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• <br />XBOW MINING 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 March 26, <br />2012 visual inspections were performed of the East Yard, West Valley Fill and II West coal mine waste disposal <br />areas. No compaction tests were performed during the quarter due to moisture and/or freezing conditions. <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 third quarter, no waste was hauled to the West Valley Fill area. The refuse <br />pile was surveyed at the approximate 6228.6' elevation. The active waste storage area will continue to be an <br />interim storage area for refuse rehandled later to II West and a staging area for miscellaneous projects . <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 II 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 1,160 CY additional coal mine waste during the <br />first quarter of 2012. The elevation of II West is at the approximate 6119.6' elevation. The material continues to <br />be worked to meet compaction requirements. The rock underdrain crest continues to be extended to <br />accommodate additional waste. The regraded outslope seeded on December 2, 2011 is stable. The portion of the <br />outslope area seeded in 2010 remains stable with no rills or gullies. Older seeded areas are performing according <br />to the plan. No springs or seeps were noted. Surface drainage control features are performing according to the <br />plan. A portion of the East Surface Rock Channel remains temporarily covered with fabric and road materials <br />while being used as an access ramp to the pile. Nothing was observed during the inspection that would indicate <br />the II West Fill has a potential for structural failure. <br />C.(An.-s A 6 ( <br />( 1. <br />Kiger <br />by Jame ger <br />Thomas C. Anderson Date <br />Colorado Licensed Professional Engineer No. 14726 <br />3737 Hwy 1 33 • P.O. Box 535 • Somerset, Colorado 81 434 USA <br />TEL (970) 929 -5122 • FAX (970) 929 -51 77 <br />