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• (Page 2) • MIME ID p OR PROSPECTING ID ~ M-77-215 INSPECTION DATE 6-9-99 INSPECTOR'S INITIALS SSS OBSERVATIONS This was a partial inspection of the Bulldog Mine, conducted as part of [he Division's on-going monitoring program for permitted mines in Colorado. The 9360 adit plug valve was closed on April 1,1999. The plug appeared to be working as designed, retaining all mine water withing the mine workings and the formation. Some water was dripping from the adit back, but did not appear to be in excess of dripping noted during prior inspections. The majority of the dripping was observed on the fourth timber set outby the plug face. It is assumed that this is where the grout, injected to seal the ground around the plug, directs the percolating water it intercepts from the ground above the plug. There was no evidence of mine water bypassing the plug. The pressure guage, measuring water pressure at floor level behind the plug, read 9.5 p.s.i. The operator indicated that the pressure appeared to have stabilized at that level. Homestake Mining Company (HMC) has committed to notify the Division if the pressure exceeds 11 p.s.i., indicating that the water, backed up behind the plug, is not flowing down the A-59 raise as planned. The pressure is currently monitored daily and reported monthly. The two seeps, DT-1 and DT-2, which were observed flowing from the 9360 waste rock dump toe during the 6-1-98 inspection, were not flowing during this inspection. DT-1, the downstream seep, was dry. DT-2, upstream, was not flowing but was moist. (DT-1 was flowing when sampled on April 1, 1999.) No flow from these seeps has been reported since the adit plug valve was closed, and no other seeps have been observed. Though a hydraulic connection between water inby the plug and the toe is possible, former, long-time employees of the mine (Bob Bopp and Mack Rober) indicate that flow from these seeps was observed when the mine was operating and the portal water was being collected and treated. The 9700 Level waste rock dump was inspected. Trees planted across the top of the dump continue to grow but grass seeding failed completely. HMC may wish to consider additional tree plantings across the dump. The reclamation plan indicates that the flows in Windy Gulch will be diverted away from all waste rock dumps. However, no evidence of a 9700 Level waste rock dump diversion was found. Review of the Division's file did not reveal any permitted variance to this commitment. HMC will need to address this apparent deviation from the approved mining and reclamation plan. Contrary to information in the original permit application, some material on the 9700 dump contains leachable minerals such as iron sulfides. Weathering of this material may contribute to the metals loading in Windy Gulch. HMC must indicate how the occurrence of sulfide minerals on the waste rock dump will be addressed, in terms of final reclamation, to protect surface and groundwater resources. Near the center of the 9700 waste rock dump the inspectors noted timbers, possibly from cribbing, in what appears to be a shallow, trench-like depression. The mining and reclamation plans show no indications of these structures. Whether they are part of the current operation or of previous, pre-law activities at the Nickel Plate mine is not known. The operator may want to consider stability of the 9700 waste rock dump with regard for these structures. HMC was in the process of realigning the upland water diversion for the lower tailings facility. The project is a measure to reduce the grade of the tailings pond inslope, in various areas, and use the excess material from those excavations as a growth medium on the tailings pond surface. A technical revision for this operation was submitted during the inspection. During the excavation that had already begun, topsoil had not been segregated from the other soils. The operator was instructed to salvage all available topsoil, and replace it as a top dressing on the reworked areas of the slopes and tailings pond surface. Responses to this inspection report should be sent to: Division of Minerals and Geology, 484 Turner Drive, Building F, Suite 101, Durango, Colorado 81301, Attn: Steve Shuey. Steve Shuey can also be contacted at phone no. 970-247-5062.