The images of the results of mountaintop coal mining—in which whole chunks of mountains are removed to get to the rich coal seams beneath the surface—are striking, and so are the details about the environmental damage caused by this practice. John McQuaid wrote about mountaintop mining last year in Smithsonian:
Since the mid-1990s, coal companies have pulverized Appalachian mountaintops in West Virginia, Kentucky, Virginia and Tennessee. Peaks formed hundreds of millions of years ago are obliterated in months. Forests that survived the last ice age are chopped down and burned. The Environmental Protection Agency estimates that by 2012, two decades of mountaintop removal will have destroyed or degraded 11.5 percent of the forests in those four states, an area larger than Delaware. Rubble and waste will have buried more than 1,000 miles of streams.
And the problem goes beyond just the destruction of forests and removal of rubble that's dumped into streams:
Mountaintop mining waste contains chemical compounds that otherwise remain sealed up in coal and rock. Rainwater falling on a valley fill becomes enriched with heavy metals such as lead, aluminum, chromium, manganese and selenium. Typically, coal companies construct filtration ponds to capture sediments and valley-fill runoff. But the water flowing out of these ponds isn't pristine, and some metals inevitably end up flowing downstream, contaminating water sources.
Mountaintop sites also create slurry ponds—artificial lakes that hold the byproducts of coal processing and that sometimes fail. In 2000, a slurry impoundment in Kentucky leaked into an underground mine and from there onto hillsides, where it enveloped yards and homes and spread into nearby creekbeds, killing fish and other aquatic life and contaminating drinking water. The EPA ranked the incident, involving more than 300 million gallons of coal slurry, one of the worst environmental disasters in the southeastern United States.
The most substantial effect of the new guidelines — which the agency will promulgate to regional offices that issue permits — will be to benchmark the permissible levels of mining runoff likely to be introduced into the waterways surrounding a proposed project. Operations that would result in levels roughly five times above normal would be considered too damaging.
Jackson suggested that one practical result of the guidelines would be to make it far more difficult for so-called valley fill operations, where layers of soil and rock are removed from mountaintops and piled in nearby valleys and streams, to receive permits.
The new guidelines place limits on what and how much mining waste can be dumped into local streams and were designed to protect 95 percent of the aquatic life throughout central Appalachia.