A safety director at a Kentucky coal mine has pleaded guilty to a federal charge of rigging dust monitoring in underground mines.

Steve DeMoss pleaded guilty last week in federal court in Owensboro. He was one of nine former supervisors and safety officers at the now-bankrupt Armstrong Coal company in western Kentucky charged with tampering with dust monitoring. The miners were charged in 2018 and 2019.

Dust levels in underground coal mines are regulated to keep miners from working in conditions that can contribute to black lung disease. DeMoss’ Jan. 12 plea agreement said he ordered workers to remove dust sampling equipment before full readings could be taken and he signed incomplete dust sample reports.

DeMoss faces up to a year in prison and a $100,000 fine at his sentencing.

An indictment says the offenses happened at Armstrong’s Parkway and Kronos mines between 2013 and 2015. DeMoss was safety director at both mines. The case originated when a group of miners who were fed up with the dust conditions at the mines hired an attorney in 2014.

Two other men charged in the original indictment, Ron Ivy and Billy Hearld, have pleaded guilty to similar charges.