2008-01-16_PERMIT FILE - M2007044

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~~CE~VEC~ JA~1 16 2008 Uwisw~ ~ ur rtec~amanon, Mining and Safety notification of an exceedance of standards within 30 days of Energy Fuels 'receipt of the sample results and the proposed or implemented measures to rectify the situation must be included with the notification to the Division. All sample results will be required as part of the Annual Report, however excedence notices must be separate from all other correspondence. Energy Fuels agrees to this requirement and will add the requirement, as stated, to the 112d Application and the Stormwater Management Plan. Regulatory standards will be based on WQCD's water quality standards for Segment 3a of the Lower Dolores River Basin. Agricultural standards will be used for any constituents not addressed in the surface water standards. 18) The hydrology exhibit submitted with the application states that the mine workings are "self draining" with regard to water seepage from aquifers located above the mine workings. The applicant should describe the fate of the water that seeps into the mine and subsequently drains out. Additionally, the application states that the unattended mine, as is the current state of the site, reached "equilibrium " with regard to the water entering the mine. The applicant should describe that equilibrium state, specifically the amount of water entering and exiting the mine and the water level throughout the workings that defines this state of equilibrium. The applicant should describe whether this equilibrium will be reached with the inclusion of the proposed bulkheads; whether it will be modified with the presence of the bulkheads; and whether the presence of the bulkheads will result in reverse flow of mine water or water in lower aquifers into overlying aquifers. As discussed above under Item 4, the volume of water seeping into the mine workings is relatively small and the Salt Wash sandstones have low hydraulic conductivity. Energy Fuels does not currently have access to all portions of the Whirlwind and Packrat Mines so it is not possible to completely quantify existing conditions. We do however have maps prepared by Umetco prior to closure that we believe accurately represented the mine conditions at that time and are probably reflective of what we will find as mine rehabilitation proceeds. Map G-3 (see Attachment C), which is based on a 1994 map prepared by Umetco Minerals, shows the mine workings with the locations of standing water delineated. Because the mine workings are extensive with several miles of drifts, the water flowing into the mine seeps into the mine floor in the lower areas of the mine before it can build up to the point where it would flow out the portals. The mudstone layer located below the mine floor dips to the west and northwest (see March 15, 2001 Memorandum by U.S. Environmental Services, Inc. in Appendix C of the 112d Application); therefore, the seepage into the mine floor would be expected to flow in this direction once it reaches the mudstone layer. The rate of flow within the saturated sandstone comprising the mine floor is believed to be very low because the rock has low hydraulic conductivity (2.9 x 10"5 cm/s) and there is only a few feet of hydraulic head driving the flow. The total estimated inflow into the Whirlwind and Packrat Mines at the current time is 5 to 7 gpm or about 1_~:~~c~~~ I~uc:l5 l~es<xir~ces C;<>r0c~ratio~~ =I=I l:!uic>n I3or~ieve~rt•cl, 5laitc Ei00 14 L,al<e~~~~ooti. C:C) 80124 PI-roi3~ :303-~~~7~-21 ~0