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Permit Area. Cropland, residential land, and alluvial valley floor • land use areas are located outside the area of influence of mining- related surface subsidence. Only undeveloped land, rangeland, wildlife habitat, surface water resources and subsurface water resources are located within areas projected to be subjected to mining-related subsidence. Predictions of maximum surface subsidence, overburden effects of subsidence, angle of draw, and a real extent of surface subsidence were developed based on the proposed five-year mining plan. This analysis of subsidence utilized the existing, site-specific data on the mine plan as well as the geologic, hydrologic, and topographic framework. Available pitching seam subsidence data in the literature was utilized in conjunction with subsidence data for the western United States. The subsidence predictions developed for the Coal Ridge No. 1 Mine are designed to provide conservative upper limits for maximum subsidence and angles of draw. • Based on the available data, the five-year mining plan will produce sub-critical subsidence conditions. A maximum surface subsidence of 19 feet may occur, based on a maximum extraction height of 90 feet. The distribution of subsidence effects in the overburden is not expected to differ significantly from that encountered above flat- lying coal seams. Major disruption of the overburden is expected to occur only up to about 120 feet above the mining horizon, based on the anticipated 40 feet extraction height. The angle of draw will be asymmetrical with respect to the mined- out area. The angle of draw should decrease in magnitude on the up-dip (rise) side of the mined-out area and increase in magnitude on the down-dip (dip) side of the mined-out area relative to the angle of draw on a flat-lying coal seam. A rise-side draw angle of 20 degrees is projected and a dip-side draw angle of 45 degrees is . NCIG - Coal Ridge #1 4-89 ASC/1145/910509 '7~-`/