2014-12-15_PERMIT FILE - M2014043 (2)

Home Browse Search

MINING PLAN EXHIBIT D(CONT) As mining progresses across the property, additional area will be stripped ahead of the mine face and any topsoil encountered will be stockpiled along the east and south sides of Stage 2, for use when reclamation begins . The salvaged topsoil may also be used on areas ready for resoiling or placed in topsoil piles around the mine perimeter for use when reclamation begins in the area where it was removed. Albert Frei & Sons agrees to salvage enough growth medium to resoil the affected lands with a minimum of 8 inches average. Please see MAP EXHIBIT F -RECLAMATION PLAN MAP for the approximate shape of site when reclamation is complete. The material to be mined will be damp so no unusual dust control problems are expected. An estimate of water needs for the mine is outlined in EXHIBIT G -WATER. The actual amounts needed will be addressed when we apply for the Senate Bill 120 Well Permit thru the Office of the State Engineer (OSE) . Most water will be used for dust control on haul roads and the processing site . On a typical operation of this type, 3 to 8 ac-ft per year is used. The SEO requires mine operators to use an amount of 4% by weight with the exported gravel for those area lying below the water table. A processing plant will not discharge anything that would affect the surface or ground water quality except dirty water. This water will be directed to the excavated area in Stage 1 and contained on the mining area. A groundwater Monitoring Plan that addresses potential impacts resulting from the planned slurry walls is provided in the Appendix. The City of Thornton has installed a slurry wall along the west side of the property. This lies west of the Bull Seep/Spring Ditch area and with the mining setback being 38 feet east of the Bull Seep this leaves a 200+ feet wide undisturbed area from the edge of the dig line to the slurry wall . To our knowledge mining can take place within 15 feet of a slurry wall and in most cases this happens where a slurry wall is installed around a gravel mine prior to mining. This common practice in the industry has proven the by leaving a stable insitu gravel slope adjacent to the wall will prevent any damage to said wall . The setback lines on the map are the indication of the mining limits, i .e. , the top of the slope into the mining area. When the setbacks will no longer be disturbed they will be reclaimed as prescribed in the reclamation plan. 10 (Revised 12/15/2014)