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• 2-27ii <br />meet the criteria of 30 CFR 77.216(a) and therefore the emergency <br />spillway can be designed to handle the 25-year 24-hour event. <br />Coal mine waste is generated from the operation in the form of coal fines, <br />roof falls and other material (high-ash coaly material) scraped up from the <br />coal yard area. This material is stored in the temporary pile adjacent to <br />the coal product stockpile. This material will be blended and shipped with <br />the product when possible. Coal mine waste is also generated from coaly <br />material excavated from ditches, sediment traps and the sediment pond. <br />The annual volume of coal mine waste produced will be variable based on <br />underground mining conditions. <br />The capacity of the coal mine waste disposal area is 38,000 cubic yards <br />which is approximately 51,000 tons. The pile is approximately 40 feet <br />high. The side slopes are no steeper than 3H:1 V. No underdrain system <br />will be installed. Rule 4.09.1(13) requires that an appropriate underdrain <br />be installed if seeps, springs or waterways, natural or manmade, are in the <br />coal waste disposal footprint area. At the time of this writing, no seeps, <br />springs, or waterways, natural or manmade are identified in the coal waste <br />disposal footprint area. The site is to be inspected for springs or seeps as <br />work progresses, and an underdrain installed only for cause. This would <br />be an alternate design as permitted under Rule 4.09.1(3) and 4.10.3(5). <br />Coal mine waste will be placed and compacted to 90 percent of its <br />maximum dry density to prevent spontaneous combustion. and to provide <br />the strength required for stability of the coal mine waste pile. Compaction <br />will be performed with a variety of equipment which is operated by <br />experienced operators. The compaction specification may be attained by <br />wheel rolling the coal mine waste with a front end loader or water truck. A <br />self propelled soil compactor may be used such as a Cat 815 or 825. <br />Alternatively a pull behind sheepsfoot roller may be utilized. Any <br />equipment that can compact the coal mine waste and achieve the <br />compaction specification may be utilized. Dry densities will be determined <br />in accordance with AASHTO T99-74. The placing and spreading of the <br />coal mine waste will be started at the lowest point of the foundation. The coal <br />i mine waste will be keyed into the natural ground. Materials will be spread in <br />TR-16 Mc-Volume I 10/08 <br />