GRANTSVILLE, MD. -- Researchers in several eastern coal states are trying to mimic Mother Nature and duplicate her way of cleaning up contaminated water flowing from abandoned mines.
Shallow ponds, dubbed wetlands, are being created throughout the Appalachian Coal Basin where rusty-colored acid mine drainage seeps from the ground.
Biologists have discovered that as the drainage percolates through these man-built marshy areas, a certain amount of potentially toxic metal disappears and does not trickle into streams and water supplies.
"What you want to do is remove the metal from the water," said Al Whitehouse with the Office of Surface Mining, Reclamation and Enforcement in Pittsburgh. "It's a potential to solve one of the most serious, if not the most serious, environmental problems associated with coal mining."
When coal is mined, certain minerals in the earth are exposed to air and water. When oxidized, they produce acid water with high concentrations of potentially toxic metals such as iron, aluminum and manganese, said R. Kelman Wieder, associate professor at Villanova University in Pennsylvania.
An estimated 10,500 miles of streams in eight states are affected by mine drainage, according to the Appalachian Regional Commission's most recent study on the problem. Ann Anderson, public information officer with the commission, said a 1969 study requested by Congress indicated that the problem was the worst in southwest Pennsylvania, northern West Virginia and western Maryland.
Problems with acid mine drainage, however, persist throughout the Appalachian Coal Basin. On a U.S. map, the basin looks like a funnel cloud in Pennsylvania that tapers south to Alabama. The coal basin also runs through parts of Ohio, Kentucky, Tennessee, Maryland, West Virginia and Virginia.
Scores of man-made ponds are being tried in these various states. Interest also has been expressed by Japan, Australia and Czechoslovakia, Wieder said. In western Maryland, nine ponds have been built in Allegany and Garrett counties, the state's only two coal-producing counties. Seven of the nine new ponds are in the area near Cherry Creek, which feeds Deep Creek Lake, a tourist and resort area in western Maryland.
"Anytime you create an acid condition it kills the vegetation; it kills all the life and, of course, makes the water undrinkable," said Fred Bagley, chief of revegetation and reclamation with the Bureau of Mines in Frostburg. "It can get into people's water supply and we have a lot of private wells in this area."
Despite some promising results, however, Bagley believes it will take years to clean up the acid mine drainage in the region, which is dotted with abandoned mines. "There's been 150 years of acid mine drainage in western Maryland and we're not going to clean it up in a year or two," he said.
Since the Surface Mining Reclamation and Control Act of 1977, coal operators have been responsible for reclaiming mined land. "It's a long, complex law," Wieder said, "but basically you have to save all the topsoil when you mine. When you finish, you have to fill in all the holes, put the topsoil back on top, establish a cover of vegetation and meet federal and state water quality requirements."
Traditionally, coal operators have treated acid mine drainage chemically to meet regulations, which has cost millions of dollars, Wieder said. Then in the late 1970s, researchers discovered that water that flowed through natural peat bogs had lower levels of acidity and various metals. Other studies found that cattail marshes produced similar results.
Contrary to popular belief, the wetland plants themselves absorb only a tiny amount of the pollutants, Wieder said. He said biologists know a lot about the chemical processes that occur in marshy areas that help to clean up acid mine drainage, but more research is needed.
"Here's the $64,000 question," Wieder said. How big a wetland is needed to treat a given volume of mine drainage flow? If it turns out that you need 100 square miles to treat a drop, then the whole thing is going to be shelved."