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season. NHN estimates that evaporation during the irrigation season could result in loss of 2.5 <br />ac-ft/ac. The evapotranspiration rate for the permit area is estimated at 2.1 ft/year (see Section <br />2.04.7, Evapotranspiration). These loss figures, added together, would result in very little water <br />being available for infiltration at the Garvey parcel. Adding the loss values for the Meehan parcel <br />would result in negative values. Percolation and infiltration rates into the reclaimed soil is <br />estimated to be moderate (0.6 to 2.0 inches per hour) suggesting that the reclaimed soil will be <br />more acceptable to infiltration than the original soil which should reduce the runoff return flow. <br />The New Horizon 2 Area Permit predicts that 13 inches/yr of irrigation water will infiltrate <br />(recharge) the backfill. Therefore, with a total of 75 irrigated acres in backfill about 81 acre -ft of <br />recharge to the reclaimed backfill would occur per year. As stated earlier, irrigation at NHN <br />Mine could begin as early as the irrigation season of 2015. The backfill material will be <br />relatively dry and will initially absorb moisture. However, channeling of infiltrating irrigation <br />water through more permeable zones will most likely occur. Experience at the New Horizon <br />Mine indicates that the backfill could begin draining irrigation water within a few months of <br />resumption of irrigation on the reclaimed backfill or as early as late summer or early fall of 2015. <br />The flow through the backfill would increase gradually as more of the reclaimed surface is <br />irrigated. At maximum steady state, the backfill flow (at full infiltration rate of 81 ac-ft/yr) would <br />average about 0.11 cfs or about 50 gpm. <br />The flow rates through the backfill material will be significantly higher than through the bedrock <br />(hydraulic conductivity of 40 ft/day, versus 2.1 ft/day). Water seeping in from all three sides of <br />the excavated pit is not expected to recharge the bedrock zones as the water will follow the path <br />of least resistance and flow to the south along the pit floor as is now the case at the old Peabody <br />Nucla Mine (New Horizon #1 Area permit ). This water will continue to issue as a spring at <br />Spoil Spring # 1(S S# 1) location (see Map 2.04.7-1). <br />Section 2.05.6(3) Page 17 March 2018 (TR -16) <br />