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Exhibit G <br />Water Information <br />Operations at the Topaz Mine are not expected to directly affect surface water or groundwater <br />quality. The following water quality control measures will be implemented atthe mine to <br />maintain water quality. <br />G.1 Surface Water <br />Water quality at the Sunday Mine Complex is regulated by CDPHE's Water Quality Control <br />Division. The Division requires that mines prepare a Stormwater Management Plan and, when <br />mine water is discharged due to mine dewatering and/or treatment, a discharge permit is required. <br />In the case of the Sunday Mine Complex, a Stormwater Management Plan (SWMP) has been <br />prepared and a permit has been issued by the Water Quality Control Division requiring Denison <br />to utilize the Best Management Practices (BMP) outlined in its SWMP. The Topaz Mine, as part <br />the Sunday Mine Complex, is covered under Colorado Discharge Permit Certification number <br />COR-040223. Surface water quality at the Topaz Mine will be maintained by use of stormwater <br />control structures, erosion and sediment control, and spill prevention control and containment. <br />G.1.1 Surface Water Diversions and Drainage Control <br />Two natural ephemeral drainages run from the south to the north of the east and west sides of the <br />surface facilities area. Surface water diversion ditches currently exist to the south, and <br />upgradient, of the surface facilities to divert stormwater away from the surface facilities. A ] 00- <br />year, 6-hour storm event was used to evaluate the sizing of these existing channels and ensure <br />that they will be of sufficient size to permanently divert water around the mining area following <br />mining activities and reclamation. These diversion ditches are large enough to contain a 100- <br />year, 6-hour storm event; however, minor slope and alignment modifications will be made. <br />Additionally, an earthen berm and catchment will be re-constructed along the toe of the expanded <br />WRA. Another berm will be located at the top of the WRA to prevent surface water from <br />running off of the surface facilities over the WRA. The catchment and berms are designed to <br />discharge a 100-year, 24-hour storm event via an emergency overflow spillway located to the <br />west of the catchment basin. The emergency overflow spillway for the 100-year storm discharges <br />to the ephemeral channel to the west of the catchment basin. The drainage report and supporting <br />calculations are provided in Attachment D of the Topaz Mine POO. <br />5-18-2007 Exhibi[ G Water Info Ci-1 <br />