Shale Gas Drilling

Shale gas drilling involves injecting water, sand, and a cocktail of chemicals at high pressure into rock formations thousands of feet below the surface. This opens existing fractures in the rock and allows gas to rise through the wells. The practice makes drilling possible in areas that 10 to 20 years ago would not have been profitable.

While gas drillers have used this fracturing process for decades, its use has expanded in the past few years as energy companies began exploring shale formations. The process has proven so successful that some experts believe that the U.S. is on the cusp of a shale gas drilling boom. Boosters of shale gas drilling claim it will play a key role in pushing the U.S. towards energy independence.

The major concern with shale gas drilling is the chemicals used in the process. Because the federal Energy Policy Act of 2005 exempted hydraulic fracturing from regulation under the Safe Drinking Water Act, shale gas drillers don’t have to disclose what chemicals they use.

A study conducted by Theo Colburn, PhD, the director of the Endocrine Disruption Exchange in Paonia, Colorado, has so far identified 65 chemicals that are probable components of the injection fluids used by shale gas drillers. These chemicals included benzene, glycol-ethers, toluene, 2-(2-methoxyethoxy) ethanol, and nonylphenols. All of these chemicals have been linked to health disorders when human exposure is too high.

Concerns are growing that many of the chemicals used in shale gas drilling are seeping into groundwater. While some of the injection fluid used in the process comes back to the surface, 30 to 40 percent is never recovered, according to the industries own estimates.

People living in the vicinity of shale gas drilling have reported foul smells in their tap water. In some instances gas well pipes have broken, resulting in leakage of contaminants into the surrounding ground. There have also been cases of improper disposal of potentially toxic wastewater from a fracturing operation. In addition, the process of drilling a well has on at least one occasion disrupted a layer of limestone containing methane, which subsequently escaped. The rapidly expanding development of shale gas reservoirs has left regulatory agencies and legislatures scrambling to keep up with the new environmental issues raised by the operations.