The Michigan Court of Appeals is scheduled to hear arguments today about a proposal to build a coal-fired plant in Presque Isle County.
Wolverine Power Supply Cooperative want to build the plant in Rogers City.
The Department of Environmental Quality approved a permit for the cooperative back in June of 2011.
Now, a coalition of environmental groups is asking the appeals court to send the matter back the DEQ for further consideration.
The Sierra Club and the Natural Resources Defense Council say the permit does not impose limits on mercury emissions required under federal law.