Laserfiche WebLink
Initial removal actions commenced on May 27, 2017, with early-on efforts focused on <br /> manual (hand-picking) removal of potentially deleterious foreign materials such as <br /> timbers, scrap iron, tree limbs, and other miscellaneous materials, all of which were placed <br /> in a common stockpile area located on the (approved area) bench immediately upslope of <br /> the EPF. <br /> Next, the non-authorized materials (e.g., commingled waste rock and bank-run material) <br /> were selectively excavated from atop the liner system utilizing a hydraulic excavator <br /> equipped with a smooth-edge bucket to minimize the potential for equipment-induced <br /> damage to the liner system. [Note: Inasmuch as excavator reach was favorable, and given <br /> that the in-place tailing materials were to be left in-place (as per the approved Plan), it was <br /> determined that the proposed lower level "access ramp" feature was unnecessary. <br /> Therefore, there was no importation of offsite material or utilization of localized bank run <br /> material for purposes of constructing an "access ramp"—and thus, no "clean" certification <br /> required] Approximately three-quarters of the "non-authorized material" was excavated <br /> from an upslope position and initially dropped on the existing (intact) waste rock surface <br /> immediately upslope of the impoundment feature, from which the excavated material was <br /> then immediately loaded by front-end loader and trammed to the approved location on the <br /> "1st Level" bench area that is further up-gradient of the impoundment feature, but within <br /> the designated boundaries of the EPF. <br /> VRI made a minor deviation from the approved Corrective Action Plan, in that the selected <br /> method for disposition of all "non-authorized material" was via an over-the-bank front-end <br /> loader drop from a '71 Level" bench location (next higher elevation bench), thus spoiling <br /> the material down to the approved/designated 1st Level" bench location, as per the <br /> approved Plan. This method differed from the approved Plan only in that it was initially <br /> proposed to ramp the material up into a stockpiled configuration on that same 1st Level" <br /> bench area. The over-the-bank dumping approach was deemed favorable due to the <br /> (previously unrecognized) limited areal extent of the lower bench area and anticipated <br /> equipment maneuverability concerns. [Note: The Corrective Action Plan was prepared on <br /> the basis of available aerial photogrammetry as the site was largely inaccessible due to <br /> snow accumulation at the time the Plan was prepared] <br /> Excavation work was completed on July 12, 2017, leaving minor quantities of fines (i.e., <br /> sand and silt), that could not be removed via excavator, atop the liner system. This <br /> material was therefore removed using hand shovels and brooms, and work continued <br /> through to August 10, 2017. <br /> The condition of the primary 60 mil HDPE liner component was then visually assessed by <br /> VRI. Numerous indentations were observed in addition to damaged or missing portions <br /> of the topmost component of the liner system (i.e., the non-woven geotextile drainage <br /> layer). A large proportion of the observed damage was attributed by VRI to probable <br /> equipment-induced damage incurred during the removal activities. Where areas of <br /> damaged geotextile drainage layer were observed, VRI cut out and removed the damaged <br /> 4 <br />