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M4. TMI states that overburden as well as excess spoil for the N Pit will be regraded into the reclamation west of the pit and placed as fill in the L Pit. Associated updated post -mining topography descriptions and maps were included in the submission. However, as per the discussion with Trapper and the Division (11 May 2018), TMI explained that additional excess spoil from the proposed N Pit will be placed within the Utility Waste Disposal Area (ash pit). As per Rule 2.05.3(6)(b), descriptions, including appropriate maps, prepared according to the standard of 2.10, and cross section drawings, of the proposed disposal site and design of the spoil disposal structures according to 4.09 are required. A map showing location of the disposal area was included with Map M47A in the submittal however, no cross section drawing of the disposal area are provided. A post mining topo series was provided, the M12 series showed cross sections for Nighthawk (N) Pit and Lancaster (L) Pit, and Map M14A provided the various cross section diagrams for N and L pits. 21. Please provide cross section drawings for the excess spoil that will be placed along the Utility Waste area. Trapper Response to Comment 21: Ash pit cross-sections are enclosed as requested. Please note that nowhere in the PR -9 Permit Application did Trapper state that 'Excess Spoil" was to be hauled from N Pit and taken to the Utility Waste Area. Trapper plans on removing 50 to 60% of the N Pit boxcut material with draglines and spoiling the material to the west of the boxcut. This material would be regraded into the existing landscape, similar to historical dragline spoil boxcuts at Trapper. Approximately 40 — 50% of the N Pit box cut material would be hauled with the truck and loader fleet to the Utility Waste Disposal Area (ash dump) south of the N Pit boxcut area to assist with reclamation efforts there. The utility waste currently is filling an area left between the dragline spoils to the south and a natural ridge to the nollh. The additional truck and loader material from N Pit would be hauled to the Ash Dump and used to finish filling the area between the dragline spoils and a natural ridge, and to create a "broader ridge feature" above the utility waste footprint so that the requirement of not having a drainage fall within 50 feet of a Utility Waste Disposal Area can be fulfilled. The material hauled from the boxcut would overlie areas of previous ash disposal and provide fill material that would create positive drainage away from the ash placement area. Trapper has never mentioned hauling this material to the "L" Pit Area as the current distance is 2.6 miles, most of which includes a steep uphill climb with loaded trucks. This haul cycle would not be economically viable for Trapper. 24 December DRMS: Trapper's response is adequate. 22. Please consider and discuss the possibility of utilizing this material to mitigate the pre and post mining elevation difference in L pit cross section E1, 441, 000, rather than creating excess spoil. (See adequacy question 20, below.) Trapper Response to Comment 22: Trapper does not consider the spoil being removed from the N Pit boxcut as "Excess Spoil" but rather additional spoil. On page 3-49 of the Trapper Permit there is a brief discussion concerning Excess Spoil. The second sentence of that discussion states, "Also, boxcut material generated during the permit period is not considered excess spoil (refer to section 3.5.4) and can be used where it occurs to achieve the approximate original contour." Trapper's opinion is that this is exactly what is taking place in that the material is being utilized to create a landform that conforms to AOC, and one that helps create a post mine drainage that reduces the potential of surface water to infiltrate into the Trapper PR9 2"`' Adequacy Prepared by: R. Reilley, LISP, M.S. Page 10 Date: December 2018