A study of drinking water in Appalachian Ohio found no evidence of natural gas contamination from recent oil and gas drilling.
Geologists with the University of Cincinnati examined drinking water in Carroll, Stark and Harrison counties, a rural region in northeast Ohio where many residents rely on water from private underground wells.
The time-series study was the first of its kind in Ohio to examine methane in groundwater in relation to natural gas drilling.
“Some people had elevated concentrations of methane in their groundwater, but the isotopic composition showed it wasn’t from natural gas” said Amy Townsend-Small, associate professor of geology in UC’s McMicken College of Arts and Sciences.
They found no increase in methane concentration or composition in groundwater over the four years of the study, despite the presence of new shale gas wells drilled in the study area.
But researchers found no relationship between the methane observed in drinking water and the new gas wells.
Lead author and UC graduate Claire Botner said the study solicited participation by homeowners who were willing to let researchers test their wells.
Researchers hypothesized that methane concentrations in the drinking-water wells they sampled would increase over time with the growth of natural gas drilling in the area.
The study concluded that methane observed in groundwater was “biogenic,” or naturally occurring and independent of natural gas drilling.
Wirkner said gas companies test the drinking water of nearby homes before and after they drill a well to observe any changes in water quality.