The federal Mine Safety and Health Administration has released the results of its April impact inspections, and two Kentucky coal mines were among the eight cited. MSHA began conducting impact inspections after last year’s explosion in a West Virginia coal mine, and the agency targets mines with a history of compliance problems.

The two Kentucky mines each received 30 citations—the most issued during the April impact inspections. This was the second impact inspection for Vision Coal’s Mine #2 in Letcher County. Inspectors found that the operator wasn’t following the mine’s roof control plan—a safety measure to protect miners from roof falls. The operator also wasn’t drilling boreholes to test for poisonous gases, like methane. Preliminary reports have suggested that a dangerous accumulation of methane was responsible for the Upper Big Branch explosion in April 2010.

The other mine cited was Leeco Coal’s #68 mine in Perry County.