|Fig. 1: A visual representation of the process of hydraulic fracking. After drilling deep into the earth, water is injected to crack the rock to allow access to the desired natural gas reserves. (Source: Wikimedia Commons)|
Hydraulic fracturing, or fracking, is the process of extracting natural gas and/or oil through a mixture of drilling and water pressure. As shown in Fig. 1, the drilling breaks apart the rock layers below the earth's surface; this fracture is then injected with a water mixture that further cracks the rock and causes the gas and petroleum to flow more freely from the well. The term fracking originated as the pressure from the drilling process fractures the rock. 
As natural gas is estimated to produce half the amount of carbon dioxide as coal combustion, it has become very popular in today's world - a world that has continued to focus on sustainable technologies and environmental protection, as evidenced by the Paris Agreement. With the shale boom, the US reduced carbon emissions by 3.8% in 2012.  In addition to its environmental benefits, fracking has allowed natural gas to become much less expensive. As companies can now access natural gas that was previously inaccessible, prices have dropped drastically - according to the Energy Information Administration, natural gas has dropped from $5 per million btu in 2014 to around $2 today.  These two factors have made natural gas the fuel of choice.
Fracking technology has existed since the 1940s, but the advanced version in use today did not exist until the 1990s.  With the 1990s, came the invention of the current design of motor drills which allow for an increased extraction of natural gas, as well as the invention of directional drilling (the ability to control the direction of the drill allowing companies to drill multiple wells from one platform). This discovery prompted the shale boom, which has brought the spotlight to rest on natural gas, its reserves, and its uses in the United States and abroad.
Although fracking has been in use in the United States since 1947, it has become increasingly popular in our current decade. Not only is it less expensive than traditional techniques used to capture natural gas and oil, but fracking permits the extraction of oil and gas reserves that were previously inaccessible. It has also decreased the United States' dependence on foreign oil, and has produced numerous jobs in regions where the majority of U.S. fracking occurs like West Virginia, Pennsylvania, and Texas. Finally, it allows for the production of electricity with a drastic reduction of carbon dioxide as compared to the fuel it supplants, coal. 
Hydraulic fracturing is detrimental to the environment for multiple reasons. First, fracking requires a sizable amount of water to complete the process, which must be transported to the fracking site. Not only does this incur increased air pollution from transporting the water by trucking it to and from the site, but also the fracking process uses fresh water, which is highly polluted through the process. In addition, it is believed that carcinogenic chemicals are leaked into underground water, contaminating the drinking water supply. Currently in the United States, some fracking companies refuse to disclose the content of their fracking fluids. While the Safe Drinking Water Act of 1974 attempts to protect drinking water, the EPA has interpreted this law to not actually apply to diesel fluids, absolving companies of the need to disclose their potentially harmful fracking fluids.  In addition, the stress caused from the drilling process has caused small Earth tremors and is predicted to cause earthquakes in the future. Critics claim that pursuing natural gas and the fracking process is distracting energy companies, who should be focusing on forms of renewable energy (e.g. solar or wind). They state that natural gas is not the answer to the national and global energy crisis, and thus should not be center stage.
The high-profile environmental problems, like unexpected and frequent earthquakes and the contamination of drinking water, has spurred the fracking ban trend. Two American states, Vermont and New York, have issued complete bans on hydraulic fracturing.  This highlights a potential trend to ban fracking due to concerns over these health risks and environmental impacts. A continuing increase in fracking may cause additional focus on these issues, which has the potential to result in additional states or the federal government issuing a ban.
© Mary Caballero. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
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