Drinking Water Contaminated with Natural Gas Near Fracked Wells

Elevated levels of methane and other stray gases have been found in drinking water near natural gas wells in Pennsylvania's gas-rich Marcellus shale region, according to new research. In the case of methane, concentrations were six times higher in some drinking water found within one kilometer of drilling operations.
"The bottom line is strong evidence for gas leaking into drinking water in some cases," Robert Jackson, an environmental scientist at Duke University in Durham, N.C., told NBC News. "We think the likeliest explanation is leaky wells," he added. 
Producing natural gas from shale rock formations involves a technique called hydraulic fracturing, or fracking, that shoots several million gallons of water laced with chemicals and sand deep underground to break apart chunks of shale, freeing trapped gas to escape through cracks and fissures into wells.