A legal battle is brewing between the oil and gas industry and Colorado cities that have voted to ban shale gas extraction, raising questions about whether local governments, with the support of residents, can lawfully prohibit the controversial practice of hydraulic fracturing, or fracking. The Colorado Oil and Gas Association (COGA) filed a lawsuit Tuesday against the towns of Lafayette and Fort Collins, Colo., which have passed ordinances prohibiting fracking, a gas-extraction process through which sand, water and chemicals are pumped into the ground to release trapped fuel deposits. Environmentalists argue that fracking can contaminate local water supplies and cause other ills, like increasing the output of climate-changing greenhouse gases. In September, environmental groups warned of potential contamination by ruptured oil and gas industry infrastructure as Colorado reeled from devastating floods . Laurie Kadrich, a city official in Fort Collins, told Bloomberg news that the lawsuit did not come as […]