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Coal Ridge No. 1 Mine C1984065: MT7 April 14, 2014 <br />from treatment through a sedimentation pond. <br />Groundwater <br />Hydrogeological field studies, including the establishment of a groundwater monitoring system of the <br />NCIG Permit Area, began in late 1981. These studies included spring and seep surveys, alluvial, <br />colluvial, and bedrock groundwater monitoring, water quality and quantity analyses, aquifer testing, <br />and geologic mapping. <br />Potential water - bearing zones were identified in the Rollins, Middle and Upper Sandstone and the <br />Wheeler Coal. The first three units have been recognized as regional aquifers where the <br />hydrogeologic conditions are suitable. Ground water occurs in both bedrock and alluvial deposits in <br />the vicinity of the proposed mining operation. The potential for groundwater within the area of the <br />mine is greatly limited by the extreme dip of the rock strata which results in prohibitive drilling <br />depths within a short distance. <br />All water from the three sandstone zones is of a sodium - bicarbonate water type. Total dissolved <br />solids range from 575 to 1,340 mg /I. This water type and range of concentrations are very similar to <br />analyses from the same geologic units taken from other locations along this structure and <br />stratigraphy sequence. <br />Climatology <br />The climate is semi -arid with an annual precipitation of 16 inches. Average monthly precipitation <br />varies little throughout the year. Precipitation varies little seasonally, averaging one to two inches per <br />month. Snowfall can reach up to 60 inches in higher elevations. <br />Summers are hot, marked by very low humidity and cool nights. Winters are cold, generally snow - <br />free, but with frequent blizzard conditions. The mine site has a typical alpine climate, experiencing <br />long, cold winters, averaging from low teens at night to 30 degrees Fahrenheit in the day, and <br />moderate summers. "Mountain top" air flow of cold night air drains from the mountain sides down to <br />the Colorado River Valley. Prevailing winds blow from west and northwest to the southeast with an <br />average velocity of 5.3 mph. <br />Soils <br />Soils in the area are characterized as moderately deep to deep, well- drained loams with a dark <br />colored surface layer. Variability in the characteristics of the soil in the area is primarily due to slope <br />and topography. Deeper soils are located in the valley bottoms and at the foot of slopes while the <br />shallower soils occupy the steeper side slopes. <br />Two soil types have been identified at the mine site. These are the Heldt silty clay, found on the lower <br />Page 5 of 28 <br />