Three years after the Kalamazoo spill, for example, cleanup crews were still working to remove oil from the ground, and residents reported experiencing headaches, breathing problems, and nausea — not to mention a negative impact on business.

But when a rail car tips over while traveling at 40 to 50 miles per hour, it has a much larger chance of exploding. That’s a more immediate threat to human life if it happens in a populated area, not to mention the smoke and fumes that are released into the air from the open burning of hydrocarbons. Most infamously, the Lac-M├ęgantic rail disaster in 2013 killed 47 people. No one was killed by the West Virginia derailment on Monday, but one person was treated and released from the hospital for inhaling toxic fumes.

So there are two separate arguments to make. You could say that more-frequent rail accidents make crude-by-rail an inherently more dangerous game than pipelines, because locomotives travel at high speeds and are more likely to explode and kill people. Or you could also say that larger spills from pipelines are worse, because they’re tough to clean up and pose long-term risks to human and environmental health.

Or, you could choose a third argument: that both rail and pipelines pose serious risks to human health, and instead of forcing people to choose between two dangerous options, we should focus on improving the safety of both modes of transport while transitioning to inherently less dangerous sources of energy.