Hugh Pickens writes "The Christian Science Monitor reports that a U.S. Energy Department advisory panel has endorsed fracking, or hydraulic fracturing, a promising technology that injects a mixture of water, sand, and chemicals underground to fracture rock and release shale gas previously thought unretrievable, paving the way for tens of thousands of new wells. If fracking can be done safely, it could be a major source of domestic energy over the next century. Shale gas makes up about 14 percent of the U.S. natural gas supply today, but is expected to reach 45 percent by 2035. But first, serious environmental concerns must be addressed. Earlier this year, a Duke University study of 68 private groundwater wells in Pennsylvania and New York state found evidence that shale-gas extraction has caused them to become contaminated with methane. One key recommendation by the panel is a call for transparency regarding the use of chemicals in the extraction process. Drillers say they would like to keep the exact formula of the chemicals they use secret because it represents a competitive advantage."