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Failure of a portion of the Old Refuse Pile into Dutch Creek will result in a significant increase in <br /> the total suspended solids loading to the Crystal River. The introduction of large volumes of <br /> sediment to the Crystal River ecosystem would likely be very detrimental to its trout fishery. This <br /> impact will occur regardless of whether the failure is of catastrophic proportions, or of smaller, <br /> intermittent slumps. <br /> In order to remediate the problem the over steepened portion of the cliff must be reduced to <br /> minimize the potential of continued head cutting. The Division proposes to remove a portion of the <br /> upper cliff face and a portion of the coal refuse from the area of the cliff which is experiencing <br /> failure. The alluvial material, along with the upper five feet of Mancos Shale will be cut from near <br /> the top of the cliff to form a stair stepped series of benches. This will result in the upper portion of <br /> the cliff achieving a slope angle of 2.5H:1 V. This slope angle should be sufficiently gentle to <br /> achieve long term stability of the cliff face. In order to achieve the target slope, and to obtain the <br /> greatest reasonable separation between the cliff and the refuse pile, some of the refuse within this <br /> portion of the Old Refuse Pile will be excavated. The Old Refuse Pile in this area will be <br /> excavated to a 2.5H:1 V or flatter slope. The excavated material will be transported to another, <br /> nearby portion of the pile which is suitable for additional refuse deposition. The excavation and <br /> disposal areas will be topsoiled and revegetated upon completion of earth work activities. Upon <br /> completion of the work, the Old Refuse Pile, Dutch Creek and the Mancos Shale terrace cliff will <br /> have achieved a much greater degree of environmental stability. <br /> ESTIMATED COST <br /> Removal of a portion of the Old Refuse Pile and underlying material adjacent to the area of <br /> potential failure will minimize the possibility of a catastrophic failure occurring. The estimated cost <br /> of accomplishing this remedial work is $125,000. Without additional funding, such as that provided <br /> by the Civil Penalty Grant, construction to alleviate the potential failure of the Old Refuse Pile into <br /> Dutch Creek could not be accomplished. <br /> A summary of the estimated cost of construction is as follows: <br /> Mob/Demob $10,000 <br /> Earth Work $84,000 <br /> Topsoil $20,000 <br /> Revegetation $11,000 <br /> Total $125,000 <br /> 4 <br />