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( "Division Procedures for the Assessment of Material Damage with Respect to Alluvial Valley <br />Floors, the Cumulative Hydrologic Impact Assessment and Subsidence at Coal Mines ") are based, <br />in part, on these standards. The Roadside Portal Mines' standards for discharge are listed in Table <br />2.05.6 A of the permit application. The mines' baseline water quality data is found in Section <br />2.04.7 of the permit application. <br />The CDPS permit had in the past included a specified salinity standard of not more than one ton <br />per day or 350 tons per year of total dissolved solids, whichever is less. The Roadside Mines <br />salinity discharge exceeds this level, primarily due to mine water discharges. As a result, the <br />operator was required by the Colorado Department of Health and Environment (DOH) to prepare a <br />report outlining possible approaches to reducing the mines' contributions of salt to the Colorado <br />River, and associated costs. This report, "Evaluation of Alternatives for Management of Salt in <br />Mine Water Discharges: Roadside and Cameo Mines; Powderhorn Coal Company; Palisade, <br />Colorado." was completed in February, 1993. Based on the report, DOH made a determination <br />that salt elimination or reduction would not be economically feasible, and granted an exemption <br />from salinity standards (3/17/93 letter, Appendix 17 -2). DOH has not revised that determination, <br />and it remains valid. <br />The Division has granted a number of small area exemptions from the use of sediment ponds due <br />to the limited size of the areas in question and due to the fact that ponds and treatment facilities are <br />not necessary for the drainage from these sites to meet the effluent limitations of Rule 4.05.2 and <br />applicable State and Federal water quality standards for receiving streams and also due to the fact <br />that no mixing of surface drainage from these areas with a discharge from underground workings <br />will occur. The small areas to be exempted are listed in Volume 3, Appendix 13 -3 of the permit <br />application (4.05.2(3)(b)(i)). <br />In 1997, Pond 12 was designed to act as a mine water treatment pond for the mine water discharge <br />associated with the Roadside North Portal Mine, NPDES discharge point 004. Discharge from the <br />North Portal Mine required pumping, which ceased in December 1999 when operations ceased. <br />Outfall 004 has been discontinued and Pond 12 has been eliminated by reclamation operations. <br />Discharge Outfall 015 had been approved for minewater discharge from the South Mine 2 West <br />Portals. The outfall was never activated and the 2 West Portals have been sealed and reclaimed. <br />Only two approved minewater discharge sites remain, both at the South Mine. Outfall 016, located <br />near the North Decline Area is the primary dewatering site. Outfall 002, the siphon discharge <br />system at the reclaimed Northwest Intake Portal, has been retained as a back -up discharge site that <br />would be used in the event of malfunction of Outfall 016. Outfall 001, a supplemental/back -up <br />discharge via 4" diameter pipe through the South Portal conveyor entry concrete seal, has been <br />permanently plugged in association with South Portal area final reclamation in 2007/2008. <br />The Division has granted an exemption from the use of sediment ponds for NPDES discharge <br />points 002 and 016 from underground mine workings because sediments are settled out in <br />abandoned underground workings before being discharged into the Colorado River. Additional <br />ponds and treatment facilities are not necessary for these discharge points to meet the effluent <br />limitations of Rule 4.05.2 and applicable State and Federal water quality standards for receiving <br />streams. <br />B. Diversions and Conveyance of Overland Flow <br />21 <br />