2013-03-26_REVISION - M1985026 (3)

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:> dui) /pil 41 L EXHIBIT E — RECLAMATION PLAN Tr, Coo 1/), �-� e 'i ) ,/ci i PROPOSED RECLAMATION PLAN SUMMARY Currently, three separate groundwater fed ponds — 14 acres, 3 acres and 3 acres in size occur within the permit boundary occupying the former mining cells. This plan will dewater the ponds, excavate, moisture condition and compact weathered shale material form the pit floor onto the side slopes to construct a compacted clay liner for each of the ponds. Following dewatering, topsoil shall be stripped from the pond side slopes and bottom and stockpiled for replacement following construction of the clay liners. The ponds have been established for over 10 years over which time significant organic materials have accumulated on the pond bottom and slopes, which will make for excellent growth media (topsoil). COMPACTED CLAY LINER DESIGN AND SPECIFICATION The purpose of this section is to provide design specifications for the pond liner. The objective is to design a compacted clay liner that will prevent groundwater leakage into the pond, at a rate greater than or equal to 0.03 feet / day / feet The source for the compacted clay liner will be the weathered zone of Pierre shale occurring an average of 17 feet below ground surface. Texturally and mineralogically continuous in a lateral direction, the Pierre shale is flat lying in this area (Porter, 1976). The weathered zone is a friable silty clay consisting of illites and small amounts of smectites (Gill et al, 1996). Approximately 91,500 cy of weathered Pierre shale will be required to construct the clay liner for the 3 lakes. This equates to removal of approximately 1 -2 ft from the pit floor areas. Source Material Sampling /Laboratory Analysis A 5- gallon sample of weathered Pierre shale was collected from the upper 3 to 4 feet of the weathered horizon on the pit floor. The shale appeared very consistent with respect to color and texture with that of the weathered shale within the proposed excavation area. Moreover, personal communication with local excavators and drillers confirm the consistency of the Pierre shale throughout eastern Loveland. This consistency is most likely due to the flat Tying nature of the shale in this region. If the source material shows any variability with respect to color, texture, or content from the sampled material, a full suite of geotechnical tests will be performed. RECEIVED MAR 2 9 2013 DIVISION OF RECLAMATION MINING AND SAFETY Challenger Pit M- 198=026 TR -04 T Page 1 of 6 ()W KO --