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~ • • ' Mine 3 Reclamation Plan Premining Topography Premining topography is presented on Map X61, Mine 3 Reclamation Plan ' Premining Contours. This map was included in the Middle Creek Mine Per- mit. Cross-sections comparing premining to postmining topography are in- cluded in this report as Map ~k4, Mine 3 Reclamation Plan - Cross- sections. Also shown on cross-sections B and C is the Middle Creek Mine portal pit prior to the proposed backfilling. t Postmining Topograph The portal pit area of the Middle Creek Mine will be backfilled as pro- ' posed below. Backfilling will prevent access to the portal area by peo- ple, livestock, wildlife, and machinery. Because the portal area will be completely backfilled, no underground mine drainage will enter surface ' waters of the Middle Creek drainage. Likewise, Colorado Yampa Coal Com- pany did not experience any acid or toxic drainage in the past mining operations so none is expected to be encountered following reclamation operations. Map 4F2 is the postmining contour map for the affected areas. The topo- graphy shown for the Middle Creek Mine portal pit area is based on CYCC's ' material balance calculations which are addressed below. The topography shown for the disturbed area south of county road No. 33 and No. 179 represents the actual regrading that has been completed. The contours ' for this area are based on actual survey information. Material to backfill the Middle Creek Mine portal pit will come from three sources. Two temporary overburden stockpiles, one located to the ' north and one located to the west of the portal pit, contain an estimated 986,000 cubic yards of spoil to be used for backfill material, Total fill requirements to achieve the proposed post mining topography in this area ' are estimated to be 1,128,000 cubic yards. The remaining required quan- tity of 142,000 cubic yards will be supplied by dozers pushing east from the county road into the pit. When using a loader/Cruck combination to haul backfill material into the pit, a minimum time of three-hundred and fifty (350) shifts would be re- quired to complete the backfill operation. By operating two loaders two shifts per day, eighteen weeks would be required. This estimate is based on good operating conditions. That is, adverse weather conditions would extend this time requirement. ' A comparison of premining to postmining contours is presented on the cross-sections shown on Map ~k4, Mine 3 Reclamation Plan - Cross-sec- ' tions. ' 1