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aao <br />Geotechnlcai f Environmenul Engineering • Materials TertinE <br />April 8, 2008 <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 prepared this report outlining our observations made during the first quarter <br />of 2008 at the Refuse Pile, which is located at Twentymile Coal Company's (TCC} Foidel Creek Mine in <br />Routt County, Colorado. During this quarter, we visited the project site on March 18, 2008 to provide our <br />quarterly inspectioNobservations. In addition, we visited the refuse pile on January '/, I:'ebtuary 2U and <br />March 19, 2008 to take compaction tests in Area 3. Nine compaction tests (#365 to #373) were taken in <br />Area 3 during these visits. AlI of the tests taken met the minimum compaction requirement of 90% of the <br />maximum standard 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 Nuclear Density Test Results (Proctor Data) <br />are as follows: Maximum DD =Maximum Dry Density and OMC =Optimum Moisture Content. Both of <br />these values have been determined in accordance with ASTM D698/AASHTO T99. <br />At the time of our site visit on March 18, 2008, we completed site inspections of the pile. Based on our <br />observations made during this visit, it appeared that the contractor was presently stockpiling the refuse coal <br />in Area 3 of the pile. <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. It should be noted that the pile was covered with 6 to 18 inches of snow <br />at the time of our site visit, with the exception of portion of Area 3 in which the refuse coal was being <br />stockpiled. It should also be noted that the roadways throughout the pile were severely rutted and a <br />considerable amount of runoff was flowing down the ruts in the roadway surface. <br />As suggested, the water levels in the monitor wells installed on October 23, 1997 and December 9, 1999 <br />were measured during this quarter on a monthly basis. A table and graphs showing the monthly water <br />levels are attached. <br />(970) 879-7888 • Fex (970) 879-7891 <br />2580 Copper Ridge Drive • Steamboat Springs, CO 80487 <br />