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Mar 24 03 04:37p <br />Mar 24 03 03: 24p <br />NWCC, INC. <br />970-879-7891 <br />P•J <br />~iECEIVE~ <br />emtech~ial / EnirnnmeNal EnaiM'ering' <br />Subject: Raise Bore Cuttings, Refuse Pile, Foidel <br />Creek Mine, Rautt County, Colorado. <br />Gentlemen; <br />December S, 2002 <br />Twen[ymile Coal Company <br />295 i 5 RCR /t27 <br />Oak Crak, CO 80467 <br />Attu; Mt. Rick Mills <br />Job Numbar; 99-3963 <br />~`tAR 2 4 200 <br />p.2 <br />[)hrision of Minerals & GsolOg~ <br />As requested, NWCC, Inc. (Northwest Cnloreda Consultants, fnc.) has prepared this report summarving <br />the laboratory test results conducted on a sample of the Raise Bore Cuttings, as well as to provide our <br />recommendations regarding the placement of these materials in the Refuse Pile that is located on the Foidol <br />Creek Minc in Routt County, Colorado. <br />As requested we visited the subject mine on November 5, 2002 and obtained a representative sample of the <br />Raise Borc Cuuings from dre temporary stockpiles that are situated to the east-northeast of the Refuse Pile. <br />The large disturbed bulk sample was delivered w our laboratory for standard Proctor and classification <br />testing, <br />The laboratory test results, which are shown in the attached figure, and our visual observations made of the <br />stockpiles indicate that the cuttings typically wnsist of a mixture of sandstone and coal fragments. The <br />slandanl Proctor test results indicate that the sample had a maximum remolded density of 86.5 pcf and an <br />optimum moisture content of I5.3 percent. Based on the classification rest results, these materials were <br />very low plastic and generally classified as a SM-GM soil in accordance with the Unifced Soil <br />Classification System. <br />Based on the laboratory test results, our observations of the temporary stockpiles and our experience with <br />the materials presently being placed in the Refuse Pile, we believe that the Raise Borc Cuuings will not <br />have any adverse affects on the stability of the Refuse Pile if they are properly placed and compacted. It <br />should be noted that t t results obtained on the sample described above were very similar [o the values <br />obtained on the waste oat aterial~presently being placed in the stockpile. <br />If you have any q s[' ns regaz~ing this report, our observations or the Inboretory test results, please <br />contact this office. <br />NORTNWESf COL RAD rNi~,42 <br />Briars ll. L z y:. 257 50 <br />(97D) 879.78~`6;M~swr(9h'a) 879.7891 • nwcclQmindslaring,com <br />2590 Copper Ridge Drive • P.O. Box 775226 • Steamboat Springs, CO 80477 <br />