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III. Hydrologic Balance - Rule 4.05 <br />The drainage and sediment control system at tfie mine and loadout were <br />reviewed for compliance with Rules 2.05.3(4) and 4.05. This <br />information is briefly described on pages 27 to 40 and pages 48 to 50 <br />of Rule 2.05. Substantial design detail can be found in Volumes 8 and <br />SA, Sheet 6, of the OVWM design specifications, Volume 6, Map 6A-2C of <br />the Waste Disposal Appendix, and Map 6A-5D of the Reclaimed <br />Configuration Appendix. <br />Findings - <br />The applicant has demonstrated that sediment ponds and/or treatment <br />facilities will function properly to ensure that disturbed-area <br />drainage will meet the effluent limitations of 4.05.2 and the <br />applicable State and Federal water quality requirements for downstream <br />receiving waters. <br />The Division has granted small area exemption status from use of <br />sediment ponds to five areas of the Orchard Valley Mine due to the <br />limited size of the areas and due to the fact that ponds and treatment <br />facilities are not necessary for the drainage to meet the effluent <br />limitations of Rule 4.05.2 and applicable State and Federal water <br />quality standards for receiving streams and also due to the fact that <br />no mixing of surface drainage with a discharge from underground <br />workings will occur. The small areas to be exempted are the OVWM fill <br />outslopes (north and south), OVWM vent fan site, training trailer area <br />outslopes, and the silo area railroad outslopes. See permit <br />application Section 2.05, page 113, 113a-c, Volume 8, pages SAE 1-30, <br />and Maps 8-lA, 8-2, 8-3, 8-6, and 8-7 (4.05.2(3)(b>(i)>. <br />Stream Channel Diversions - <br />Clean water diversions above the main facilities areas of both Orchard <br />Valley Mine and OVWM direct undisturbed area flows around the <br />facilities areas to minimize surface water flow through these sites. <br />A system of lined and unlined ditches convey waters from the disturbed <br />areas to the sediment ponds. Design details can be found in the <br />approved permit application, Volumes 6, 8, and SA. <br />In order to minimize water quality Impact to water flowing through the <br />Orchard Valley West Mine area; water from East Roatcap Creek is <br />diverted to West Roatcap Creek. To verify that no water is lost <br />through diversion of the Overland Ditch, surface water monitoring <br />point SW-09 was moved to, and is currently monitored at ,. the point of <br />the diversion from East Roatcap Creek. <br />Sedimentation Ponds - <br />The Orchard Valley mine plan is designed to minimize the impacts of <br />the project on the surface water hydrology of the region. Disturbed <br />area drainage from the mine benches, parking area, west portal fill, <br />and loadout site is collected and treated on the site. Four sediment <br />-26- <br />