Natural gas rush stirs concerns

ALBANY — Advanced drilling techniques that blast millions of gallons of water into 400-million-year-old shale formations a mile underground are opening up “unconventional” gas fields touted as a key to the nation’s energy future.

These deposits, where natural gas is so tightly locked in deep rocks that it’s costly and complicated to extract, include the Barnett shale in Texas, the Fayetteville of Arkansas, and the Haynesville of Louisiana. But the mother lode is the Marcellus shale underlying the Appalachians.

Geologists call the Marcellus a “super giant” gas field. Penn State geoscientist Terry Engelder believes it could supply the natural gas needs of the United States for 14 years.