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C-IQga-osc~ rthwest Geotechnical /Environmental Engineering • Materials Testing October ]0, 2004 Twentymile Coal Company 2951 S 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. RECEIVEp ocr 14 2ooa Division of fginerals S Ge°lo9Y Mr. Nettleton, As requested, NWCC, Inc. has prepared this report outlining our observations made during the third quarter of 2004 at the Refuse Pile, which is located at Twentymile Coal Company's (TCC) Foidel Creek Mine in Routt County, Colorado. During this quarter, we visited the project site on July 6, 14 and 22, 2004 to test the compaction of the waste coal materials being placed and compacted in Area 2`h. We also visited the project site on September 28, 2004 to provide our quarterly inspection/observations. At the time of our site visit on July 6, 2004, we took four (4) compaction tests (#278 to #281) across Area 2'/z of the refuse pile. All of the tests taken met the minimum compaction requirement of 90% of the maximum standard Proctor density. We visited the site a second time on July 14, 2004 and took compaction tests on the fill materials placed in Area 2%,. We took four (4) compaction tests (#282 to #285) on this date. All of the tests taken on this date met the minimum compaction requirement of 90% of the maximum standard Proctor density. We visited the site a third time on July 22, 2004 and took compaction tests on the fill materials placed in Area 2%z. We took three (3) compaction tests (#286 to #288) on this date. All of the tests taken on this date met the minimum compaction requirement of 90% of the maximum standard Proctor density. Copies of the compaction test results and the daily field report 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/AASHTO T99. At the time of our site visit on September 28, 2004 we met with Jerry Nettleton of RAG/Twentymile Coal Company at his office. Mr. Len and Mr. Nettleton completed a site inspection on this date. Based on our observations made during this visit, it appeared that the contractor was pushing the previously stockpiled materials in Area 3 to Area 2% and [hen compacting them with the dozer. We also observed that they were currently stockpiling the refuse materials in Areas 1 and 2. At the.time of our visit, we did not observe any signs of instability, structural weakness or hazardous conditions at the pile. (970) 879.7888 • Fax (970) 879.7891 2580 Copper Ridge Drive • P.O. Box 775226 • Steamboat Springs, CO 80477