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COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division <br />Rationale - Page 2, Permit No. CO-0001244 <br />Since the last renewal of the permit the water quality in Ralston Creek below the Schwartxwalder has <br />been found to exceed the water quality standard for total recoverable uranium, based on the water supply <br />designation. The former WWTF was disassembled by the Cotter Corporation, and a new one is being <br />set in place to resume treatment of contaminated water. A treatment process similar to that which was <br />used previously at the WWTF is being installed. The outfall location 001 is also being moved <br />downstream from it's previous location. The new location for outfall will be below all mine workings <br />just upstream from the Schwartzwalder mine property boundary. New standards for dissolved Cd, total <br />recoverable U, total recoverable Th, total recoverable Sb, E. coli, and temperature are now effective on <br />segment COSPCLI7B. The designation of the segment also changed from Use Protected to <br />Undesignated. <br />III. RECEIVING STREAM <br />A. Waterbody Identification: COSPCLI7B, Ralston Creek <br />B. Water Quality Assessment: <br />An assessment of the stream standards, low flow data, and ambient stream data has been performed to <br />determine the assimilative capacities for Ralston Creek for potential pollutants of concern. This <br />information, which is contained in the Water Quality Assessment (WQA) to this fact sheet, also includes <br />an antidegradation review, where appropriate. The Division's Permits Section has reviewed the <br />assimilative capacities to determine the appropriate water quality-based effluent limitations as well as <br />potential limits based on the antidegradation evaluation, where applicable. The limitations based on the <br />WQA and other evaluations conducted as part of this fact sheet can be found in Part I.A of the permit. <br />Outfall 001A will be the authorized discharge point to the receiving stream. <br />IV. FACILITY DESCRIPTION <br />A. Industry Description <br />Type of Industry - This facility is an inactive underground uranium mine. The new treatment <br />facility that is being installed will be used for the clean up of contaminated alluvial water in the <br />Ralston Creek drainage, and possibly in the mine workings of the Schwartzwalder uranium mine. <br />The permittee is attempting to obtain closure status and complete all reclamation activities. The <br />mine workings have been allowed to flood as part of this process. The Division of Reclamation <br />Mining and Safety has not approved the closure status and may require the permittee to pump and <br />treat the mine workings. <br />2. Sources to the Treatment Plant - The currently proposed sources of contaminated water to the <br />treatment plant will be existing groundwater sumps placed in the alluvium of Ralston Creek within <br />the property boundaries of the Schwartzwalder uranum mine. Additional sumps may be added as