My Going Green column this week covers a new study that contains the strongest independent scientific case yet that shale-gas production can contaminate nearby water wells. A team of Duke researchers examined groundwater wells in northeastern Pennsylvania and New York state—the gasland I visited for our recent cover story on shale—and found evidence that methane levels were 17 times higher in wells that were close to shale gas operations. While the study isn’t perfect—the gas industry argues that without baseline data, it’s hard to assign blame to drilling—it raises questions that gas companies need to answer, at the very moment when the federal government is taking a hard look at the shale industry. You can download a PDF of the study here, and find a PDF of a white paper the Duke researchers put together that includes smart recommendations for future research and regulation of shale gas.