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Geoteehnieal I Environmental Engine 0 • Materials Testing <br />April 8, 2011 <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 />Foidel Creek Mine, Routt County, Colorado. <br />Mr. Nettleton, <br />As requested, NWCC, Inc. (NWCC) has prepared this report outlining our observations made during the <br />first quarter of 2011 at the Refuse Pile located at Twentymile Coal Company's (TCC) Foidel Creek Mine in <br />Routt County, Colorado. During this quarter, Tim Travis of NWCC visited the project site on March 31, <br />2011 to provide the quarterly inspection/observations of the Refuse Pile. <br />In addition, a representative of NWCC visited the refuse pile on January 4, 2011 to take compaction tests in <br />the new Expansion Area of the refuse pile. A total of four compaction tests (#454 to #457) were taken in <br />Expansion Area during this quarter. All of the tests taken during this quarter met the minimum compaction <br />requirement of 90% of the maximum standard Proctor density. Copies of the compaction test results and <br />the daily field reports are attached. It should be noted that the abbreviations given in the Nuclear Density <br />Test Results (Proctor Data) are as follows: Maximum DD = Maximum Dry Density and OMC = Optimum <br />Moisture Content. Both of these values have been determined in accordance with ASTM D698. <br />At the time of our site visit on March 31, 2011, we completed a cursory site inspection of the existing <br />refuse pile. Based on our observations made during this visit, it appeared that the contractor was presently <br />stockpiling the refuse coal in the new Expansion Area. <br />The surface drainage conditions generally appeared to be adequate across the top and sides of the pile. <br />However, the shallow erosion channels located on the lower bench on the east side of the refuse pile, as <br />noted in our previous inspection report, did not appear to have been repaired. We recommend that these <br />erosion areas be re-graded so that the runoff does not concentrate in these areas and cause further erosion. <br />It should be noted that at the time of our visit, we did not observe any signs of instability, structural <br />weakness or hazardous conditions at the pile. It should also be noted that our observations were limited by <br />the amount of snow cover, approximately 6 to 12 inches, across a majority of the pile. It should also be <br />noted that the internal roadways in the new expansion area of the pile were in good condition. The upper <br />(970) 879-7888 • Fax (970) 879-7891 <br />2580 Conner Ridae Drive • Steamboat Springs, CO 80487