2010-03-16_REVISION - M1981185 (29)

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Mayday Mine and Mill Site, Wildcat Mining Corporation, 110(2) Permit Amendment Exhibit C prior to construction activities. Use of the Idaho augmentation ponds and water use for the Mayday Mine has been authorized by the State Engineer and approved in accordance with the State Engineers decreed water right. • Augmentation Pond # 2 outlined in the Court Water Decree (06CW91) will be designed and built if necessary. (See Figure 10 and 11 Attachment C -3). If the pond is deemed necessary Wildcat Mining Company will submit a Technical Revision to DRMS for approval and the placement of an appropriate bond. Ponds will be maintained pursuant to the stipulations outlined in the water right decree (see Water Rights discussion in Exhibit B — Site Description and Attachment C -3). The disturbed area within the permit area to construct and maintain the impoundments and distribution corridors are estimated to be approximately 1.5 acres. Water will be trucked from the Mayday -Idaho Augmentation pond to the Mayday Mine if water is not available from the Mayday underground workings. (i) Protection of Surface Water and Groundwater Resources (Rule 3.1 6) Surface Water Wildcat will establish a quarterly surface water monitoring points (Exhibit E -6) to be located in the following areas: • La Plata River upstream of Deadwood Gulch (SW -1) • La Plata River downstream of Deadwood Gulch (SW -2) • May Day Level No. 1 underground workings (SW -3) • Seep within the Idaho Permit boundary (SW -4) Surface water will be controlled using designed and best management practices (BMPs). To the extent possible ditches, and inlet structures flow velocities will be controlled to the extent practicable to convey the design storm where flow velocities exceed 4 feet per second (fps) Wildcat storm water will be managed to divert water from mine disturbed areas. Where practicable, V notch diversion ditches (Figure E -5) no less than 18 inches deep with side slopes of equal to or less than 1:1 side slopes will be cut above the Mayday No.1 portal at a depth of at least 1.5 feet. (See Table C -1 for design calculations). Water will be conveyed to minimize drainage across the surface disturbed area and diverted to the undisturbed drainage below the bench. (Figure E -5) for Mayday bench diversion drainage ditch - calculations are presented on Table C -1). If necessary, debris basins will be constructed to reduce surface water flow rates or to reduce the potential to increase down gradient erosion and sedimentation impacts. Whole rock analysis (Table C -2) did not detect the presence of sulfur. Field leach testing indicates that the waste rock is not acid generating, with the leachate having a pH >9.0 (Table C -2, Attachment C -4). Both field leach testing (Table C -3) and Synthetic Precipitation Leachate Potential (SPLP) testing (Table C-4) did not have leachate concentrations above Leachate Reference Concentrations (CDPHE Colorado Soil Evaluation Values; http:// www .cdphe.state.co.usthm/csev.htm accessed 3/10/2010 0 March 12, 2010 Amendment M- 1981 -185