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r~ ~J MINE SITE EVALUATION INSPECTION REPORT PAGE 7 Blue Ribbon Mine Road cut slopes may pose a stability problem along the haulroad. The permit application stated that the cut slopes do not have a safety fac- tor of at least 1.5. According to the MLRD regulations, slopes steeper than 1v:1.5h in unconsolidated material or 1v:0.25h in rock may be authorized if a geotechnical analysis demonstrates that a safety factor less than 1.5 will not result in significant environmental harm or harm to the public health and safety. A stability analysis performed by Rocky Mountain Geotechnical, dated 5/26/82, indicated that a moderate to very stable condition exists where excavations penetrate 13 feet or less of coLluvial soil measured perpendicular to the slope face. Some sloughing of the cut bank material was evident during the inspection, and should be monitored especially during freeze-thaw conditions. Surface drainage controls were in the process of being upgraded to con- form to the standards of the new permit. A contractor has .been employed for this purpose, which will include bringing the ponds up to specifica- tions, improving the portal bench grade and diversion network, constructing a drop drain and plunge pool for undisturbed drainage south of the haulroad switchback and just east of pond 4, and construction of evaporation pond at. the scale facility. All aspects of the surface drainage control system were inspected. Ponds 1, 2, 3, and 4 were not discharging. The ponds are not certified to be constructed as designed but will be certified upon completion of the improvements. The portal bench is to be regraded to establish posi- tive drainage to a 10-inch culvert pipeline (still under construction, at the time, at the north end of the bench) and eventually to ponds 2 and 1. Undisturbed drainage from above the road cut bank will be routed to a drop drain at the haulroad switchback and into a plunge pool east of pond 4 and subsequently discharged. A road culvert approximately 100 feet ciownslope of the switchback effectively conveys road drainage to ponds 3 and 2. Drainage from a coal refuse storage area on the west side of the Hubbard Creek access road is routed through a road culvert to pond 4. Topsoil was stockpiled immediately northwest of the portal bench out- slope and on the western edge of the coal refuse storage area. Both stockpiles ~oere relatively small sized. The stockpile near the bench outslope was marked and supported some vegetative growth. A small amount. of construction material, consisting of a few sections of narrow pipe and corrugated sheet metal, was placed on the stockpile pending completion of the 10-inch culvert pipeline on the northern end of the bench. The permittee was advised to remove the material and refrain from disturbing stockpiled topsoil.