2012-04-13_HYDROLOGY - C1980004 (2)

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POND CAPACITY - ACRE FEET Water Sediment Total 0.67 0.28 0.95 McClane Canyon Mining, LLC McCLANE CANYON MINE IMPOUNDMENT YEARLY INSPECTION In accordance with Rule 4.05.9(14), all impoundments shall be inspected at least yearly to determine if the impoundment has been maintained as designed, and in accordance with the approved plan and the applicable regulations. This yearly inspection is for the impoundment located at the McClane Canyon Mine. On March 15, 2011, I performed the required yearly inspection. I, J. E. Stover, have a wide variety of experience in the design and construction of earth fill embankments. Nothing was observed during the inspection that would indicate the pond has a potential for failure. There was no appearance of erosion, instability, structural weakness or other hazardous conditions. There are no required monitoring procedures or instrumentation other than quarterly and yearly inspections. There are no aspects which might affect stability and there is no required maintenance. The sediment pond had water standing one foot below the level of the primary spillway at approximate elevation of 5456. The pond /impoundment was not discharging during the inspection. The required capacity of the sediment pond is 0.55 A -F. The required water capacity of the sediment pond is 0.36 A -F and the required sediment capacity is 0.19 A -F (ref. PAP Section 2.4.1 and Table 4.2 -12). The actual size of the pond exceeds the required capacities listed in the permit. The sediment pond has the following estimated capacity based on the existing water level in the pond: To the best of my knowledge and belief, McClane Canyon Mine has been main t `� approved plan and applicable regulati# • tQ ent/sediment pond at the and in accordance with the " i *: � 19230 • James E. Stove t W it Ii-- � f Date Colorado Profes y Epgineer.•'. # Registration No. 19 .�`O = � N,•