Governor Bill Ritter is speaking out against a proposal to store thousands of tons of mercury in Grand Junction.
Ritter said he plans to write a letter to the Department of Energy to lay out his concerns.
He says it's dangerous to transport the poisonous material across highways next to rivers and says the risks to air and ground water are too great.
Earlier this week the Department of Energy held a meeting in Grand Junction to get public input and they are accepting comments until next month.
Grand Junction is one of seven sites being considered for mercury storage.