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C-1981-022 <br />RN-05 Findings <br />February 2009 <br />springs are shown on Map 2.04-M5. <br />With Permit Revision No. 5 (PR-05), Oxbow Mining LLC undertook a new survey of surface water <br />resources in the Elk Creek Mine tract. While there are no adjudicated water resources in that tract, <br />the USFS and USBLM requested that OMLLC inventory the resources. Resources identified were <br />added to Map 2.04-M5. <br />The topography of the region is characterized by steep canyons cut by the North Fork of the <br />Gunnison River and its tributaries, with several remnant alluvial terraces above the valley of the <br />North Fork. Proceeding downstream below Somerset, Colorado, the canyon widens. At Paonia, <br />Colorado, the canyon has given way to a broad alluvial plain with interspersed remnant alluvial <br />terraces. The coal to be mined is located in the Somerset Coal Field. The strata exposed in the <br />Somerset Coal Field consist of the Mancos Shale and the coal-bearing Mesaverde Formation of <br />Upper Cretaceous Age, and of the Ohio Creek Conglomerate, the Wasatch Formation and the Quartz <br />Monzonite Porphyry of Early Tertiary Age. Coal is mined from the Mesaverde Formation, a 2,500 <br />foot thick sequence of sedimentary strata overlain by the Ohio Creek Conglomerate and underlain by <br />the Mancos Shale. The strata in the Sanborn Creek and Elk Creek Mines permit area dip three to <br />five degrees north-northeast within the permit area, but varies locally. <br />The Mesaverde Formation contains a number of coal-bearing members. The Somerset Mine mined <br />coal from the B-2 seam of the lower coal bearing (Bowie) member of the Mesaverde Formation. The <br />Sanborn Creek and Sanborn Creek East additions mined the B and C seams of this member. The Elk <br />Creek mine ramps down to the D-seam and will mine that level. The Lower Coal member ranges <br />from 260 to 350 feet thick in the Somerset Coal Field and bears three minable coal seams. This <br />member consists of interbedded and lenticular sandstones, siltstones and coals, and is overlain by a <br />massive sandstone 25 to 225 feet thick which lies directly on the C seam and marks the bottom of the <br />upper coal member. <br />Three categories of potential aquifers exist in the general area: alluvial deposits associated with the <br />North Fork of the Gunnison River and its tributaries, the Rollins Sandstone, and lenticular <br />discontinuous sandstones of the Upper Mesaverde Formation. <br />The largest alluvial aquifers are associated with the North Fork of the Gunnison River. Smaller, <br />more isolated alluvial aquifers are associated with several tributaries of the North Fork. <br />The Rollins Sandstone is the only known sandstone with sufficient porosity and lateral extent to be <br />considered a regional bedrock aquifer. The only wells in the region which are completed in this <br />aquifer are located near the Hawk's Nest Mine along the North Fork. <br />Localized perched bedrock aquifers exist in the discontinuous, lenticular, fine-grained sandstones of <br />the Upper Mesaverde Formation. The amount of ground water in these sandstones is controlled by <br />faulting and fracturing of the strata (secondary porosity) and the topography of the recharge area. No <br />known wells are completed in the sandstones of the Upper Mesaverde Formation above the mine <br />7