"Fracking Can Contaminate Drinking Water"

               The demand for natural gas has been increasing in recent years due to its versatility as an energy source, its availability, and its ease of transport. Natural gas is used in heating, steam production, and thermoelectric power production all over the world, currently producing 21% of electricity in the United States. The natural gas reservoirs can hold large quantities, making it widely available -- one of the largest reserves in the U.S., the Marcellus Shale, holds recoverable gas quantities nearing 500 trillion cubic feet. Natural gas reserves are found all over the United States, so it is easily transported, Additionally, demand for natural gas has increased due to its efficient combustion, making it a "greener" alternative to other fossil fuels (1).  

               With increasing demand for natural gas comes increasing concern for the safety of drinking water near extraction sites. Shale gas is a type of natural gas that is found trapped underneath shale formations. In order to extract the gas, wells must be drilled down into the shale where fluid is injected to increase pressure and produce fissures in the formation. The gas and flowback fluid are forced up the surface where they can be collected. This process is called Hydraulic Fracturing. The concern for the safety of this process comes from the fact that shale formations and ground water sources can be linked together by fissures in the shale, allowing the fracking liquid to contaminate drinking water. Additionally, there is some concern that flowback fluid is not properly disposed of at the surface and can be released back into the environment (1).

                Fracking fluid is a mixture of water, various proppants (to hold open the fissures), antimicrobials, friction reducers, and scale inhibitors. Common constituents of fracking fluid include: sand, resins, ceramics, metals (1), salt solutions, diesel fuel, methanol, ethanol, and CO2 foam (3). Only about 10-40% of the fracking fluid returns to the surface (1), meaning that much of this fluid is left in the ground and can leech into natural fissures and potentially contaminate ground water. You can imagine the negative health effects that consuming these chemicals consistently may have on a population. For example, consumption of methanol can cause permanent nerve damage and blindness (2).

             A paper published in Environmental Science & Technology (2016) by Dominic DiGiulio was research on possible fracking fluid contamination in Pavillion, Wyoming. The introduction of this paper describes the means by which groundwater is protected from contamination by oil and gas extraction: anything that provides water to the public for drinking is labeled as an Underground Source for Drinking Water (USDW) and is not to be contaminated. However, the Energy Policy Act of 2015 exempted hydraulic fracturing from this, under the logic that "dilution, adsorption, and biodegradation" returns these chemicals to safe levels before reaching domestic wells. The Pavillion, Wyoming natural gas field sits on top of a USDW called the Wind River Formation. The EPA conducted an investigation of the area when residents complained about a foul taste and odor coming from their water. They installed two monitoring wells and sampled two domestic wells and analyzed them for major ions, organic compounds, and methanol. They also examined the integrity of the production wells and casings. The EPA concluded that the water contained “inorganic and organic anomalies" and had "anomalous potassium, chloride, and sulfide concentrations" in production wells. DiGiulio attributes the contamination to leakage of fracking fluid into the Wind River Formation via fractures, casing failure, and leakage from unlined pits designed to hold diesel fuel, mud, and flowback from hydraulic fracturing. In addition to the inadvertent contamination of the aquifer, they found that fracking fluid had been injected directly into the Wind River Formation (3).  
            DiGiulio's research was covered in a Scientific American (2016) article titled “Fracking Can Contaminate Drinking Water”  by Gayathri Vaidyanathan. Vaidyanathan's interview of DiGiulio reveals that the EPA's draft report did indeed suggest that the groundwater in Pavillion contained diesel, benzene, and other chemicals, but the final report from this investigation was never actually published. Pushback from the gas and oil industry about their methods caused them to retest the wells and develop a gas chromatography-flame-ionization-based method to detect methanol, which would be more indicative of fracking fluid contamination. They then handed the investigation over to the state and never published the results of the methanol testing. After retiring from the EPA, DiGiulio took it upon himself to publish the final report after submitting a Freedom of Information Act request and obtaining public data. Even though DiGiulio's results strongly suggest fracking is contaminating the water supply, the report from Wyoming state regulators concluded that the contamination of Pavillion was not related to fracking and that the water is safe for consumption. Vaidyanathan claims that this reluctance to admit concern about the safety of the process of hydraulic fracturing is due to the promotion of natural gas by the Obama administration (2)

Overall, I would rate Vaidyanathan's article 9/10. The Scientific American article accurately represented DiGiulio's research conclusions, and went deeper into the issue than just regurgitating the paper. Vaidyanathan provided the important political context of hydraulic fracturing through interviews with DiGiulio and spokespeople from the EPA, the Wyoming Department of Environmental Quality, and the oil and gas industry. Including this additional perspective helps the reader understand how the contamination was allowed to occur and why more has not been done about it. Because Scientific American is a "science" magazine geared toward readers who may have a scientific background or a science interest, I think their authors do a better job of relaying information from a scientific journal. Their readers would probably be more critical of inaccuracies. The article was also not overly dramatic: other news sources, like the Huffington Post or Yahoo,  might have used more fear tactics or dramatics to gain readership. However, I do think the science aspect of the issue was a little lacking as there were no figures from DiGiulio's research represented nor was there a lot of detail about the experimental set up, I think this is in part due to the complexity of the politics surrounding hydraulic fracturing. I think the amount of politics used in this article was appropriate.

1.  Gregory, K. B., Vidic, R. D., & Dzombak, D. A. (2011, June). Water Management Challenges Associated with the Production of Shale Gas by Hydraulic Fracturing. GeoScienceWorld, 7(3). Retrieved from http://elements.geoscienceworld.org/content/7/3/181.full

2. Vaidyanathan, G. (2016, April 4). Fracking Can Contaminate Drinking Water. Scientific American. Retrieved from https://www.scientificamerican.com/article/fracking-can-contaminate-drinking-water/

3. DiGiulio, D. C., & Jackson, R. B. (2016, March 29). Impact to Underground Sources of Drinking Water and Domestic Wells from Production Well Stimulation and Completion Practices in the Pavillion, Wyoming, Field. Environmental Science & Technology, 50(8). Retrieved from http://pubs.acs.org/doi/full/10.1021/acs.est.5b04970