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Table 6. Curve Numbers <br /> Area (ac) Cover Description Soil Type Curve Number <br /> 51.1 Disturbed for north pit Various 89 <br /> 24.3 Disturbed for south pit Various 89 <br /> 2.6 Rangeland north Sandy Loam (A) 55 <br /> 0.16 Rangeland south Sandy Loam (A) 55 <br /> 14.8 Rangeland north Cobbly Sandy Loam (D) 85 <br /> 2.99 Rangeland south Cobbly Sandy Loam (D) 85 <br /> Table 7. Runoff and Storage Volumes <br /> Drainage Area Peak Runoff Runoff Volume Pit Volume <br /> Basin (ac) (cfs) (cy) (cy)* <br /> South Pit 27.45 21.24 4.082 >2.000.000 <br /> North Pit 68.5 30.76 9,555 >3,000,000 <br /> *calculated in CAD <br /> Groundwater <br /> Expected groundwater levels are known to be 80 feet below the current mine floor(>120-feet <br /> below the pre-mined surface) based on a single exploration drill hole placed in the current pit <br /> near the southern perennial drainage in 2022. No known aquifers exist within the deposit to be <br /> mined. and there are no water rights associated with it. No non-tributary, not non-tributary, or <br /> tributary water rights are fed by groundwater flows from this site. Therefore, groundwater will <br /> not be encountered during continued mining of the current pit nor during mining of currently <br /> undisturbed phases. <br /> In the very unlikely event that groundwater is encountered during mining, excavation will <br /> immediately stop, and the area will be backfilled with at least 2 feet of overburden type material <br /> to cover any exposed water. No pit dew atering will take place as the groundwater table is below <br /> the bottom of the quarry elevations (pre-mine and post-mine) shown on Maps C-2 and F-1. <br /> Siskin Pit <br /> ei 1 CNN ICkI 0! t\WICiatc. <br /> January 2024 G-4 <br />