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| Fig. 1: A mountaintop removal work site. Source: Wikimedia Commons |
Coal burning is the most widely used method of generating electricity, accounting for about 51% of total U.S. electricity production in 2008. [1] An important energy resource, coal is formed by the compression of organic material underneath the weight of overlying sediment for hundreds of millions of years. [2] Deposits lie deep underground and must be mined to obtain coal for use as a fossil fuel. In the United States, 70% of all coal is obtained through surface mining. [3] To date, over 500 mountains have been leveled in a form of surface mining called mountaintop removal, representing 1500 square miles or an area roughly the size of Rhode Island. [4] This widespread use of mountaintop removal mining is concerning because of the technique's serious environmental, economic, and health implications.
Mountaintop removal is a type of surface mining, where the summit or summit ridge of a mountain is removed to expose underlying coal reserves. Explosives blow away layers of rock and dirt called overburden, which is transferred into nearby valleys for storage. Uncovered coal seams are excavated and sent to plants for processing. This method of removing overburden and harvesting coal seams is repeated multiple times to reach deep coal deposits, causing large topographical changes to the mountain range. Once coal excavation is completed, mountains are regraded to resemble their natural states. [5]
The use of mountaintop removal has been driven by its efficiency and cost-effectiveness as compared to other forms of coal mining. The explosive extraction methods of mountaintop removal produce about three times as much coal per worker than traditional underground mines. In 2008, the production per underground miner was 3.15 short tons per hour, in contrast to 9.82 per surface miner. [3] Large, expensive labor forces have been replaced with cheaper explosive and machinery costs, which have incentivized the increased use of mountaintop removal over the past 30 years. [6,7] While economically beneficial for coal companies, mountaintop removal's efficiency has led to mining job losses, particularly in areas where the technique is most used. One example is Kentucky, where the number of miners has decreased from 47,190 people in 1979 to 15,522 in 2004, despite increased coal production levels. [8,9]
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| Fig. 2: An explosive blast at a mountaintop removal mining site in Eunice, West Virginia. Source: Wikimedia Commons |
The environmental effects of mountaintop removal include water contamination, air pollution, decreased plant and animal life, and landscape changes.
Mountaintop removal begins with stripping an area of all vegetation and removing the upper portion of a mountain. [5] Although sediment is replaced on the excavation site once mining is complete, the former mountain cannot accurately be recreated and is essentially leveled. Topographic changes alter water flow and limit plant growth for years after a mining site has been closed. Mountaintop removal has been correlated with decreased biodiversity and studies demonstrate that it leads to increased runoff from the soil. [7] Runoff, contamination by explosives, and chemicals involved in surface mining pollute waterways, leading to increased sulfate, magnesium, calcium, bicarbonate, and heavy metal levels. [10] Selenium is well above toxic levels and accumulates in algae, fish, and other bio-aquatic organisms. [7] Surface mining also pollutes both ambient and work zone air quality, increasing total suspended particulate matter, respirable particulate matter, and benzene soluble matter. [11]
Mountaintop removal mining is correlated with high incidence of chronic and acute health problems. It has been hypothesized that contaminated water and hazardous dust from this form of surface mining are the cause of increased health risk.
Birth defects in Appalachian counties using mountaintop coal removal are higher than in counties using other mining-techniques or in non-mining counties, including elevated incidence of circulatory, respiratory, central nervous system, musculoskeletal, gastrointestinal, and urogenital defects. [12] Adult chronic pulmonary disease, hypertension, heart disease, kidney disease, and mortality increase by county as a function of increasing coal production. [13] Cancer rates are higher in areas with mountaintop removal compared to areas without. [7] Measures of health-related quality of life demonstrate that mountaintop mining areas are associated with the greatest reductions in physical, mental, and activity limitation, and self-reported health compared to areas with other forms of mining. [14]
Mountaintop removal mining has serious health, environmental, and local economic impacts for the Appalachian region. Inexpensive coal retrieval should not come at the expense human life or devastating ecological consequences. Therefore, a shift toward more sustainable mining practices is necessary in the coming years.
© Claire Durkin. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] R. W. Asplund, Profiting From Clean Energy (Wiley, 2008).
[2] E. S. Moore, Coal: Its Properties, Analysis, Classification, Geology, Extraction, Uses and Distribution (Wiley, 1922).
[3] "Annual Coal Report 2009," U.S. Energy Information Administration, DOE/EIA-0584(2009), 2009.
[4] D. B. Botkin, Powering the Future: A Scientist's Guide to Energy Independence (FT Press, 2010).
[5] U.S. National Research Council, Surface Coal Mining Effects on Ground Water Recharge (National Academies Press, 1990).
[6] J. W. Gunnet and V. Price, "Cost Effective Mountaintop Removal," Min. Congr. J. 68, 41 (1982).
[7] M. A. Palmer et al., "Mountaintop Mining Consequences," Science 327, 148 (2010).
[8] "Annual Coal Report 2004," U.S. Energy Information Administration, DOE/EIA-0584(2004), 2004.
[9] "Coal Production," U.S. Department of Energy, Energy Information Administration, 1979-1992.
[10] K. J. Hartman et al., "How Much Do Valley Fills Influence Headwater Streams?" Hydrobiologia, 532, 91 (2005).
[11] M. K. Ghose and S. R. Majee, "Characteristics of Hazardous Airborne Dust Around an Indian Surface Coal Mining Area," Environ. Monit. Assess. 130, 17 (2007).
[12] M. M. Ahern et al., "The Association Between Mountaintop Mining and Birth Defects Among Live Births in Central Appalachia, 1996-2003," Environ. Res. 11, 838 (2011).
[13] M. Hendryx and M. M. Ahern, "Mortality in Appalachian Coal Mining Regions: the Value of Statistical Life Lost," Public Health Rep. 124, 541 (2009).
[14] K. J. Zullig and M. Hendryx, "Health-Related Quality of Life Among Central Appalachian Residents in Mountaintop Mining Counties," Am. J. Public Health 101, 848 (2011).
[15] "Mountaintop Mining/Valley Fills in Appalachia: Final Programmatic Environmental Impact Statement," U.S. Environmental Protection Agency, October 2005.
