_INSPECTION - C1981019 (41) - Laserfiche WebLink

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May 24,2011 C-1981-019/Colowyo Coal Mine JHB The OSM representatives concluded their portion of the inspection at this time: 2pm Tuesday 5/24/2011. Blasting Records: The inspector reviewed April 1st to May 23rd blasting records. Records are maintained in Gary Anderson's office. Field copies of drill report are in center file cabinet. Seismograph records are maintained by environmental staff. Blasting records are complete and contain information required by Rule 4.08.5. HYDROLOGIC BALANCE -Rule 4.05 Drainage Control 4.05.1,4.05.2,4.05.3; Siltation Structures 4.05.5,4.05.6; Discharge Structures 4.05.7, 4.05.10; Diversions 4.05.4;Effluent Limits 4.05.2; Ground Water Monitoring 4.05.13; Surface Water Monitoring 4.05.13; Impoundments 4.05.6,4.05.9; Stream Buffer Zones 4.05.18: Sediment ponds throughout the mine were inspected. Section 16 pond was not accessed due to muddy light use road conditions. All other ponds were visited. Prospect pond,Gulch A pond, Gossard pond, West Taylor, East Taylor and Streeter pond were discharging. Prospect Pond: 0.2 on staff gauge 30"flume= 0.81 cfs Gulch A Pond: trickle. Not measurable on staff gauge Streeter Pond: 0.1 on staff gauge 12"flume=0.12 cfs West Taylor Pond: 0.18 on staff gauge 12"flume=0.29 cfs East Taylor Pond: not measurable on staff gauge. Flume is not level. flow was on side of flume away from gauge. visual estimate—0.1+/- East Taylor Pond was full of sediment to just below the riser pipe discharge elevation. East Taylor Pond needs sediment clean out as soon as practicable. Initial observation of the discharge looked cloudy. A TSS water sample was collected at 2:47 pm 5/25. Sample was slightly cloudy at the time of collection. This sample was tested for TSS using an Imhoff cone on 5/25. Result=2.5/L. TSS was well below level of concern. A gully has formed on the outslope of East Taylor Pond adjacent to the discharge pipe. The gully extends—10 ft on the surface of the outslope and at the deepest is approximately 18". This gully ends at the point that the discharge pipe extends through the embankment. There was no moisture in the bottom of the gully other than surface precipitation. The bottom of the gully was not wet,just damp.There were no signs of instability or piping on the inslope of the pond near the discharge structure or higher up on the inslope. This feature appears to be a surficial feature that does not extend further into the embankment. The pond was discharging through the discharge pipe so there does not appear to be leakage from the discharge pipe. There was no evidence of piping through the embankment. The operator is mobilizing a backhoe to repair and pack the gully, and will continue to monitor this feature. CCC has an excavator with a large bucket mobilized for these repairs. The excavator started digging out sediment from the East Taylor light use road sumps on 5/24 to walk the equipment south to the East Taylor pond. During evaluation of the access to the pond,there was concern that this excavator was too large to clear the powerlines in the drainage. A smaller backhoe is scheduled to return to the mine on Friday 5/27. CCC committed this piece of equipment to complete the repair to the outslope of East Taylor Pond. CCC will photograph the repairs and forward them to the Division. This is acceptable to the Division. Number of Partial.Inspection this Fiscal Year: 8 Number of Complete Inspections this Fiscal Year: 4 Page 3 of 12