PITTSBURGH — A new study being done by the Department of Energy may provide some of the first solid answers to a controversial question: Can gas drilling fluids migrate and pose a threat to drinking water?

A drilling company in southwestern Pennsylvania is giving researchers access to a commercial drilling site, said Richard Hammack, a spokesman for the National Energy Technology Laboratory in Pittsburgh.

The firm let scientists conduct baseline tests, allowed tracing elements to be added to hydraulic fracturing fluids and agreed to allow follow-up monitoring. That should let scientists see whether the drilling fluids move upwards or sideways from the Marcellus Shale, which is 8,100 feet deep at that spot.

“It’s like the perfect laboratory,” Hammack said.

Hammack said he believes this is the first time such research has been done on a commercial gas well.

“Conceptually, it sounds like a really great idea,” said P. Lee Ferguson, a Duke University civil and environmental engineering professor who is not involved with the project. “I have wondered about this since I started thinking about fracking. Which compounds are mobile and which aren’t?”

Environmentalists have claimed the fluids associated with drilling could rise and pollute shallow drinking water aquifers. The industry and many government officials say the practice is safe when done properly, but there have also been cases where faulty wells did cause pollution.

Ferguson cautioned that no single study will answer all questions about fracking and the potential for pollution. “The complicating factor is some of the compounds don’t act in the same way underground,” he said of fracking fluids.

Hammack said the study is designed to see whether the fracking fluids or naturally occurring salty brine reach a testing area located at about 4,000 feet.