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COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division <br />Rationale — Page 6, Permit No. C00036251 <br />B. Compliance With Terms and Conditions of Previous Permit <br />1. Effluent Limitations — The data shown in the preceding tables indicate apparent violations of the <br />permit. As indicated in Table V -la, 55% of sample reports from outfall OO1A for uranium exceeded <br />the permit limit. Uranium report of 10/31/2005 exceeded the permit limit by 110 %. Likewise, <br />several permit violations were noted from Outfall 002A. Radium 226 +228 sample result of <br />12/31/2004 exceeded the permit limit by 418 %. Others are total radium 226 of 12/31/2004, exceeded <br />the permit limit by 159 %; radium 226 of 02/29/2004, exceeded the permit limit by 220 %. There <br />were also several non - numeric violations such as late submission of discharge monitoring reports. <br />An August 9, 2006 letter from the Division's Enforcement Unit informed the Cotter Corporation that <br />the Division was initiating a review process to determine whether a formal enforcement action was <br />warranted. The Division requested a written response with a deadline of August 23, 2006, for Cotter <br />Corporation to inform the Division of measures they have taken or will take to abate the non- <br />compliance. Cotter Corporation's response dated August 30, 2006, informed the Division that they <br />had ceased dewatering activities at both mines and would evaluate methods to maintain the Total <br />Uranium content at outfall 001A, prior to any discharge. Cotter Corporation also informed the <br />Division that they began the use of anionic flocculant at outfall 002A in April 2005, in an effort to <br />aid the settling of suspended matter and subsequently reduce radium 226. Cotter stated that prior to <br />any discharges at 001A at JD7 they would evaluate methods to maintain the total uranium content in <br />the future discharges below permit conditions. This may require a simple gravity flow ion exchange <br />system at the discharge to outfall 001 A. The last reported discharge from outfalls 001A and 002A, <br />were dated June 30, 2006. <br />As a result of the permittee's compliance history, the Division finds it necessary to include <br />additional provision that requires the permittee to contain the effluent until analyses have confirmed <br />that all numeric effluent limitations can be met. This requirement to contain the effluent applies to <br />all outfalls with numeric limitations. <br />VI. TERMS AND CONDITIONS OF PERMIT <br />A. Discussion of Effluent Limitations <br />1. Technology Based Limitations <br />a. Federal Effluent Limitation Guidelines — The Federal guidelines that apply to this type of facility <br />are found under 40 CFR 440.32, titled Ore Mining and Dressing Point Source Category; Subpart <br />C — Uranium, Radium and Vanadium Ores subcategory. ELGs continue to be applied to Outfalls <br />OO1A and 002A, which receive dewatered mine water. Water from the JD -7 mine and JD -9 mine <br />waste dumps (1.98 acres and 2.4 acres respectively), described in the Cotter Corporation's <br />Stormwater management Plan (SWMP), have been included in this permit as process water and <br />as also subject to effluent limitation guidelines. This process water was mis- categorized in the <br />SWMP as stormwater. The Federal guideline regulations at 40 CFR 440.132 include "wastes <br />and rock dumps" in the definition "mine" and "mine drainage" "means any water drained, <br />pumped, or siphoned from a mine ". Wet weather flows from active mining areas were included <br />in developing the effluent guideline regulations and therefore are subject to the regulations. <br />Rainfall that comes into contact with waste piles also meets the definition of process wastewater <br />(process water) at Regulation 61.2(82). The Division has a Policy and Guidance on the <br />