_GENERAL DOCUMENTS - C1981017 (310)

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Redstone is partially dependent upon the tourist industry, which in turn is dependent upon the natural beauty of the area. The Crystal River derives its name from its clarity. If the Crystal River were to flow muddy as a result of large failures at the Coal Basin Mine, it is possible that negative economic impacts would be felt in Redstone as tourism fluctuates. An initial plan to remediate the problem the over-steepened portion of the cliff has been developed. In order to stabilize the cliff, the slope angle of the alluvial material and of the upper portion of the Mancos Shale exposure must be reduced. Reduction of the slope angle to a more stable configuration will minimize the potential for continued head cutting and slope retreat. The Division proposes to remove a portion of the upper cliff face from the area of the cliff which is experiencing failure. The alluvial material, along with the upper five feet of Mancos Shale will be cut from near the top of the cliff in order to form a stair-stepped series of benches. This will result in the upper portion of the cliff achieving a slope angle of 2.5H:IV. This slope angle should be sufficiently gentle to accommodate long term stability of the cliff face. In order to achieve the target slope, and to obtain the greatest reasonable separation between the crest of the newly created slope and the refuse pile, some of the coal refuse within this portion of the Old Refuse Pile will be excavated. The refuse in this area will be excavated to a 2.5H:1 V or flatter slope. The excavated material will be transported to another, nearby portion of the Old Refuse Pile which is suitable for additional refuse deposition. The excavation and disposal areas will be topsoiled and revegetated upon completion of earth work activities. Upon completion of the work, the Old Refuse Pile, Dutch Creek and the terrace cliff will have achieved a much greater degree of environmental stability. ESTIMATED COST Removal of a portion of the Old Refuse Pile and underlying material adjacent to the area of potential failure will minimize the possibility of a catastrophic failure occurring. The estimated cost of accomplishing this remedial work is $145,000. Without additional funding, such as that provided by the Civil Penalty Grant, construction to alleviate the potential failure of the Old Refuse Pile into Dutch Creek can not be accomplished. A summary of the estimated cost of construction is as follows: Mob/Demob $12,000 Earth Work $84,000 Topsoil $38,000 Revegetation $11,000 Total $145,000 m Aim p\sgr\orpgrant.wpd 4