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r ~ • (Page 2) • MINE ID ~ OR PROSPECTING ID }` lS-94-117 INSPECTION DATE X5/95 INSPECTOR'S INITIALS ACS Tailing Pond Observations The fold-over in the flexible membrane liner, located near the center of the upstream face of the dam, and that was identified during the 11/30/95 site inspection, had been acceptably repaired. Several cuts in the liner at the back of the pond remain to be repaired, including 5 or 6 that may be below the elevation of the tailing dam crest. It is reiterated here that all liner flaws and defects must be repaired using an extrusion welding apparatus, and that all z~epaire must be vacuum tested. It is the operator's responsibility to carefully examine the entire lined area and identify any flaws that exist. The ^ivieion has not yet received the certification report for the liner repairs that were completed by In-Line Plastics of Houston, Texas. Final acceptance of these repairs will not be granted until the certification report ie submitted and found to be acceptable. The certification report should include subgrade acceptance by the liner contractor, ae well ae a eta:tement that the repairs were completed in general accordance with the In-Line Plastics, Inc. QA/QC Manual, and a statement that all accessible repairs were vacuum tested. Haze:L-A Adit Observations A complete inspection of the Hazel-A ad it was conducted in order to assess the tailing slimes removal project. The operator reported that the vacuum truck used to suck the tailing out of the ad it had completed the job on 12/3/95. The entirety of the Hazel-A underground work:inge were inspected. The operator reported that water from the tailing pond was pumped into the decant eyetem, and used to wash down the ribs and sill of the ad it, and to direct all detritus toward the vacuum intake. The tailing removal was found to be well done, and is acceptable to the Division. The high water line in the ad it was clearly visible on the rib, and demonstrates that the adit was driven at an upward gradient, thus limiting the water storage capacity in the adit. The operator is required to survey the adit and report the storage capacity available behind the bulkhead to the Division. The Hazel-A adit has intersected several minor, near vertical shear zones that are oriented perpendicular to the axis of the ad it. Stub drifts had been driven along these minor shear zones at several locations, the longest of which is approximately 85 feet and is located just inby of the bulkhead. It appears that the majority of the ground water inflow to the Hazel-A ad it occurs at these zones. Four steel-cased bore-holes were observed in the Bill of the ad it at a point where the water line on the rib indicated that water would be about one foot deep when the adit ie filled to capa~~ity. By dropping a piece of core down these holes, it was determined that they could be several tens of feet deep. The operator was directed to seal these bore-holes eo that they do not act as an infiltration gallery to ground water when the adit is flooded with prow=_se water. At the time of this inspection, the operator still had to rebuild and re-seal the Hazel-A bulkhead in accordance with the plan approved on 11/22/95. This plan includes caulking the joints between the bulkhead and the ribs, and lapping the bulkhead plastic liner to the rib using a rubberized latex paint (swimming pool paint). The plastic should be lapped to the rib using a fiberglass or similar mesh. Also, the sump-pump and pump-back eyetem needed to be reestablished behind the coffer-dam outby of the bulkhead. Other Observations The +irea behind the tailing pond that was compacted by the vacuum truck needs to be scarified and needed. This was listed as a compliance issue in the 11/30/95 inspection report for the Gold Hill Mill.