2011-08-09_REVISION - M1981185 (56)

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Age Formation San Juan Basin Hydrogeologic Unit Hydrologic Characteristics Upper Cretaceous Mancos Shale Confining Layer Well yields as much as 10 gpm Dakota Sandstone Dakota Aquifer Well yields as much as 10 gpm Upper Jurassic Morrison Formation Morrison Aquifer Well yields as much as 25 gpm Junction Creek Sandstone Sandstone porosity ranges from 1 to 8% Wanakah Formation Entrada Sandstone Not significant in Colorado Jurassic and Upper Triassic Dolores Formation Not considered significant in Colorado Permian Cutler Formation Base of San Juan Basin -not considered significant in Colorado Rico Formation Pennsylvanian Hermosa Formation Water Information Exhibit G presented in the Storm Water Management Plan (SWMP) as summarized in Exhibit U, Attachment U -3. (b) Known Aquifers (Rule 6.4.21(8)(a) and (b)) The permit area is located at the northern boundary of the San Juan Hydrogeologic Basin (Topper et al., 2003). The Morrison Aquifer is the only hydrogeologic unit of the San Juan Basin present within the permit area. Except for wells completed in the La Plata River alluvium, all of the water wells that were identified within a 2 -mile radius of the proposed May Day Idaho Mine Complex boundary are completed in the Mancos Shale, the Dakota Sandstone or the Morrison Formation (Exhibit U, Figure U -1). With the exception of the Morrison formation, the geologic units capable of yielding water to a well are not present in the project area and all of these geologic units are structurally above the geologic units within Wildcat's study area (Exhibit U, Figure U -2, Figure U -3 and Table U -2). There is no domestic or agricultural production or monitoring water wells currently completed in the permit area (Table G -2 and Table G -3 summarize the completed wells adjacent to the project area). The May Day and Idaho mines are located within southward- dipping sedimentary rocks cut by a series of east -west faults. The May Day Idaho Fault System consists of two eastward- trending reverse faults, each with a down throw to the south with vertical displacement along the two faults of 350 -475 feet. The sedimentary units associated with the San Juan Basin are shown below and a broader discussion is presented in Exhibit U Section 6.4.21(8). The shaded units are located in the mine area. (Sources: Eckel, 1949). Wildcat Mining Corporation May Day Idaho Mine Complex — 112d Permit Application Revised August, 2011 Exhibit G — Rule 6.4.7 Page 3 of 6