Mountain Top Removal Mining and Valley Fills
The soil and rock removed during Mountain Top Mining (MTR) are called overburden. Because rock and soil have been removed from their compacted nature, air gets into the mix, creating what is commonly referred to as “swell”, which may actually increase the original volume as much as 30 percent. Due to this swelling of overburden the volume of the rock and soil increases. Therefore, there is more overburden than is needed to restore the land to approximate original contour (AOC). Excess overburden cannot be returned to the mine bench and is moved to a nearby hollow, creating what is called a valley fill. Figure 3 demonstrates this process.
Valley fills have significant ecological impacts on the region’s water, forest communities and biodiversity. The U.S. Environmental Protection Agency estimates that mountaintop removal “valley fills” are responsible for burying more than 2,000 miles of vital Appalachian headwater streams, and poisoning many more. The U.S. Environmental Protection Agency estimates that by 2012, mountaintop removal had destroyed 1.4 million acres of Appalachian forest. After the topsoil and upper portions of a mountain’s rock have been removed, the remaining soil is incapable of producing native hardwood forest. The numerous wildlife species that rely on mature forest habitats, fish and other aquatic species on the lower tier of the food chain have experienced habitat degradation, declining populations, and increasing cases of developmental abnormalities.
As of 2010, valley fills in West Virginia encompass 62,807 acres in 27 of the 55 counties. There are 2428 occurrences of valley fills, with the largest number of occurrences in Mingo, Boone and Logan county. These counties also contain 1/3 of the total acreage of valley fills. Figure 4 shows the areas consumed by valley fills in West Virginia. Click on the following link to view a graph of the valley fill occurrence by county.
Valley fills have significant ecological impacts on the region’s water, forest communities and biodiversity. The U.S. Environmental Protection Agency estimates that mountaintop removal “valley fills” are responsible for burying more than 2,000 miles of vital Appalachian headwater streams, and poisoning many more. The U.S. Environmental Protection Agency estimates that by 2012, mountaintop removal had destroyed 1.4 million acres of Appalachian forest. After the topsoil and upper portions of a mountain’s rock have been removed, the remaining soil is incapable of producing native hardwood forest. The numerous wildlife species that rely on mature forest habitats, fish and other aquatic species on the lower tier of the food chain have experienced habitat degradation, declining populations, and increasing cases of developmental abnormalities.
As of 2010, valley fills in West Virginia encompass 62,807 acres in 27 of the 55 counties. There are 2428 occurrences of valley fills, with the largest number of occurrences in Mingo, Boone and Logan county. These counties also contain 1/3 of the total acreage of valley fills. Figure 4 shows the areas consumed by valley fills in West Virginia. Click on the following link to view a graph of the valley fill occurrence by county.