Waste Management Outlook for Mountain Regions

CASE STUDY

Mountain-top Coal Mining

Removing the tops of mountains is a coal mining method that is widelypracticedintheAppalachianMountainsoftheUnitedStates. Prior to the 1970’s coal in the area was only mined underground, but now surface mining, that brings down mountains, makes it profitable for companies to mine seams of coal that were once too shallow or too thin to be viable (Bernhardt et al 2012). Generally, between 150 and 250 meters of the mountain top is removed to access the coal. It’s amethod that produces huge amounts of waste – it is estimated that for every ton of coal 16 tons of overburden (waste rock and soil) are removed (McQuaid 2009). This waste is disposed in a controversial process known as valley fill. In 2012, Bernhardt and Palmer (2012) estimated that valley filling had buried over 2000 km of stream channels in the Appalachians. But overburden is not the only waste produced at mountain top mines. The coal is washed prior to shipment, to remove sulphur and other impurities, including clay and rock, leaving behind a contaminated slurry that contains known carcinogens (Epstein et al 2011 and refs. therein). This slurry is stored in impoundments or sometimes injected into abandoned underground mines. The more common impoundments are generally constructed by building a wall of coal waste across a valley to create a dam (OSMRE 2015). The Appalachian region has many of these dams. InWest Virginia alone, there are more than 120 containing over 100 billion gallons of coal slurry (Epstein et al 2011). There are regular spills and leakages from the impoundments – one of the largest occurred in 2000 when the

Massey Energy-owned sludge dam broke releasing more than 300 million gallons of slurry into undergroundmine shafts (Eades, 2000). The sludge flowed from the mine openings, heavily contaminating local creeks and rivers (Scott et al 2005). Studies have also confirmed that leaking coal slurry from underground storage locations can contaminate water supplies (Eckstein 2011). Areviewoftheimpactsofmountain-topminingintheAppalachians by Palmer at al (2010) reported reduced stream biodiversity and water quality, including elevated pH, and increased concentrations of metals including seleniumand increased sulphates below valley fills. Increased surface runoff was also responsible for an increased frequency and magnitude of downstream flooding. Studies by the United States Geological Survey (USGS) also suggest that even after mine remediation, domestic wells inmined areas have higher levels of potentially toxic mine-derived chemical constituents than well-water from unmined areas (McAuley and Kozar 2006). In 2014 Appalachian coal companies started to file for bankruptcy as the coal price fell due to the emergence of cheaper coal seam gas. In 2015 one of the biggest coal companies in the world, Alpha Natural Resources, the operator of dozens of mines in the region, joined them(CBS 2015). Alpha has since emerged frombankruptcy, but the failure of companies and continuing uncertainty in the industry leaves the mountains of waste and the communities living with them in an increasingly vulnerable position.

The tophas beenblastedoff thismountain ridge in SouthWesternVirginiaanda large damconstructed to store sludgewaste. Photo © OVEC/VivianStockman

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