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(c) Known Aquifers (Rule 6.4.21(8)(a) and (b)) <br />The permit area is located at the northern boundary of the San Juan <br />Hydrogeologic Basin (Topper et al., 2003). The Morrison Aquifer is the only <br />hydrogeologic unit of the San Juan Basin present within the permit area. Outside <br />of wells completed in the La Plata River alluvium; all water wells identified <br />within a 2 -mile radius of the proposed May Day Idaho Mine Complex boundary <br />are completed in the Mancos Shale, the Dakota Sandstone or the Morrison <br />Formation. With the exception of the Morrison formation, the geologic units <br />capable of yielding water to a well are not present in the project area and all of the <br />geologic units are structurally above the geologic units within the study area. <br />There are no domestic or agricultural production wells completed within the <br />permit area <br />The May Day and Idaho mines are located within southward -dipping sedimentary <br />rocks cut by a series of east -west faults. The May Day Idaho Fault System <br />consists of two eastward -trending reverse faults, each with a down throw to the <br />south with vertical displacement along the two faults of 350-475 feet. The <br />sedimentary units associated with the San Juan Basin are shown below. The <br />shaded units are located in the mine area. (Sources: Eckel, 1949); <br />Age <br />Formation <br />San Juan Basin <br />Hydrogeologic Hydrologic <br />Characteristics <br />Unit <br />Upper Cretaceous <br />Mancos Shale <br />Confining Layer Well yields as much as 10 gpm <br />Dakota Sandstone <br />Dakota Aquifer Well yields as much as 10 gpm <br />Upper Jurassic <br />Morrison Formation <br />Morrison Aquifer Well yields as much as 25 gpm <br />Junction Creek Sandstone <br />Wanakah Formation <br />Entrada Sandstone <br />Not significant in Colorado <br />Jurassic and <br />Upper Triassic <br />Dolores Formation <br />Not considered significant in <br />Colorado <br />Permian <br />Cutler Formation <br />Base of San Juan Basin -not considered significant in <br />Colorado <br />Rico Formation <br />Pennsylvanian <br />Hermosa Formation <br />Further discussions on the relationships of aquifers with respect to the mining M <br />operations are presented in Section 6.4.21(8), Exhibit U. <br />cz <br />a, <br />Sunrise Mining, LLC <br />112(d) Permit <br />M -1981 -185 -AM -2 <br />Revised September 30, 2017 <br />Exhibit G — Rule 6.4.7 Page 3 of 10 <br />