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1987 C Pit Permit Revision 2.2 Blastine Activities Following the completion of topsoil stripping in Colt pit, overburden blast- ing will commence. Blasting procedures as outlined in Sec. 3.4 of Trapper's Mining and Reclamation Permit will be followed. Most of the area to be blasted in 1987 will occur within a horizontal dis- tance of 500 feet from the underground workings of Empire Energy Corpora- tions, Eagle No. 5 mine. Map PR-1-1 shows the area [o be blasted and Empire's underground workings that lie within the 500 foot horizontal distance of the blasting area. The underground workings shown are mostly abandoned room and pillar areas for which an estimated 85~G extraction was accomplished. No currently active headings fall within 500 horizontal feet of the planned blasting area. Trapper is requesting. a variance from the 500 horizontal feet limit for sur- face coal mining over an active or abandoned underground mine. The safety of the underground workings will no[ be compromised as more than 800 vertical feet separate the bottom of the lowest mineable seam of Col[ Pit from [he highest mineable seam of Empire's underground workings. To further insure safety of Empire's underground workers, blasting within 500 foot of the underground workings will be done during Empire's shift changes when none of [heir workers are in [he area. To insure the safety of Empire's activities, Trapper mine will use a controlled blasting schedule which will he coordi- nated with Empire Energy Corporation. By allowing Trapper to blast and subsequently surface mine this area, an improved resource recovery may be obtained from Stale Coal Lease 463-13, Federal Coal Lease C-25948 and County Coal Lease 1177ti4. The area that lies within 500 feet, horizontally, of the underground workings encompasses approxim[ely 75 acres. An estimated 930,000 tons of surface coal is recov- erable. This tonnage may be lost if not removed prior to Empire's longwall mining underneath the surface mineable coal seams. No surface water should enter [he underground workings from the surface dis- turbance and blasting. The 800 fee[ vertical separation between the workings will prevent this. Additionally, no effect is foreseen on the Twenty Mile sandstone aquifer as i[ lies more than 200 feet below [he lowest mineable surface coal. The strata separating the R coal seam (lowest coal seam to be mined) and the twenty mile sandstone, consists of materials of such low per- meability that water movement would be significantly retarded. Further sup- port concerning a negative impact on the twenty mile sandstone is supported by the Empire Energy permit concerning subsidence and the twenty mile sand- stone during longwall mining operations.