The Maryland company said May 15 that it expected a 14- to 17-day impact on production, but spokesman Rick Nida told International Longwall News the longwall, which is operational and advancing, is running "substantially slower than normal" at the face.

“We are working to improve the stability of the roof in an area with adverse geological conditions," he said.

“We believe that we will be back to normal longwall operations in the near future, but cannot precisely predict the timeline."

Meanwhile, the mine's continuous miner sections continue to run at normal levels.

To date, production has been impacted by about 175,000 tons. Nida told ILN that the company cannot predict the total reduction until it knows more about the timeline that will return the longwall to full production levels.

Until Emerald returns to full production, Foundation said its force majeure on output will remain in effect. Nida noted that its Northern Applachian mines are on target for a year-end production estimate of 14 million tons.

Foundation president Kurt Kost said Wednesday the company was proud of its staff for working "creatively and safely" through the issues and the process to improve roof stability.

Nida confirmed that no significant manpower changes have been required to date.