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Mountain Coal Company Exhibit ~? <br />• West Elk Mine Characteristics of West Elk Iviine Soil Mapping Units <br />can be disturbed, transported, and relocated for new seedbeds without serious loss of <br />good physical condition. <br />The soils of this group are subject to some packing if continuously traversed by heavy <br />machinery, and form a structureless mass if handled near saturation. These conditions <br />can be corrected with conventional tillage. All physical qualities indicate that these soils <br />are eood sources of seedbed material: however. [heir water tables present severe <br />problems to their accessibility. <br />The soils of mapping unit number 27 have very low shrink/swell ratios. Total potential <br />extensibility ranges from 0 to 0.8 inch fora 40-inch section. No evidence of mass <br />movement was noted and the potential for such movement is negligible. <br />In their natural state, the soils of this unit have low susceptibility to either wind or water <br />erosion except for bank cutting where they border the North Fork of the Gunnison River. <br />If native vegetation is destroyed or soils disturbed, susceptibility to wind erosion <br />increases to a moderate level, but because of their level topography, water erosion is <br />low. The possibility of accumulation of sediments from flood waters is moderate in <br />• either condition. <br />Chemical Properties and Natural Fertility -These soils are immaturely developed, having <br />no genetic horizonation other than darkened surface horizons (A horizons). Normally <br />they lack horizons of secondary carbonate accumulation. The control section (10 to 40 <br />t inches) is neutral to mildly alkaline while the C horizon is neutral to moderately alkaline <br />and, while normally noncalcareous, may contain some free carbonate in a few localities. <br />Under such conditions the cation exchange complex (portion of the soil having an ability <br />to hold and exchange cations) is normally base saturated with calcium being the <br />predominant cation, but there is not enough free calcium and magnesium carbonate to <br />seriously depress the availability of other plant nutrients. Natural fertility levels are high <br />in the upper horizons of other plant nutrients. Natural fertility levels are high in the <br />upper horizons of the soil but gradually decrease with depth as organic content decreases. <br />No evidence of deficiencies of essential plant nutrients or of trace elements is present. <br />Nitrogen supplies and availability are closely associated with the amount and <br />decomposition of organic matter in the soil. Any operation that involves the loss of the <br />organic rich upper soil horizons, more rapid than normal decomposition of organic <br />matter, or the prevention of an annual return of organic plant remains could cause <br />temporary nitrogen detciencies. Supplemental fertilization of disturbed areas tha[ are <br />to be revegetated can insure the best and most vigorous seedling growths. <br />• <br />Exhibit '_7-21 <br />