2008-05-23_PERMIT FILE - M2008027

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1 10 Permit Application Colorado Division of Reclamation, Mining and Safety placed outside of the active mining activity area and storm water conveyance structures. Following the cessation of mining and site grading the soil will be reapplied as a part of reclamation plans (Exhibit D). (C) Rule: specify the thickness of overburden or quantity of waste rock, if any, to be removed to reach the deposit. The location of any overburden stockpiles or waste rock fills must be shown on Exhibit E - Map. Response: No overburden or waste rock will be generated. A thin layer of topsoil covers bedrock with no or minimal weathered bedrock present. Usable material directly underlies the topsoil layer. While not anticipated, if unsuitable materials are encountered, they will be stockpiled on the northern portion of the affected area adjacent to the topsoil stockpile. The unsuitable materials will be placed back at the toe of the final highwall slope and incorporated into final reclamation plans. (D) Rule: specify the thickness of the deposit to be mined. Response: The maximum thickness of the deposit to be mined is approximately 40 feet. The total vertical relief between the toe and the top of the highwall is 54 feet. (E) Rule: describe the major components of the mining operation such as: roads and access routes, pit, office, shop/maintenance buildings, plant, processing facilities, and any underground openings such as adits or ventilation facilities. These components must be located on Exhibit E - Map. Response: Access to the affected area will be on private Tepee Park Ranch roads. The permit area will be entered directly off of the existing road. No road improvements facilitating access to the permit area are planned as part of this permit. However, the approximately 275 foot section of road proposed to be inside the permit area may have coarse material placed on it and will have two 18-inch nominal diameter culverts installed across the road at the north and south end of the affected area. The culverts will convey bypassed storm water (clear water) around the pit area and convey pit storm water following its retention in a small pond on the southern boundary of the pit. Diverging surface water flow paths above the affected area, effectively routing overland flows away from the pit, and the relatively small disturbance area (0.54 acre) will minimize the quantity of water generated during storm events. A separate permit being prepared for the oil and gas well drilling program documents actions associated with road improvements on the ranch property and public rights of way. The pit dimensions will be approximately 23,750 square feet including the cut face (highwall), pit bottom, topsoil storage area, clear water bypass ditches, and the storm water retention pond (Exhibit E). The highwall will be progressively mined back to a final reclamation grade averaging 1.2:1. A four to six foot wide bench will be constructed halfway up the highwall to break the slope into two 20 to 25 foot subslopes. The mined material will consist of interbedded siltstone, sandstone, and shale beds of the Green River Formation. The formation is relatively flat lying and competent in this location and will support a steep slope. An additional 11,350 square feet adjoining the proposed disturbance area is included in the permit area to include the road immediately adjacent to the pit and previously disturbed surface area above the pit. The additional area will allow for placement of culverts underneath the road and equipment maneuvering space. Tetra Tech April 2008 (May 2008 Application Amendment Page) 8