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longwall mining may create depressions along Scullion Gulch and Red Wash which will act as sediment <br />• traps until filled. Increased suspended solids are therefore not expected. The chemical quality (TDS, TSS, <br />total iron, pH and total manganese) of surface waters will not be adversely affected due to proper sediment <br />control. <br />II.C.S.b Impact on Groundwater The impact of the proposed mine on groundwater will be very localized, <br />with no significant impact expected on a regional basis. This is due primarity to the small quantity, low <br />transmissivities of the bedrock strata and poor quality of groundwater in the area. <br />Water encountered within the mine will be utilized as much as practicable underground for dust suppres- <br />sion, etc. As a result, only those inflows which temporarily exceed storage capacities (this is not expected <br />to occur) and mine use requirements should be discharged to the surface and lost from the groundwater <br />system. However, since this water would normally have been destined for the White River, its discharge to <br />the surface will not remove it from the hydrologic system. In fact, by removing water from the groundwater <br />system, the quality of the water flowing into the White River should be improved since less dissolution will <br />take place on the surface than would have occured 'rf the water had been allowed to flow through the rock, <br />prolonging the Ume required to reach the river. <br />Because in-flowing water will be utilized as much as is practicable in the Deserado Mine system, the only <br />water lost to the hydrologic system will be that which leaves the mine mouth as indigenous water <br />• associated with the coal and losses through mine ventilation humidity. As noted previously, this <br />groundwater will eventually make its way to the Whke River as part of the natural groundwater flow pattern. <br />As explained earlier, subsidence will generally cause fracturing for a limited distance above the mine and <br />surficial tension cracks. These surface cracks will eventually fill with sediment and debris. Groundwater <br />recharge may increase slightly while the cracks remain because they will collect some water and provide <br />increased opportunity for deep percolation. Of course, as explained earlier, the strata into which deep <br />percolation must pass greatly restricts water movement as pumping tests and monitoring indicate these <br />strata are aquitards. Consequently, the effects on the groundwater table from subsidence will be limited to <br />the area mined and should not affect adjacent areas. Mine workings may provide drains that will tend to <br />lower the groundwater table very locally. This effect is also quite insignificant because of the absence of <br />any existing or projected use of the groundwater in these formations. Any water that is intercepted and <br />used within the mine will reduce the amount that must be pumped from the alluvial wells adjacent to the <br />White River. <br />As mentioned earlier, leaks within the mine are not expected to produce more than five or ten gallons per <br />minute. If fractured zones are encountered, flows up to 100 gallons per minute or even more may be <br />encountered for a short time. These flows will diminish as equilibrium is reestablished. As mentioned <br />previously, groundwater flows within the abandoned Staley Gordon Mine are only about one gallon per <br />minute. After mining is completed, equilibrium will slowly be reestablished (i.e. the mine workings below the <br />original water table fill with water and the water table returns to a stabilized position). The Ume for this <br />Permit Renewal #3 (Rev. 1/00) II.C-84 <br />