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i/ ~ III IIIIIIIIIIIIIIII n^+~'~r~F~: INSPECTION REPORT 999 / ~' Site: National King Coal Mine, Hesperus, Colorado ` `~' ~ :~ inspected By: Don R. May, P.E., Project Engineer ;.,.,/ ~;.c%;~~ _~ .~ , iL Ins ection Date: Quarter) Ins ection, October 10, 1998 ~ ~~~~~'. ~ ~J ~~ Ponds: The east and west sedimentation ponds and their embankments generally appear in good condition. The west pond is show n in photograph 1. As seen, recent rains have resulted in some storage of water in the pond. The low flow outlet should drain the active portion of the pond in 72 hours. The low flow outlet should be checked (for proper elevation and possible blockage) to assure compliance with the drainage plan and thus proper operation of the pond. Sediment deposited near the entrance to the pond should be removed. Photograph 2 show the overFlow pipe connecting the east pond to the west pond. The elevation of the inlet, relative to the highwater level in the west pond should be confirmed. In addition, the entrance to this pipe should be covered by a screen to prevent blockage by debris. All pipe inlets, outlets and spillways should be periodically cleaned. Drainage Ditches: The east side (below waste pile) and west side drainage channels appear in good general condition. The ditch draining the hillside behind the shop has been cleared since the last inspections and appears in good conditions. The recently installed pipe under the haul road beneath the conveyor belt is also clean and in good working order. The remainder of the yard drainage features appear in good shape. Ditches have been cut down the face of the water rock pile on both sides as required by the recently modifications to the reclamation plans. The north side (left looking up the pile) is a clear water diversion ditch and the south side carries contaminated flow to the west sedimentation pond. In both cases the ditches have not been armored and some erosion is occurring. Due to the rocky nature of the material, erosion has been restricted and does not pose any immediate threat. However, in the long run, these ditches need to be armored with rip rap (or alternative treatment) as stated in the plans. Photographs 3 and 4 show the north and south side ditches, respectively. All drainage features, with the exceptions stated above, have been constructed and are operating as stated in the drainage plan submitted to the Division of Minerals and Geology. Coal Waste Pile: The mine waste rock pile has been reshaped to conform to reclamation plan. The design slope for the pile face is 2.5:1. A survey performed on June 30'" showed that most of the pile was at or below the design slope. The upper'/+ along the entire length is slightly steeper and should be flattened. Refer to the June 30 Inspection Report for details. The design for the finished top of the pile calls for a cross slope from north to south of 2% and a longitudinal slope (along the length of the pile) of 1 % from the back toward the front face. The June 30"' 1998 survey resulted in a cross slope of about 0.8% and