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.. • Tab 25 - Bonding 1. SCC has revised the bonding calculations to account for a swell factor of 17 percent, and all appropriate worksheets have been adjusted. When using the 17 percent swell factor, the postmining landform elevations changed less than one foot over the entire area. Therefore, no changes were made to Exhibit 20-2 since they would be negligible on a map with 10- foot contour intervals. 2. The worst case disturbance year was determined from the information presented in Tables 25-2-1 and 25-2-2, and Exhibit 12-2. The last open pit area for each year was digitized to produce a polygon. These polygons were imported into the STAMP program to determine the depths of each pit (see Table 25-2-2). Pit volumes were then calculated based on an average pit width of 120 feet. The results show that 1997 does, in fact, have the greatest volume of open pit, almost twice as much volume than the next closest year. The 1997 pit data was then loaded into the RANGER program. RANGER compiled the information in Table 25-2-3, Reclamation Volumes (1997 reclamation) and the range drawing in Attachment 25-3, Worksheet No. WA-1. Therefore, we have provided to the Division the STAMP and RANGER outputs that predicted the worst case disturbance. This information is also consistent with • what has been submitted for the Seneca II and II-W bond estimates. 3. A cost for spoil sampling prior to topsoil replacement has been included in the estimate. 4. A cost for additional ripping on the contour of severely compacted final graded areas has been included in the estimate. 5. In Attachment 25-3, Mine Area Worksheets, the costs incurred to final grade the open pit area are calculated on Worksheet Nos. WA-5 through WA-7. They are also in the Cost Summary, Page 9 under Backfilling and Grading. SCC has estimated these costs using a D-11N bulldozer. This bulldozer will effectively grade the final pit area to the desired postmine contour topography. A motor grader could certainly be used in finish grade work, but that type of accuracy is not warranted for this particular project. Also, scrapers will be traveling across these graded areas to replace topsoil. A motor grader and water truck are used as support equipment in this phase of the reclamation cycle. Costs for this equipment are summarized in the FPC sheets in Attachment 25-6. 6. SCC has proposed in the postmine land use to retain a portion • of the haul road as a permanent access road. SCC will provide the Division with the necessary landowner consent forms for the proposed postmine land use by March 15, 1995. It should 25