Much of the focus on hydraulic fracturing (or fracking) for natural gas pertains to potential effects of this technology on water resources, as I discussed in an earlier blog entry.
Yet, the process of fracking, oil and gas production, natural gas processing, natural gas transmission, and natural gas distribution also releases a variety of potentially harmful gases into the atmosphere.
EPA initiated a voluntary program to reduce emissions related to natural gas production, called "Gas STAR." But, in response to a consent decree entered by a court as a result of a lawsuit by environmental groups for EPA's failure to control these emissions under the Clean Air Act, the EPA has proposed new rules to regulate and control air emissions throughout the natural gas extraction and production process.
The natural gas development process causes the release into the atmosphere of a variety of toxic emissions: methane, ethane, volatile organic compounds, n-hexane, benzene, toluene, ethylbenzene, xylene and sulfur dioxide, to name just a few. In fact, much of the emissions are themselves possible fuel sources. In North Dakota, so much gas is produced during oil drilling that gets burned off in flaring operations that, if collected, it could heat 500,000 homes and releases two million tons of carbon dioxide annually - as much as 384,000 cars or a medium-sized coal-fired electrical plant, according to an article in the New York Times.
A General Electric report estimates that worldwide $20 billions of dollars worth of natural gas is wasted through flaring. In addition to flaring, much of the emissions occur during the "flowback" process, where the fracking fluid, groundwater and gas come to the surface before the natural gas is collected for transmission to processing facilities.