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stock pond from the area of disturbance, no surface water impacts are <br />anticipated. <br />Impacts to the surface water system for mine water dischazges have been <br />experienced. High TDS (>5,000 mg/1) in the dischazge water led to failure <br />of Whole Effluent Toxicity (VJE1~ tests from 1989 through mid 1993. The <br />WET tests were performed in cooperation with the Colorado Water Quality <br />Control Division (WQCD). WFU has taken the following measures to reduce <br />the toxicity of the effluent: <br />• On-site aeration structures were installed for HzS removal before <br />discharging the effluent. <br />• A pilot test was conducted to identify a flocculent for removing high <br />levels of oil and grease from the effluent. <br />• The main water sourrs of the mine was changed from the high TDS <br />(> 5,000 ppm) alluvial well water to a significantly lower TDS (500 <br />ppm) surface lagoon. <br />• The raw water tank was thoroughly cleaned and disinfected to remove <br />sludge built up over yeazs. The sludge was found to contain significantly <br />high levels (1,000 colonies/ml) of bacteria. <br />• An MSHA waiver was received to stop the use of Wendon Dustrol-10 <br />surfactant in the water spray at the longwall face. The surfactant has <br />been found to be lethal to fish life at 500 ppm. <br />The WQCD sent an effluent sample and prior toxicity reports to the EPA <br />laboratory in Duluth, Minnesota, to investigate the cause of toxicity. The <br />results have not yet been received. <br />During the last two quarters of 1993 and the fu•st quarter of 1994, the effluent <br />was found to be non-toxic to fathead minnows and daphnia magna. <br />3. Impact of the Mining Operation on Ground Water <br />The impact of the proposed mine on ground water will be very localized, with <br />no significant irnpact expected on a regional basis. This is due primarily to <br />the small quantity of ground water in the area. <br />Water encountered within the mine will be utilized underground for dust <br />suppression. As a result, only those inflows which temporarily exceed <br />storage capacities and mine use requirements should be discharged to the <br />surface and lost from the ground water system. However, since this water <br />would normally have been destined for the White River, its discharge to the <br />surface will not remove it from the hydrologic system. <br />16 <br />