This Waste Can Clean Up A Coal Acid Creek
AS RAIN AND GROUNDWATER slosh through 15,000 acres of deserted coal mines in southeastern Ohio, pyrite in the shafts and tailing piles oxidizes into an acid brew that spills into Monday Creek. On a bad day, the stream's pH value approaches that of battery acid. Now, a patchwork of government agencies and environmental groups wants to clean up Monday Creek--with the help of industrial waste from a local power company.
The idea isn't far-fetched. To scrub sulfur dioxide from smokestack gases, power plants use calcium carbonate, which gets converted to highly alkaline calcium sulfate and sulfite. This by-product of flue gas desulfurization (FGD) has previously been used to neutralize acid pollution, but not on the scale planned for Monday Creek.
Ohio University's Mary Stoertz, an assistant professor of geology, says the cleanup coalition wants to mix FGD into the mine tailings, known as gob piles, that blight the region's landscape. They'll also use FGD to line a network of culverts and dikes designed to keep rainwater away from pyrite concentrations. American Electric Power Co. plans to donate the FGD, hauling it from its power plant in nearby Conesville.