A highly productive method, longwall mining yielded 176 million tons of coal in 2007—15 percent of total U.S. production. An estimated 10 percent of all U.S. electricity now depends on coal from longwall mines, which have grown in Appalachia and in Illinois, Utah, Colorado, and New Mexico. Structures above a longwall mine almost always suffer subsidence, forcing homeowners to contend with such damages as shattered foundations, crooked roofs, and cracked plaster. Longwall mining also dams, diminishes, and dries up water sources. Scientists have found the practice is permanently lowering the area’s water table and draining its aquifers.

A highly productive method, longwall mining yielded 176 million tons of coal in 2007—15 percent of total U.S. production. An estimated 10 percent of all U.S. electricity now depends on coal from longwall mines, which have grown in Appalachia and in Illinois, Utah, Colorado, and New Mexico. Structures above a longwall mine almost always suffer subsidence, forcing homeowners to contend with such damages as shattered foundations, crooked roofs, and cracked plaster. Longwall mining also dams, diminishes, and dries up water sources. Scientists have found the practice is permanently lowering the area’s water table and draining its aquifers.