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APPENDIX C MINE INFLOW STUDY C-1 NEW ELK MINE During the third quarter of 1989, the New Elk Mine was sealed and access to the mine workings terminated. Mine inflows are flooding the abandoned mine workings. Previous studies and reports suggested an inflow of 177 gallons per minute (gpm) and calculated inflows ranged from 142 to 468 gpm based on measurements taken at Station NEW-4. A number of approximations were made in the calculation of rates of inflow. From mine maps, the dip of the mine floor was determined to be 5%, and the water line crosses approximately 12,000 linear feet of mined areas. The available volume is based on an average extraction of 60 %. The calculations assume that the entire mined azea below the water level measured in NEW-4 is flooded (i.e., no trapped air pockets). Graph C-1.1 Grormdwater Recovery, New Elk Mine, portrays the rise of groundwater in (flooding of) the sealed New Elk Mine. As expected, a trend of lowering inflow rates might be developing. The trend could represent a lower quantity of inflows due to some recharge taking place or reduction of inflows due to hydrostatic pressures at depth. Continued monitoring will provide the information to clarify the phenomena, and permit a more accurate projection of hydrologic consequences. C-2 GOLDEN EAGLE MINE • The 1995 Golden Eagle Mine Inflow Study was performed August 31, 1995. Flows, conductivity, and pH were acquired form seventeen locations in the mine. Most of the flow was derived from entries 3, 4, and 5, 3rd North (#56) and SE-1 TG (#15) (Table C-2.1) Mine inflow is estimated indirectly in this analysis in the following Table C-2.2. Point source inflows are from faults, fractured roof, fractured floor, exploration drill hole, etc. Area wide inflows were observed as drainage from seals to abandoned mine workings; areas of weeping coal faces, roof, or floors; and unsealed mine azeas; etc. Locations of mine inflows are shown on Exhibit 2. HYDRP795.292\12\03-29-96(7:06am) C-1