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projects must also be added to the permit. For those projects where adits are present, <br /> requirements related to adit closure or treatment should be added to the permit to <br /> address flow other than storm water. <br /> The MRPs will need to be modified to be in compliance with these permit conditions. <br /> Review and approval of the work plans should be through the permit process rather <br /> than the consent decree. <br /> Response: The Mine Remediation permit has been revised to incorporate criteria <br /> which are very similar to the requirements of the above-referenced sections of the <br /> General Permit for Stormwater. <br /> The Mine Remediation permit has been written as an individual permit instead of a <br /> general permit, and must be amended to include any additional MRP's or modify <br /> MRPs. Also, this Mine Remediation Permit was intended to cover more than just <br /> stormwater discharges. Because of these differences, the suggested changes were <br /> determined by the Division to be inappropriate. <br /> In those cases were adits are present, the receiving streams have been classified such <br /> that there is no need for treatment of adit flows, provided the activities of the <br /> permittee do not increase the loading of pollutants from such discharges. In all cases, <br /> the permittee has submitted MRPs that either will not affect adit discharges, or will <br /> reduce or eliminate pollutant the loading of pollutants being discharged. <br /> American Tunnel Permit CO-0027529 <br /> 3. Comment: After reviewing data from the existing facility, EPA believes that there is a <br /> reasonable potential for toxicity at this site under present conditions. EPA <br /> understands that once treatment of Cement Creek begins and the tunnel discharges <br /> lessen, there is likely to be an overall reduction in toxicity of Cement Creek below the <br /> facility. However, until it can be shown that there has been a substantial reduction in <br /> toxicity of Cement Creek downstream of the tunnel discharge (over present conditions) <br /> Whole Effluent Toxicity (WET) monitoring and limits should apply to the Discharge. <br /> Response: Cement Creek is not classified for aquatic life use. Therefore, it would <br /> be inappropriate to perform instream WET testing for Cement Creek. The first <br /> downstream segment classified for aquatic life is the Animas River. While the <br /> Division is concerned about controlling the toxic effects of the American Tunnel <br /> upon the Animas River, it would also be inappropriate to perform any instream WET <br /> testing there, due to the large number of other pollutant sources that may also be <br /> contributing toxicity. <br /> Instead, the Division has relied upon calculations involving flows and pollutant <br /> 11 <br />