Laserfiche WebLink
r _ <br />~'^`~ <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 <br />October 16, 2007 ~J~O <br />Ms. Tania Watson ~~G~ ~QQ1 <br />Colorado Department of Health, WQCD C.` 1Q \ <br />Permits and Enforcement Section 0~ , sec ~e" <br />WQCD-PE-B2 `~`5~o~~9and <br />4300 Cherry Creek Drive South o ~~ <br />Denver, CO 80246-1530 <br />Re: CDPS Permit No. 000000132, September 2007 Dischazge Monitoring Reports, Oxbow <br />Minine, LLC., Elk Creek Mine. <br />Dear Ms. Watson: <br />Enclosed are the September 2007 Dischazge Monitoring Reports (DMR's) for the Oxbow <br />Mining, LLC., (OMLLC) Elk Creek Mine. <br />The enclosed DMRs indicate a 9/24/2007 dischazge from Outfa11012 which exceeded the <br />primary effluent limitations for total suspended solids (TSS) but meeting the alternate effluent <br />limits for settleable solids (SS). The sediment pond experienced surface runoff inflow from <br />rainfall from a series of Pacific cool fronts passing through western Colorado. The attached <br />September 2007, National Weather Service rainfall report for Paonia indicates that <br />approximately a combined 1.46" of precipitation occurred in the region on September 23 and 24, <br />2007. <br />The pond dischazge valve was opened on 9/24/2007 at 0800 and outflow sampled at 1600. The <br />valve was closed 9/25/2007 at 1400. The manually operated headgate valve was opened to <br />insure capacity and stability of the pond. In accordance with the October 24, 2004 Permit <br />Amendment No. 1, Permit Part I(b) Alternate Limitations we aze requesting relief of primary <br />total suspended solids (TSS) limitations for an event less than or equal to the 10-yeaz, 24 hour <br />precipitation event or snowmelt equivalent. <br />The data indicates a TSS of 92 mg/1, which would exceed the primary 35 mg/130-day average <br />requirement and the daily maximum requirement of 70 mg/l. However, since the dischazge is a <br />result of rainfall induced inflow it is appropriate to claim the alternate effluent limit for SS. The <br />analytical results for SS indicated <0.1 mUUlu which is well below the 0.5 ml/Uhr requirement. <br />Please see the attached analytical results for additional information. Overall, we aze pleased that <br />the pond has functioned well and in accordance with the approved design and CDPS Permit. <br />• Page t <br />