A Closer Look At Coal Dust In The Northwest: Part Two

Mar 12, 2013

Credit Marketplace/APM

For the last year EarthFix has been looking at the issue of coal being exported through the Northwest.

There are five proposed coal export terminals under consideration in Washington and Oregon. They would be built to transfer coal off of trains from Wyoming and Montana mines and on to ships bound for Asia.

Some coal dust will escape along the journey from the mines to the terminals.

The Black Thunder mine  located near Gillette, Wyoming is one of the largest open pit mines in the world.

Keith Williams runs the mine.  Behind where we’re standing, a strip of train tracks disappears beneath a giant silo.

“Right here this is a coal silo you see all the different conveyors, tubes coming in," he says.  "The train car will come over. The bottom of that bin comes down and it will dump the coal into that train car.”

As it’s loaded the coal is shaped into piles that look like round black bread loaves nestled into baking tins. This loading technique has reduced coal loss from rail cars – the coal used to be piled right up to the rim of the cars.

Trains from this mine deliver coal to power plants all over the country. Right now some trains go through the Northwest to export terminals in British Columbia. There the coal is loaded onto ships bound for Asia.

If terminals are built in Washington and Oregon, coal from this mine could be sent to one of those new terminals.

Computer monitors with multi-colored lights line the walls of the control room where we meet Paul Barber.

He's the plant superintendent.

Barber explains how the train loading operation at Black Thunder works and then I ask him a what happens if it rains on an uncovered coal train?

“They have weep holes in ‘em so water don’t necessarily pool in the car grooves," he says. " It drains and allows the water not to accumulate and drain out of the car.”

And as that water drains out of those weep holes, it could take coal dust with it.

The Environmental Protection Agency says that if rain falls on piles of coal it can flush out heavy metals – like arsenic and lead.

Elevated levels of arsenic have been found in the soil surrounding a large coal export terminal in Virginia.

You might think about coal trains as moving piles of coal, traveling across the landscape.

But their journey won’t be land-locked. Coal trains will also follow the Columbia River to the coast and some trains could travel north along Puget Sound.

“The fact that mussels and oysters filter feed means that small particles of coal will be taken up by these organisms," says Gary Shigenaka.  He's  a marine biologist with the National Oceanic and Atmospheric Administration. He has over 20 years of experience working emergency response on events like the Exxon Valdez oil spill in Alaska and Deepwater Horizon in the Gulf.

We asked him what happens to marine animals if they ingest coal dust. The answer? Scientists aren’t sure.

“We call that the so what question and that’s the really hard question to answer," Shigenaka says. "You’re exposing an organism to contaminant A, contaminant B – so what? Why should we care about it?”

There are some who say, maybe we shouldn’t. Coal occurs naturally, after all. In Alaska there are places along the coast where waves crash directly onto exposed seams of black coal.

Peter Chapman is a scientist with Golder Associates, an environmental consulting firm. The company has conducted research for the fossil fuel industry.

“Basically coal dust, it shouldn’t have an adverse effect on the marine environment," Chapman says.

And sure, coal has heavy metals in it, but Chapman says it’s a rock like any other. It’s crystalline structure locks in the arsenic, mercury and other heavy metals. That, he says, means shellfish and other animals that ingest coal dust can’t get at the harmful substances inside.

“Unless you have some very strong acids or ways of changing the matrix they will be held in there and they won’t be what we call biologically available," he says.

John Incardona is a biologist and toxicologist with the National Oceanic and Atmospheric Administration. He's an expert on the impact of fossil fuels on fish. 

"You can’t just say, blanket statement “coal’s not bioavailable” you have to look at specific coal and do the study and answer the question.," he says.

More research needs to be done on just how much heavy metals may escape from coal dust. One thing to consider, however: the coal coming from Wyoming and Montana is softer than the coal mined on the Eastern side of the country. That means it breaks down into dust more easily. And that might make it more readily available to animals – especially the filter feeders at the bottom of the food chain.

But Incardona says heavy metals might not be the most concerning contaminant in coal dust.

His research focuses on what are called Polycyclic Aromatic Hydrocarbons or PAHs. You’ll find these compounds in fossil fuels, including coal. And they’re a problem for fish.

“It’s a very simple matter if it leaves the PAH source and goes into the water and gets taken up by the fish it will be toxic," Incardona says. "It doesn’t matter if it’s coming from coal dust or fuel.”

PAHs have been connected with liver disease and lower reproductive rates in English Sole in Puget Sound. Incardona’s research has shown that when salmon and zebrafish embryos are exposed to PAHs in the lab, their hearts don’t develop normally. That can affect their growth as well as their ability to survive and reproduce.

Scientists don’t know exactly how much heavy metals and PAHs escape from coal – especially when it’s in dust form as opposed to solid chunks. But Incardona says it wouldn’t be too hard to find out.

“There is a lot of simple science that can be done to answer these basic questions but even with oil, almost all things relating with fossil fuel, seems like nobody really wants to get those answers,” says Incardona.

Trains have been carrying coal around the country for decades. But there is little research that looks specifically at the environmental impacts of chronic exposure to coal dust.

So far the Environmental Protection Agency, The Washington Department of Ecology and The Oregon Department of Environmental Quality have raised concerns about coal dust.

Some say coal dust isn’t as much of a concern as the larger environmental impacts of coal exports – like global CO2 emissions, air pollution from Asia or diesel exhaust from locomotives. But as communities in the Northwest consider coal export terminals, and the significant increase in coal train traffic that those terminals will bring, some experts believe coal dust merits a closer look.

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