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Inc Mr. Kim Lawrence July 7, 1998 Page 3 2.2 Water Lost Throueh Ooerations Wash Pond Evaporation -The wash pond will be about 3.3 acres in size. The resulting annual evaporation during mining operations is 8.83 acre-feet (see Table 3). Dust Control -Hall-Irwin will apply water to haul roads and stockpiles as necessary to prevent fugitive dust. It is estimated that one load from a 3,000-gallon capacity water truck twice a day (Monday through Friday) for nine months is required for dust control. This results in a consumptive use of 3.6 acre-feet per year. Concrete Batchine - It is estimated that two million gallons of water will be used in the concrete production process per year. This results in an annual consumptive use of 6.1 acre-feet. Asohalt Production -During the first years of operation, no asphalt will be produced at the site. Once asphalt production begins, it is estimated that 1.0 acre-foot of water per year will be used for asphalt production. 2.3 Water Lost with the Material Hauled Offsite Hall-Irwin estimates the site contains eight million tons of materials. It is anticipated that mining will begin in the Fall of 7 998, and will continue for up to 25 years to remove the material. Annual production will depend on the demand for construction material and may impact the total life of the project. Based on these assumptions, water lost with the mined product will total 9.4 acre-feet per year, calculated as shown below: (8,000,000 tons/25 years = 320,000 tons/year x 2,000 Ibs/ton = 640,000,000 Ibs x 4°/ - 25,600,000 Ibs 25,600,000 Ibs/62.4 Ibs per cubic foot = 470,256 cubic feetr43,560 square feet per acre - 9.4 acre-feet per year) Typically, Hall-Irwin will mine 10 percent of its material during December, January, and February with the balance being removed uniformly through the remainder of the year. Thus, monthly water loss from transporting the material would be approximately: /an Feb Mar Apr May /un lul Aug Sep Oct Nov Dec Total 03t 0.31 0.94 0.94 0,94 0.94 0.94 0.94 0.94 0.94 0.94 0.37 9.4 2.4 Total Depletions During Mining The total depletions during mining of the Section t pit at the site are estimated to be 28.75 acre-feet per year as shown on Table 4. It is anticipated that it will take approximately two years to mine Section 1. The total depletions during mining of the Section 2 pit at the site are estimated to be 30.03 acre-feet per year (Table 4). It is anticipated that it will take approximately three years to mine Section 2 (following mining at Section 1).