2009-08-25_PERMIT FILE - M2009062

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EXHIBIT D - Mining Plan a) Mining Method & Schedule it is anticipated that sand and gravel excavation, processing (rock crushing and screening), and stockpiling at the Pierce North site will be intermittent with excavation, processing and stockpiling by County employee crews occurring during the late fall and winter using loaders, excavators, and mine haul trucks confined to the site. Mining and processing equipment is County-owned and operated. During spring and summer construction seasons, trucking of processed materials to area construction sites will occur. Excavation and stockpiling volumes are anticipated to be approximately 100,000 tons per year. The Pierce North site likely has only 5 to 8 years of gravel and sand reserves. It is anticipated that sand and gravel excavation, processing, and stockpiling will commence upon receipt of approval from the Colorado Division of Mining and Geology and receipt of other necessary permits. Gravel excavation and processing will be seasonal with stockpiling of gravel for later County uses depending upon the local road repair and construction needs. b) Earthmoving will include topsoil removal and stockpiling onsite followed by excavation of sand and gravel materials. Topsoil thicknesses at the Pierce North site are thin, typically less than 6 (six) inches. Topsoil will be stockpiled at the location shown on the mine plan map (see Exhibit D). The gravel deposits proposed to be mined are stream channel deposits associated with Lone Tree Creek, an ephemeral stream that crosses a portion of the Pierce North site. Therefore, the thickness of overburden to be removed during gravel extraction is expected to be minimal. Minimal stockpiling of overburden is anticipated. Mined soils unsuitable for construction use will be separated from the mined gravels and may be stockpiled at the site. These soil stockpiles will be utilized for excavation backfill and site reclamation. C) The Pierce North pit site lies on 160 acres of cultivated farmland currently planted in winter wheat. There are no trees on the site. Lone Tree Creek, an intermittant stream crosses the Pierce North site. This drainage is typically dry year-round. The Pierce North gravel pit will not intersect groundwater - this will be a dry pit. The excavation and material processing areas will be below the current land surface. As with the mine plan utilized for the reclaimed Pierce pit located V2 mile to the south, any flows from the creek reaching the gravel pit will be diverted around active excavation areas and any ponded water will infiltrate the base of the excavation to the ground water table. Since the pit will be located below existing grade, no stormwater is anticipated to leave the site and enter surface drainages. It is anticipated that sand and gravel excavation, crushing, and stockpiling at the Pierce North site will not disturb surface water or ground water quality. Consistent with CDPHE requirements, eErosion control measures (Best Management Practices) will be installed along the perimeter of disturbed areas and at the south margin of the site to protect the adjacent intermittent creek area from runoff and sediment that may be discharged from the mine access road and or buffer areas surrounding the excavation. d) It is estimated that between 20 and 40 acres of the 160 acre site will be actively worked at any one time. The dimensions of any significant disturbances are shown on the mine plan map as `limit of gravel mining area' and the gravel processing and soil stockpiling areas (see Exhibit D). The enclosed mine plan map (Exhibit D) also shows the proposed locations for the haul road, gravel processing (crusher location), soil and gravel product stockpile areas. e) It is anticipated that sand and gravel excavation, processing, and stockpiling will commence upon receipt of approval from the Colorado Division of Mining and Geology and receipt of other necessary County and State permits. In any year, gravel excavation and processing will be seasonal, primarily in the fall and winter, with stockpiling of gravel for later County use for local road repair and construction needs. Trucking of previously stockpiled materials to County construction projects will occur primarily in the spring, summer, and early fall each year. The Pierce North site likely has only 5 to 8 years of gravel and sand reserves. Areas of the pit where mining is completed will be graded back to stable MADAVE B\Pierce North\DMG permit\Exhibits-Revl.doc 8/21/2009