2013-05-23_PERMIT FILE - M2013031

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Exhibit Page 15 overburden stockpiles, sizes, and locations are not shown in this plan, but will be shown on annual report maps. SURFACE WATER MANAGEMENT: Temporary structures will be constructed: (a) along the south edge of the mining area to control runoff from the affected areas, (b) on the other edges of the mining area to prevent or control water entering the mining area, (c) on the west edge of the 8.5 -acre work area to prevent water from leaving the work area, (d) on the other edges of the work area to prevent water entering the work area, and (e) along roads being improved, to control sediment, erosion, and runoff from roads and improvements to roads. As much as possible, water runoff will be directed to sediment basins where the water will pond and soak into undisturbed sand and gravel and overburden (mostly loams and silts) and flow downhill underground. If possible and water rights can be claimed, some of these basins may be sealed (on -site clay lining) to allow water to be available for future livestock use (see reclamation plan). As much as possible, all drainage will flow to the south and into the existing drainages but through the ground with no surface discharge. Where or if discharge is necessary, it will be controlled and treated as required by water quality regulations' and permits to ensure that no sediment from the pit is discharged into the Lost Canyon Creek's unnamed tributaries. Berms will be designed to minimize the size of the face facing out, so that minimal storm water and erosion and sediment control are necessary. Use of swales or silt fencing may be required as some points, to be determined during construction. Inside the bermed or ditched areas, as necessary, stockpiles other than berms may have perimeter ditches /swales and berms with silt fence, straw bales, or rock check dams, to reduce /prevent sediment in any runoff from the site, but will not have such features for internal drainage. ASSUMPTIONS USED IN MINING PLAN: The mining plan is based on several key assumptions, stated herein for evaluation. These assumptions are not intended to imply or claim that certain actions will be done. 1. Annual demand for sand and gravel from this pit will be up to 150,000 tons. Demand, and therefore production, may vary significantly from year to year, and therefore acreages affected during a given year may be either larger or smaller than shown in this plan, thus impacting on stockpile size and other matters. (Since 2008, private production of sand and gravel from operations on Hay Camp Mesa have varied from 70,000 to 100,000 tons per year, due to economic conditions.) 2. Based on this assumed maximum /average annual tonnage, and assuming an average gravel deposit thickness of 20 feet, the life of this pit is approximately 10 -15 years, with mining of 2.5 -6 acres each year. 3. Major activities on the site (stripping, mining, stockpiling, etc.) will be done primarily during the later summer /early fall period, from mid - August to mid - November. 4. The gravel being mined may be covered by as much as 10 -20 feet of overburden (primarily clay and Y -12" of soil), and is assumed to average five feet in thickness. For planning and estimating purposes, the upper 6 inches (% foot) is considered usable soil. 5. Generally a layer of unusable material (clay and silt) of 1 to 1 -1/2 feet is found between the gravel being mined and the shale bedrock. This outcrops south /downhill of the mining area (obscured by outwash in many places). 6. The water table is not exposed by mining. 7. While all potential areas are shown as being mined, some areas may NOT be mined due to excessive overburden or poor quality of materials. 8. Based on areas eroded following construction and use of the road along the pylons in the WAPA easement, in- place material is fairly resistant to erosion but in the long -term must be stabilized. 9. Sand and gravel processing will be done on -site; other plants (ready -mix concrete and hot -mix) may be located for varying times on site for specific projects or general use. These are specifically to be included in the mining plan, and may require further county approvals (and other permits) when actual size /capacity/location is known. 1 This is described in the surface water management plan, which provides detailed information.