Hydraulic fracturing is a process of fracturing rock with the help of mixed fluid pressurization to obtain gas from the shale. Shallow wells have limitations of gas production due to low permeability of sedimentary rock containing gas. Hydraulic fracturing facilitates the fluids to flow in the rock and production of gas from the shale (Arthur and Coughlin, 2008).
Water based fluids are the most common fracturing fluid however foam based, oil based, acid based, alcohol based and emulsion based fluids can be used in hydraulic fracturing (Gandossi, 2013). Enormous amount of freshwater is needed in fracturing process and the waste water has to be treated before releasing into the environment. Fracturing processing may increase the risk of drinking water contamination of the adjacent areas. Environmental risks such as methane pollution, air pollution impacts, blowouts due to gas explosion, fracking-induced earthquakes may be associated with hydraulic fracking and production of gas (Hoffman, J., 2012).
Toxic chemicals used during the fracturing process and release of toxic and radioactive chemicals are detrimental to the environment (networkforphl.org, n.d.). Chemicals such as hydrochloric acid, ammonium chloride, ammonium persulfate, isopropanol, formic acid, potassium metaborate, triethanol -amine zirconate, methanol, citric acid, lauryl sulfate, naphthalene are used in the mixed fracturing fluid (fracfocus.org, 2015). Chemicals used in the fracturing process acts as clay stabilizer, breaker, biocide, cross- linker, friction reducer, gelling agent, iron control, pH adjusting agent, scale inhibitor and surfactant (fracfocus.org, 2015). Shales containing organic acids, volatile organic compounds, trace elements such as mercury, lead and arsenic and radioactive elements such as radium, thorium and uranium can be released into the environment (networkforphl.org, n.d.).
Arthur, J.D. and Coughlin, B.J. (2008) Evaluating the Environmental Implications of Hydraulic Fracturing in Shale Gas Reservoirs [Online] Available at http://www.all-llc.com [Accessed on 23 February 2015].
FracFocus (2015) What Chemicals are Used [Online] Available at http://www.fracfocus.org [Accessed on 23 February 2015].
Gandossi, L. (2013) An Overview of Hydraulic Fracturing and other Formation Stimulation Technologies for Shale Gas Production [Online] Available at http://www.ec.europa.eu [Accessed on 23 February 2015].
Hoffman, J. (2012) Potential Health and Environmental Effects of Hydro fracturing in the Williston Basin, Montana [Online] Available at http://www.carleton.edu [Accessed on 23 February 2015].
Network for Public Health Law (n.d.) Environmental Impacts Associated with Hydraulic Fracturing Available at http://www.networkforphl.org [Accessed on 23 February 2015].