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SUNDAY MINE COMPLEX-HYDROGEOLOGIC REPORT <br /> The combined low permeability and slight hydraulic gradient in the Top Rim unit aquitard are <br /> controlling characteristics for groundwater flow velocity. Even in the case of a hydraulic gradient <br /> toward the Dolores River, groundwater flow velocity is slow and the travel time along this <br /> pathway is measured in thousands of years. This flow path may be further encumbered if the <br /> Top Rim unit pinches and swells in thickness or is actually discontinuous in this area. <br /> Groundwater in the Top Rim Sandstone of the Salt Wash is likely a minimum of tens of <br /> thousands of years old and the water chemistry data support this as TDS and various <br /> constituents increase in concentration toward the syncline axis. <br /> Flooding of the mine workings will not disturb the hydrologic balance in such a way that it will <br /> cause significant environmental impact. During flooding, flow is toward the workings, not away <br /> from them. Flooding of the workings will result in a lateral displacement of Salt Wash <br /> groundwater from a saturated portion of the aquitard to an unsaturated portion. In time, the <br /> movement of groundwater to the workings will slow and cease when the static potentiometric <br /> head is achieved. If recharge rates to the aquitard do not adequately compensate for this <br /> redistribution of groundwater, then the process may have the overall effect of decreasing the <br /> ambient potentiometric head in the aquitard. This impact is expected to occur slowly, possibly <br /> over hundreds to thousands of years. Conceivably, the system will re-equilibrate and the <br /> potentiometric head may return to a semi-static"natural" condition. <br /> After static equilibrium is reached, some flow away from the mine toward Disappointment Valley <br /> and the Dolores River may occur, but this is expected to occur at very slow average linear <br /> velocities resulting in thousands of years of travel time. Water quality originating at the mine <br /> may initially be elevated in uranium, vanadium, TDS and other constituents, but with the effects <br /> of hydrodynamic dispersion, this groundwater may not differ significantly from the existing <br /> chemistry at downgradient locations. The mining/removal of the mineralized portions of the Top <br /> Rim unit will also reduce the presence of these constituents in the saturated rock in the lower <br /> mine workings. <br /> 13.0 SUMMARY AND CONCLUSIONS <br /> This hydrogeologic report was prepared to support regulatory permitting requirements for the <br /> SMC, as administered by the DRMS and the BLM. The DRMS administers the state mining <br /> permit for the SMC and the BLM administers the project under the Federal Land Policy and <br /> Management Act (FLPMA) and the National Environmental Policy Act (NEPA). The report is <br /> Western Water& Land, Inc. 52 <br />