The process of “hydraulic fracturing,” known as fracking, has come under attack by activists for allegedly contaminating drinking water. And while they’ve been unable to confirm any such instance, they point to Pennsylvania as a likely source because of all the activity surrounding the Marcellus shale reserve. But a new study by the Department of Energy should allay these concerns. According to DOE, after injecting manmade tracers in Pennsylvania’s Greene County, they’ve been unable to find any drilling fluids higher than 5,000 feet underground – far below the depth of a typical drinking well. With other studies showing identical results, it appears this drinking water hype keeps coming up dry.