The Montana Department of Environmental Quality has partially approved the proposed expansion of the Rosebud Mine, while also partially disapproving acreage where mining could potentially damage groundwater.
DEQ formally issued a surface mining permit for the expansion, which would add 6,746 permitted acres to the existing coal mine. Known as "Area F," the expansion about 12 miles west of Colstrip would yield approximately 70.8 million tons of recoverable coal and extend the operational life of the mine by about eight years, meaning mine operations at Rosebud lasting up to 19 years.
As required by DEQ, mine owner Western Energy posted a reclamation bond of $13.75 million, which covers the first five years of mine development.
The area of disturbance would be approximately 4,260 acres, of which 2,159 acres would be mined. The remainder would be disturbed by highwall reduction, soil storage, scoria pits, haul road construction and other mine-related activities.
In addition, DEQ conducted a highly detailed Cumulative Hydrologic Impact Assessment, which identified the possibility that mining near the northwestern border of the project could impact groundwater outside the proposed permit boundary. The CHIA is part of the Record of Decision/Written Findings document on which DEQ based its decision to permit the expansion.
Because of the potential risk to groundwater, DEQ partially disapproved permitting of 74 acres (2.2 million tons of coal reserves) of the proposed expansion. If the mine operator demonstrates through additional studies that mining of all, or part of, the 74-acre area could be accomplished without damaging groundwater, DEQ could permit future coal mining in this area.
For more information, visit http://deq.mt.gov/Public/ea/coal.
