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000 <br />OXBOW MINING, LLC <br />3737 Hwy 133 P.O. Box 535 Somerset, Colorado 81434 USA Tel (970)929-5122 Fax <br />(970)929-5177 Reclewth <br />January 10, 2011 <br />Ms. Tania Watson <br />Colorado Department of Health, WQCD <br />Permits and Enforcement Section <br />WQCD-PE-B2 <br />4300 Cherry Creek Drive South <br />Denver, CO 80246-1530 <br />Div4AI 13 011 <br />nof? <br />c1y <br />Re: CDPS Permit No. 000000132, December 2010 Discharge Monitoring Reports Oxbow Mining <br />LLC., Elk Creek Mine. <br />Dear Ms. Watson: <br />Enclosed are the December 2010 Discharge Monitoring Reports (DMR's) for the Oxbow Mining, LLC. <br />Elk Creek Mine. <br />Due to inflows from an extensive rainfall and snow precipitation event occurring from December 19 <br />through 21, 2010, the enclosed DMRs indicate discharges on 12/21/2010 from Outfall 009, Outfall 012 <br />and Outfall 016 that exceeded some primary effluent limitations. See the attached Table 1- December <br />21, 2010 discharges for a summary of the analytical data. Attached also is a summary table for December <br />2010 West Elk Mine - Precipitation obtained from our neighbor the West Elk Mine, and Laboratory <br />Analysis Reports from SGS Minerals Services Division for the outfalls in question. <br />The information indicates that a combined 1.16" of precipitation in the form of rainfall and snow occurred <br />in the region during the three days prior to the December 21, 2010 discharge sampling of the resultant <br />sediment pond discharges. <br />In accordance with the January 25, 2006 Permit Amendment No. 3 and May 16, 2005 Amendment #2, <br />and October 28, 2004 Amended Permit, Permit Part I(b) Alternate Limitations we are requesting relief of <br />primary total suspended solids (TSS) limitations and Total Iron limitations for an event less than or equal <br />to the 10-year, 24 hour precipitation event or snowmelt equivalent. <br />The Division should be aware that the sedimentation ponds are designed in accordance with Regulations <br />of the Colorado Division of Reclamation, Mining and Safety to contain or treat a 10 yr, 24-hr storm event <br />of 1.9" of rainfall or snowmelt equivalent. These sedimentation ponds treated the runoff in accordance <br />with the permitted and approved designs and the resulting discharges represent little more than the routine <br />and anticipated discharge of such stormwater events. <br />Outfall 009 - Pond A <br />The pond outfall is a passive treatment discharge point with a riser pipe serving as the primary discharge <br />point. The discharge was sampled on December 21, 2010 at 0930. The data indicates a TSS of 140 mg/l, <br />which exceeds the primary 35 mg/l 30-day average requirement and the daily maximum requirement of <br />70 mg/l. However, since the discharge is a result of rainfall induced inflow it is appropriate to waive the <br />0 Page 1