Research Shows Groundwater Quality Changes With Expansion of Hydraulic Fracturing, Horizontal Drilling
New research from The University of Texas at Arlington (UTA) demonstrates that groundwater quality changes alongside the expansion of horizontal drilling and hydraulic fracturing but also suggests that some potentially hazardous effects may dissipate over time.
The new research, published on 26 April in the journal Science of the Total Environment in the article “Temporal Variation in Groundwater Quality in the Permian Basin of Texas, a Region of Increasing Unconventional Oil and Gas Development,” is the first to analyze groundwater quality in the Cline Shale region of West Texas before, during, and after the expansion of hydraulic fracturing and horizontal drilling.
The research team collected and analyzed private water well samples on the eastern shelf of the Permian Basin four times over 13 months to monitor basic water quality, metal ions, organic ions, and other chemicals. They discovered the presence of chlorinated solvents, alcohols, and aromatic compounds exclusively after multiple unconventional oil wells had been activated within 5 km of the sampling sites. Large fluctuations in pH and total organic carbon levels also were detected in addition to a gradual accumulation of bromide.
“These changes and levels are abnormal for typical groundwater quality,” said Kevin Schug, lead author of the study and UTA’s Shimadzu Distinguished Professor of Analytical Chemistry and director of the university’s Collaborative Laboratories for Environmental Analysis and Remediation, or CLEAR lab.
“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 areas of high unconventional drilling may degrade or become diluted within the aquifer over time,” Schug said. “The next step is more research to precisely quantify and understand contamination cycles as well as to understand aquifer resilience to pollutants.”