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immediately south of, and adjacent to Dutch Creek. The terrace consists of about twenty to twenty- <br /> five feet of weathered Mancos Shale underlying ten to fifteen feet of unconsolidated alluvial <br /> materials. The north face of the terrace forms an estimated thirty-five feet tall cliff. The base of the <br /> cliff is immediately adjacent to Dutch Creek. The Mancos Shale portion of the cliff forms a very <br /> steep slope, on the order of 65 degrees or steeper. The upper ten to fifteen feet of alluvial material <br /> forms a much steeper cliff face, approaching vertical in most areas, with overhanging soil apparent <br /> in places. Due to the significant over steepening of the uppermost portion of the cliff, retreat of <br /> the upper portion of the cliff toward the refuse pile occurs every year. The continued retreat of the <br /> cliff threatens the stability of the western portion of the Old Refuse Pile. <br /> It is believed that the retreat of the upper, alluvial portion of the cliff is a function of the cliff <br /> attempting to achieve equilibrium via head cutting processes, rather than a function of Dutch Creek <br /> cutting the toe of the Mancos Shale slope. The head cutting process continues, with the spalled <br /> material falling onto the underlying Mancos Shale slope. In recent years, the cliff has cut back <br /> about one to two feet per year. However, in 1997, the rate of retreat markedly increased. <br /> Approximately seven feet of retreat was measured between April and November 1997. As this <br /> process continues, the cliff retreats toward the Old Refuse Pile. The toe of the coal refuse is <br /> approximately twenty feet away from the cliff edge. Eventually, as the upper portion of the cliff <br /> continues to fail, the portion of the Old Refuse Pile in this area will slide into Dutch Creek. <br /> Dependant upon stream flow at the time of failure, the refuse material will either by washed <br /> downstream into the Crystal River, or a blockage of Dutch Creek will occur. Dependent upon the <br /> characteristics of the blockage, a catastrophic failure of the blockage could occur, resulting in a <br /> threat to human health and safety, as well as to environmental degradation. In either case, it is <br /> probable that a significant amount of coal refuse will be carried down Coal and Dutch Creeks to the <br /> Crystal River. At a minimum, failure of the cliff face and the overlying coal refuse will <br /> significantly contribute to the total suspended solids loading within Dutch and Coal Creeks, and of <br /> the Crystal River. This process could continue for years as the cliff face continues its retreat until <br /> the head of the cliff reaches a stable slope angle. <br /> In its present condition, the cliff face poses a threat to human health and safety, and to the general <br /> welfare of the surrounding community. The general public increasingly is using Coal Basin, <br /> including the Old Refuse Pile. Mountain bikers,hunters, hikers and cattle ranchers on horseback <br /> have all been observed to traverse the Old Refuse Pile this past year. It is anticipated that as <br /> reclamation is completed, and as the Forest Service acquisition of the property is fulfilled,public <br /> use will increase. The upper portion of the cliff is so over steepened that overhangs of relatively <br /> unconsolidated soil material have developed. People walking along the edge of the cliff are in <br /> danger of causing a surficial cliff failure,possibly resulting in serious injury or death. <br /> Degradation of the Crystal River will have direct negative impacts upon the community of <br /> Redstone. These negative impacts would be environmental as well as economic in nature. <br /> Redstone is partially dependent upon the tourist industry, which in turn is dependent upon the <br /> natural beauty of the area. The Crystal River derives its name from its clarity. If the Crystal River <br /> were to flow muddy as a result of large failures at the Coal Basin Mine, it is possible that negative <br /> economic impacts would be felt in Redstone as tourism fluctuates. <br /> 3 <br />