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Mr~ror Revisroir No. 231 page 3 November S, 1997 Two additional inclinometers were installed; one is located to the south of MB-1 (I- 50) and the other near the Material Storage Bench access road (I-51). The location of these two inclinometers are also shown on the enclosed map. I-50 is 99 feet deep and I-51 is 19 feet deep. Both holes are 4-inches in diameter. Reestablishing the Stacktubes Haul/Access Road on the Enlarged RCC Buttress With the expansion of the RCC buttress below the screening building, the Stacktubes hauVaccess road (between the upper and lower stacktube pads) was narrowed in width. MCC plans to reestablish the road width in the area of the RCC buttress back to a 24-foot wide road. MCC will reestablish approximately 400 feet of the road. Approximately 6,000 CY of subsoil material will be required. The material to be used will originate from the keyway that will be constructed for the Water Tank Topsoil Stockpile (MR#225). The roadway will be surfaced with gravel and approximately 600 feet of guardrail will be installed. In addition, approximately 400 feet of guardrail will be installed on the inside of the road to protect the anchor bolts in the RCC buttress. As MCC will re-establish a previously existing road, the reclamation plan as presented in the permit will not change. Drilling Boreholes in Meadow Above Portals To continue our investigation of groundwater that may be contributing to the slope stability issues of the mine site, MCC proposes to drill a maximum of six boreholes in the area of the meadow above the portals. The locations are shown on the enclosed map. All holes will be located outside the historic record study area. Minor road building in previously undisturbed areas will be required to access holes 1, 2, and 3. Topsoil will be windrowed to the side and will be replaced following drilling. Topsoil will be removed from all six drill pads by pushing it to one side of the pad, but will not be removed from the access to holes 4, 5, and 6 as the drill rig can simply drive across the meadow without significant disturbance. The drill pads will be no larger than 20- feet by 40-feet. The holes will be drilled at a 6-inch diameter. Three of the holes will be approximately ] 00-feet deep and the other three holes will be approximately 150-feet deep. All water and drilling mud will be contained in tanks during drilling and treated in the sedimentation pond. Two of the six holes will be completed by reaming the hole and installing 8-inch PVC casing. The other four holes, if drilled, will be sealed according to Rule 4.07.3. The two cased holes will be reclaimed in the same manner when no longer needed. Topsoil will be replaced and the areas broadcast seeded with MCC's approved seed mix. Depending on the drilling results, the two cased holes may be converted to pumping wells, if needed.