Each stage of the fracking operations creates the opportunity for potential drinking water contamination. When mixing freshwater with fracking fluids, spills or chemical transportation accidents can occur. During well injection, the fluid can migrate into aquifers. Once the initial well injection is completed and the flowback period has commenced, holding pits and containment tanks for the produced waters can percolate
61 O’Sullivan, Francis; Paltsev, Sergey. Shale gas production: potential versus actual greenhouse gas emissions. Environmental Research Letters. Nov 2012. Can be accessed at
(http://iopscience.iop.org/1748‐9326/7/4/044030/pdf/1748‐9326_7_4_044030.pdf). Page 4. 62 Osborn, page 8175; Howarth , page 2011.
into subsurface water sources. During treatment of the residual fluids, incomplete treatment and wastewater transportation accidents could unintentionally taint water supplies.63 Because of the intimate relationship between fracking operations and water, much of the literature focuses on establishing concrete causal relationships between the density of fracking operations in an area and the deterioration of water quality in that area.
Sally Entrekin, Michelle Evans-White, Brent Johnson, and Elisabeth Hagenbuch’s work looks at the different stages of fracking and the potential for water contamination at each stage of the process. This work is especially relevant to the research at hand because the lead researchers are biologists at universities in Arkansas, and their water samples are from the areas of Central Arkansas that will be investigated in later chapters. These researchers stressed that because of the large volume of water needed for fracking operations, which averages approximately three million gallons of water per well,
withdrawal rates from local water supplies contribute to water shortages and droughts and reduction of streamflow. This is especially troublesome in rural areas where both gas drilling operations and agriculture coexist.64 Regulation of withdrawals is left to the states, and currently there is a dearth of literature comparing state-to-state policies on withdrawal permits and how natural gas extraction is prioritized comparable to residential and agricultural withdrawal.
63 EPA 2012, page 9.
64 Entrekin, Sally; Evans‐White, Michelle; Johnson, Brent; Hagenbuch. Elisabeth; Rapid Expansion of Natural Gas Development Poses a Threat to Surface Waters. Frontiers in Ecology & the
These researchers additionally used spatial analysis to determine that, while these well sites are typically constructed more than 100 kilometers from public drinking water supplies, that the wastewater from these operations can travel long distances and thus can affect distant water supplies. Their results found a strong positive correlation between turbidity65 and well-density in a given area. The NYSDEC draft report identified turbidity as one of the most prevalent effects of fracking on groundwater supplies, and this
suspension of solids can lead to eutrophication and affect aquatic life. However, the report also found that “the majority of these situations correct themselves in a short time.66 The United States Geological Survey conducted a sample of water sources in the same area as Entrekin et al’s research, covering Van Buren and Faulkner Counties of Central Arkansas, but their research focused on groundwater sources. Their study found that “no regional effects on groundwater are apparent from activities related to gas production in the Fayetteville Shale in north-central Arkansas”, but did acknowledge that their work was conducted relatively early in the process of gas-production.67
The industry continues to maintain that not a single instance of groundwater contamination has occurred as the result of fracking operations.68 However, an EPA study of water wells in Pavillion, Wyoming provides a compelling case against the industry’s claims. In their two year long study, the EPA found an increase in detectable
concentrations of benzene, xylene, diesel, and hydrocarbons near open pits that hold 65 The EPA defines turbidity as an “expression of the optical property that causes light to be scattered and absorbed by particles and molecules rather than transmitted in straight lines through a water sample”, caused by “suspended matter or impurities that interfere with the clarity of the water”. 66 NYSDEC 2011, 6‐40 67 United States Geological Survey (USGS). Shallow Groundwater Quality and Geochemistry In the Fayetteville shale Gas‐Production Area, North‐Central Arkansas, 2011. Can be accessed at (http://pubs.usgs.gov/sir/2012/5273/). Page 27. 68 Wiseman, pages 8‐9.
fracking wastewater with increasing concentrations as the study progressed.69 Their research conclusively asserted that fracking operations were responsible for the
contamination of deep sources of groundwater, but that further investigation was needed to determine if these operations opened up pathways for the materials to migrate up into shallower drinking wells.70 Previous to this study, the results of various studies were highly polarized. Whenever studies were released demonstrating a correlation between fracking operations and degraded water quality, the industry could easily punch holes in the lack of baseline data for comparison, or claim that the detected chemicals were naturally produced in the soil or the result of other industrial activities. The results of this case study were able to definitively link the contamination to fracking operations because of the unique chemical signature present that was proven to be used by fracking
operations. These findings provide a scientifically sound rejection of the assertion that fracking fluids left underground could not possibly migrate upwards to drinking water sources because of natural barriers of rock strata underground.
This pivotal case in Pavillion, with such extensive documentation and credibility, is rare. What the USGS report and the Entrekin et al paper share, and many of the
scientists who currently study the effects of fracking on the environment share, is the agreement that baseline testing of communities before fracking operations commence is severely lacking in most areas and that these reports are of the utmost importance in determining the extent of connections between natural gas drilling and the health of public water supplies.
69 EPA 2010, page 24. 70 Ibid 39.