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XVI. BACKFILLING AND GRADING (Rules 2.05.5(6), 2.05.4(2)(a)&(c), 4.13 & 4.14) The application observes that the mining plan for Seneca II-W was developed in conjunction with~the Seneca II Mining Plan. The pit progression design was based on standard mining practices, tried and proven at the analogous Seneca II Mine. The mining plan and its backfilling and grading details are found within TAB 12. The applicant completed projections of overburden bulking, in order to project post-mining topography within the mined area. The projections included within the original application were completed prior to submittal of the original application in 1982. Subsequently, in connection with operations at the existing Seneca II mine, the applicant has completed topographic observations of reclaimed land. These aerophotogrammetric 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 projects an average overburden swell factor (loose swollen overburden volume divided by bank overburden volume) of 1.32. Further, the applicant projects 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. The amended reclamation plan requests approval for delay in contemporaneous reclamation, as allowed under Rule 4.14.1(1)(c). This request is necessitated by the amended mine plan. The original plan called for deposition of boxcut spoil outside the mined pit. However, in response to Division adequacy concerns, that plan was amended to eliminate the deposition of box cut spoil outside the mined area. This mine plan modification resulted in the rehandling of the box cut spoil, which will remain unreclaimed from 1985 though 1987. The applicant does not propose to temporarily reclaim this area, because the vegetation would have an insufficient growing season prior to permanent reclamation. A second area for which the applicant requests variance from the normal contemporaneity requirements is northwest of the box cut location, near the end of the 1986 mined area (see Map 12-1). At that time the dragline will return to the box cut location. This will leave approximately 3,200 feet of open pit, and at least several rows of ungraded spoil piles. This area cannot be permanently reclaimed until mining recommences in 1991 and progresses further toward the northwest. A similar situation in encountered near the southeast terminus of the mined area in 1990. Approximately 3,400 feet of pit will be left open at that location for two years. The Division finds the requested variances from strict contemporaneity to be permissable.