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0 <br />• The eastern portion of the pile was graded flat with a small area of loose <br />dumped material. The surface of the pile appeared well compacted based upon the <br />lack of rutting or deformation under the rubber-tired backhoe used to excavate the <br />test pits, and evidence of previous traffic. <br />In the western portion of the pile, loose dumped material was present. The <br />pile surface was irregular, showing signs of relatively deep rutting from previous <br />traffic and areas of surface water collection. This material also rutted under the <br />weight of the rubber-tired backhoe used to excavate the test pits. <br />Based upon our discussions with Mr. Ron Thompson of Basin Resources, and <br />Mr. Sam Lopez, a local contractor, we understand they have on several occasions <br />placed ditch cleaning material or pond dippings on the pile surface. The ditch <br />cleaning material is a mixture of native soils and coal materials cleaned from ditches <br />in the New Elk Mine area. This material was difficult to distinguish from coal <br />development waste placed in the pile since both materials are dark brown to black. <br />We based our estimate of the depth of ditch cleaning materials based upon the <br />generally finer nature of the material, and lack of gravel, cobble or boulder sized <br />material. <br />Based upon our visual observations, it appeared the depth of ditch cleanings <br />• was on the order of 4 feet deep in test pits in the western portion of the pile, and on <br />the order of 2 to 3 feet in the eastern portion of the pile. We obtained bulk and hand- <br />drive samples of the fill material. The hand-drive samples were obtained by driving <br />a brass liner (1.9 inches diameter) into the fill. The results of laboratory Proctor <br />testing of a sample is shown on Fig. 3, the results of remaining laboratory testing is <br />summarized on Table I. The density results obtained from the hand-drive samples <br />generally indicate adequate density. However, based upon our visual observations, <br />we do not believe sufficient compaction is present in the western portion of the pile <br />where the material is rutting and relatively wet. We believe the material can exhibit <br />a wide variation of maximum dry density in the standard Proctor (ASTM D 696) test <br />due to the high difference in the specific gravity between shale and sandstone and <br />coal. Variable coal percentages can result in variable maximum dry densities <br />according to the Proctor test. <br />To summarize, the test pit investigation identified approximately 2 to 3 feet of <br />suficial fill in the eastern portion of the pile, and approximately 4 feet of surFicial fill <br />in the western portion of the pile. The fill in the western portion does not appear to <br />have adequate compaction and will require re-working. The approximate location of <br />the area requiring re-working is shown on Fig. 2. We recommend the following <br />process to re-work the top of the pile and obtain satisfactory compaction. <br />1. The loose dumped fill in the eastern portion of the pile should be <br />spread and compacted. The remaining surface of the pile should be <br />. compacted by wheel-rolling or tracking with a dozer to prepare the <br />surface for additional fill. <br />LORENCITO COAL COMPANY, LLC <br />NEW ELx GOAL DEVELOPMENT WASTE PITE <br />CTLR 26,600 2 <br />