THERES] NEVER BEEN ONE CASE—DOCUMENTED CASE—OF GROUNDWATER CONTAMINATION IN THE HISTORY OF THE THOUSANDS AND THOUSANDS OF HYDRAULIC FRACTURING [WELLS] SEN. JAMES INHOFE, R-OKLA., APRIL 2011 The senator is incorrect. In the past two years alone, a series of surface spills, including two blowouts at wells operated by Chesapeake Energy and EOG Resources and a spill of 8000 gallons of fracking fluid at a site in Dimock, Pa., have contaminated groundwater in the Marcellus Shale region. But the idea stressed by fracking critics that deep-injected fluids will migrate into groundwater is mostly false. Basic geology prevents such contamination from starting below ground. A fracture caused by the drilling process would have to extend through the several thousand feet of rock that separate deep shale gas deposits from freshwater aquifers. According to geologist Gary Lash of the State University of New York at Fredonia, the intervening layers of rock have distinct mechanical properties that would prevent the fissures from expanding a mile or more toward the surface. It would be like stacking a dozen bricks on top of each other, he says, and expecting a crack in the bottom brick to extend all the way to the top one. Whats more, the fracking fluid itself, thickened with additives, is too dense to ascend upward through such a channel. EPA officials are closely watching one place for evidence otherwise: tiny Pavillion, Wyo., a remote town of 160 where high levels of chemicals linked to fracking have been found in groundwater supplies. Pavillions aquifer sits several hundred feet above the gas cache, far closer than aquifers atop other gas fields. If the investigation documents the first case of fracking fluid seeping into groundwater directly from gas wells, drillers may be forced to abandon shallow deposits—which wouldnt affect Marcellus wells.
Posted on: Sun, 02 Feb 2014 03:27:25 +0000
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