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REC~94l~~ Northwest Colorado Consultants, Inc. NOV ~ 3 ?QQQ '4 Geocechnital /Environmental Engineering • Materials Testing Bivision of Minerals and Geology October 31, 2000 ~ Twentymile Coal Company _ 29515 RCR N27 Oak Creek, CO 80467 Attn: Mr. Rick Mills lob No. 99-3983 Subject: Qurterly Inspection Report, Refuse Pile, _ _Foidel Creek Mine, Routt County, Colorado. Ladies & Gentlemen; As requested, NWCC, Inc. (Northwest Colorado Consultants, Inc.) has prepazed this letter outlining our inspections made during [he third quarter of 2000 at the Refuse Pile, which is located a[ the Foidel Creek Mine in Routt County, Colorado. During [his quazter, we visited the project site on September 7 and 15, 2000 to test the compaction of the waste coal materials being placed and compacted, as well as to provide our quarterly inspections. At the time of our site visit on September 7, 2000, we conducted six (6) compaction tests (N186 to H191) across [he portion of the waste coal azea in which the compacted lift had been placed in Areas 1 and 2. A copy of the compaction test results and daily report are also 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 de[etirtined in accordance with ASTM D698lAASHTO T99. We also visited the site on September I5, 2000 and met with Mr. Rick Mills to inspect the conditions at [he Refuse Pile. Based on our observations, it appeared that the contractor had spent a considerable amount of time regrading the previously compacted fill materials to improve the surface drainage features at the site. In fact, [he surface drainage conditions at the site were greatly improved and appeared to be in very good condition. It should be noted that we did not observe any adverse drainage or geotechnical conditions at the time of our site visit. Based on our part-time observations and inspections, it appears that the waste coal materials that were recently tested, were placed and compacted in general accordance with [he project plans and specifications. As suggested in our previous quazterly report, [he water levels in the monitor wells installed on October 23, 1997 and December 9, 1999 were measured during this quarter on a monthly basis. A graph showing the monthly water levels is attached. (970) 879.7888 • Fax (970) 879.7897 2063 Snow Bowl Plaza, P.O. Box 775226 • Steamboat Springs, CO 80477