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COLO DEPT OF HEALTH Fax 303-759-5355 May 12 2011 10:15am P002/003 <br />2003 Annual ALARA Report 30 April, 2003 <br />RML CO-369-03S Page 10 of 13 <br />1. Surface Water (continued) <br />Non-routine impacts that the site licensed facilities may have on Ralston Creek <br />include spills of radioactive and non-radioactive materials from site operations <br />or surface water run-off during storm events. Spilled materials represent the <br />greatest short-term potential for negative impacts on the creek and the <br />discharge of stormwater runoff from the licensed facilities is prohibited- The <br />mine site ground surface was contoured with catch basins and sumps were <br />installed to capture stormwater or other surface runoff in the old Ore <br />Crusher-Sorter and WWTP areas. Runoff collected onsite can be pumped, if <br />necessary, to a holding pond and tank located at the old wastewater treatment <br />plant and treated under CDPS Permit No. CO-0001244 for the treatment and <br />discharge of mine drainage, surface runoff, and other process waters. <br />Routine impacts on Ralston Creek -- <br />Data collected to monitor routine site activities at each of the monitoring <br />locations in 2003 were somewhat elevated in comparison with recent (1991 <br />1998) historical data at the locations upstream of the east property line sample <br />location (BP/L). The results are consistent enough with the historical data that <br />no conclusions can be drawn from the data. The results recorded at the BP/L <br />monitoring location and downstream of the BP/L location were considerably <br />elevated in comparison with recent historical data (1991-1998) during very low <br />to no flow periods in Ralston Creek- This indicates a strong positive <br />contribution to the uranium concentrations in Ralston Creek from the alluvium <br />underlying the site surface facilities since the shallow surface pumps have been <br />shut down. The true origin of the increased uranium values is not yet know. <br />Reclamation and decommissioning activities that disturbed previously <br />undisturbed colluvial materials may have resulted in a short term increase in <br />uranium values that will be followed by a decline as the newly exposed <br />materials are weathered. The increase in uranium values in Ralston Creek may <br />also be fully, or in part, caused by natural seepage from the uranium <br />mineralized zone that is no longer being intercepted by the shallow ground <br />water pumping system. There were no spills of radioactive materials into <br />Ralston Creek in 2003 that could have contributed to the increase in uranium <br />values in Ralston Creek. Radium values in Ralston Creek remained well below <br />any applicable limits. An initial evaluation of the alluvial ground water and <br />Ralston Creek interaction is part of an outside consultant's draft report currently <br />under internal review. This report will be forwarded to the Uranium and Special <br />Projects Group upon its completion in final form. <br />Non-Routine Impacts on Ralston Creek <br />There were no non-routine impacts on adjacent surface waters in 2003 from the <br />licensed facilities.