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<br /> <br /> <br /> 25 C1981-041 RN7 findings <br /> <br />A. Water Quality Standards and Effluent Limitations <br /> <br />With the exception of approved small area exemptions, all surface discharges from the <br />Roadside Portal Mines were routed through sediment ponds or treatment facilities designed <br />to ensure that all discharges meet applicable effluent limits under the operator ’s Colorado <br />Discharge Permit System (CDPS) permit, for the Roadside Portal Mines. Water discharged <br />from underground workings is clarified by sufficient settling time in underground sumps or <br />abandoned mine workings prior to discharge into the Colorado River. A storm water permit <br />and spill prevention containment and control plan associated with the CDPS permit also <br />dictate preventative and mitigation measures for ensuring that all water leaving the mine site <br />meets applicable effluent limits. <br /> <br />Receiving stream standards for the Lower Colorado River have been set by the Colorado <br />Department of Health and Environment in their publication "Classification and Numeric <br />Standards for Lower Colorado River Basin." The Colorado River at this point is within <br />segment 2 of the Lower Colorado River sub-basin and basin and Coal Creek is within segment <br />4 of the Lower Colorado River sub-basin and basin. CDPS permit limitations on discharge, <br />the permit's discharge standards, and the Division's standards for determining material damage <br />to the hydrologic balance ("Division Procedures for the Assessment of Material Damage with <br />Respect to Alluvial Valley Floors, the Cumulative Hydrologic Impact Assessment and <br />Subsidence at Coal Mines") are based, in part, on these standards. The Roadside Portal Mines’ <br />standards for discharge are listed in Table 2.05.6 A of the permit application. The mines' <br />baseline water quality data is found in Section 2.04.7 of the permit application. <br /> <br />The CDPS permit had in the past included a specified salinity standard of not more than one <br />ton per day or 350 tons per year of total dissolved solids, whichever is less. The Roadside <br />Mines salinity discharge exceeds this level, primarily due to mine water discharges. As a <br />result, the operator was required by th e Colorado Department of Health and Environment <br />(DOH) to prepare a report outlining possible approaches to reducing the mines' contributions <br />of salt to the Colorado River, and associated costs. This report, "Evaluation of Alternatives <br />for Management of Salt in Mine Water Discharges: Roadside and Cameo Mines; Powderhorn <br />Coal Company; Palisade, Colorado." was completed in February, 1993. Based on the report, <br />DOH made a determination that salt elimination or reduction would not be economically <br />feasible, and granted an exemption from salinity standards (3/17/93 letter, Appendix 17-2). <br />DOH has not revised that determination, and it remains valid. <br /> <br />The Division had previously granted a number of small area exemptions from the use of <br />sediment ponds due to the limited size of the areas in question and due to the fact that ponds <br />and treatment facilities are not necessary for the drainage from these sites to meet the effluent <br />limitations of Rule 4.05.2 and applicable State and Federal water quality standards for <br />receiving streams and also due to the fact that no mixing of surface drainage from these areas <br />with a discharge from underground workings will occur. The small areas to be exempted are <br />listed in Volume 3, Appendix 13-3 of the permit application (4.05.2(3)(b)(i)). <br /> <br />In 1997, Pond 12 was designed to act as a mine water treatment pond for the mine water