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August 2002 -12- 003-2203 <br />• the crown pillars blasted into the mined void. For the one lateral in Phase IVa (UG-45~, the <br />lateral crown pillaz was collapsed, ground surface graded and geogrid was then placed over the <br />area of the lateral as per the drawings. <br />All blast holes that did not intercept the underground working were completely grouted with <br />bentonite slurry prior to blasting the crown pillaz and remediating the working. <br />The Squaw Mountain Tunnel is located near the Phase I VLF boundary and extends below the <br />Phase I VLF. Given the close proximity of the Squaw Mountain Tunnel to the VLF liner <br />system, blasting of this feature was not recommended. The tunnel was remediated in the <br />following sequence: <br />- Confirmation drilling was conducted to locate the depth, limits, and <br />dimensions of the working. <br />• - Three rows of holes on five foot spacing were drilled along the length of <br />the working on the Eastern boundary of the working. Each row consisted <br />of two to three "Plug" holes and were cased with 4-inch ID PVC pipe. <br />- Three-eighths-inch poorly-graded river gravel was poured into each of the <br />Plug holes until refusal. <br />- Between the existing limits of the Phase I VLF and the western plug holes, <br />Flowfill holes were drilled. <br />- The Flowfill was poured into the filling holes until refusal and the volume <br />of Flowfill was recorded. <br />Underground working remediation activities for the Phase Na Area were performed from <br />August 2001 through May 2002. <br /> <br />~:wouzmioaoo~c<nx~oeo_~oozzao3.oaoo w~aw,:a~ Golder Associates <br />