2012-01-06_GENERAL DOCUMENTS - C1982057

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original application were completed prior to submittal in 1982. Subsequently, in connection with operations at the existing Seneca II Mine, the applicant has completed topographic observations of reclaimed land. These aerial observations have determined that the actual bulking factor slightly exceeded the original projection (19.8% in the operator's terminology, versus 15.3 % projection). In completing its review of the amended application, the Division converted the applicant's analytical projections into an analytical format more familiar to the Division. The applicant projected an average overburden swell factor (loose swollen overburden volume divided by bank overburden volume) of 1.32. Further, the applicant projected a bulking factor (swollen backfilled volume divided by excavated pit volume) of 0.91. Considering the average mined depth and extracted seam thickness, this suggests an average post- mining topographic deflation of 4.6 feet. Adjusted for the possible 4.5 percent discrepancy in observed versus original projected bulking discussed above, the post- mining topography might rise by an additional 1.8 feet, resulting in an average post- mining topographic deflation of 2.8 feet. In either case, the projected post- mining topographic configuration is considered by the Division to constitute an acceptable approximate original contour configuration. In the first permit term, the Division approved a reclamation plan allowing a delay in contemporaneous reclamation under Rule 4.14. l(1)(c). The approval was granted due to the nature of the operation plan, which involved concurrent mining of two separate mining areas (north and south) with a single dragline, in the original permit area. Pit development in both the north and south blocks began with an initial box cut. Development progressed from each box cut in opposite directions at different times during the operations plan. The sequence of pit development did not allow for backfilling and grading to be completed within 180 days of coal removal. At the point of maximum disturbance, there were projected to be two open pits within each mining block. Pursuant to Rule 4.14.1(1)(c), the Division approved a variance from the requirement that rough backfilling and grading be conducted within 180 days following coal removal. This variance applied to the entire original permit area. In addition, a variance from the requirement that there be no more than 4 spoil ridges behind the pit currently being work was approved for a 25.5 acre area of the north block and a 41.8 acre area of the south block, within the original permit area. Rough backfilling and grading had been completed throughout the original permit area as of October 2004, with the exception of a 300 foot segment of the Wadge "ridgeline pit" along the eastern ridgeline, at the extreme southern end of the original permit area. Most of this pit is within the south extension area, and it was subject to a separate variance approval and backfilling deadline, addressed below. Seneca II -W Findings Document 45 C- 1982 -057 Permit Revision No. 6 January 6, 2012