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nsultants, Inc. ~^~~~,-t,~ t 4'" 'w°'~ Geotechnical /Environmental Engineering • Materials Tenting _ JUL 1 ~/ 2002 DIYISIOn Of Minerals and Geology July 12, 2002 Twentymile Coal Company 29515 RCR #27 Oak Creek, CO 80467 Attn: Mr. Rick Mills Job Number: 99-3983 Subject: Quarterly Observation Report, Refuse Pile, Foidel Creek Mine, Routt County, Colorado. Gentlemen: As requested, NWCC, Inc. (Northwest Colorado Consultants, Inc.) has prepared this letter outlining our observations made during the second quarter of 2002 ai the Refuse Pile, which is located at the Foidel Creek Mine in Routt County, Colorado. During this quarter, we visited the project site on May 6 and June 26, 2002 to provide our quarterly observations, as well as to test the compaction of the materials being placed and compacted. A[ the time of our site visit on May 6, 2002, we met with Mr. Rick Mills of Twentymile Coal Company to observe the conditions at the Refuse Pile. At the time of our visit, it appeared that the majority of the refuse materials (waste coal) that were produced during this visit were being stockpiled in [he south end of Area 2, where the overburden clays had been previously removed. At the time of this visit, we also noted that the client was beginning to spread and compact the fill materials in Area I and had already spread out and compacted the refuse materials in the northern portions of Area 2. Based on our observations, it appeared that the east face of the refuse pile below Bench #1 appeared stable. We did not observe any signs of slope failure, seepage or slumping in these areas. In addition, i[ appeared that the vegetation in the previously seeded slopes was starting to come in. At the time of our site visit on June 26, 2002, we conducted ten (10) compaction tests (#210 to #219) across [he portion of the refuse pile in which the compacted lift had been placed in Areas 1 and Area 2. A copy of the compaction test results and daily report are also attached. Based on the compaction test results, i[ appeared that the compaction and moisture content of the fill materials placed in these areas were highly variable. Three failing tests were recorded. Based on our observations and test results, we recommended to Rick Mills and Dave Wallace of Twentymile Coat Company that no additional materials be placed or stockpiled in these areas until the entire exposed fill surface has been scarified, thoroughly mixed and then recompacted. We recommended that our firm retest the failing test areas, as well take additional tests after they have scarified, mixed and recompacted these areas. [t should be noted that the abbreviations given in the Nuclear Density Tes[ Results (Proctor Data) aze as follows: Maximum DD =Maximum Dry Density and OMC =Optimum Moisture Content. Both of these values have been determined in accordance with (970) 879.7888 • Fax (970) 879.7891 • nwcc@cmn.net 2580 Copper Ridge Drive • P.O. Box 775226 • Steamboat Springs, CO 80477