MINOT (AP) - Drilling has started on five Burke County sites in an unminable coal seam to test the idea of storing carbon dioxide underground.

The five wells are in the extreme southeastern corner of the county. The project is being headed by the University of North Dakota's Energy and Environmental Research Center.

"This is going to be a very controlled injection of the CO2 into the coal seam," EERC research director John Harju said. "What we have is one well that will be utilized for the injection, and we have four surrounding wells into that same coal seam to look at the fate of that CO2 upon injection."

Researchers also hope to extract any natural gas or methane from the coal bed.

"We view this as a very significant win-win for everyone," Harju said. "We're looking at the resource potential and the potential extraction of valuable materials in the form of natural gasses, as well as the potential to store CO2 over the long term to fight climate change."

Harju said he hopes to have data from the tests by next spring.

EERC officials say sequestration is one way being studied to reduce the amount of carbon dioxide produced by burning fuel and other activity. Carbon dioxide molecules attach to coal, helping to ensure the CO2 will remain stored, researchers say.

The EERC is conducting the study through the Plains Carbon Dioxide Reduction Partnership, one of seven lead organizations designated by federal Energy Department to investigate carbon capture and sequestration options.