_GENERAL DOCUMENTS - C1981017 (232)

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approximately cubic yards will be used as fill on the north slope of the Old Refuse Pile to achieve the design slope. The remainder will be hauled to the designated area for disposal. At certain portions of the Old Refuse Pile, refuse excavated from one area may be used as fill in another area in order to achieve the post construction contours. A number of special construction requirements are necessary for the fill areas. (1) Prior to initiating any fill placement, that portion of the north slope of the Old Refuse Pile which may receive fill material will be staked in advance of filling by CONTRACTOR. Any existing topsoil and vegetative material found to exist within the staked fill area will be removed until only coal refuse material is exposed. The topsoil and vegetative material removed from the area will be stockpiled at the location noted on Map 3, Project Area. Upon completion of staking and topsoil / vegetation removal, and prior to initiating fill operations, CONTRACTOR will receive approval of PROJECT MANAGER to begin fill operations. Fill operations MAY NOT be initiated without such approval. If such fill operations begin prior to receiving such approval, PROJECT MANAGER may direct that CONTRACTOR, at his / her expense, remove the fill material until the original refuse pile material is encountered. (2) Coal refuse materials will be placed in horizontal lifts no greater than twelve inches (12 ") in thickness. (3) Each lift will be thoroughly compacted by a non - vibrating sheeps foot roller prior to beginning placement of the succeeding layer. Optimal compaction of the material is ninety percent (90 %) of maximum dry density. (4) In order to achieve the optimal dry density during compaction, it may be necessary to add water to refuse which appears dry during placement in the lift. (5) In no instance shall the outslope formed during construction of fills be steeper than 2H:1V. (6) Dependent upon conditions, it may be necessary to construct one or more under - drains at fill areas near the base of the Old Refuse Pile. The purpose of the drains is to allow ground water which may be present at the fill area(s) to drain from the fill without saturating the coal refuse material. A typical drain dimension is shown in Figure 1, Typical Underdrain. Note that the drain length is unknown, and that cross sectional area may vary based upon site conditions. PROJECT MANAGER will make a determination whether to construct an under drain prior to CONTRACTOR initiating fill operations. Underdrains, if constructed, will be built to the specifications described in Task 7, Underdrains. These features will be paid per the price bid in Item 7 of the Bid Schedule per lineal foot installed. 14