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underground mining activities. As projected these impacts are localized and will most <br />probably continue in the proximity of the mined area. <br />As projected, subsidence in Red Wash initially resulted in water ponding in the stream <br />bottom. The high content of silt and clay carried by Red Wash rapidly filled the ponds. The <br />silt and clay layers have sealed any cracks that formed in the alluvium as the result of <br />subsidence. Water continues to flow in the surface channel in Red Wash. <br />3.3 Significance of Impacts to Use of Water <br />The current rate of withdrawal of water from the lagoon in the White River alluvium is well <br />below that projected at full production. Based on the current level of production and the <br />current rate of withdrawal, BME is not likely to exceed the projected withdrawal rates even at <br />higher production levels. <br />3.4 Effectiveness of Mitigation Measures <br />Mitigation measures at the Deserado Mine primarily include impoundment structures to <br />control runoff from surface sites and coal refuse piles. These structures have worked well <br />as no out of compliance discharges of 10-year runoff event and possibly contaminated water <br />from these impoundments have occurred. Reclamation of areas disturbed during <br />construction and operation is effective in controlling both erosion and suspended solids <br />during runoff events. Sediment control structures such as berms, ponds and sediment <br />fences are used to control runoff from disturbed areas until they are revegetated and <br />stabilized. <br />3.5 Changes Necessary to Minimize Impacts <br />Based on the success of mitigation measures to date and the impacts so far observed, no <br />changes in mining operations or procedures are warranted. <br />14 <br />