2010-02-11_REVISION - M2000158 (6)

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EXHIBIT L -- RECLAMATION COSTS The largest area that will be disturbed during the life of this mine is during the construction of the embankment for reservoir C1. The worst case scenario assumes that 50% of the reservoir C1 embankment has been constructed and the overburden has been removed from all of the areas outside of the reservoirs' footprints (and is outside of the floodway). This scenario also assumes that the Division would regrade the embankment rather than constructing the remaining 50% and that all regrading would occur outside of the slurry wall (to preserve the ability to store water in the approved vessels). Since all mining will be conducted at a 3:1 slope, no grading should be necessary inside of the slurry wall. 50% of reservoir embankment to be regraded: 530,000 cubic yards Area to replace topsoil and reseed - approximately 330 acres We request that the Division calculate the reclamation costs associated with this amendment. Reclamation Bond for Slurry Wall We request that the reclamation bond be calculated using the "regulated construction option" as described in the "Guide to Specification Preparation for Slurry Walls and Clay Liners as a Component of a Colorado Mined Land Reclamation Permit," Division of Minerals and Geology, September, 2000. For the areas that have already been disturbed by the mining operation, we request the 20% bonding option. Refer to Exhibit L, for quantities for the reclamation cost estimate. For the areas that have not been mined, we request that bonding for the slurry wall be waived. • The slurry wall specifications and quality control/quality assurance standards are included with this application. • Construction of the slurry wall will be conducted under the approved Temporary Substitute Water Supply Plan that will account for evaporative loss of water exposed in slurry trenches and the consumption of water entrained in the gravel to be surrounded by the slurry wall. • The permittee will conduct in-situ testing prior to exposing groundwater in the pit to demonstrate that the slurry performs up to State Engineer Standards. The above is consistent with the requirements set forth in the "Guide to Specification Preparation for Slurry Walls and Clay Liners as a Component of a Colorado Mined Land Reclamation Permit," Division of Minerals and Geology, September, 2000 on page 13, bullet 3: PERMITTING OPTIONS • There are circumstances where an Applicant proposes to install a slurry wall prior to initial excavation in the pit. This method has the advantage minimizing water inflows and dewatering costs during mining. If an Applicant commits to complete installation of the slurry wall prior to exposing groundwater in the pit, and can demonstrate that the slurry wall performs up [to] the standards established by the State Engineer, bonding for the slurry wall may be waived. AMENDMENT TO PERMIT M-2000-158, PLATTE SAND & GRAVEL, LLC; S& H MINE