Yet Another UTA Study Fails to Link Fracking with Well Water Contamination
Tuesday September 27, 2016
Last week, researchers at University of Texas – Arlington (UTA) published a study claiming to have found abnormalities in well water samples taken from the Eagle Ford shale region in South Texas. While the study authors suggest these abnormalities are indicative of possible contamination from unconventional oil and gas development, the researchers fail to make such a connection.
In fact, the study directly states that the main abnormality in water quality, the ratio of bromide and chloride concentrations, is “unlikely to be attributed to contamination form UD [unconventional development] activities.” Additionally, issues with methodology and misleading the public about the study findings cast serious doubt on the legitimacy of this report.
Methodology
To support their claims, the authors tested for various chemicals and substances in 77 private water wells across five counties within the Eagle Ford Shale. In addition to using an insignificant sample size of only 77 wells – something this same UTA research team received criticism for in the past – the depth of over half of the wells (42) studied was determined by “owner recollection and available documentation”, with the depths of the remaining wells left unknown.
Since the study compared concentrations of compounds found in the water against well depth to determine a possible source, not knowing the depths of 45 percent of the wells sampled undoubtedly interferes with the accuracy of the results.
Authors admit contamination “unlikely to be attributed” to O&G activities
From these samples, the authors categorized the wells into two distinct groups based on the different ratios of chloride and bromide found in each well – one group with normal chloride/bromide levels (Group A), which made up about 86 percent of the wells, and another with abnormal levels (Group B). As the study states:
“An analysis of bromide/chloride ratios revealed two distinct subpopulations: one that appears to fall on a mixing line exhibiting bromide/chloride ratios around 0.0034 (n=66, hereafter Group A), which is close to seawater composition (Davis et al., 1998; Hem,...