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Worst Case Discharge <br />With a pore volume of 416 ac.ft., and assuming a total recharge of 16" per year <br />from all sources over the 768 acres of spoil, annual recharge equals (16/12)(768) <br />= 1024 ac.ft. per year after full irrigation in 2013. It should be noted that a <br />portion of the reclaimed area will be restored to dryland pasture and therefore <br />will not contribute irrigation recharge. However, other areas will have a greater <br />recharge than 16" total; therefore, the average of 16" over the reclaimed area is <br />reasonable. From the year 2003 to 2013, the expected recharge should only be <br />10% of this amount, since irrigation will not be used on the majority of the area <br />and the fresh - placed spoil will be relatively dry. <br />Spoil spring discharge (Spoil Spring Recharge) (Seepage into Low Wall) <br />Seepage into Low Wall = (10 ft. thick permeable sandstone bed in low <br />wall)(8500 ft. wide seepage area)(0.10 ft. per day seepage velocity)(1 /43,560 cu. <br />ft. to ac. ft.)(365 days per year) = 72 ac.ft. <br />Spoil Spring Discharge = (1024 ac.ft. recharge) — (72 ac.ft. seepage into low <br />wall) = 952 ac.ft. In the year 2000, the NPDES 001 discharge at the New <br />Horizon 91 Mine showed an average flow of 271,000 gallons per day or 320 <br />acre -feet per year. The NPDES 001 discharge is for practical purposes composed <br />entirely of spoil water. The New Horizon 92 spoil area is much bigger; therefore, <br />the predicted flow of 1024 acre -feet per year for this area is a reasonable <br />maximum flow when compared to what is being observed at the 91 Mine. <br />Worst case time to spring discharge (Pore Volume) /(Recharge Volume) <br />= (416 ac.ft.) / (952 ac.ft.) = 0.4 years to actual spring flow after full irrigation is <br />resumed on the reclaimed land in 2013. This is in the worst case scenario with <br />the maximum amount of spoil exposed to irrigation water. <br />Realistic Discharge <br />Roughly 422 acres of irrigated land will be constructed in reclamation of the <br />New Horizon 42 mine. An analysis of these areas separately will provide a more <br />realistic calculation of the potential spoil discharge. <br />With a pore volume of 416 ac.ft. and assuming a total recharge of 16" per year <br />from all sources over the 422 acres of spoil, annual recharge equals (16/12)(422) <br />= 563 ac.ft. per year after full irrigation in 2013. It should be noted that a portion <br />of the reclaimed area will be restored to dry land pasture and will therefore will <br />not contribute irrigation recharge, however, other areas will have a greater <br />recharge than 16" total; therefore, the average of 16" over the reclaimed area is <br />reasonable. From the year 2003 to 2013, the expected recharge should only be <br />33 <br />