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GeotechniW I Endronmental Engineering ~ Materiah Toting <br />October 8, 2007 <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. has prepazed this report outlining ow observations made during the third quarter <br />of 2007 at the Refuse Pile, which is located a[ Twentymile Coal Company's (TCC) Foidel Creek Mine in <br />Roun County, Colorado. During this quarter, we visited [he project site on September 26, 2007 to provide <br />ow quarterly inspectionJobserva[ions. In addition, we visited the refuse pile on August 14 and 18, 2007, as <br />well as September 24, 2007 to take compaction tests in Areas 2, 2 th and 3. Four compaction tests (#354 to <br />#357) were taken on August 14, 2007 in Areas 2 and 2 1/2. Two compaction tests (#358 and #359) were <br />taken on August 18, 2007 in Area 3. Two additional compaction tests (#360 and #361) were taken on <br />September 27, 2007 in Area 3. All of the tests taken met the minimum compaction requirement of 90% of <br />the maximum standazd Proctor density. Copies of the compaction test results and the daily field report are <br />attached. It should be noted that the abbreviations given in the Nucleaz Density Test Results (Proctor Data) <br />are as follows: Maximum DD =Maximum Dry Density and OMC =Optimum Moistwe Content. Both of <br />these values have been determined in accordance with ASTM D698/AASHTO T99. <br />At the time of ow site visit on September 26, 2007, we completed site inspections of the pile. Based on our <br />observations made daring this visit, it appeared that the contractor was presently stockpiling the refuse coal <br />in Areas 2 and 3 of the pile. It should also be noted that the pond sediment materials that were being <br />stockpiled in the extreme south end of Area 3 had been removed. <br />The surface drainage conditions generally appeared to be adequate across the top and sides of the pile. It <br />should be noted that at the time of our visit, we did not observe any signs of instability, structural weakness <br />or hazardous conditions at the pile. <br />As suggested, the water levels in the monitor wells installed on October 23, 1997 and December 9, 1999 <br />were measured during this quazter on a monthly basis. A table and graphs showing the monthly water <br />levels are attached. <br />(ego) eye-rasa • Fa. (e7o) sus-peal <br />2580 Copper Ridge Drive • Steamboat Springs, CO 80487 <br />