What Does the Data Actually Tell Us about the Risks Associated with Fracking?

Ask a Scientist - October 2013

Patrick Simon of Oscada, MI, asks "With all the polarized discussion about fracking in the news lately, what does the evidence and data actually tell us about the risks associated with this extraction process for oil and natural gas?" and is answered by Dr. Gretchen Goldman, an analyst with Center for Science and Democracy at the Union of Concerned Scientists.  

Technological advances such as horizontal drilling and hydraulic fracturing (commonly known as “fracking”) have resulted in the rapid expansion of unconventional oil and gas extraction from shale and other tight rock formations that had been previously deemed inaccessible or too costly to tap. While these techniques have been used for several decades to extract oil from shale in Texas and elsewhere, fracking for oil and natural gas has now expanded into some 28 U.S. states, creating new risks in new places. 

One of the risks is the potential for drinking-water contamination. Many fracking sites around the country have operated successfully with no known water contamination issues. But the risk of serious problems is real and borne out by the evidence. We have already seen documented cases of groundwater contamination near oil and gas wells from fracking fluids as well as from gases, including methane and volatile organic compounds. Surface waters also face contamination risks from potential spills and leaks of chemical additives, diesel or other fluids from equipment on site, or leaks of wastewater from facilities for storage, treatment, and disposal. Water quantity issues can also present risks: the large volume of water used in fracking operations has already raised concerns about water availability in some water-scarce regions. 

Water issues may get more attention in the media, but unconventional oil and gas development also poses documented risks from air pollution. Some areas where drilling occurs have experienced increases in concentrations of hazardous air pollutants, particulate matter, and ozone. Air pollutants are emitted during the well completion phase, when most of the water and chemicals flow back from a well, and during onsite processing to separate the fuels from other substances. And some communities have faced significant air pollution from the increased truck traffic carrying water and materials to and from the well site. 

Earthquake risks are also a serious consideration. Oil and gas production using hydraulic fracturing is not generally associated with earthquakes detectable at the surface. Rather, concern about seismic activity stems primarily from the deep injection of wastewater from hydraulic fracturing operations. This wastewater injection has been linked to large earthquakes, such as one earthquake on November 5, 2011 that was felt in 17 states. 

As serious as these particular environmental risks may be, communities must also weigh the socioeconomic impacts of oil and gas development that use fracking, considering effects on the social fabric, crime rates, public services, and community resources. Such impacts are complex and will be different for different localities. If you live in a community considering fracking, it is important to question decision makers and the companies involved on a wide range of issues until you are satisfied with the answers. To help communities ask the right questions, UCS has developed a toolkit for communities faced with decisions around fracking. It draws upon advice and experience from leading experts and community stakeholders who attended a forum about fracking held by the Center for Science and Democracy this summer in Los Angeles, California. 

For even more details on the evidence about risks associated with unconventional oil and gas development, and the challenges communities face in making science-informed decisions about fracking, check out the new UCS report, Toward an Evidence-Base Fracking Debate: Science, Democracy, and Community Right to Know in Unconventional Oil and Gas Development.  

As an analyst for the Scientific Integrity Initiative at the UCS Center for Science and Democracy, Gretchen Goldman researches influences and interference in how science is used in federal government policies. Dr. Goldman holds a Ph.D. and M.S. in Environmental Engineering from the Georgia Institute of Technology and a B.S. in Atmospheric Science from Cornell University.

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