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Mountaintop removal is a form of
surface mining.
This kind of mining is used when the minerals are close to the
surface of the land. Some kinds of coal are mined this way.
In the beginning, all of the trees on the top of the
mountain are cut off at the ground level. Then the top surface
is dynamited and blasted down to the level of the first coal
vein. This leaves a whole lot of dirt, tree roots, and rocks.
A ‘drag line’, which is like a giant band, is pulled across the
top of the mountain to gather all of that together. Big
bulldozers, loaders, and trucks haul this down to the valleys to
dump into places called
valley fills.
Each level of coal is taken off and the surrounding layers
of other materials are dumped in the valley fills until the coal
is gone. Mining companies will also quit digging if the cost to
dig any deeper cuts into the money they will make by selling the
coal. Then the dirt and rocks that were dumped in the valley
are hauled back to the top of the mountain and the mine is
filled in.
There is a lot of disagreement over this kind of mining
because it makes huge changes in the land that’s mined AND the
area around it. When the mountain top dirt, roots,
and rocks are dumped in the valley, it buries streams, land, and
plants. The top of the mountain, the water flow, and
the environment of and around the mountain are destroyed.
Mountains help drainage and water is cleaned as it flows
down through the layers of rock and dirt inside the mountains. This
part of the water cycle is changed. This causes problems
in water supply, water quality, and watersheds.
Click here to see pictures of what happens to the environment
with this kind of mining.
Types of materials that are mined with mountaintop removal:
Types of machinery used:
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