State officials are saying drugs are affecting workers in what can be a dangerous line of work.
A new law is making miners take random drug tests but some are going back to work soon after they fail the test.
"If the person is under the influence at all, it could certainly be for a hazardous situation," says Premier Elkhorn Coal Safety Manager Dave Wilder.
If an employee fails a drug test, they're suspended and managers submit them to Office of Mine Safety and Licensing for review where they could potentially lose their miners certification. State officials say they've suspended 125 miners across the state since July, but at least 50 have already been allowed to return to coal mining.
"Where we can, we certainly want to give people chances to come back," says Susan Bush, Commissioner for Department of Natural Resources. "As long as they remain drug free."
Wilder says he still has concerns over bringing these people back.
Some safety managers worry not enough is done to make sure the miners really are drug free, but state officials stand by their decisions.
"They hadn't flunked a drug test prior," says Bush. "These guys have been described as good employees."
State officials say they're not investigating a miner's past, they're checking his current condition. Bush says those who got their certificates back are on probation for a year and could still lose their license for good if they fail another drug test, but coal managers still worry what could happen in the meantime.
State officials say they do tell other states' officials when a miner is suspended for drugs so they cannot get a job in a neighboring state.