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• The resultant drain will be covered with a filter fabric to *++;n;m;~e fines migration. The type of <br />filter fabric utilized will be based on manufactures recommendations predicated on the specifics of <br />the application. <br />Additional Geotechnical Study -Evaluation of Reclaimed Slopes <br />A geotechnical study (Tab 3), analyzes the long-term slope stability of the post-mining reclaimed <br />bench cuts. The results of the preliminary geotechnical study and an additional test boring created <br />sufficient geotechnical information for this study. The study found that the proposed reclaimed <br />fill slopes in the portal facilities area exhibited a factor of safety 1.7 and 1.9. <br />Additional Geotechnical Study -Road Cuts and Topsoil Pile <br />An additional geotechnical study (Tab 4), analyzes the slope stability at various critical cross <br />sections along the portal haul road and the topsoil stockpile. This analysis is important because it <br />predicts the long-term stability of the steeper cut and fill slopes retained along the haul road <br />during operations and post-mining land-use. Conservative factor of safety results from the study <br />varied from 1.4 to 1.5 for the haul road slopes analyzed and 1.5 to 1.6 for the topsoil stockpile <br />sections. <br />• This report recommends that a qualified person observe and assess conditions during construction <br />to identify conditions which may be detrimental to stability. BRL commits to this <br />recommendation. A qualified geotechnical observer will be on site during geotechnically sensitive <br />construction operations to observe the construction of the proposed cut and fill slopes and to <br />identify conditions which may be detrimental to stability of a slope (ground water, soft or loose <br />soils, or conditions not encountered in the Maxim borings). BRL fiuther commits to the proper <br />engineering and remediation of conditions which are determined to be detrimental to slope <br />stability. Some typical remediation techniques are presented in the report. To the extent possible, <br />slope remediation devices will be left in place after reclamation. <br />Any cut slope, fill embankment, or drainage facility design modification or mitigative implementation <br />will be discussed verbally with the DMG prior to its implementation. After construction is complete, <br />an as-built summary geotechnical construction report will be submitted to the DMG, summarizing the <br />geotechnical problems encountered, and the mitigative methods implemented during the construction. <br />The reclamation plan will be reviewed and revised if necessary to address geotechnical problems <br />encountered during site construction. <br />Slope monitoring is briefly discussed in this report. The report recommends that any indication of <br />slope movement such as tension cracks near the top of a slope or bulging near the toe should be <br />observed by a qualified person. BRL commits to this recommendation. BRL will also commit to <br />monitoring slopes that aze determined to be at risk by the above mentioned qualified person. At <br />risk slopes are defined as slopes which 1) require remediation techniques or; 2) slopes which were <br />• identified to have conditions which were potentially detrimental to stability but proper engineering <br />-3- 2/13/97 <br />