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Aquifer ~H SOa m I TDS (m~/I) <br />Annand Draw Alluvium 7.5 632 (avg.) 816-1802 <br />Grassy Creek Alluvium 7.02-7.42 167 ?517 X46-4030 <br />Sage Creek Alluvium 6.7-8.3 <539 344-1146 <br />Lennox Coal 6.7-7 303-480 920-1200 <br />Lennox Overburden 6.8-6.9 1790-4157 2030-6432 <br />Wadge Overburden 6.5-8.8 99-1737 549-3052 <br />Wadge Coal**** >12 <500 234-1232 <br />Wadge Underburden 6.9-7.0 14-696 996-1550 <br />Wolf Creek Coal 6.9-8.5 346-416 904-988 <br />Trout Creek Sandstone 7.2-8.25 -412 -871 <br />Climate <br />The average annual precipitation for the town of Hayden, 8.5 miles northwest of the mine site, is <br />approximately 15.9 inches. Precipitation for Hayden is relatively uniform throughout the year. The <br />mean annual temperature is 42° F, with average maximum and minimum temperatures of 66° F and <br />17° F, respectively. The predominant wind direction at the Seneca II-W mine, located west of the <br />Yoast Mine, is from the east-southeast. This direction is in conformance with the topography at that <br />site, and therefore may not be indicative of expected wind directions at the Yoast Mine. The average <br />wind speed at Seneca II-W is 3.5 knots, with an average maximum of 15.4 knots, and an average <br />minimum of .17 knots. <br />Vegetation <br />Five major vegetation community types occur within the proposed Yoast permit area. These major <br />vegetation community types are: Mountain Brush, Sagebrush, Aspen, Steep Mountain Brush, and <br />Western Wheatgrass/Alkali Sagebrush. Additional community types occur within the proposed <br />permit azea but at considerably smaller acreages. These additional vegetation types include: Upland <br />and subirrigated improved pasture, mesic drainage, lands in the Conservation Reserve Program, <br />cropland, Alkali Sagebrush/Greasewood, and Alkali Meadow. <br />Shrub stands in the pre-mine landscape are dense and reduce the utility of the area for livestock <br />grazing. Pre-mine densities determined from baseline sampling data are: 12,562 stems per acre in <br />the Mountain Brush community, 7039 stems per acre in the Aspen community, and 6087 stems per <br />acre in the Sagebrush community. All vegetation types within the permit aze characterized by cool <br />season species. <br />Soils <br />The proposed permit site is located in an "ustic-acidic" soil moisture regime and a "cryic-frigid "soil <br />temperature regime. Moisture is limiting within these soils, but the soil moisture is present during <br />the growing season as a result of the quantity and distribution of precipitation. The majority of soils <br />found within [he permit area are suitable for topsoil salvage in a depth of 0.5 to 3.5 feet. The <br />Yoast Mine 13 March 6, 2001 <br />