By Maureen Halsema
Natural gas is one of the cleanest burning fossil fuels, but as it grows in popularity, concerns are expanding about extraction methods and the gas’ inherent volatility. The Appalachian Basin region is home to one of most expansive reserves of natural gas—the Marcellus Shale. This reserve lies over a mile beneath the surface and covers a 54,000 square mile area, encompassing West Virginia, Kentucky, Tennessee, Pennsylvania, New York, and Ohio. The region is believed to contain 50 trillion cubic feet of natural gas, enough to fill the New Orleans Superdome approximately 327,000 times. According to the U.S. Department of Energy, “Natural gas consumption in the United States is expected to increase from about 22 trillion cubic feet in 2006 to 23 trillion cubic feet by 2030.”
Over the last couple of years, several gas leaks across the nation have led to reported incidents. In some cases, explosions result from gas migration caused by mining operations. According to Pennsylvania’s Department of Environmental Protection, “Active underground mining operations can lower groundwater levels, reducing pressure in aquifers occurring above and adjacent to the area of coal extraction. This reduction in pressure can allow gases within the overlying rock layers to migrate into nearby wells.” If these wells are not properly vented, the accumulated methane can lead to explosion, which is what happened in Dimock, Pa., earlier this year. Maintenance of the vast lengths of pipelines that transport the gas is also risky. For instance, on Sept. 14, 2008, a Williams Gas pipeline burst due to external corrosion in Appomattox, Va. The blast shot flames 300 feet in the air, leveled two homes and injured five people. The pipeline that exploded was one of three lines that run from the Gulf of Mexico to New York.
The most commonly employed method of natural gas extraction is called hydraulic fracturing. This process involves injecting a mixture of sand, millions of gallons of water, and an undisclosed chemical cocktail into the gas wells. The pressure of this injection fractures the coal bed seams and forces the release of natural gas. One of the major concerns involved with hydraulic fracturing, is that as of 2005, natural gas companies have been exempted from the Safe Drinking Water Act, which protects the public’s drinking water and dictates what chemicals can legally be injected into the ground. “As the law currently stands, the EPA is not allowed to set conditions for hydraulic fracturing or even require states to have regulations of their own,” said Abrahm Lustgarten in his article, “Natural Gas Politics” published in ProPublica in May. “States often look to the federal agencies for guidance on how to craft environmental rules. And hydraulic fracturing is an especially complicated process that scientists say warrants more study.”