On December 19, 2013, the Pennsylvania Supreme Court issued a divided opinion that may breathe new life into an ancient environmental law concept: the public trust doctrine. In Robinson Township, Washington County v. Commonwealth of Pennsylvania, __ A.3d __, 2013 WL 6687290 (Penn. Dec. 19, 2013), the state’s high court resolved constitutional challenges to Act 13 of 2012, an amendment to the Pennsylvania Oil and Gas Act. See 58 Pa. C.S. §§ 2301-3504. The Act established a state-wide land use regime to facilitate the state’s burgeoning development of unconventional oil and gas resources in the Marcellus Shale formation. Act 13 preempted local regulation of oil and gas operations and gave power of eminent domain to natural gas corporations. The plurality agreed with local government…