Amid U.S. gas boom, split over 'fracking'
At the heart of the issue is a drilling technique known as hydraulic fracturing of underground rocks by injecting chemicals and water to release trapped gas.

FRACKING: Natural gas reserves could supply U.S. needs for 110 years, but critics say the industry has moved too fast with little regulation and cite concerns about spills, leaks and contamination from chemicals used in the process. (Photo: Marcellus Protest/Flickr)





















