A first-ever scientific study conducted by the U.S. Geological Survey concludes that oil and gas development in the Williston Basin has not impacted groundwater quality.
“It’s great news that we found nothing of concern, but it doesn’t answer all the questions,” said Joel Galloway, chief of hydrologic studies in the USGS Bismarck office.
For example, he noted that the study examined the Fort Union aquifer in North Dakota and Montana only, the most used groundwater source in the region.
The study—a collaborative effort between the USGS North Dakota, Montana and Colorado offices—included the Bakken and Three Forks formations. It compared concentrations of several chemicals to health-based drinking water standards, analyzed correlations between concentrations and evaluated methane for indications of deep production-zone gases.
Based on carbon-14 dating, most of the sampled water was more than 1,000 years old. Galloway said the measurements revealed that all water was older than the 1950s when oil drilling began while the oldest went back more than 30,000 years. If contaminants were present in the groundwater, they wouldn’t have moved far from their source.
Galloway noted that the USGS is conducting another study focused on glacial aquifers, although the results won't be released for some time. He said other state and federal agencies, such as the North Dakota Department of Health, are also involved in monitoring groundwater quality.