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downstream. With an average pH of 8.3, the water is slightly alkaline. Hardness averages 796 <br />mg/l, and is considered very hard. <br />Climate <br />The average annual precipitation at the mine site is approximately 16 inches. The precipitation is <br />consistent throughout the year with no significant dry periods. The mean annual temperature is <br />42°F. The average maximum and minimum temperatures are 66°F and 17°F respectively. <br />Regionally, wind directions run east -west following the Yampa River Valley. More localized <br />wind patterns trend along the side valleys. <br />Land Use <br />The current and historic land uses of the area in which the operation is located are grazing land for <br />livestock and habitat for wildlife. Regional land use patterns are oriented in three relatively distinct <br />bands. Irrigated cropland is closely associated with the floodplain of the Yampa River. To the <br />south, non -irrigated crops are grown on the sloping upland surfaces. The area nearest the mining <br />operation is mostly hilly and mountainous terrain and used primarily as rangeland for livestock <br />grazing and wildlife habitat. Land use in the mine area is undeveloped rangeland, with a small <br />area classified as industrial due to an oil well site. <br />Soils <br />The soils found within and adjacent to the mine plan area are typical of soils found in the cold, <br />semi -arid regions of the Western United States. The soils are generally moderately deep (20 to 40 <br />inches) to shallow (10 to 20 inches) and have developed in weathered, interbedded fine sandstone, <br />siltstone, and shale, and in local slope wash and colluvium. Most of the soils are Borollic Vertic <br />Camborthids, Lithic Cryoborolls, and Pachic Cryoborolls. <br />Most of the soil types found in the mine plan area contain at least six inches of suitable topsoil <br />material. The best sources of topsoil material are the Splitro silt loam, the Winevada Loam, and <br />the Cochetopa Loam, which comprise significant portions of the area to be disturbed. Salvage <br />depths vary from 6 to 64 inches, resulting in an overall average soil replacement depth of 1.3 feet <br />(15.6 inches) over regraded areas in the original permit area. Average soil replacement thickness <br />in the South Extension area is 1.1 feet (13.2 inches), with the exceptions of aspen establishment <br />areas, where average replacement thickness is 4 feet, and upland shrub establishment areas <br />topsoiled in 2006, where average replacement thickness is 0.6 feet (7.2 inches). <br />Vegetation <br />Vegetation in the vicinity of the mine is characterized by three vegetative types: mixed brush, <br />sagebrush grassland, and aspen. Aspen forest is the dominant vegetation type within the Wolf <br />Creek/Sage Creek mine block disturbance area. Because of livestock grazing, shrubs have <br />increased in density while forbs and grasses have decreased. <br />►1 <br />