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III IIIIIIIIIIIIIIII` <br />999 <br />STATE OF COLORADO <br />Roy Romer, Governor <br />c <br />c° <br />DEPARTMENT OF NATURALRESOURCES <br />MINED LAND RECLAMATION DIVISION <br />FRED R. BANTA, Dlraetor <br />December 22, 1988 <br />Mr. Dennis Conn <br />West Elk Coal Company <br />P.O. Box 591 <br />Somerset, Colorado 81434 <br />RE: Lower Waste Pile Semi-Annual Monitoring Report; Mt. Gunnison No. 1 Mine, <br />C-80-007 <br />Dear Mr. Conn: <br />We have reviewed the survey monitoring and compaction test data submitted by <br />WECC on the 1st of November. The survey monument monitoring data documents <br />that the facial slopes of the partially completed waste pile are stable. <br />However, the compaction test results appear high. These results vary from <br />a relative compaction of 107.29 % to 123.13 %, with an average of 115.62%. It <br />is not impossible to achieve occasional relative compactions in this range, <br />but it is uncommon for an entire set of results to group this high. These <br />uniformly high results suggest that the Proctor density being used as the <br />optimum dry density standard may be too low. While the Division does not <br />believe that a compaction problem exists at the lower waste pile, we will <br />require West Elk Coal Company to perform a Proctor test on material obtained <br />from the current working surface of the pile in order to ensure that relative <br />compaction results are being correctly determined and reported to the Division. <br />If the results vary by more than 5 pct from the previous Proctor standard, <br />West Elk should also recalculate the results of August 25, 1988 testing and <br />submit an appropriately amended letter report. In addition, West Elk should <br />perform a Proctor Test whenever the average relative compaction results of a <br />suite of tests are less than 90.0% or more than 110%. <br />Your entire quarterly report is acceptable. P7 ease do not hesitate to ca77 if <br />you have any questions. <br />Sincerely, <br />G~ ~,' v <br />Matthew S. Hayes <br />Reclamation Specialist <br />MSH/yjb <br />2168E <br />215 Centennial Building, 1313 Sherman Street Denver, Colorado 80203-2273 Tel. (303) 866-3567 <br />