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Whirlwind Mine Groundwater Characterization Report <br /> dewatering phase will remove millions of gallons of groundwater that is currently flooding the <br /> lower decline and some small workings in the Salt Wash. Water currently in the flooded portion <br /> of the decline and within the workings of the Salt Wash is likely infiltrating into and being stored <br /> within the surrounding rock. Based on the last, almost 20-year period of flooding in the decline, <br /> the static water level in the decline was reached when the water level attained the elevation of <br /> the inflow point in the lower Brushy Basin sandstone in the decline. Flooding occurred because <br /> the infiltration rate in the surrounding rock was less than the inflow rate. The inflow rate has <br /> been estimated at one to two gpm. <br /> Treatment and discharge of the Whirlwind Decline water is necessary as the Brushy Basin <br /> groundwater entering the decline and water that has come into contact with the mineralized Top <br /> Rim sandstone of the Salt Wash exceeds Colorado groundwater quality standards. It is <br /> estimated that it will take 2 to 3 months to treat and discharge water that has flooded the decline <br /> and related workings. Discharged water will meet state surface water quality standards. The <br /> treated groundwater will be discharged within its watershed of origin and tributary to the Dolores <br /> River, thereby maintaining overall balance to the watershed. <br /> During the last dewatering of the decline in 2008, the treated water was discharged to the <br /> middle fork of upper Lumsden Canyon. The water ran down a side gully and infiltrated into the <br /> channel before entering the main channel of Lumsden Canyon. Discharge of the treated mine <br /> water causes an accelerated but temporary depletion of Brushy Basin groundwater. Had the <br /> Whirlwind Decline not been constructed, the Brushy Basin groundwater would have remained in <br /> the aquifer system possibly contributing to overall aquifer storage. This stored water may have <br /> discharged by way of springs or by evapotranspiration. A benefit of dewatering the decline is <br /> that previously unsaturated portions of the lower Brushy Basin and the Top Rim sandstone of <br /> the Salt Wash will no longer be subjected to a hydraulic head and potentially receiving <br /> groundwater flux (recharge) from the flooded decline. <br /> Under normal mining operations, groundwater entering the Whirlwind Decline from the lower <br /> sandstone of the Brushy Basin will continue to discharge into the mine, likely at a 1 to 2 gpm <br /> rate. Pumped water not discharged at the ground surface as described above will be used in <br /> accordance with the amounts and uses decreed in the Whirlwind Mine Well water right. Such <br /> uses will result in minor consumptive losses attributed to evaporation and retained moisture in <br /> mined product and waste materials removed from the mine. Any ambient groundwater that may <br /> Western Water& Land, Inc. 54 <br />