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Ground hater <br />• [?ithin the vicinity of the Trapper mine, ground water exists in both bed:roc}: <br />and alluvial aquifers. Lfajor bedrock aquifers in the area are in the Trout <br />Creek, ?fiddle, Twenty-?file, and [:fiite Sandstones. The major alluvial aquifers <br />in the area are those associated with the Yampa ant Llil:tiams Forl: Rivers. <br />?fang of the coals, discontinuous sandstones and siltstones, and some of the <br />smaller alluvial formations are also water-bearing. However, they contain - <br />insufficient quantities of water to be considered major aquifers. <br />The [Jhite Sandstones (1st, 2nd, 3rd) are stratigraphica:Lly located about 20-50 <br />feet above the H coal seam, a seam to be recovered in tlae northern limits of <br />mining a[ the Trapper ?fine. Only the lower [Jhite Sandstone, the 3rd, is <br />proposed to be disturbed by mining. When miring is complete, the 3rd [Jhite <br />Sandstone will be in direct hydrologic contact with reclaimed spoils. The <br />aquifer generally recharges at its outcrop and discharges at its subcrop into <br />the Yampa River alluvial aquifer. The ~:ater quality of the 3rd [Jhite <br />Sandstone can be generally categorized as being poor for domestic purposes and <br />good for irrigation and livestock watering purposes. Total dissolved solids <br />values range from 602 to 982 mg/1. The range in pH is Erom 6.6 to 10.65. The <br />water can be characterized as being a calcium bicarbonate type. Sulfate, <br />iron, and TPS concentrations consistently exceed drinking water standards. <br />Alluvial Valley Floors <br />Several areas near the Trapper Mine meet the geomorphic criteria of an <br />alluvial valley floor (AVF). They are No Name, Johnson, Pyeatt, and Flume <br />Gulches and the Yampa and Williams Fork Rivers. Of these, No Name, Johnson, <br />• and Pyeatt Gulches have been determined not to be AVFs for the following <br />reasons: 1) limited presence of unconsolidated stream-laid deposits and the <br />lack of sufficient water quantities to support irrigated agricultural <br />activities within the proposed permit area (No L7ame Gulch and Pyeatt); 2) lack <br />of irrigation potential and currently irrigated cropland (Johnson Gulch and <br />Pyeatt) and 3) lack of sufficient water available in the drainage for <br />agricultural benefit - the alluvial valley water table is too deep for wheat <br />and native grasses to be subirrigated (Johnson Gulch). Furthermore, the <br />alluvial deposits associated with these gulches are either upstream or <br />downstream of the permit area and will not be physically disturbed by mining. <br />Flume Gulch, Yampa and Williams Fork Fivers, have a positive AVF <br />determination. These AVFs are located either downstream of the permit area or <br />on the other side of [he drainage divide. The potential hydrologic impacts on <br />these AVFs, because of mining, will be discussed in the environmental impacts <br />of this alternative. <br />Fish and [:ildlife <br />Wildlife species (excluding threatened and endangered species which ate <br />discussed in the following section) on or adjacent to the mine plan area <br />include mule deer, elk, sage grouse, sharp-tailed grouse, blue grouse, and <br />golden eagle. <br />-5- <br />C l <br />