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• -5- <br />entries. An interceptor drain will be provided near the spoil toe to collect <br />any seepage and surface runoff. Surface drainage within the pit will be <br />directed toward the west, to a sump where water collected could be removed by <br />pumping. Access roads into and out of the pit will be provided near the east <br />and west ends of the pit. Coal removed from the underground mine initially <br />will be trucked out of the pit. <br />FIELD INVESTIGATIONS <br />Our field investigation was concentrated on exploring subsurface condi- <br />tions near the toe and crest of the existing spoil slope and determining bed- <br />ding and joint patterns in the highwall. Shallow bac:khoe test pits were ex- <br />cavated to observe subsurface conditions within the spoil. Our geologist <br />• mapped the stratification and bedding and joint patterns of the rock exposed <br />in the highwall. Subsurface information was supplemented by logs of a core <br />hole drilled north of the existing highwall (designated 82 -74C). <br />Highwall Conditions <br />Lithographic conditions were observed along the entire 1,700± feet <br />of exposed highwall and logged in detail at five pit stations. The pre- <br />sent height of the wall varies from about 50 feet near Sta. 0 +00 to <br />about 65 feet near Sta. 16 +00. Stratigraphy generally consists of hard <br />sandstone with interbedded layers of softer shales. The sandstone appears <br />to be resistant to weathering while the shale exhibits varying degrees <br />of slakeability. Most of the soils above bedrock have been removed in <br />the area of the exposed highwall. <br />