CHEYENNE, Wyo. (AP) — An environmental review panel is sending plans for Wyoming's first major new coal mine in years back for more work.

The Wyoming Environmental Quality Council voted 4-1 Tuesday against moving ahead with a state permit for the proposed Brook Mine.

Lexington, Kentucky-based Ramaco wants to open the mine near Sheridan in northern Wyoming to supply coal for research into carbon-based materials.

Wyoming is the top coal-producing state but Ramaco's idea is a new approach. The vast majority of Wyoming coal is burned in power plants.

The Wyoming Department of Environmental Quality has deemed Ramaco's mine permit application complete. Council members have several concerns including that the mine could leave people nearby without well water after lowering the water table.

Ramaco attorney Jeffrey Pope declined comment.