A controversial natural gas production technique, which is key to a century of U.S. domestic supply, is causing contamination of drinking water, a report released by the National Academy of Sciences said on Monday.
Scientists from Duke University collected 68 drinking water samples which showed potentially harmful levels of methane in drinking water near drilling sites in Pennsylvania and New York associated with the process of hydraulic-fracturing, or fracking.
"In aquifers overlying the Marcellus and Utica shale formations of northeastern Pennsylvania and upstate New York, we document systematic evidence for methane contamination of drinking water associated with shale gas extraction," the report said.
Fracking involves releasing natural gas trapped in shale formations by blasting a mix of water, sand and chemicals into the rock. It has unlocked reserves that could supply the United States for 100 years, though environmentalists say that ...