2009-06-22_GENERAL DOCUMENTS - C1981033 (2)

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Climatological Information and Air Resources - Rules 2.04.8.2.05.4(2)(h Climatological and air resource information is contained in Sections 2.03.10, 2.04.8 and 2.05.6 and 4.16 of the Bear No. 3 Mine permit application. Local temperature is inversely related to elevation. Mean annual temperatures along the mountain peaks are much colder than the mean annual temperatures of adjacent valleys. The mean annual temperature of Paonia, Colorado is approximately 50°F. Temperature extremes recorded at Paonia are -28°F (January 1913) and 100°F (June 1927; July and August 1934). Precipitation is directly related to elevation. The valley in which Paonia and Somerset are situated is semi-arid with average annual precipitation of 15 inches. Mean annual precipitation increases with elevation, approaching 40 inches per year on the summit of Mt. Gunnison. Annual snowfall on mountain peaks south of Somerset, Colorado, is greater than 300 inches. Average annual snowfall at Paonia, Colorado, is approximately 58 inches. The May to September precipitation is five inches for the lowlands, and 13 inches for the nearby mountain peaks. The remaining majority of precipitation occurs during the months of October to April. Average annual precipitation at Somerset, Colorado, is twenty-five inches. Information from the West Elk Mine permit application indicates that approximately two-thirds of the annual precipitation occurs between October and April of each year. The remainder of the precipitation occurs between the months of May and September. The Wilcox Ranch Station, located near Bowie, Colorado, is the closest weather station to the Bear No. 3 Mine. Data collected at this station indicate that a similar precipitation pattern has been present for seventy years. The Wilcox Ranch Station is at a lower elevation than Somerset; therefore, the location exhibits less precipitation. Wind direction at the mine site is generally west-northwest and east-southeast. The wind direction is controlled by the east-west orientation of the North Fork of the Gunnison River canyon. Diurnal heating and cooling of the land surface produce typical mountain-valley wind patterns. Winds from the west occur during most of the day while weaker winds from the east occur at night. Geology - Rules 2.04.5 and 2.04.6(2) Information describing the geology of the permit area is presented in Sections 2.04.5 and 2.04.6 of the Bear No. 3 Mine permit application. Additional geological information is presented on the Regional Geology Map (Map 5), Geology Hydrology Map (Map 6), the Geologic Cross Section (Map 7), and Drill Hole Logs (Exhibit 8) of the Bear No. 3 Mine permit application. The mine is within the Paonia Coal Field. The rocks exposed in the Paonia Coal Field consist of the Mancos Shale and the coal-bearing Mesaverde Formation of Upper Cretaceous Age, the Ohio Creek Conglomerate, the Wasatch Formation of Early Tertiary Age, and a quartz monzonite porphyry of Tertiary Age. The Mesaverde Formation is of Late Cretaceous Age and conformably overlies the Mancos shale. This formation consists of approximately 2,500 feet of marine and terrestrial sedimentary rocks. The Mesaverde Formation is the coal-bearing formation in the region and is divided into four members. The members in order of decreasing age are the Rollins Sandstone, the Lower Coal Bearing (Bowie) member, the Upper Coal Bearing (Paonia) member, and the Barren (Undifferentiated) member. Three coal seams exist in the Lower Coal Bearing (Bowie) member, the A-Seam (Old King), the B-Seam (Somerset seam), and the C-Seam (Bear). The A-Seam is immediately above the Rollins Sandstone and was not mined. The B-Seam contains two coal zones and occurs about 20 to 120 feet above the Rollins Sandstone. This seam was mined at the Somerset Mine. The C-Seam occurs 50 to 100 feet above the 5