The EPA announced in March that it will conduct a comprehensive study of hydraulic fracturing, a practice used to extract natural gas from deep within the ground.

Specifically, the agency will be studying the impact of the process, known as fracking, on drinking water, groundwater and human health. The EPA is allocating $1.9 million from the fiscal year 2010 budget and will be requesting additional funds in 2011.

"The study will be conducted through a transparent, peer-reviewed process, with significant stakeholder output," said Paul Anastas, EPA assistant administrator, in a statement.

Fracking is the process of drilling horizontally into deep layers of rock to create fissures, then pouring millions of gallons of chemical-laced water into the rock formations to soften them.

Gas companies can then suck out the gas, compress it, and transport it around the nation. But when the gas comes up, so does a large part of the water-called flowback. It is not only laden with the lubricating chemicals that the gas company added but also elements like radium, which naturally occur in the rock.

Drilling activity has exploded in the Chesapeake Bay watershed because of the Marcellus Shale, a rock formation stretching across New York, Pennsylvania and West Virginia.

Several residents in Dimock, PA, have discovered contaminated water wells. As drilling spreads across Pennsylvania, which has the bulk of the shale, residents are becoming increasingly worried about all the unknowns associated with the process.

This attempt is not the EPA's first to study fracking. In 1997, the U.S. Court of Appeals ordered the agency to regulate fracking chemicals after some families in Alabama sued, alleging drilling had contaminated their drinking water. By the time EPA began studying the issue, Dick Cheney had been elected vice president.

Cheney had been CEO of Halliburton, the energy giant largely credited with inventing the fracking process. By 2004, the EPA declared fracking fluids were not of sufficient concern to regulate, although several agency scientists protested that the study was incomplete.

For information, see "Marcellus Shale: Pipe dreams in Pennsylvania?" (December, 2009). The article is also available as a reprint.