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(Page 2) • MINE ID # OR PROSPECTING ID # M-77-2 INSPECTION DATE 11-13-97 INSPECTOR'S INITIALS SSS OBSERVATIONS This partial inspection was conducted to evaluate the portal re-opening process and mine drainage problems encountered due to higher-than-expected discharge volumes. The miners were slowly removing the roof fall material approximately 300 feet inby the portal, at what ie termed "Daylight Curve". Water was issuing from the pile of material at a height of approximately 2.5 to 3 ft. above the floor. The mine discharge flow that day was measured at 35 g.p.m. The discharge is clear and recent field parameters have the pH at the mid 6's. The operator indicated that the discharge through the pile was issuing out along the roof timbers when the high flows were first encountered approximately 11-6-97. There was water dripping from the roof every several feet as we proceeded into the 6390 adit. Water staining inside the portal seems to indicate that water level behind the bulkhead, before it's removal was approximately 4.5 to S ft. above the floor. The operator indicated that the roof above the full set timbers, in the area of daylight curve, is approximately 30 ft. up for as far as he can see in both directions. This is of concern because of possible subsidence to the county road which lies approximately 200 ft. above. Homestake will need to address this concern. There were three of the five or six sprinkler sets operating to dissipate the 35 g.p.m. mine discharge. Ice mounds were building up around the sprinkler heads and were also built up around the non-operating sets. The temperature was cold and no evidence of melting was noted around the non-operating sets. The operating sets had runoff that was observed flowing into a puddle at the crest of the waste dump, near where Windy Gulch rises to the level of the top of the dump. Though water was flowing into the puddle, it was not discharging. It is evident that this water is infiltrating into the dump at a point where it most assuredly makes its way into Windy Gulch. Homestake must address this problem and prevent it from occurring in the future. If operation of all sprinkler sets does not disperse the water enough to prevent surface accumulation and infiltration into or through the waste dump, then the operator will need to use the infiltration trench to lower the volume of water that the sprinklers have to handle or propose some other remedial action. The infiltration trench was not being used at the time of inspection. No springs were noted along windy gulch from the 6390 portal level down to the toe of the waste dump. No flow was heard trickling beneath the surface rock in Windy Gulch along the toe of the dump. I & E Contact Address cc: Tom Gillis, DMG ^ CE NAME Alan Cox ^ gL OPERATOR Homestake Mining Comoany! ^ FS STREET 6 0 ai; o nia ^ HW CITY/STATE/ZIP can F an ;s o al;fnrn;a aaina ^ HMWMD (CH) ^ SE ^ WQCD (CH) ^ OTHER