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<br /> <br />relatively low permeability and cohesive. Based upon results of this analysis, we do <br />not believe that excessive seepage or piping will be a concern for the embankments. <br />Gravel and sand soils were found at depths of 7 feet at Pond 010 and also at <br />a depth of 4 feet in the lower portion of Pond 012. These material are relatively <br />permeable and cohesionless and are not considered suitable for embankment <br />construction. <br />At Pond 010 near the coal load-out, the soils anticipated after removal of 4 feet <br />of topsoil will consist of gravel and sand soils. These materials are cohensionless <br />with very little fines. Based upon an infinite slope analysis for these soils, a factor of <br />safety of 1.4 was calculated fora 2.5:1 cut slope. These soils are susceptible to <br />erosion and shallow sloughing when pond levels fluctuate. Erosion control will be <br />important to maintain these slopes. <br />• Our analysis anticipated that the embankments will be constructed of clayey <br />sand or clay soils. The soils can generally be obtained from borrow excavations <br />within the sedimentation ponds. Another source of material would be excavated <br />bedrock. The bedrock material is suitable for embankment construction but will <br />require processing to break the material down to a soil-like material with a maximum <br />particle size of 3 inches. <br />Construction of the embankments should be performed as outlined in the <br />following section. <br />CONSTRUCTION RECOMMENDATIONS <br />Following is a discussion of recommended construction procedures, material <br />requirements, and compaction specifications. Prior to pond construction, we <br />understand topsoil removal will be performed at all pond locations. At Pond 013 the <br />• <br />LORENLITO COAL COMPANY, LLC <br />SMALL SEDIMENTATION EMBANKMENTS <br />LTL/T 36,559 1 0 <br />