EcoWatch: In 2012, journalists began warning of an impending bust in Pennsylvanias fracking boom. Since 2010, experts found, drilling in the Marcellus Shale formation--one of the largest in North America--has seen a 50 percent decline in natural gas production, according to the Philadelphia Daily News. The number of drilling rigs skyrocketed from 20 in 2009 to 120 in 2011, making the state the de facto ground zero for the fracking revolution. Now that number has dropped to 90--though the total number of wells...