2013-09-03_REVISION - M2005044 - Laserfiche WebLink

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EXHIBIT D HOFFMAN PIT MINING PLAN The operation in the extension of the Hoffman Pit will commence in late fall of 2013 and given the quantity of material available continue until 2025. This operation will be active but will be used less than 180 days per year. Topsoil runs from 2 to 6 inches in depth and will be salvaged and stockpiled for use in the reclamation of the site. These stockpiles, if needed, will be seeded with a fast growing cover crop, prosso millet, to stabilize the stockpiles and prevent erosion until the final pit reclamation is started. Lincoln County plans to accomplish the final reclamation in phases in order to minimize the area open and subject to either wind or water erosion. These stockpiles will be separated from overburden stockpiles and separated from operation traffic and any naturally occurring stream channels or drainage ways. The overburden at this site varies in thickness from 1 to 4 feet. Some of the overburden will be utilized to provide binder for the sand and gravel being mined. The overburden not used as binder will be stockpiled separate from the topsoil and seeded with a cover crop in the same manner as the topsoil to prevent erosion. The sand and gravel removed by this operation runs from 10 to 20 feet in thickness. Below the sand/gravel being mined lies a layer of conglomerate rock and clay that will not be mined. No secondary will be mined or extracted. The sand/gravel mined will be used in the construction and maintenance of Lincoln County Roads in Districts I and 2. A tracked dozer or front end loader working from north to south or east to west will push the sand and gravel being mined into stockpiles. A front end loader will then load this material into the haul trucks. The stockpile of sand/gravel could remain in place for several weeks. The pit as it is worked will be day lighted out to the south as was the Fisher Pit just to the west of this site. The north slopes of the pit will be reclaimed to 4 to 1 or flatter when finally reclaimed; during mining operations these slopes may be slightly steeper than the finished slopes. The haul road used to access the site (see map EXHIBIT E) is approximately 400 feet long by 18 feet wide and entirely within the pit boundaries; the other access route will be through land leased from the Shriner's Children Hospital and County Road 28. No new or improved roads will be required to operate at this site as the haul road already exists. No drainage structures will be required. The only permanent man- made structures at this site consist of the barbed wire and electric fences on the north, west and south boundaries of the pit. No processing equipment will be located in the pit area. All equipment used to mine and haul the sand and gravel will be mobilized to the site each time material is to be extracted and then removed from the site. This will be an open pit operation with the material being pushed by either a tracked dozer or front -end loader into a stockpile that is then loaded into trucks by a front -end loader for removal from the pit. At any one time at least 5 or 6 stockpiles of material will remain in the pit. There will be at least two stockpiles of topsoil covering approximately 0.5 acre: two to three stockpiles of overburden covering from 0.75 to 1.0 acre and one small stockpile of sand and gravel of less than 0.25 acre. The maximum area of this pit that is not reclaimed at any one time should not exceed 10 to 12 acres. No water will be used in conjunction with this operation. No ground water has been encountered in the operation of this pit to date. In order to minimize any disturbance to the hydrologic balance only a small area of the pit will be exposed and sloping will be done to control any runoff. Erosion Control BMP's such as temporary berms, erosion control bales or temporary seeding would be utilized to protect any drainages. No existing water rights should be affected by operations at this site. No petroleum products such as fuel or lubrication products will be stored on site. All the equipment will be serviced and refueled off site except for the loader or dozer these will be fueled and serviced on the haul road. After the current phase of mining is completed the county will reclaim this area and mining will move to Phase Two which is slightly east of the currently mined area.