PARKERSBURG — A trade association and an environmental group are taking opposing positions on a study about groundwater contamination and natural gas development of the Utica Sale.

The West Virginia Oil & Natural Gas Association said the University of Cincinnati study, slated to be published in the June issue of “Environmental Monitoring and Assessment,” is more research showing no impact on groundwater from shale gas development.

However, the sampling in the study was not enough to be accurate, said Cheryl Johncox, an organizer of the Beyond Dirty Fossil Fuels initiative in Ohio, a program of the Sierra Club. The study is “really not something to get excited about,” she said.

“I have to say it’s a very small sample size,” Johncox said.

The study is titled “Monitoring concentration and isotopic composition of methane in ground water in the Utica Shale hydraulic fracturing region of Ohio.” Most of the monitoring took place in Carroll County and the surrounding area, including Stark, Columbiana, Harrison and Belmont counties.

The study began in January 2012, at which time 150 drilling permits had been issued in Ohio, which increased to 1,600 by the end of February 2015, the study said.

Researchers collected 180 samples through February 2015. Of those, 118 were collected from 24 drinking water wells, from two to eight times over the course of the study, in Carroll, Harrison and Stark counties.

Sites were based on landowner interest and participation was voluntary, the study said.

No relationship was found between CHI4 (methane) in ground water and its location to active well sites, the study said.

“Despite the relatively small number of analytes, our data indicate that the dominant source of CH4 (methane) in ground water in the Utica Shale region is biogenic, and that neither the CH4 concentration nor its source change with an increasing number of shale gas wells or with changing distance to shale gas wells,” the study said.

The study was partly financed by groups opposed to natural gas development and found no groundwater contamination from development of the Utica shale, Anne Blankenship, executive director of the West Virginia Oil & Natural Gas Association, said.

“We can add this report to the pile of twenty or more similar studies showing no threat to ground water from shale gas operations,” Blankenship said.

Based on a theory natural gas methane concentration would increase with the increase in shale gas wells, “the results were just the opposite,” she said.