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HomeMy WebLinkAbout1.06 Mining planDivision of Reclamation Mining & Safety Permit Application RTZ INDUSTRIAL SAND & GRAVEL MINING OPERATION GARFIELD COUNTY, COLORADO 6.4.1 Mining Plan Overview The RTZ Industrial wishes to include 136.558 acres in the permit boundary, of which approximately 40.7 acres will be mined. Accessary facilities, such as an office, are incorporated into this Mining Plan (see Exhibit 8). The reclamation of the property will be done concurrently with mining as reining progresses generally north and west. For planning purposes, the market for construction materials from the proposed resource is 150,000 tons per year. Description of Overburden, Deposit and Underlying Stratum Topsoil on the proposed reclamation permit site is highly variable, consisting of six feet of soil in some reaches of the site up to twelve feet of topsoil cover in other locations. The alluvial deposit consists of sand and natural gravel, as well as larger unconsolidated stone material and sand and gravel with traces of shale. Other than topsoil the site is level with only overburden covering the deposit. Phase I — 14.7 Acres Phase II — 9.5 Acres. Phase III —16.5 Acres Mininp, Methods The proposed method of mining is surface extraction, typical of shallow alluvial deposits. Due to the presence of groundwater in the deposit, dewatering, as detailed below, is indicated to facilitate the efficient recovery of sand and gravel. Mining will progress in three phases. Prior to commencement of production mining, topsoil will be stripped prior to mining in each phase. Topsoil and overburden will be stored outside the pit area inside the gravel pit boundary. The overburden storage area is located on the southwest portion of the parcel. This portion of the parcel will be used for storage of overburden only and will reduce the amount of transport of overburden. Construction materials will be extracted and moved on -site with excavators, front -end loaders, strippers and off -road haul vehicles. The mining limit for the project will be at least 25 feet from utility easements in the southeast section of the parcel and 50 feet from Division of Reclamation Mining & Safety Permit Application county road and railroad right -of -way. The mining limits of the southern boundary of the parcel will be at least 200 feet from the Colorado River. These setbacks ensure the stability of the structures in the vicinity throughout the period of mining and reclamation. Phased Mining and Processing Phase I commences with topsoil and overburden stripping as needed and moved to the overburden storage location. Mining will be initiated at the southeast corner of the Phase 1 mining area, creating a sump area for dewatering operations. The sump area is intended to retain pumped water for dust control and eventual discharge through outfail 001 and for controlled re- distribution to wetland areas to maintain soil moisture. The direction of mining in Phase 1 will generally move north and west. The processing plant, including screening and crushers to be used during mining in Phase 1 and 2 will be located in the northeast section of Phase 3 mining area as shown on the Mining Plan. (Exhibit 8). Reclamation will begin in areas within Phase 1 within one year of the completion of this phase of mining. Mining in Phase 2 will begin with stripping and stockpiling of topsoil and overburden as needed in Phase 1. The overburden will be used to as reclamation of Phase 1. The mining will start in the southeast corner of the Phase 2 mining area. After the completion of Phase 2 and prior to the mining of Phase 3 the excess overburden and top soil will be removed from Phase 3 and the processing plant, including screening and crushers will be used in Phase 2 for the mining of materials in Phase 3. The mining of Phase 3 will continue with the stripping of topsoil and overburden from Phase 3. The mining will begin in the southeast corner of Phase 3 and move northwest. The Phase 3 is the final section of the pit area to be mined and reclamation will begin within one year of completing mining in this phase. The processing plant will be moved off -site, allowing for the efficient r 1 Mining Slopes The operator will not be limited to mining to approximate reclamation slopes in the event slopes in the event that backfill material is generated in sufficient quanitites to facilitate recovery of construction materials within the cross - section of the slope to the pit bottom. Mining to near - vertical slopes will be permitted where backfill material are available for reasonably contemporaneous placement along mined slopes. Final sculpting of reclamation slopes of 3:112:1, in accordance with Construction Materials Rule 3,1.5(7), may occur at the time of mining or with concurrent reclamation. Earthmoving Operations and Maximum Disturbance Division of Reclamation Mining 6 Safety Permit Application The vegetation and plant growth medium within pit boundary will be cleared and salvaged in the permit boundary. Topsoil, as available, can be used to construct 6 -foot screening berms in determined locations. Standard equipment, including excavators, backhoes, loaders and haul trucks will be used in earthmoving operations at the RTZ Industrial Gravel Pit. Site disturbance will be minimized through the use of phasing plan and the reclamation plan. Dewaterin� The RTZ Gravel Pit will be equipped with pumps to allow for dry- mining. Water impacts associated with dry- mining have been addressed in Exhibit G and the water right decree. The RTZ Gravel Pit will pump water to the detention pond located on the west end of the project for discharge to the existing stream and sample point 041. This will allow for a dry pit arcs and give access to the pit floor. If only partial dewatering is obtained; mining methods will be adapted accordingly. The wet pit run will be removed with a track hoe and set on the pre - mining area for temporary drying and renrovcd with a loader. This two stage mining will be used where groundwater pumping is limited due to on or off -site constraints. Primary and Secondary Commodities The primary commodities to be mined are sand and gravel. These are expected to be used for road bed material and oil and gas pads. There is no secondary commodity. Incidental Products There should be no incidental products expected from this operation Explosives _ Explosives are not planned to be used in this proposed operation. ` � ^ 46 7 1A I - REV mo. DATE RVASION MADE CHKDIAPPDI MINE PLAN RTZ INDUSTRIAL MURE NO.