"Quandry Over Quarry"
"A limestone 'quarry alley' 45 miles west of downtown Louisville resembles the scarred landscapes of eastern Kentucky, flattened by blasting for coal. ... Limestone, it turns out, is the key ingredient for stripping sulfur dioxide from smokestacks, helping to reduce acid rain and asthma-inducing haze."
Source: Louisville Courier-Journal, 08/18/2009