The question Dr. Kevin Schug set out to answer was refreshingly simple: Does drilling activity in the Barnett Shale contribute to groundwater contamination? There is no shortage of assurances of safety from industry, or claims of mysterious illness from aggrieved landowners and environmental types. So, Schug and a fellow researcher at the University of Texas at Arlington, Dr. Brian Fontenot, decided to let science sort it out in 2011. In a study that is the first of its kind in the Barnett, the researchers tested 100 private water wells in a 13-county area. Some were located at various distances from natural gas wells. Others were completely outside of the Barnett Shale.
|UTA researchers, from left to right, Brian Fontenot and Kevin Schug.|
They analyzed the groundwater for arsenic, heavy metals and compounds commonly found in the concoction of chemicals, fine sand and water blasted thousands of feet beneath the surface at enormous pressures. Many of these contaminants occur naturally in the Barnett Shale. But on average, they were found in high concentrations in the water wells nearest drilling activity. In the study's active drilling-area, arsenic was detected in 29 water wells at levels exceeding federal limits. "It was clear in times where we found really high arsenic levels, you're up close to a wellhead," Schug tells Unfair Park.
Though the study, published last week in the journal Environmental Science & Technology, identified a correlation, Schug is quick to point out that they haven't singled out a mechanism for what could be causing the contamination. It could be a failure in the casing designed to protect groundwater. Mechanical vibrations might be disturbing particles in neglected water well equipment. Perhaps it's the lowering of the water table by the fracking process.
"I think our biggest conclusion is that more work needs to be done," Schug says.More »