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Coal Resource Protection and Conservation <br />Mining at Yoast involves extraction of a single coal seam having varying overburden depths. The • <br />initial choice of mining equipment type and size was based upon the type of mining conditions, <br />production requirements, the life of the mining operation, types and thicknesses of overburden, <br />localand regional dip, and thickness of the coal seam. Experience in mining at Yoast has resulted in <br />the anticipated mix of excavation and support equipment. Auxiliary equipment has been matched to <br />the primary excavator and its capabilities. Mining activities are conducted to maximize the recovery of <br />coal while maintaining environmental integrity. <br />During reserve development, all the coal encountered during drilling is recorded. The correlatable and <br />estimated mineable seams are cored and analyzed. These data are utilized to finally determine <br />mineable reserves. The quality of the seams as well as their occurrence in the geologic column is <br />considered when determining whether the seam is mineable or nonmineable. <br />The design of the cut widths are based upon the machine performing the excavation to prevent the <br />pits from becoming too wide resulting in spoil material being placed on uncovered coal and leaving <br />coal fenders. Sloughing of spoil material onto uncovered coal is anticipated to occur infrequently. If <br />sloughing should occur, auxiliary equipment will be utilized to remove the spoil material so that the <br />coal can be removed. All coal fenders will be mined. Negligible amounts of coal should be lost • <br />because of either of these two conditions. Further, it is in the operators best interest to recover the <br />maximum amount of coal possible once the overburden has been removed and the coal seam exposed. <br />The efficiency of [he mining operations can be measured by the number of tons of coal produced per <br />acre foot ITPAFI. Based on drill hole data regarding seam thickness, coal partings, and extent and <br />laboratory analysis of specific gravity 11.301, in-place reserves are estimated to be 1,760 tons per acre <br />foot. Actual production will be calculated monthly using scale measurements and stockpile <br />fluctuations. This production would be defined through the use of monthly aerial or engineering <br />surveys to an area where coal was actually removed to produce the TPAF recovered for each month. <br />The historical average recovery for the Seneca II-W mine is approximately 91 percent. Mined tonnage <br />is, therefore, estimated at 1,620 TPAF. This recovery is well within industry standards (Wood, 19631. <br />Although uncommon at the neighboring Seneca II and II-W Mines, coal fires may occur in the mined <br />cut and spoil, coal handling facilities, or reclaimed highwalls. It is in Seneca's best interest to control <br />fires and prevent loss of coal resource. Burning coal in these areas will be extinguished by removing <br />and mixing the material with noncombustible material to the extent practicable and burial with at least <br />four feet of noncombustible material, if appropriate. Water may be utilized in the coal handling <br />facilities. • <br />9c Revised 7/99 <br />