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subsidence that may occur will not lessen the present or foreseeable use of the land. <br />I.A.6.e General SubsidenceControl. BME has distributedthe mining schedule to the U.S. Bureau of <br />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 activitiesthat could cause subsidence, and subsidence <br />prevention measures. <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 <br />undergoing active subsidencewill be monitored and measures will taken to prevent sudden outflows of <br />water from them. <br />I.A.6.f Red Wash and Scullion Gulch. Red Wash and Scullion Gulch are ephemeral stream beds <br />which 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 subsidenceover a longwall system the disturbance to the hydrologicalflow 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 <br />30-40 feet above the top of the seam. Following the initial violent caving of the immediate roof, the <br />overlying strata deflects slowly with only minimal fracturing. <br />Expert hydrological consultants were asked to predict the effect of subsidence on the Red Wash and <br />Scullion Gulch drainage areas. It was generally agreed that there will be same temporary disturbance <br />to the hydrologicalflows of the drainages. This prediction was consistent to what occurred when BME <br />mined under Red Wash. <br />Rio Blanco County Special Use Permit #81-1 <br />Exhibit B-Mining Plan <br />September2000 <br />11 <br />