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<br />Bob Liddle <br />-2- <br />June 22, 1983 <br />The analysis observes; "Under most conditions analyzed the bench slopes below <br />the portal were found to have theoretical factors of safety less than 1.0." <br />This observation has been verified by failure of the bench this spring, a <br />reoccurrence of previous failures in past years. The consultant recommends <br />that the bench .. be regraded to a slope of 250 or less with utilization <br />of a cut and fill balance approach." The operator should commit to, and <br />expand, this proposal. Appropriate cross-sections and plan view maps should <br />be included within the amended permit documents. <br />The analysis presents three options for backfilling and reyrading of the slope <br />above the portal bench. The operator will have to clarify exactly what option <br />it intends to utilize. Appropriate cross-sections and plan view maps should <br />be included within the amended permit documents. <br />Stipulation No. 3, as included within the permit findings, required the <br />"analysis of the proposed backfill configuration of all mine facilities and <br />the haul road." The stipulation response document does not appear to address <br />the reclamation of the haul road, and must be amended to address reclamation <br />of the haul road. <br />The report prepared by Rocky Mountain Geotechnical, Inc. recommends the <br />installation and maintenance of ground water monitoring piezometers and slope <br />stability survey monuments. The operator should specifically commit to the <br />installation and maintenance of these monitoring facilities within the amended <br />permit documents. <br />/mt <br />cc: Ed Bischoff <br />Doc. No. 3708 <br />