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<br />Rich Domingue -2- July 23, 1982 <br />by observing; <br />"Our experience in the area has been that virtually all cuts in the <br />access road are founded in the bedrock. The slope stability model <br />utilized in this analysis is predicated on that assumption. Based <br />on the results of our analysis, we feel a moderate to very stable <br />condition will exist wherever excavations penetrate a thickness of <br />not more than 13 feet of colluvial soil (measured perpendicular to <br />the slope face). <br />If exceeding the maximum depth of colluvium cannot be avoided, we <br />~•~ould recommend that the excavated slope be flattened as close as <br />possible to approximate natural slope conditions or other methods <br />of shoring the slope be utilized." (Page 3, Rocky Mountain~Geo- <br />cal Report, 17ay 26, 2982.) <br />This report and the supplemental permit materials submitted by the operator <br />fail to discuss the implications of a rather Large landslide ~~~hich occurred <br />in conjunction with an unpermi.tted z•oad excavation by the operator in an <br />area adjoining the haul road. Blue Ribbon Coal, in an effort to retrieve <br />equipment from an abandoned exhaust fan portal adjoining the site, enlarged <br />road cut slopes on an old, pre-law access road. ~~ring the relatively high <br />precipitation spring and summer of 1982, a landslide originated above those <br />enlarged road cuts, resulting in continued movement of colluvial material <br />onto the enlarged roadway. The consultant should address the implications of <br />this series of events on the immediately adjoining slope. <br />Assuming that the implication of this event does not affect the technical <br />conclusions within the consultant's analysis, Blue Ribbon Coal Company should <br />be required to resolve the following remaining deficiencies: <br />(1) A map of the haul road area should be prepared which specifically <br />indicates those intervals of the haul road cut slopes which expose greater <br />than 8.5 feet of colluvium. These areas constitute the potentially sub- <br />standard static slope safety factor portions addressed by the consultant. <br />(2) For those areas i~~hich are substandard, as indicated on the map <br />addressed above, the applicant should propose appropriate remedial activities, <br />such as the slope reduction or shoring methods suggested ~•~ithin the consultant's <br />concluding remarks. <br />(3) The applicant should amend its discussion included within the "Reclama- <br />tion Plan" (Section 2.05.4, pa ye 108) portion~of its amended application to <br />sp~cificaZly commit to an analysis of the proposed reclaimed configuration <br />for the haul road, in conjunction with its earlier commitment to complete an <br />analysis of the stability of the proposed portal bench backfilled configuration. <br />