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Pagel 3 <br />west to east. Final reclamation of the processing area in phase 1 will be performed once all mining is <br />complete. <br />10. Comment: Please provide a description of the "slot" mining method proposed during the pre-operational <br />inspection and how the method will protect the cottonwood trees it is intended to protect. <br />Response: The intent of the "slot" mining approach in the areas adjacent to existing cottonwood <br />trees is to limit the length of time that the mine face will be open and acting to draw water out of the <br />soils around the cottonwoods. With this in mind, the applicant has agreed to maintain a 50' buffer <br />from the mine face to the trees and limit the overall width of the blocks as shown on the mine plan <br />map. Mining will start along the boundary and proceed to create a 1.25:1 slope to the bottom of the <br />gravel seam. As soon as space constraints at the bottom of the pit allows, clean fill will be placed and <br />compacted along the mine face to bring the reclaimed slopes to a 3:1 slope and keyed into the pit <br />bottom. The width of the compacted fill will be 10 feet at the top and slope at 3:1 to the bottom of <br />the pit thereby creating a wedge of material more impermeable than the existing sands and gravels <br />that will slow the dewatering effect around the cottonwoods. A typical "slot" mining detail has been <br />added to the Mining Plan Map to graphically depict the above description. <br />11. Comment: Rule 6.4.4(e) states the applicant must provide an approximate timetable to describe the <br />amended mining operation. The timetable is for the purpose of establishing the relationship between <br />mining and reclamation during the different phases of a mining operation. The applicant will not be <br />required to meet specific dates for initiation, or completion of mining in a phase as may be identified in the <br />timetable. <br />Response: The amount of gravel mined per year will depend on the economy and local demand for <br />these resources. Approximately 200,000 tons of gravel has been sold in average years from this pit. <br />Approximately 500,000 tons was sold in the peak year. The following is the anticipated timetable for <br />the amended mining operation, <br />2009-2010 Existing Pit Complete mining & reclamation phase 1 (south of power lines) <br />2010-2011 Expansion Area mining & reclamation of blocks 1 & 2 <br />2011-2012 Expansion Area mining & reclamation of blocks 3 & 4 <br />2011-2013 Expansion Area mining & reclamation of blocks 5 & part of 6 <br />2013-2014 Expansion Area mining & reclamation of blocks part of 6 & 7 <br />2014-2016 Expansion Area mining & reclamation of block 7 <br />2016-2018 Expansion Area mining & reclamation of block 8 <br />2018-2019 Expansion Area mining & reclamation of block 9 <br />2020-2021 Expansion Area mining & reclamation of block 10 <br />2021-2022 Expansion Area mining & reclamation of block 11 <br />2022-2023 Expansion Area mining & reclamation of block 12 <br />2023-2025 Expansion Area mining & reclamation of block 13 <br />2025-2029 Existing Pit mining & reclamation of phase 2 (north of power lines) <br />12. Comment: The applicant intends to install a conveyor structure and private bridge over Trout Creek. Please <br />provide additional information regarding the conveyor structure and private bridge (i.e. composition, <br />length, width, height, foundations, etc.) and a specific plan for reclamation of the structures. In addition, <br />please provide documentation for the legal right to enter the easement associated with the conveyor <br />structure and bridge proposed over Trout Creek. Precision Excavating, Inc. agreed to submit construction <br />details for the proposed bridge and conveyor structure over Trout Creek to the Division prior to <br />construction in a letter dated June 16, 2009. Please address the remaining issues. <br />Response: The bridge and conveyor will each have a span of 70 feet. Both structures will be <br />supported by reinforced concrete abutments. The span will allow a buffer between the abutments <br />and the banks of Trout Creek so no work will be necessary within the creek bed. This approach was <br />discussed with Nathan Green of the U.S. Army Corps of Engineers during a site visit in the spring of <br />2009. Nathan found this approach acceptable to minimize impact to the creek during construction <br />and avoid any permitting requirements through the USAGE. The low chord of both the bridge and <br />conveyor will be set with one foot of freeboard over the ordinary high-water elevation within Trout <br />Creek. The bridge will have a steel substructure, a galvanized metal deck with compacted road base <br />for a driving surface, and 3 foot high sideboards to prevent spill of gravel into the creek. It is