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1) Evaporation Losses From Dewatering Trench 1 and Settling Pond for Pond 1 Note that Hall-Irwin is mining the site in sections (see attached Mining Plan Map). They will construct a dewatering trench prior to mining each section to prevent the groundwater from entering the area to be mined. The dewatering trench will initially be constructed around Section 1. It will be extended to encompass each section right before mining will occur. For example, several weeks before Hall-Irwin is ready to begin mining Section 5, they will expand the dewatering trench that would exist around the perimeter ofSections I - 4 to include Section 5. Thus, when Section 6 is being mined there will be a dewatering trench aoound the entire perimeter of Pond 1. When Hall- Irwin is ready to begin mining Section 7, all of Dewatering Trench I will be reclaimed. It is estimated that this trench will be about .85 acres. Since they are mining the site in sections, only one settling pond will contain water at any given time. As mining proceeds north, finished sections and the associated settling pond will be reclaimed and a new settling pond will be dug. It is estimated that each settling pond will be about .11 acres. Evaporative losses from Dewatering Trench 1 and the settling pond will total 2.42 acre-feet. 2) Evaporative Losses from Dewatering Trench 2, Settling Pond and New Pond 1 We estimate that Dewatering Trench 2 will be about .65 acres. Each settling pond will be about . L 1 acres and the new Pond ] will be about 82.8 surface acres. Thus, evaporative losses will be about 210.81acre-feet. 3) Water Lost Through Operations Wash Pond Evaporation The wash pond will be about 2 acres in size. Thus, the resulting net annual evaporative consumptive use during mining operations is 5.05 acre-feet per year. Dust Control Hall-Irwin will apply water to haul roads and stockpiles as necessary to prevent fugitive dust. [t 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. Concre[e Botching Water will be used in the concrete batch plant. It is estimated that two million gallons of water will be used in the concrete production process. This results in an annual consumptive use of 6. l acre-feet. .9sphalt Production Water will also be used to produce asphalt. It is estimated that 1.0 acre-foot of water per year will be used for this process. Hall-/rwrn Minrng Proposes/ jot the Shores - ~LILRB / 12 Permit 28