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Comments Submitted by Denver Water <br />August 20, 2010 <br />are contributing to overland flow and contain uranium, then these sumps should be <br />considered a source of pollutant. <br />5A question mark denotes information that has not been quantified, measured, or <br />calculated. <br />6Maximum concentration reported. Values in excess of 30 mg/I are more typical. A <br />comparison of the unit loading rates indicates that the Mine Pool contributes <br />significantly more pollutant load than the alluvial fill area. <br />7Maximum effluent limit permissible under Reg. No. 31 paragraph 31.48. <br />aThe relative contribution of the mine pool is significant compared to other pollutant <br />sources. <br />9 It is questionable whether the 100 gpm treatment rate for remedial activities is <br />adequate to control seeps in the alluvial area. History suggests that it is not adequate <br />(i.e., seeps still exist at the average flow rate) and a seasonal high of 400 gpm has <br />occurred (see Page 1-2). <br />10Tables similar to Table 1 need to be developed for contaminants other than uranium. <br />New Source <br />Denver Water believes this permit should not be a renewal of the original mining <br />wastewater treatment facility ("WWTF") discharge permit since the remedial groundwater <br />treatment system addresses a new objective and is significantly different than the processes <br />previously used. Cotter, on page 11 of the Technical Memorandum prepared by Whetstone <br />dated July 31, 2010 titled "Response to DRMS Letter dated May 19, 2010 regarding <br />Schwartzwalder Mine EPP Adequacy Review #2 (distributed as an attachment to the Revised <br />EPP), describes this as a new treatment system. The purpose of the new treatment system <br />is to address inadequate or failed reclamation, comply with the Mined Land Reclamation <br />Board's corrective action, and to attain water quality standards in Ralston Creek. The <br />purpose is not related to active mining, which ceased in 2000, or management of <br />stormwater. The new treatment system consists of pressure vessels with zeolite ion <br />exchange media and removes only uranium. The earlier WWTF consisted of barite <br />precipitation of radium and uranium, settling ponds, and resin-based ion exchange. In <br />addition, since the new treatment system is different than the earlier WWTF and treats a <br />new source of pollutants in the alluvial fill in a remediation role, federal effluent limitations <br />are not applicable. <br />Designation of Ralston Creek <br />The circumstances warrant that Ralston Creek be designated impaired, that a TMDL <br />approach be adopted, and that compliance schedules be implemented to assure attainment <br />of water quality standards. 33 U.S.C. § 1313(d)(2); See City of Arcadia v. State Water <br />Resources Control Board, 135 Cal. App. 4th 1392, 1418 (Cal App. 2006) (holding that the <br />California state agency may simultaneously submit to the EPA the identification of an <br />impaired water body and a TMDL); 5 CCR 1002-61.8(1)(b)(iv), (e). If the permit is issued in <br />Page 4 of 8