2022-04-08_PERMIT FILE - C1981044 (4)

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MT8 2.05-29 Revised 02/28/22 intervals. The ditches will be maintained until the vegetation becomes established. It is anticipated that the ditches would fill with sediment in the initial years following vegetation establishment. Therefore, no reclamation will be necessary. On completion of backfilling and grading operations, the salvaged plant growth media will be redistributed over the area. The postmining topography of the area is shown on the Reclamation Plan Map (Map 29). The regraded areas will be planted with a cover crop and subsequently drill-seeded with the appropriate seed mixture (rangeland/wildlife for sloping areas and pastureland for flatter areas). The seed will be applied with a rangeland drill at the rate of 17.25 pounds PLS/acre for the rangeland/wildlife mixture and 17.0 pounds PLS acre for the pastureland mixture. Where it is necessary to broadcast the seed, the seeding rate will be doubled. No. 9 Mine Portal Area and 7-North Angle Well As previously discussed in Section 2.05.3, Operation Plan - Permit Area, an additional coal refuse disposal site was established in the No. 9 Mine Portal Area. Prior to establishment of the refuse disposal area, electrical equipment, surface coal haulage equipment (conveyor belt system), ventilation equipment, and miscellaneous mining scrap located in the portal excavation were dismantled and removed from the site, the portal entries, located at the bottom of the portal excavation were sealed and covered with 15 feet of material, and all exposed coal seams were covered with a minimum of four feet of inert backfill material. In conjunction with coal refuse placement activities, a monitoring well was established adjacent to the coal refuse disposal area. The well is monitored on a quarterly basis, consistent with schedule and parameters outlined in Exhibit 29. Once the initial backfilling was completed, waste material including coarse reject was hauled to the waste area and placed and compacted in 2-foot lifts. Placement continued until the refuse reached a level four feet below the planned reclaimed surface. In 2008, as part of a larger site reclamation project, the No. 9 Portal Warehouse Building was demolished, a solid waste disposal site was permitted and established in the portal backfill area, and the remainder of the portal excavation and refuse area were backfilled and covered with a minimum of four feet of suitable material using materials stockpiled from the original portal excavation. The reclaimed areas were then graded to blend with the surrounding terrain and to reestablish effective drainage consistent with the design postmining topography (Refer to the Reclamation Plan Map, Map 29). The regraded surface was left in a roughened condition to minimize slippage and promote root growth and moisture infiltration. Soil material, which was temporarily stored adjacent to the No. 9 Portal Area, was redistributed over the regraded area to a depth of approximately 6 inches. The No. 9 Dewatering Installation below old County Road 13 (7-North Angle Well) is no longer needed to support ongoing or anticipated future operations and reclamation has began. The building and facilities have been removed, and plugging and sealing of the dewatering borehole is planned for 2022, consistent with applicable State Engineer requirements. The power have not been disconnected and will remain in place for the time being. On completion of sealing the well, the facilities area will be regraded. The No. 9 Dewatering Installation will be returned to a postmining land use of pastureland. The reclaimed areas either have been or will be reseeded with a cover crop and the appropriate reclamation seed mixture using a rangeland seed drill. Where necessary to apply the seed by the broadcast method, the seeding rates are doubled. It is anticipated that the area to be planted to pastureland or rangeland. No. 9 Coal Refuse Disposal Area Given the sloping topography of the refuse disposal area, initial pile construction began at its southern limits, with the initial lifts progressing to the north until the pile surface is level. Once the pile was level, construction was generally from north to south. Lift thicknesses was about 24 inches and each lift was compacted to 90 percent of maximum dry density determined by T-99 procedures. Pile construction specifications are presented in Exhibit 21, Waste Disposal Site.