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(Page 2) NINE ID ~ OR PROSPECTING ID f M-88-112 INSPECTION DATE 11-22-93 INSPEC'TOR'S INITIALS ACS OBSERVATIONS Activities related to Phase II - Raise 1 construction that were on-going at the time of this inspection included: 1. Strippine of overburden in the west mine pit. The overburden consists of Santa Fe Formation materials which are typically lightly cemented eiltstones, sandstones, and conglomerates; these overburden materials are being used to construct the tailings dam raise. 2. Screeninc of soils borrowed from the pit that was opened up to facilitate Phase II construction. A vibratory screening plant ie set up on the floor of the borrow pit. The screening operation has allowed the operator to exploit a portion of the borrow area that produces a soil with a lower fines content to use ae liner cover, while still being assured that no oversize rocks are placed with the liner lover. 3. Placement and compaction of Raise 1 lifts. A CAT DB dozer and a motor grader were levelling and compacting_Santa Fe Formation materials hauled directly from the west mine p~E to the north end of the raise. 4. Placement of liner cover material. A dozer was pushing liner cover material up the steep elope near the north abutment of the dam. The liner cover material was being hauled from screened stockpiles in the borrow pit. 5. Extrusion weldine of oeoevnthetic liner. Placement of Phase II geosynthetic liner was completed early in November. Serrot, the liner contractor, was recalled to cap certain seams that had subsequently failed specified peel testa of the seams. The Serrot teem was expected to complete all work on the geosynthetic liner by the end of the day of the' inspection. All activities described in the preceding list were observed during the inspection. The afternoon of this inspection was partly cloudy and unseasonably warn. Most of the snow had melted at the mine site with the exception of north slopes. No frczen or snow covered fill was observed at any of the above listed locations. There is a large area of geosynthetic liner at the east end of the. upper pond that has not been covered with drainage blanket. If weather prohibits placement of liner cover in this area, the VLDPE material will be exposed to the elements until next spring. The bank excavation of the Santa Fe Formation materials in the west pit encountered an area of blocky, more cemented conglomerate at the time of the inspection. Several truck loads of the blocky material were dumped at the current crest of the raise (the current raise crest elevation coincided with the elevation of the main embankment crest at the time of the inspection). Glen Guyer, project engineer, upon observing the blocky material, directed the west pit stripping and hauling crew to send the overburden from the west pit to a waste pile until better material for dam construction was once again encovnterec. Also, the dozer operator at the dam raise was directed to crush the blocky conglomerate with the tracks of the D8. This procedure was observed almost to its completion, it was noted that the weight of the dozer was sufficient to break down the conglomeritic boulders.