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,0?0 <br />^ <br />VIN /MwINI,p.LL3?v ?a <br />ENGINEERING INSPECTION <br />EAST YARD, WEST VALLEY FILL AND H 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 March 16, <br />2010 visual inspections were performed of the East Yard, West Valley Fill and II West coal mine waste disposal <br />areas. Four successful compaction tests were performed during the quarter on February 16, 2010. Copies of the <br />tests are attached herein for the Division's information. <br />EAST YARD - The East Yard disposal area has reached its design capacity, and no new waste material has been <br />placed since June of 2001. The revegetated slope was inspected for signs of erosion or instability. No erosional <br />features were noted on the slope. The covering of the waste pile is considered complete. Nothing was observed <br />during the inspection that would indicate the pile has a potential for structural failure. <br />WEST VALLEY FILL - During the first quarter, no waste was hauled to the West Valley Fill area. The <br />elevation of the waste pile was surveyed at the approximate 6228.06' elevation. The active waste storage area <br />will continue to be an interim storage area for refuse rehandled to II West at a later time. <br />The revegetated outslope located between the fill slope toe to the approximate 6200' elevation was inspected for <br />signs of erosion and instability. No erosional features were noted on the slope. The third bench (approximate <br />6200' elevation) setback remains established for the final lift of waste material and the ramp constructed on the <br />waste pile to provide access to the It West Coal Refuse Facility light use road and haul road. These two roads <br />continue to be utilized. 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 West Valley Fill has a <br />potential for structural failure. <br />II WEST - The II West disposal area received approximately 1,840 CY of additional coal mine waste material <br />during the first quarter of 2010. The elevation of waste material is at the approximate 6101.9' elevation. The <br />material has been worked to meet compaction requirements. The 2009 outslope area seeded on Nqvember 19, <br />2009 appears stable with no rills or gullies. No springs or seeps were noted. Surface drainage control features <br />are 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 />V1 <br />Inspected by James A. IXiger <br />Thomas C. Anderson Date <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