Many times throughout this summer I have found myself stuck: stuck on a paper I couldn’t understand, stuck on an error I couldn’t find in my code. But this past Tuesday, I was actually stuck: stuck knee deep in mud at the edge of a river, staring at an almost 10 foot vertical bank. I’m not entirely sure why I thought after just one week of field work that I had the skills to scale this slippery slope, but something about the lure of data, or more immediately the promise of a milkshake when we were done, compelled me to look down from top of the bank and think, “Yeah, I can totally climb that.”
I should explain why I got myself into this mess. We know that mountaintop mining increases the saltiness of local streams. When the pyrite minerals in coal residues are exposed to air and water, sulfuric acid is produced. This process produces the acidic mine drainage associated with underground mining.
In the process of mountaintop mining, however, this acid is exposed to huge quantities of carbonate waste rock, which it quickly weathers. When water moves through this weathered rock, it accumulates alkaline mine drainage ions and deposits them in receiving streams, making the streams salty. Now, we want to know if we can see an increase in salt content at a regional scale, and if so, how far away from the mines that increase extends.
To find out, we followed a river…for 75 miles, stopping every 5 miles to run out of the truck into the river to grab some water samples and take a conductivity reading (a proxy measurement for ion content). This river, the Mud River, drains water from the largest surface mining complex in Appalachia. Below is a map of our survey results:
Conductivity above the mining complex was 208 μS/cm, which spiked to 1446 μS/cm just five miles later as water from mined streams began entering the river. At no point below the mines did conductivity dip below the EPA’s threshold of 300 μS/cm, above which the agency has determined local extinction of sensitive organisms can occur. These data indicate that mining salts may be propagated over 70 miles downstream of surface mines.
When I think about the issues associated with mountaintop mining, I get the feeling I had stuck at the bottom of the river bank: overwhelmed, but not resigned. At the end of this summer, I have fewer answers to the issues of mountaintop mining than I had when I started. I am, however, taking a cue from how I pulled myself out of the mud. I got a little creative and grabbed some particularly strong poison ivy vines and hoisted myself up. In the same way I pulled myself out of the mud, our solution to the economic and environmental realities of this problem may be a little painful, or in my case itchy, in the short term, but if we work creatively together, our long term solution can be a sustainable and prosperous one.
Bernhardt, E. S., Lutz, B. D., King, R. S., Fay, J. P., Carter, C. E., Helton, A. M., Campagna, D., Amos, J. (2012). How many mountains can we mine? Assessing the regional degradation of central Appalachian rivers by surface coal mining. Environmental Science and Technology, 46, 8115-8122.
Ross, M. R. V., McGlynn, B. L., Bernhardt, E. S. (2016). Deep Impact: Eﬀects of Mountaintop Mining on Surface Topography, Bedrock Structure, and Downstream Waters. Environmental Science & Technology, 50, 2064−2074.