Laserfiche WebLink
North Anomaly <br /> The north near surface anomaly(NSA) is shown on Figure 2 of Fugro's August 23, 2016 <br /> report. The ERT survey did not show a connection between the north NSA and the air <br /> shaft. The excavation shown on Figure 14-17 uncovers a portion of the north NSA. <br /> Mitigation of this area will be to place and compact the native soils back up to original <br /> grade. <br /> Rock Pile Sinkhole <br /> The rock pile sinkhole feature is shown on Figure 14-17 and Figure 3 of Fugro's August <br /> 23, 2016 report. Although Fugro's August report identified two other horizontal <br /> anomalies, the data did not identify any horizontal anomaly extending from the rock pile <br /> feature. Water was dumped into this feature prior to the survey and as a result, any <br /> horizontal anomaly extending from this location would have been identified during the <br /> survey. During the addition of water to the rock pile sinkhole, the water reached <br /> equilibrium and overfilled, spilling out on to the adjacent ground. The water did not <br /> disappear down hole which indicates no hydrologic connectivity. No mitigation is <br /> proposed for the rock pile sinkhole. <br /> Surface Disturbance <br /> The backhoe repair plan will disturb 0.4 acres. The existing light use road encompasses <br /> 0.15 acres. If a reclaimed area involves a very small acreage, there are both practical as <br /> well as statistical limitations to success evaluations. Please see Appendix 14-16 for a <br /> discussion of how this small reclaimed area can achieve revegetation success. <br /> Sediment Control <br /> Run-off from the repair area and adjacent light use road is not directed to a sediment <br /> pond. Run-off from the light use road will flow to the Fontanari ditch or the Carey pond <br /> so there will be no offsite impacts from the light use road. Run-off from the repair area <br /> will be filtered through sediment traps. The sediment traps will be straw bales, silt <br /> fences, straw logs, straw wattles or other approved devices.The sediments traps will <br /> slow and remove sediment from repair area run-off. <br /> Topsoil <br /> In an effort to establish ground cover of living plants not less than required to control <br /> erosion and vegetation that is equal to or greater than the adjacent area, SCC will strip <br /> the top 6" of topsoil and place in a stockpile as shown in Figure 14-17. <br /> Topsoil stockpiles will be constructed to reduce erosion of the stockpiles by either wind <br /> or water. The topsoil stockpiles will be located on stable surfaces where they will not be <br /> disturbed by the mining operation. In the unlikely event this topsoil stockpile remains in <br /> place for more than ninety days it will be seeded as soon as practical and berms will be <br /> constructed around the base of stockpiles where necessary to prevent loss of topsoil <br /> material from the stockpiles. <br /> TR-69 14-35 12/16 <br />