The Patriot-News is reporting on a new study published in the February 2014 Bulletin of the American Association of Petroleum Geologists: "Natural gas, the study shows, is often already in the water before any drilling begins. *** The study *** is based on more than 2,300 gas and water samples collected from 234 gas wells and 67 private groundwater-supply wells, the largest data set of any such study thus far."
Moreover: "Krancer [PA Environmental Protection Secretary] said, 'Many have hastily concluded that the presence of thermogenic methane in shallow groundwater in the vicinity of drilling activities means that the methane contamination is caused by the drilling operations. This study shows that this is not necessarily so.'" (Emphasis is ours.)
Pretty significant findings. You can get a copy of the study here.