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W MINING, LL <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 December <br />2, 2013 visual inspections were performed of the East Yard, West Valley Fill and II West coal mine waste <br />disposal areas. On November 12, 2013 four (4) compaction tests were conducted (attached) with all meeting <br />design requirements. <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 fourth quarter, no waste material was hauled to the West Valley Fill area. <br />The refuse pile remains surveyed at the approximate 6228' elevation. The active waste storage area will <br />continue to be an interim storage area for wet refuse rehandled later to H West and a staging area for <br />miscellaneous projects. Due to the idling of the mine, the area also serves as a temporary parking lot for out -of- <br />service mine equipment. <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 Il West Coal Refuse Facility light use road and haul road. These two roads <br />continued to be utilized during the quarter. 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 West <br />Valley Fill has a potential for structural failure. <br />II WEST — The II West disposal area received 240 cy of additional coal mine waste material during the fourth <br />quarter of 2013. II West waste remains at the approximate 6141' elevation. The new 2013 regraded outslope <br />was seeded on November 7, 2013. The areas associated adjacent to the extended east surface rock channel and <br />the lower access ramp filled with refuse and covered with soil material were also seeded. Older seeded areas <br />continue to perform according to the plan. No springs or seeps were noted. Surface drainage control features are <br />performing according to the plan. The underdrain continues to be extended to the north and covered with filter <br />fabric material according to the plan. Nothing was observed during the inspection that would indicate the H West <br />Valley Fill has a potential for structural failure. <br />I pected by James A. ger <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 <br />