2009-06-22_GENERAL DOCUMENTS - C1981033 (2)

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The limited amounts of groundwater present in the B-Seam that were disturbed by mining at the Bear No. 3 Mine will not result in any impact on any naturally occurring springs associated with the B-Seam. Vertical subsidence-induced fractures will not extend into aquifers that supply water to springs associated with the Barren Member; therefore, no impact on these springs is anticipated. No significant depletion of groundwater in the B-Seam is expected to result from mining activities at Bear No. 3. Small amounts of water entered the mine from walls, roof and floor in recently mined areas. These inflows reportedly ceased one to two weeks after the area was mined. The small inflows directly related to mining and the lack of any recorded mine discharges indicated that there was a low potential for significant impact to groundwater resources due to Bear Coal Company's mining activities in the B-Seam. However, due to the increase in B-Seam mining area that resulted from approval of Permit Revision No. 2, it is likely that infiltration into the subsided B-Seam may occur in volumes significant enough to cause discharge into the North Fork of the Gunnison River via the B-Seam contact. If this occurs, the water is likely to be of degraded quality, especially with respect to dissolved solids. It is not believed that this will have a significant overall impact on water quality in the North Fork of the Gunnison River. Precipitation and snowmelt on the Bear No. 3 Mine facilities area will infiltrate the underlying alluvial material. The North Fork of the Gunnison River is hydrologically connected to the alluvial material. Therefore, groundwater quantity and quality in the alluvial material underlying the Bear No. 3 Mine facilities are closely related to water quality and flow of the adjacent river. Disturbance of the alluvial material is not expected to significantly reduce the quantity of water present in the alluvial material underlying the facilities area. Some degradation of the alluvial aquifer below the Bear No. 3 Mine facilities area is anticipated primarily due to the potential for contaminants to leach from the former coal pad stockpile area. The potential impacts are not considered significant, because adequate dilution of any effluent generated at the Bear No. 3 Mine will mitigate any effects of reduced water quality in the Bear No. 3 Mine facilities area alluvium. In addition, the coal stockpile was removed during reclamation activities at the Bear No. 3 Mine site. 3. Surface Water Effects Mining activities at the Bear No. 3 Mine are not expected to degrade the water quality of the North Fork of the Gunnison River. The disturbed area for the Bear No. 3 Mine is about 8.4 acres in size, and is extremely small in comparison to the entire North Fork of the Gunnison River drainage basin. The small contribution of surface water runoff from the Bear No. 3 Mine disturbed area will be diluted by flow in the North Fork of the Gunnison River. The Bear No. 3 Mine sediment pond rarely discharges, and any effluent is required to meet NPDES discharge standards. The water quality of the North Fork of the Gunnison River is not expected to be impacted by water that infiltrates the alluvium of the Bear No. 3 Mine facilities area. The small contribution to the flow of the river is insignificant. Any water which enters the alluvium will be diluted by groundwater flowing through the alluvium. The 18