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CONSTRUCTION PLAN <br />Site Work Prior to Embankment Construction <br />The embankment construction area will be dewatered as much as practicable ' <br />to allow heavy equipment to operate in the area. To accomplish this, a <br />dewatering trench or trenches will be excavated with a small backhoe. A i <br />pump will be set in the trench to lower the local water table. Peabody i <br />has received a Construction Dewater•ing Wastewater Discharge Permit from <br />the Colorado Department of Health. This permit will allow Peabody to <br />discharge this water down drainage away from the construction activities. <br />Embankment Design and Construction <br />The embankment foundation area will be cleared of organic matter prior to <br />construction. The fill material will be free of sod, large roots, other <br />large vegetation matter, frozen soil, and coal processing wastes. <br />Material for both the keyway and the embankment will come from a borrow <br />area adjacent to the site. Topsoil from the borrow area (approximately <br />• one acre-foot) will be salvaged and stockpiled in topsoil stockpile I-I <br />(see Exhibit 12-1). Approximately 14,000 cubic yards of material will be <br />needed from the borrow area for keyway and embankment construction. An <br />average depth of seven feet of suitable material will be removed from the <br />borrow area for construction purposes. <br />The placing and spreading of fill material will proceed from the lowest <br />point on the embankment (keyway) in horizontal layers of such thickness as <br />to allow for a minimum compaction of S3 percent of standard proctor. <br />Compaction tests will be run on approximately every 2,500 cubic yards of <br />material placed in the embankment. Results of these tests will be kept on <br />file at the mine engineering office and will be available for inspection <br />if requested. Both the upstream and downstream slopes of the embankment <br />will be 3h:ly or flatter. <br />During the 100-year storm, with the emergency spillway functioning as <br />designed, there will be 2.6 feet of freeboard. Taking into account 5 <br />7-6e-14 Revised 05/27/87 <br />