The study, conducted by the University of Texas at Arlington, found contamination is found more often and in greater amounts in water wells close to natural gas drilling operations, while wells further away from drilling sites have little-to-no contamination, The Dallas Morning News reported.
Researchers said they could not pinpoint the cause of the contamination, but they have ruled out fluids from the process of hydraulic fracturing, or fracking. Other possible causes researchers cited include soil disturbance from gas drilling, failures of casings meant to keep gas and production fluids out of aquifers, and surface-level mismanagement of gas drilling wastes.
The results of the study do not prove hydraulic fracturing routinely or systematically contaminates water wells, the researchers said.
Notable deaths of 2014 [PHOTOS]