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Phase I Bond Release 2 Marr Strip Mine 720 Pit Area C-80-006 II. CRITERIA AND SCHEDULE FOR RELEASE OF PERFORMANCE BONDS Phase I -Rule 3.03.1(2)(a) states, "Up to sixty percent of the applicable amount shall be released when the permittee successfully completes backfilling, regrading, and drainage control in accordance with the approved reclamation plan:' With regard to Phase I bond release for the 720 Pit area, the approved reclamation plan calls for the following: ' backfill 720 Pit with material from adjacent overburden stockpile, reduce and backfill 720 Pit highwalls to result in stable slopes not steeper than 3.5 H:1.0 V; ` regrade disturbed areas to blend with surrounding topography and to approximate premising topography; ' install contour furrows on the steeper reclaimed slopes to aid in reducing overland flow, controlling erosion and encouraging revegetation; and ' establish permanent stable drainage pattern. Specifically excluded from this bond release request are the disturbed areas referred to as the "pre-law" reclaimed Marr Strip, the office and facilities area, the railroad loadout location, and Pit 1. The approved reclamation plan requires bacldilling, regrading, and sediment control activities for the office and facilities area, the railroad loadout, and Pit 1 area. As such, any reclamation liability or bond monies associated with the office and facilities area, the railroad loadout, and Pit 1 area will be withheld from this Phase I bond release request and decision. Also withheld from this bond release request are bond amounts associated with reclamation of sediment control structures which are required to remain at this time. III. FINDINGS AND OBSERVATIONS The approved reclamation plan calls for postmining slopes and drainage patterns to approximate premising topography. The operator has supplied map 47A, "Actual Reclaimed Topography, 720 Pit Partial Bond Release', which demonstrates that the disturbed areas of the 720 Pit have been backt-filled and regraded in accordance with the approved reclamation plan. The approved plan calls for reclaimed slopes to be no steeper than 3.SH:1.OV. Field investigations by the DMG verified that reclaimed slope gradients for the 720 Pit are within approved gradients. Material from the overburden stockpile was utilized to backfill the 720 Pit, all spoil piles and depressions have been eliminated. All highwalls associated with the 720 Pit have been eliminated. The regraded slopes do not exhibit any evidence of geotechnical instability. The permittee has submitted a slope stability analysis for the 720 Pit which shows a slope safety factor of 1.5. Rule 4.14.2(1)(b) requires a minimum static safety factor of 1.3. The final graded slopes approximate the premising slopes and contours.