Laserfiche WebLink
2. Benches. Benches will be cut into the existing slopes to form "keys" for <br />the dam embankment to better adhere to the existing slopes. <br />3. Disposal of Excavated Material. Any excavated material in excess of that <br />required for the dam embankment will be graded into the adjacent topography <br />above the high water level. i <br />4. Unsuitable Material. Any unsuitable material encountered shall be disposed <br />of in accordance with Colorado Rules and Regulations. <br />B. Embankment Construction. Embankment construction will consist of the placement <br />of all materials to lines, grades, and cross section. Grading will be done to <br />conform with the typical sections. <br />A keyway will be cut below existing ground. Suitable material from the <br />excavation area wiil be placed in the keyway. The piacing and spreading of fiii <br />material will proceed from the lowest point on the embankment (keyway) in <br />horizontal layers of such thickness as to allow for a minimum compaction of 93 <br />percent of standard proctor. Compaction tests will be run on approximately <br />every 2,500 cubic yards of material placed in the embankment. Results'of these <br />tests will be kept on file at the mine engineering office and will be r5vailable <br />for inspection if requested. Both the upstream and downstream slopes of the <br />embankment will be 3h:ty or flatter. <br />During the 25-year storm, with the emergency spillway functioning as designed, <br />there will be 3.0 feet of freeboard. Taking into account 5 percent settlement <br />{0.8 ft.), there will still be 2.2 feet of freeboard. <br />The entire embankment, including adjacent disturbance areas, disturbed 6y <br />construction will be stabilized with respect Lo erosion by seeding the area <br />immediately after construction is complete in accordance with the Reclamation <br />Plan. Areas in which the vegetation is not successful or where rills and <br />gullies develop, shall be repaired and revegetated in accordance with Peabody's <br />rill and gully plan. '~ <br />Selected References ~, <br />~, Barfield, B.J., Warner, R.C., and Haan, C.T. 1983. Applied Hydrology and Sediimentology <br />for Disturbed Areas. Oklahoma Technical Press, Stillwater, Oklahoma. ~'i <br /> <br />13-5-11 <br />