Anadarko Petroleum drills for deep shale gas in Noble County, Ohio, where natural gas development is getting underway. The readily apparent and well-documented benefits of the surge in fuel supplies, though, are pitched on the slippery rocks of watery risks. Developers bring the gas to the surface by pumping, at ultra-high pressure, a 4-million to 6-million-gallon mixture of sand, water, and chemicals into each well to fracture the rock and release the fuel. In neighboring Pennsylvania, the state Department of Environmental Protection determined that drilling new wells in the Marcellus shale damaged the water supplies of at least 161 Pennsylvania homes, farms, churches and businesses between 2008 and the fall of 2012.