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oraoo t,onsuitants <br />Geo[echnical /Environmental Engineering • Materials Testing <br />October 4, 2006 <br />Twentymile Coal Company <br />29515 RCR #27 <br />Oak Creek, CO 80467 <br />Attn: Mr. Jerry Nettleton <br />Job Number: 99-3983 <br />Subject: Quarterly Observation Report, Refuse Pile, <br />Poidel Creek Mine, Routt County, Colorado. <br />D-car Mr. Nettleton, <br />RECEIVED <br />OCT 1 12006 <br />Division of Reclamation, <br />Mining and Safety <br />As requested, NWCC, Inc. has prepared this report outlining om observations made during the third quarter <br />of 2006 a[ [he Refuse Pile, which is located a[ Twentymile Coal Company's (TCC) Foidel Creek Mine in <br />Routt County, Colorado. During this quarter, we visited the project site on August 9, 2006 to test the <br />compaction of [he processed waste coal being placed in Areas 2 and 2 ''/z. We also visited [he project site <br />on September 25, 2006 to provide our quarterly inspection observations. <br />At the time of our site visit on August 9, 2006, we took 4 compaction tests (#328 to #331) in Area 2'/z of <br />the refuse pile and 4 compaction tests (#332 to #335) in Area 2 of the refuse pile. All of the tests taken met <br />the minimum compaction requirement of 90% of the maximum standard Proctor density. Copies of the <br />compaction test results and the daily field report are attached. It should be noted that the abbreviations <br />given in the Nuclear Density Test Results (Proctor Data} are as follows: Maximum DD =Maximum Dry <br />Density and OMC =Optimum Moisture Content. Both of these values have been determined in accordance <br />with ASTM D698/AASHTO T99. <br />At the time of our site visit on September 25, 2005, we completed a site inspection of the pile. Based on <br />our observations made during this visit, it appeared that the contractor was presently stockpiling the refuse <br />coal in Areas 2 and 2'/z of the pile. I[ also appeared that [hey had completed removal of the previously <br />stockpiled coal from Areas 3 and 4. It appeazed that natural clays were exposed at the ground surface in <br />these areas. The surface drainage conditions generally appeazed [o be adequate across the top and sides of <br />the pile. <br />At the time of our visit, we did not observe any signs of instability, structural weakness or hazazdous <br />conditions at the pile. We did not observe any signs of instability, structural weakness or hazardous <br />conditions at the pile. <br />(970) 879-7888 • Fax (970) 879-7891 <br />2580 Copper Ridge Drive • Steamboat Springs, CO 80487 <br />