2007-07-30_GENERAL DOCUMENTS - C1981041

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The permittee has made a demonstration, based on site-specific precipitation rates, percent of grade, and soil properties, that use of alternative specifications for culvert and bridge sizing will not result in increased erosion. The Division therefore proposes to approve the use ofthe alternative specifications for the following culverts or bridges, also referred to as the "dip-sections," where Haul Roads 2, 3, and 4, cross Coal Gulch. The structures are depicted on Exhibits 8A, 9A, I OB, l9, and 51 (4.03.1(4)(e)(vi)). 2. The operator and landowners have requested retention of Haul Road 4 from the CRDA-1 turnoff to the CRDA-3 turnoff, and the entire length of Haul Road 5. Also, Haul Road 3 between the county road and the rail loop will be modified and retained for the postmining land use. In conjunction with reclamation of the unit train loadout, Haul Road 3 will be reduced to a 16 foot travel width. The subject roads comply with all applicable performance standards, retention is compatible with the approved postmining land use, and written landowner requests for road retention have been provided (4.03.1(1)(f). B. Access Roads The operator and landowners have requested the retention of a short segment of Access Road 1, and the entirety of Access Roads 1 A, 2, and 3 as documented in Appendix 14-5. Retention is compatible with the approved post mining land use and landowner desires, and the roads comply with all applicable performance standazds. Therefore, the Division proposes to approve retention of the access roads as specified in Appendix 14-5 (4.03.2(I)(t)). II. Hydrologic Balance -Rule 4.05 A. Water Quality Standards and Effluent Limitations W ith the exception of approved small area exemptions, al l surface dischazges from the Roadside Portal Mines will pass through sediment ponds or treatment facilities designed to ensure that all discharges meet applicable effluent limits under the operator's Colorado Discharge Permit System (CDPS) permit, for the Roadside Portal Mines. Water dischazged from underground workings is clarified by sufficient settling time in underground sumps or abandoned mine workings prior to discharge into the Colorado River. A storm water permit and spill prevention containment and control plan associated with the CDPS permit also dictate preventative and mitigation measures for ensuring that all water leaving the mine site meets applicable effluent limits. Receiving stream standards for the Lower Colorado River have been set by the Colorado Department of Health and Environment in their publication "Classification and Numeric Standards for Lower Colorado River Basin." The Colorado River at this point is within segment 2 of the Lower Colorado River sub-basin and basin artd Coal Creek is within segment 4 of the Lower Colorado River sub-basin and basin. CDPS permit limitations on discharge, the permit's discharge standards, and the Division's standazds for determining material damage to the hydrologic balance ("Division Procedures for the Assessment of Material Damage with Respect to Alluvial Valley Floors, the Cumulative Hydrologic Impact Assessment and Subsidence at Coal Mines") are based, in part, on these standards. The Roadside Portal Mines' standards for discharge are listed in Table 2.05.6 A of the permit application. The mines' baseline water quality data is found in Section 2.04.7 of the permit application. Permit Revision No. 3 July 30, 2007 Permit No. C-1981-041 Page 21