Environmental consequences of mountaintop coal mining

Mountaintop mining is a widespread practice in eastern Kentucky, West Virginia and southwestern Virginia. It involves removing forests, clearing topsoil and using explosives to expose buried coal. Excess rock is pushed into nearby valleys, disturbing habitats and blocking streams.

Regulations require minimizing environmental impacts on land and water channels, but a 2010 study by the University of Maryland and other institutions, “Mountaintop Mining Consequences,” shows that the long-term impacts of mountaintop mining are significant and not easily reversed. The study was published in the journal Science in 2010.

The study’s findings include:

• Streams from valley fills release toxic or debilitating chemicals such as sulfate, calcium and magnesium that reduce biodiversity.
• Recovery of biodiversity in mining waste-impacted streams has not been documented, and sulfate pollution persists long after mining ceases.
• A survey of 78 streams from valley fills found that 73 had water with sulfate concentrations greater than the threshold for toxic bioaccumulation.
• In some freshwater food webs, sulfate has accumulated to four times the toxic level, which can cause deformities in larval fish and expose birds to reproductive failure when they eat fish. Animals feed on streambed algae that can concentrate sulfates as much as 800 to 2,000 times that in water.
• Even after mine-site reclamation, groundwater samples from domestic supply wells have higher levels of mine-derived chemical constituents than well water from unmined areas.
• Many reclaimed areas show little or no regrowth of woody vegetation and minimal carbon storage even after 15 years.
• In reclaimed forests, projected carbon sequestration after 60 years is only about 77% of that in undisturbed vegetation in the same region.

Based on the evidence obtained, the authors conclude that the impacts of mountaintop mining are “pervasive and irreversible” and that mitigation cannot compensate for losses. Because of the effects on the health of people living in surface-mining regions of the central Appalachians, they state, “Permits should not be granted unless new methods can be subjected to rigorous peer review and shown to remedy these problems.”

Photo by Jeff Gentner of the Associated Press. Tags: carbon, coal, fossil fuels, mining, pollution, biodiversity.