The two mines, which together employ about 1000 workers, plan to develop a new coal preparation refuse site but the state's EPA claims the structure's site will risk the habitat of fish and a rare salamander, according to the Associated Press.
The agency and the state Department of Natural Resources are opposing the company's water quality certification application.
The current coal waste site is nearing capacity, and the EPA has asked Murray Energy to locate a second suitable site.
While the final order can be appealed by the operator, if the decision on the certification stands the operator will be forced to close both mines permanently, the news service said.
A request for comment by International Longwall News from Murray Energy was not returned by press time.
However, the company’s general counsel told the AP that its suggested location is the best option.
Standards of water quality would be upheld at this location, he added, and the operator expects the EPA to weight the employment of the impacted miners with the environmental issues.
About half of Ohio's coal is produced from Century and Ohio Valley, according to various reports.
Approximately 2300 Ohio residents are employed statewide as coal miners.