A U.S. Bureau of Land Management office in Wyoming is seeking public input until Jan. 16, 2015, on the modification of a federal coal lease at the Bridger Underground Coal Mine, located about 35 miles northeast of Rock Springs in Sweetwater County.
The BLM intends to prepare an environmental assessment (EA) for the proposed action to modify a federal lease to incorporate about 120 acres adjacent to the existing 8,500-acre Bridger Underground Coal Mine permit boundary. Bridger Coal, a joint venture of PacifiCorp and Idaho Power, has operated the underground coal mine since 2004. The mine feeds coal into the adjacent Jim Bridger power plant, which is co-owned by those same parties.
Public comments will help determine the scope and development of the EA and are most useful when they substantively address specific issues, concerns, ideas or mitigation opportunities, BLM said.
Incidentally, PacifiCorp and Idaho Power plan to cut Bridger Coal production in coming years and take more coal from outside supplier Black Butte Coal. Cindy Crane, President and CEO of PacifiCorp d/b/a Rocky Mountain Power, described that change in heavily-redacted Nov. 14 testimony filed at the Washington Utilities and Transportation Commission.
The underground mine has been unable to maintain two 12-hour shifts, six days per week, due to limited workforce availability. Since its inception early last decade, the underground mine has experienced high turnover rates as underground miners have gained experience and pursued jobs in the trona industry in Southwest Wyoming.
Due to the workforce shortages, Crane added, the mine has been unable to sustain continuous miner development, which is essential to keep from idling the longwall system. The updated production rate allows the underground mine to balance advancement of the longwall system and continuous miner development; the steady rate of longwall production minimizes idling of the longwall and roof stability concerns.
Also in the future, the heat content of Bridger Coal deliveries decreases from 9,301 to 9,153 Btu/lb due to increased ash content of the underground mine. The geological modeling in a July 2014 plan was updated to reflect actual mining conditions in areas where the coal seam height is less than 10 feet. Since the longwall is not capable of mining below 10 feet without cutting the floor or roof, the ash content was increased by approximately 2% in these areas, which contributed to a lower Btu content of coal produced from the underground mine.