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Compaction tests will be taken at a frequency and location of not less than one per every <br />other layer, at random locations across the pile. On average, when coal mine waste is <br />being placed, compaction testing occurs weekly. Test locations and results will be <br />reported to the Division in the appropriate construction reports. <br />Coal mine waste materials from activities located outside of the permit area, such as <br />those activities at other mines or abandoned waste piles, will not be placed in the coal <br />mine waste bank unless approved by the Division. <br />In accordance with Buckhorn Geotech recommendations, by report dated September 22, <br />2008, regarding taking the 5:1 gob slopes to 3:1 slopes, all subsoil and topsoil was <br />removed and stockpiled for later use. <br />Placement of additional coal waste shall commence from the bottom and proceed up the <br />slope. Additional coal waste must be keyed or benched into the existing (previously <br />placed) coal waste. The vertical cut for each key into the coal waste should be on the <br />order of 4 to 6 feet high. Keying the additional coal mine waste into the existing waste <br />will eliminate a potentially weak surface along the previous and newly places waste. If <br />any zones of seepage are encountered during the benching/keying operations, we <br />recommend construction of a gravel drain to allow drainage and relieve pore pressures. <br />Care will be taken during fill placement, keying and benching to not damage the vibrating <br />wire piezometers and inclinometers installed at CWDA. The piezometers have cables <br />that are routed through the coal waste to the bench located 50 feet above the toe of the <br />waste bank. <br />Inspection <br />The waste rock disposal area will be inspected for stability by a qualified registered <br />engineer or other qualified professional specialist experienced in construction of earth <br />and rockfill embankments under the direction of a qualified professional engineer, on a <br />quarterly basis, beginning within 7 days after the preparation of the disposal area begins. <br />In addition the area will be inspected during the following critical periods: removal of all <br />organic material and topsoil as previously described, placement of underdrainage <br />systems, installation of surface drainage systems, placement and compaction of fill <br />materials, and during revegetation. Inspections shall include such observations and <br />tests as may be necessary to evaluate the potential hazard to human life and property, to <br />ensure that all organic material and topsoil have been removed and that proper <br />construction and maintenance are occurring in accordance with the approved plan. A <br />report will be provided to the Division by the inspecting engineer within two weeks of the <br />completed inspections. A copy of this report will be kept at the mine site. <br />TR -98 -14- 01/15 <br />