Evidence that mountaintop mining is impacting water quality

Aug 10 2010

In Science, an article that has uncovered details of exactly how mountaintop mining or mountaintop removal, the destructive practice of  blasting the overburden in order to access coal seams instead of digging under them, is indeed affecting streams in the same ways that traditional mines have.

Bernhardt and her colleagues overlaid images taken by satellites and aircraft of mining activity in West Virginia's Appalachian Mountains onto topographic maps of the area, allowing them to estimate the amount of mining taking place in mountain watersheds between 1996 and 2009. The research team also had access to data on water quality and invertebrate biodiversity for 478 sites in the area, collected over the same period by the West Virginia Department of Environmental Protection.

The EPA's current acceptable measure of minerals in the water, its ionic content, is up to 500 microsiemens per centimeter (µS cm−1). The UOM "siemen" represents overall conductivity. The higher the ionic content (dissolved minerals, or sometimes not so dissolved) the higher the measure.

The data reveal a very obvious exception (emphasis mine):

Mining had occurred at 208 of those sites, where the average water conductivity was 650 µS cm−1. In the most intensively mined areas, where 92% of the watershed had been mined at some point, conductivity levels rose to 1,100 µS cm−1. Bernhardt says that even in areas where just 2.5% of the watershed had been mined, some 30% of streams still had conductivity levels greater than the EPA's recommendation. The team also noted "sharp declines" in some stream invertebrates in areas where as little as 1% of the watershed had been mined.

Compare those numbers, and even the acceptable EPA limit to those recorded from streams in developed areas, which had an average conductivity of 228 µS cm−1. Without mining or development, the average was 105 µS cm−1.

The National Mining Association is obviously not happy with the results of the study, claiming that, "Conductivity should not be used as an exclusive tool for isolating impacts from mining activity from the many other sources or factors that may impact water quality."

To illustrate the extent of these mines visually, take a look at the growth of the Hobet Mine in WV over 25 years, from 1984 to 2009:

Hobet 1984


Hobet 2009


As you can see, the mine crept west, and as the operation expanded, they implemented reclamation procedures on the area already stripped (light green cover). Restoring the ecology is not as simple as planting a few species of grass and trees and calling it a day however. This area will not recover for a very long time. The soil column is homogenized, the water polluted and the alpha diversity completely shot. This doesn't even consider any public health consequences or the impact on the area's economy.

When I was in college we spent an entire day in the field measuring the conductivity and invertebrate compositions of streams in the middle Appalachian mountains, beginning with a highly polluted stream running through an old coal mining shaft at the top of the system, running through a small town and finally, down into an undeveloped region of a local state park. The ionic content of the initial stream was so high that much of it had fallen out, so to speak, and the rocks almost glowed orange and red. Obviously, the stream was more or less dead.

I spent a lot of time in these areas, saw the worst of it, but I never had to live with it long term. The strip mines can be seen everywhere in the area from the highways. Ambitious wind farmers are starting to build on these areas, making the claim that it's a productive use of the land. It's a conflicted, complicated area that rarely makes headlines because of how quiet, how far away it seems. There are very few large cities in the midst of the energy development, the coal and wind industry in particular, and perhaps that lack of urbanity shifts the focus away. Perhaps it's just the nature of how we as a society deal with most environmental issues; wait until it's the worst it can be and then act.

There are a lot of people working to provide support in Appalachia, however. Sometime this week I'll have a post up about a suite of solutions proposed for the area, a sustainable framework built upon a solid foundation of proper ecological and resource management.

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