Laserfiche WebLink
-2- <br /> Rock Tunnel Underground Development Waste Structure <br /> An analogous investigation and testing program was performed at the smaller <br /> rock tunnel underground development waste disposal pile. Similarly, Geo-Hydro <br /> Consultants concluded that mudslide-type flow activity also occurred due to <br /> end-dumping of materials and grading over the crest of the temporary facial <br /> slopes. As the consultant observes, however, the eventual stability of this <br /> inter-zone material is not affected, but "That end-dumping or pushing of the <br /> material over the crest of the pile may have a very negative influence on the <br /> stability of the waste pile' s outerslopes." The Division concurs with this <br /> observation, because the compacted outer-zone slopes will eventually be <br /> constructed in areas into which the mudslides are being deposited, some <br /> portions of which are as yet undisturbed areas. <br /> Geo-Hydro recommends that the operator proceed with construction of the outer <br /> compacted slopes at this point in time, rather than waiting until later. <br /> These slopes should be built with care. Indeed, the original design <br /> recommendations called for placement in lifts not to exceed 12" in thickness <br /> and compaction to achieve 90% of standard proctor density. The consultant <br /> also recommends engineering supervision and compaction testing of this <br /> structure. <br /> The Division concurs with the recommendations of the consultant for remedial <br /> treatment of the rock tunnel underground development waste disposal pile. The <br /> consultant also recommends deletion of the originally approved terraced facial <br /> configuration. In order to obtain approval for this modification, the <br /> operator would be required to submit an appropriate revision application, <br /> including a stability analysis of the proposed amended facial configuration. <br /> /ep <br /> cc: Brian Munson <br /> Doc. No. 1430 <br />