Mountaintop Removal Mining Overview

An explosive is detonated at an A & G Coal Corporation surface mining operation in the Appalachian Mountains on April 16, 2012
Mario Tama/Getty Images News/Getty Images

Mountaintop removal mining is a controversial practice in which mining companies do exactly what the name implies: they remove the tops of mountains to get at the coal buried underneath, leaving the land forever changed.

Mountaintop removal mining (also known as mountaintop mining) is a particularly destructive coal-mining practice that has been used with increasing frequency since the 1970s in Appalachia (especially Kentucky, West Virginia, and Tennessee) and a few other coal-rich regions of the United States.

Instead of tunneling into the mountain and sending miners underground to locate, dig and extract the coal, the tops of ridges are removed to expose the coal underneath and to make it easier and less expensive to mine.

What Happens During Mountaintop Removal Mining?

At a typical mountaintop removal mining site, a mining company starts by clear-cutting miles of hardwood forest and understory growth from the top of a mountain, destroying wildlife habitat and nesting sites for native and migratory birds. Next, the company drills hundreds of holes and packs them with powerful explosives to blast through rock and reduce the elevation of the mountain by as much as 800 feet. Toxic dust is carried towards human populations, causing significant negative health effects. Flooding and erosion often follows when heavy rains wash over the exposed ground.

Huge shovels clear the tailings, often dumping it into adjacent valleys where it buries streams, destroys more habitat, and sometimes contaminates community drinking water with heavy metals and toxic chemicals.

Appalachia is renown for its stream salamander diversity, and these amphibians are particularly hard hit by habitat destruction.

Giant machines called draglines—some 20 stories high and weighing 8 million pounds—dig into the rock to expose the coal. Other machines scoop out the coal and dump millions of additional tons of rock and soil called "overburden" into the surrounding valleys.

Does the Land Ever Recover After Mountaintop Removal Mining?

The Surface Mining Control and Reclamation Act of 1977 requires mining companies to reclaim all areas disturbed by mountaintop removal mining operations in one of several post-mining land-use options. The core requirement is for mining companies to return the land to its "approximate original contour." Usually, grading work is done, followed by planting of grasses and trees. Vegetation regrowth is slowed by compacted soils and lack of nutrients, and wildlife remains sparse. Rebuilding a healthy soil layer will take hundreds of years.

The law allows variances for development projects that would benefit the local community, such as housing, schools or shopping centers. In most cases, however, the proposed projects never materialize, and paving mountaintops after the mining is over does nothing to help the environment or to restore what is lost.

In the surrounding streams, recovery is also very slow. A common issue is acid mine drainage, when mining waste is exposed to oxygen and releases sulfuric acid in streams, lowering the pH and killing aquatic life. Acid mine drainage is very costly and difficult to mitigate.

In early 2016, a new federal rule proposed to protect mountain streams from coal mining was held back by the House.

Edited by Frederic Beaudry.