A study organized by a University of Texas at Arlington chemistry professor finds that naturally occurring heavy metals, including arsenic, tend to be present in higher concentrations in water wells that are near natural gas wells in the Barnett Shale. The same study did not find volatile organic compounds generally associated with oil and gas production, such as benzene, in its tests of nearly 100 wells in 13 North Texas counties. Researchers conclude that by some mechanism, ranging from lowering the water table to disturbing accumulated deposits of heavy metals on water wells to spills and accidents, the metals show up more often closer to gas wells.
The authors have also launched a similar study of about 60 water wells in West Texas' Permian Basin region in areas that have not yet experienced hydraulic fracturing, a drilling technique frequently criticized for its potential to contaminate underground water supplies. In that study, researchers will collect water samples before and after fracturing and production, producing a timeline that they believe will prove especially useful in determining how much risk fracturing and the production of oil and gas present to water supplies. The study was recently accepted for publication by the peer-reviewed journal Environmental Science & Technology.
-- Jim Fuquay