Drilled
Frack Effects
Research shows that hydraulic fracturing causes sporadic changes in groundwater quality
Fracking and other methods of drilling for oil and gas can have a significant effect on groundwater
Efforts to drill for oil—particularly new technologies like hydraulic fracturing, or "fracking"—come with their share of controversy. New research by scientists at UTA is adding to that conversation, as it has found that fracking and horizontal drilling do cause changes in groundwater quality, but air contamination from hazardous chemicals is likely due to operational inefficiencies, not the process itself.
For the first study, researchers collected and analyzed samples of water from private wells in the Permian Basin over 13 months. They found chlorinated solvents, alcohols, and aromatic compounds present in the water exclusively after multiple experimental oil wells had been activated nearby. The team also detected large fluctuations in pH and total organic carbon levels, as well as a gradual accumulation of bromide.
"These levels and changes are abnormal for typical groundwater quality," says lead author Kevin Schug, the Shimadzu Distinguished Professor of Analytical Chemistry. "But the results also suggest that contamination from unconventional drilling may be variable and sporadic, not systematic, and that some of the toxic compounds associated with high amounts of unconventional drilling may degrade or become diluted within the aquifer over time."
The study, developed in collaboration with the University of North Texas, Baylor University, and sampling firm Inform Environmental LLC, is the first to analyze groundwater quality in the Cline Shale stretch of West Texas before, during, and after the expansion of fracking and horizontal drilling.
In a separate but related study, Dr. Schug and his team investigated the air quality in and around fracking gas drilling sites in the Eagle Ford shale region. Their findings, published in Science of the Total Environment, showed that the highly variable levels of ambient BTEX—benzene, toluene, ethyl benzene, and xylene compounds—present at the sites were the result of operational inefficiencies.
"These variable contamination events—attributable in many cases to specific natural gas flaring units, condensation tanks, compressor units, and hydrogen sulfide scavengers—indicate that mechanical inefficiencies, not the inherent nature of the extraction process as a whole, result in the release of these compounds into the environment," Schug explains.