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Coal Ridge No. 1 Mine C1984065: MT7 April 14, 2014 <br />Corcoran and Rollins Sandstones are the bottom and top, respectively, of the Iles Formation, and the <br />upper three members belong to the Williams Fork Formation [see Figure 3.3 -3 in the Permit <br />Application Package (PAP)]. <br />The Wheeler coal seam, which was planned to be mined at the Coal Ridge No. 1 Mine, is in the <br />Williams Fork Formation within the Bowie member. Coal seams in the Bowie member are the most <br />continuous of any of the Mesaverde coals. Their cumulative thickness is 33 to 54 feet. <br />The Wasatch and Ohio Creek formations unconformably overlie the Mesaverde Group. These <br />formations consist of red and buff shale, red sandstone, and red to gray conglomerate and form the <br />ridge bluffs of the Grand Hogback. <br />Quaternary unconsolidated sediments in the mine area, as represented by surface features, fall into <br />three geomorphic categories: <br />1) Alluvium: These Quaternary deposits include all sediments associated directly with the active <br />portions of the various stream channels and alluvial fans. <br />2) Terraces: Sediments associated with the inactive portions of the stream channels, particularly <br />those at much higher levels, have been categorized as Quaternary Terraces. <br />3) Colluvium: Colluvial deposits are considered to be loose, heterogeneous rock masses composed <br />of soils and rock fragments which have been deposited chiefly by mass - wasting, usually at the <br />base of steep slopes. <br />Hydrology <br />Surface Water <br />The Coal Ridge No. 1 Mine permit area is located in the Upper Colorado River Basin, in portions of <br />three watersheds: the Colorado River, Alkali Creek, and South Canyon Creek. Proposed mining <br />operations beneath portions of the Alkali and South Canyon Creek watersheds did not occur. <br />Water from the Colorado River is of good quality and is used for domestic and irrigation purposes. <br />Salinity concerns have resulted in the establishment of standards for the upper and lower Colorado <br />River basin (including the Colorado River and Alkali Creek). Water was monitored in the Colorado <br />River through 1988. The Colorado Department of Public Health and Environment receiving stream <br />standards for some metals were occasionally exceeded in both the Colorado River and Alkali Creek, <br />but the elevated metals were not determined to be mine related. See PAP pages 3 -40 through 3 -49 <br />for more information on surface hydrology. <br />Only small ephemeral drainages cross the site. Although no longer required, all surface runoff from <br />disturbed areas is either directed to a sedimentation pond or approved for exemption (small areas) <br />Page 4 of 28 <br />