In Pennsylvania, the closer you live to a well used to hydraulically fracture underground shale for natural gas, the more likely it is that your drinking water is contaminated with methane. This conclusion, in a study published in the Proceedings of the National Academy of Sciences USA in July, is a first step in determining whether fracking in the Marcellus Shale underlying much of Pennsylvania is responsible for tainted drinking water in that region.For relevant background, see my 2011 post on fracking (with videos "My water's on fire tonight" and a trailer for "Gasland.")
Robert Jackson, a chemical engineer at Duke University, found methane in 115 of 141 shallow, residential drinking-water wells. The methane concentration in homes less than one mile from a fracking well was six times higher than the concentration in homes farther away. Isotopes and traces of ethane in the methane indicated that the gas was not created by microorganisms living in groundwater but by heat and pressure thousands of feet down in the Marcellus Shale, which is where companies fracture rock to release gas that rises up a well shaft.
From Scientific American, via Reddit.