The company, which inserted the news into its quarterly financial report released November 13, said that the Ohio County mine, which extracts from the West Kentucky No. 9 seam, has experienced “significant operating inefficiencies” since July 2013 because of geological conditions in the reserve it has been mining.

“As a result of the ongoing mining difficulties, a final decision was made during the third quarter of 2014 not to continue advancing under the current mine plan, but rather to retreat and mine only in the eastern portion of the reserve,” officials said in the report, adding that, as a result of the change, it opted to accelerate the depreciation of the remaining net book value of the capitalized costs associated with the development of the mine as it has been in production just two years.

Armstrong outlined the net book value of the asset as about $9.2 million (as of September 30, the end of its third quarter), a figure that will continue to be depreciated using the units of production method over the remaining estimated recoverable reserves; it recorded $3 million in additional depreciation from Lewis Creek in the third financial period alone.

The remaining section should be mined out sometime in the first quarter of 2015, the producer said. At that time, the existing portal will be abandoned and all of the employees and equipment will be relocated to other Armstrong mining operations.

Armstrong, which is projecting 9.7 million tons in coal sales next year, is currently developing another underground operation at its Parkway complex in Muhlenberg County. That operation is expected to be producing by midyear and will mine from the healthier No. 8 seam.