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.P <br />r.j:; <br />/-\ <br />THIItD QUARTER 2007 <br />ENGINEERING INSPECTION <br />EAST YARD, WEST VALLEY FILL AND II WEST <br />COAL MINE WASTE DISPOSAL PILES <br />The approved Oxbow Mining, LLC (OMLLC) Mine permit includes a requirement for quarterly inspections of <br />coal mine waste piles for stability. The inspection is to be performed by a registered engineer or other qualified <br />professional specialist, who is experienced in the construction of earth and rockfill embankments. On <br />September 28, 2007 visual inspections were performed of the East Yard, West Valley Fill and II West coal <br />mine waste disposal areas. Compaction testing was not performed during the quarter. <br />EAST YARD -The East Yard disposal azea has reached its design capacity, and no new waste material has <br />been placed since June of 2001. The revegetated slope was inspected for signs of erosion or instability and <br />vegetation establishment. No erosional features were noted requiring repairs to revegetated areas. The covering <br />of the waste pile is considered complete. The lower portion of the ramp was seeded in the 4"' quarter, 2006. <br />Nothing was observed during the inspection that would indicate the pile has a potential for structural failure. <br />WEST VALLEY FILL -The West Valley Fill received approximately 771 cy of additional waste material <br />during the third quarter of 2007, primarily as sediment pond cleaning material. Much of the pond cleanings <br />will be rehandled and placed into the II West disposal area. The elevation of the waste pile remains at the <br />approximate 6226' elevation. <br />The revegetated outslope located between the fill slope toe to the approximate 6200' elevation was inspected <br />for signs of erosion and instability. No erosional features were noted requiring repairs to any vegetated areas. <br />The third bench (approximate 6200 elevation) setback remains established for the fmal lift of waste material <br />and the ramp constructed on the waste pile to provide access to the II West Coal Refuse Facility light use road <br />and haul road. These two roads continue to be utilized. No springs or seeps were noted. Surface drainage <br />control features are performing according to the plan. Nothing was observed during the inspection that would <br />indicate the West Valley Fill has a potential for structural failure. <br />II WEST - The II West disposal area received 1,340 cy of additional coal mine waste material during the 3rd <br />quarter of 2007. The elevation of waste material is approximately 6068' elevation. The source of the materials <br />is primarily from pond dredging and the material is being worked to progress towards moisture and compaction <br />requirements. No compaction testing occurred during the quarter. The outslope of the pile received further <br />grading as required. No springs or seeps were noted. Surface drainage control features are performing <br />according to the plan. Nothing was observed during the inspection that would indicate the II West Fill has a <br />potential for structural failure. <br />In pected by James A. iger <br />Thomas C. Mderson a <br />Colorado Licensed Professional Engineer No. 14726 <br />3737 Hwy 133 P.O. Box 535 Somerset, Colorado 81434 USA <br />TEL (970) 929-5122 FAX (970) 929-5177 <br />