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The most significant occurrence of groundwater in the general area is associated with the alluvium <br />of the North Fork of the Gunnison River, located approximately two miles southeast of the mine <br />portals and 1,500 feet lower in elevation. Significant alluvial sand and gravel deposits averaging <br />34 feet thick exist along the North Fork from the mouth of T error Creek to the confluence of the <br />Gunnison River. There are numerous wells in the area which draw water from this alluvium; well <br />yields range from 5 gpm to 120 gpm, with average yields of approximately 17 gpm (Section 2.04.7, <br />Volume 1). <br />Steven's Gulch, an ephemeral stream located in the center of the permit area, drains an area of 6.0 <br />square miles and contains several reaches of shallow alluvium/colluvium. Most of these reaches <br />have little ground water except during periods of stream flow. The most significant area of <br />alluvium/colluvium occurs in the NW'/a of Section 13, Township 13 South, Range 92 West <br />(Steven's Gulch ,wllfield), where a 25 -foot -thick sandstone outcrop has created a topographic <br />restriction such that a considerable thickness of alluvial sands and colluvial material has been <br />deposited. Test wells drilled by the BRL indicate that the alluvium in this area can support a <br />pumping rate of approximately 28 gpm (Ground Water Hydrology Appendix, Volume 4). BRL <br />installed a production well and used this water for domestic use, dust control, and fire control. <br />The recharge to the Steven's Gulch well field area is through flow from the adjacent colluvial <br />deposits and from a leaky pipeline aqueduct. The ground water flows through the colluvium <br />downslope to the alluvium, where it becomes trapped or temporarily stored. This situation is <br />somewhat modified by the presence of landslide complexes which occur throughout the general <br />area in the Bowie and five adjoining quadrangles (Colorado Geological Survey Information Series <br />5, 34p.). <br />Ground water will tend to move down through the more permeable material and along lateral <br />shears of these landslide complexes. The sources of ground water discharges from the Steven's <br />Gulch alluvium at the well field are through the BRL's wells, through underflow within the <br />alluvium down the old bedrock channel of Seven's Gulch, and through discharges to the stream <br />during high water table conditions in spring and early summer. <br />Water quality analysis for the Steven's Gulch well water indicates good quality water, with none <br />of the parameters exceeding the recommended standards of the Colorado Department of Public <br />Health and the Environment. <br />Alluvial/colluvial deposits in the T error Creek drainage near the Morrell CowCamp are also being <br />utilized for water supply purposes. However, no impact is predicted for these areas since lands <br />affected by mining lie to the south and east. <br />Occurrences of ground water have been noted in the Mesaverde Formation from information <br />obtained from drilling, experience in the mine and from the presence of springs and seeps in the <br />permit area and hydrologically adjacent area. This information indicates that the only potential <br />regional aquifer in the area is the continuous Rollins Sandstone, located stratigraphically <br />approximately 200 feet below the D coal seam. Recharge to the Rollins Sandstone occurs along <br />outcrops and along subcrops beneath the alluvium of T error Creek to the east and Steven's Gulch <br />to the southwest. However, due to the steepness of the topography in the outcrop areas (i.e. <br />sandstones are cliff formers) and the narrowness of the stream valleys, the Rollins Sandstone <br />