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• BME contends that there will be no damage to the building structures in the permit area, and the only <br />use of the surface above the mine is for access and limited sheep grazing. Therefore, any subsidence <br />that may occur will not lessen the present or foreseeable use of the land. <br />III.A.7.i General Subsidence Control. BME has distributed the mining schedule to the U.S. Bureau <br />of Land Management, the only property owner within or adjacent to the area above underground <br />workings. BLM is in receipt of an R2P2 Plan for the permit area. The R2P2 Plan contains information <br />about specific areas of mining, dates of mining activities that could cause subsidence, and subsidence <br />prevention measures. <br />BME intends to abide by all State and Federal regulations to reduce possible subsidence. Any damage <br />to the surface grazing land, such as tension cracks, will immediately be filled in if found to be a safety <br />hazard to livestock. If a large number of major cracks are found to exist in a close area, BME will <br />enclose this particular area with a fence until the initial effect of subsidence has passed and the cracks <br />have started to close. <br />Underground mining will not be conducted beneath or adjacent to any perennial stream or <br />impoundment having a storage volume of 20 acre-feet or more. Stockponds and reservoirs undergoing <br />active subsidence will be monitored and measures will be taken to prevent sudden outflows of water <br />from them. <br />• III.A.7.j Red Wash and Scullion Gulch. Red Wash and Scullion Gulch are ephemeral streambeds <br />that flow only in periods of snowmelt and heavy rainfall. Red Wash traverses from north to south <br />across the eastern edge of the permit area. Scullion Gulch traverses from northwest to southeast <br />across the permit area. Parts of these drainages are expected to subside and tension fractures are <br />expected to open in the crust. <br />Due to the nature of subsidence over a longwall system the disturbance to the hydrological flow in and <br />below the drainages is expected to be minimal. Subsidence occurs in a wave action following the <br />longwall face. The extent of horizontal reaction in front of the longwall face is dependent on the angle <br />of draw. As the longwall passes, cracks will open as the ground is placed in tension and then close as <br />the stress wave proceeds beyond any given location. It is generally believed that any cracks that <br />develop in the crust will be discontinuous. <br />It was not considered possible for water to flow from the surface and enter the mine area. There was <br />600-1,200 feet of overburden above the coal seam in the Red Wash area. When the coal is extracted <br />the roof caves immediately behind the longwall. The swell of the shales and sandstones is expected to <br />soon fill the open cavity. It is expected that there will be no active collapse and caving more than 30-40 <br />• Technical Revision #65 (4/2008) III-19 <br />