‘Fracking’ linked to higher methane concentrations in ground water

National Geographic : A study by Robert Jackson, of Duke University, and colleagues, has found evidence that methane has escaped into ground and drinking water in areas where shale gas drilling was under way. Shale gas is extracted via hydraulic fracturing, or “fracking"; water is pumped into rock deep underground until the resulting pressure causes the rock to crack, which in turn releases the natural gas within. The researchers found methane in the majority of water wells they sampled. They analyzed methane concentrations in 60 ground-water wells across Pennsylvania and New York and found explosive concentrations of the gas as far away as 3200 feet from an active drilling site. Average methane concentrations in wells near drilling sites were 17 times those in wells where shale gas drilling had not occurred. Methane isn’t regulated in drinking water because it doesn’t alter color, taste, or odor, nor does it affect water’s potability. However, it is an asphyxiation and explosion hazard in confined spaces.