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<br />~OVI/ ~ill-Olt-NG, LLC <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 />December 18, 2007 visual inspections were performed of the East Yard, West Valley Fill and II West coal mine <br />waste disposal areas. Six successful compaction tests were performed during the quarter on November 7, 2007. <br />Copies of the test are attached. <br />EAST YARD -The East Yard disposal area 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 - 300 cy of waste were rehandled from the West Valley Fill to II West during the <br />Fourth quarter. The original source of the material was Pond B cleanings moved to WVF earlier in the year and <br />allowed to dry. The elevation of the waste pile remains at the approximate 6227' elevation. <br />The revegetated outslope located between the fill slope tce 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 760 cy of additional coal mine waste material during the 4th <br />quarter of 2007. The elevation of waste material is approximately 6070' 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. Successful compaction testing occurred during the quarter. The outslope of the pile received <br />further grading and seeding as required. No springs or seeps were noted. Surface drainage control features are <br />performing according to the plan. Nothing was observed during the inspection that would indicate the II West <br />Fill has a potential for structural failure. <br />;~- <br />`'" ~,POOr~o9 <br />G ~~1~~ <br />Date <br />Engineer No. 14726 <br />••~~ <br />373~'ti~ r_~ ~°;','~ P.O. Box 535 Somerset, Colorado 81434 USA <br />TEL (970) 929-5122 FAX (970) 929-5177 <br />