2014-01-10_REPORT - C1982056 - Laserfiche WebLink

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Geotechnlcat I En r nmental Engineering • Materials Testing Celebrating 20 Years of elvice 1992 t 112 l_ January 9, 2014 Twentymile Coal Company 29515 RCR #27 Oak Creek, CO 80467 Attn: Mr. Jerry Nettleton Job Number: 99 -3983 Subject: Quarterly Observation Report, Refuse Pile, Foidel Creek Mine, Routt County, Colorado. Mr. Nettleton, As requested, NWCC, Inc. (NWCC) has prepared this report outlining our observations made during the fourth quarter of 2013 at the Refitse Pile located at Twentyrnile Coal Company's (TCC) Foidel Creek Mine in Routt County, Colorado. During this quarter, Timothy Travis of NWCC visited the project site on December 31, 2013 to provide the quarterly inspection/observations of the Refuse Pile. At the time of our site visit, we completed a cursory site inspection of the existing refuse pile. Based on our observations made during this visit, it appeared that the contractor was presently stockpiling and compacting the refuse coal in the new Expansion Area. At the time of our site visit the refuse coal had been placed and compacted to an elevation near the second bench along the east side of the stockpile. In addition, a representative of NWCC visited the refitse pile on October 18, 2013 to take compaction tests in the new Expansion Area of the refuse pile. A total of six compaction tests ( #506 to #511) were taken in Expansion Area during this quarter. All of the tests taken during this quarter met the minimurn compaction requirement of 90% of the maximum standard Proctor density. Copies of the compaction test results and the daily field reports are attached. It should be noted that the abbreviations given in the Nuclear Density Test Results (Proctor Data) are as follows: Maximum DD = Maximum Dry Density and OMC = Optimum Moisture Content. Both of these values have been determined in accordance with ASTM D698. It Should also be noted that at the time of our visit the majority of the refuse pile Was covered With I to 2 feet of snow. Based on our limited observations, the did not observe any signs of instability, structural weakness or hazardous conditions at the pile. The internal roadways in the new expansion area of the pile were in good condition; however, the upper haul road to Areas 2, 3 and 4 of the refuse pile Was covered with snow and these areas were not accessible. Based on limited observations, the surface drainage conditions generally appeared to be adequate across the top and sides of the pile. In addition, NWCC was advised by TCC that the drainage port and erosion channels on the haul road to Areas 2, 3 and 4 had been repaired in October. (970) 879 -7888 • Fax (970) 879 -7891 2580 Copper Ridge Drive • Steamboat Springs, CO 80487