A study led by environmental researchers at The University of Texas at Arlington suggests a disconnect between the perception of groundwater contamination and the extent to which that contamination is attributable to oil and natural gas extraction.

Members of the Collaborative Laboratories for Environmental Analysis and Remediation (CLEAR) at UTA found that samples from only five of 36 private water wells showed any potential indications of contamination from unconventional oil and gas development, a multifaceted process that includes hydraulic fracturing. The samples were collected from the Barnett, Eagle Ford, Haynesville and Marcellus Shale regions in response to anecdotal claims of oil- and gas-related contamination.

The study, "Characterizing anecdotal claims of groundwater contamination in shale energy basins," appears in the journal Science of the Total Environment.

Kevin Schug, Shimadzu Distinguished Professor of Analytical Chemistry and co-founder and director of CLEAR, led the study along with CLEAR co-founder Zacariah Hildenbrand. Other authors were Doug Carlton, CLEAR project manager; Paige Wicker, a graduate research assistant in the CLEAR lab; Sabrina Habib, an assistant professor at the University of South Carolina; and Paula Stigler-Granados, an assistant professor at Texas State University.

"We found that the water quality data very rarely aligned with the perceptions that the well owners had of their individual situations," Schug said. "This disconnect between perception and reality is possibly attributed to prevailing negative sentiments toward hydraulic fracturing as well as myriad environmental factors that make point source attribution very challenging."

The team suggests that as hydraulic fracturing and unconventional oil and gas development continue to expand, collaborations with concerned citizens who are trained to collect reliable measurements may be beneficial.

"These measurements could help guide scientists through larger datasets in larger study areas than what is presented in this study," Schug said. "Conversely, scientists should provide unbiased knowledge to communities to help decision-making that is based on scientific evidence, offering benefits and possible risks of hydraulic fracturing in a clear and transparent manner."

Hildenbrand said the recent CLEAR study provides vital findings for better understanding the environmental implications of shale energy extraction.

"This is a seminal piece of research where anecdotal claims of contamination were examined exclusively," he said. "With these findings, we now have a hierarchical method for examining the presence of manmade contamination under the most variable of hydrogeological conditions."

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