By: Robert Miles, July 2013
Natural gas produced from shale formations, commonly referred to as “shale gas”, has become increasingly important in the energy supply market for the U.S. and worldwide. Obtaining natural gas from shale reserves was not considered economically feasible until recently because of low permeability of the shale rock formations. New developments in hydraulic fracturing technology have led to a boom in domestic shale gas production since massive scale utilization in 2003. The United States has experienced economic benefits via revenue and job creation in predominantly rural areas while simultaneously increasing the energy security of the U.S. by decreasing dependence on foreign oil supplies. However, the resounding question remains: at what cost? In order to realize the implications of this question we first need to understand some basics about the hydraulic fracturing process and the uncertainties that continue to surround the shale gas industry. In this report I will primarily focus on the environmental impacts of hydraulic fracturing and well development, but it is important to realize that direct impacts on the environment can and will extend to affect human health.
Hydraulic fracturing, or “fracking,” is a stimulation process used to extract natural gas, and in some cases oil, from deep shale reserves 5,000-8,000 feet below the ground surface. This process allows energy companies to access previously unavailable energy sources in states that have deep oil and gas reserves. The fracking process involves pumping a mixture of water, chemicals and sand at high pressure into a well, which fractures the surrounding rock formation and props open passages that allow natural gas to freely flow from rock fractures to the production well. Once the well is developed, the carrying fluid can then flow back to the ground surface along with the gas.