2008-02-27_PERMIT FILE - M2008010

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Mud Creek Pit -Reclamation Permit Application - 112 (C) Exhibits Page 30 of 67 assumptions listed below Table B-5-4, the estimated operating uses of water for the Mud Creek Pit are shown in this table.15 ~ aoie v-4. iviaximum rro ect water Ke uiirements Activi Acre-Feet Period Flow Remarks er ear al/da Dust control of roads 2.5 0.1 in/day, 120 days 6,788 2.5 acres max Dust control of plant sites 6.1 0.1 in/day, 30 days 10,589 3.9 acres max Dust control of pit area 2.5 0.1 in/day, 60 days 16,291 5.0 acres max Water removed with materials mined 0.06 Variable 19,185 4% of weight of product Washing of materials 2.7 130 days 6,667 Evaporative loss Total water re uired 13.86 acre-feet Worst-case Water available 28.37 As needed Not includin direct reci itation ~ ~ n, w uaseu un ine ronowmg assumptions: • 120,000 tons per year produced. (Production of 200,000 tons per year would reduce this by about 50 percent, to about 9acre-feet.) • Maximum (all roads in operation): total affected area for roads is 5.0 acres, but only 50% of this (2.5 acres) will actually require application of water. • Plant areas include long-term stockpiles, storm water structures, and other areas with no traffic and no need for dust control. Total plant areas are 11.7 acres, but only 1/3 (3.9 acres) will require regular dust control. Plant sites are also seasonal: the asphalt plant will operate approximately 8 months per year, the concrete plant will operate approximately 9 months per year. • Maximum pit area with exposed surface including temporary topsoil stockpiles is 5 acres, which are assumed to be completely open and require application of water for the entire period of their use, but actual mining and processing (crushing/screening) is expected to take approximately 60 days per year. • No precipitation during any operations on site. (In actuality, as many as 30 days per year we can expect at least 0.1 in/day and so require no watering.) (Annual precipitation in the area is 17 inches per year.) • No dust control chemicals be used. (In actuality, air permit requirements will have to be met and magnesium chloride brine, sodium lignite, or other dust control chemicals will be applied to areas with high traffic. • No water from off-site be used for dust control. • No open water except wash pits (included in wash water use). NWS estimates evaporation from free water surface (shallow lake) to be 50 inches per year for the location of the pit (NWS OHHRL map). As no ground water is exposed (by mining below the water table) and no water is retained in surface impoundments (actually incised basins), no requirement for a substitute water supply plan to be prepared and submitted to the State Engineer, pursuant to SB 89-120 and SB 93-260 has been identified. A temporary water use agreement will probably be necessary to allow irrigation water to be used on a temporary basis each year for the above purposes, with such water to be provided together with irrigation water delivered for the normal irrigation season. Based on preliminary calculations, the existing irrigation water supply for the site appears to have adequate water rights to substitute for water used for mining purposes. As water will be required for pit operations during periods when water is not normally available for irrigation, the operator will be required to store water on-site for use during the off-season. Such water storage will be done in one or both plant sites, and will include storage in tanks or other containers to prevent evaporation loss. Based on anticipated operations, it is estimated that approximately Y4 of water consumed will be needed during the non-irrigation season, requiring storage for approximately 3.1 acre-feet of water. Colorado soil management and conservation rules will be implemented to protect surface and ground water quality and improve watershed management. 8. Prohibited actions necessary to protect water systems: None known at this time, other than compliance with best management practices, which forbid the discharge of heavily sediment-laden waters and implementation of spill control and countermeasures actions to prevent discharge 15 Based on assumptions as discussed in Exhibit M. McStone Aggregates, LLC 15 FEB 2008 ©WASTELINE,INC 2008 PN 5006.1-4(009)