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• magnitude on the down-dip (dip) side of the mined-out area <br />~ relative to the angle of draw on a flat-lying coal seam. A <br /> rise-side draw angle of 20° is projected and a dip-side draw angle <br /> of 45° is projected. <br /> The subsidence effects from the 5-year mining plan are not <br /> expected to change the pre-mining and post-mining use for the <br /> structures and renewable resource lands within and adjacent to the <br /> proposed permit area. All existing structures and proposed mine <br /> facilities are located outside the area of mining-related <br /> subsidence. The croplands, residential lands and alluvial valley <br /> floor areas are also located outside the area of mining-related <br /> subsidence. Undeveloped land constitutes the majority of the <br /> existing land use within the areas potentially subject to <br /> mining-related surface subsidence. Rangeland, wildlife habitat, <br /> surface water resource land and subsurface water resource land are <br /> also located within the area potentially subjected to subsidence. <br /> However, in all cases, the pre-mining and post-mining land use is <br /> expected to remain the same for renewable resource lands subjected <br />;• to mining-related subsidence. <br /> A limited monitoring program consisting of installed <br /> monitoring points and observations of the surface is proposed. A <br /> monitoring line will be positioned above the area where the <br /> maximum anticipated open span should occur as a result of the <br /> S-year mining plan. During surveys of the monitoring line, Storm <br /> King proposes to make observations of the surface to determine the <br /> existence, development and magnitude of surface cracking, should <br /> it occur. The surface area above the mine is remote, inaccessible <br /> and subject to heavy snow accumulations during the winter. Access <br /> is difficult and time consuming under the best of conditions. The <br /> location of the monitoring line, as well as the installation and <br /> monitoring schedules, will be a function of weather conditions, <br /> site accessibility and mining schedules. <br /> The worst possible consequences analysis of subsidence <br /> indicates that the development of sinkhole subsidence and slope <br /> instability are low probability events. STORM KING has outlined <br /> proposed mitigation measures in the unlikely event that sinkhole <br /> subsidence occurs or slope instability develops. <br />(Rev. 05/24/84) <br />page 3 <br />