This undated handout frame grab taken from video, provided by the Pennsylvania Department of Environmental Protection shows bubbling due to impaired cementing in an unconventional gas well in ... more 
This undated handout frame grab taken from video, provided by the Pennsylvania Department of Environmental Protection shows bubbling due to impaired cementing in an unconventional gas well in Pennsylvania, In Pennsylvania’s fracking boom, new and more unconventional wells leaked far more than older and traditional wells, according to a study of inspections of more than 41,000 wells drilled. And that means that that methane leaks could be a problem for drilling across the nation, said the author of the study, which funded in part by environmental activist groups and criticized by the energy industry. The study was published Monday by the Proceedings of the National Academy of Sciences. (AP Photo/Pennsylvania Department of Environmental Protection) less 
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Associated Press | Photo By Pennsylvania Department of Environmental Protection
Mon, Jun 30, 2014 2:48 PM EDT