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III IIIIIIIIIIIII III <br />STATE OF COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />Department of Nawral Resources <br />1513 Sherman SL, Room 215 <br />Dem•er, Colorado 80203 <br />Phnne: 13(131 86h-3567 <br />FAX: 13031 832 8106 <br />DATE: December 20, 1995 <br />T0: Christine Johnston <br />FROM: Jim Pendleton <br />RE: 3rd Quarter <br />Mine Site I~S.~ <br />Coal Company, <br />No. C-80-007" <br /> <br />~r`` <br />DEPARTh1ENT OF <br />NATURAL. <br />RESOURCES <br />Ruy Rnmer <br />Guvernrn <br />lames S Lochhcad <br />E~ecu~ive Dueaor <br />Michael B. Lonti <br />Division Direr~nr <br />r5, nd, Stockpile and <br />ion Reports, Mountain <br />West Elk Mine, Permit <br />I have reviewed the collection of materials you forwarded to my <br />attention, which included the third quarter 1995 compaction <br />monitoring for the lower waste pile and lone pine stockpile at the <br />West Elk Mine. That packet included compaction reports and proctor <br />test records conducted at the two piles during the third quarter of <br />1995. <br />Proctor Test Reporting Inconsistencies <br />The compaction test report for the lower refuse pile includes a <br />proctor test curve, used to develop the standard used for <br />comparison for the September 1, 1995 compaction determinations (lab <br />number 6049). The summary sheet lists the "Maximum Dry Density" as <br />83.0 pcf, but the plotted curve indicates 93.0 pcf. Obviously this <br />discrepancy needs to be resolved. If 93.0 pcf is the actual <br />proctor maximum dry density, two of the ten measured field <br />densities would be below the specified 90% relative compaction. <br />After discovering the discrepancy, I reviewed past compaction test <br />reports. An analogous discrepancy exists on the proctor summary <br />report sheet for the proctor test conducted on April 27, 1995 (lab <br />number 5830). This proctor summary sheet, also conducted on <br />materials from the lower refuse pile, lists the "Maximum Dry <br />Density" as 77.5 pcf, but the plotted curve indicates 87.5 pcf. In <br />this case, if 87.5 pcf were the actual proctor maximum dry density, <br />seven of the ten measured field densities would be below the <br />specified 90% relative compaction. <br />Lambert and Associates should examine the original proctor test <br />data sheet to determine whether these errors were graphical or <br />actual. If the error is actual, Mountain Coal will need to retest <br />