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7_1 Surface Water Handling—Mining <br /> Surface water runoff will be handled the same way throughout 23 '/4 West Pit's mine life: water <br /> from all mining disturbance areas will drain into the active mining areas. The area drainage basin <br /> (Map G-1) includes some areas just north of the site and the west side of 23 '/4 Road. The entire <br /> drainage basin drains into the pit areas. The site road will be graded to drain into the pit areas. <br /> Grading of the site to drain internally, along with the buffers of undisturbed ground between the <br /> mine cell and the Colorado River, will ensure that no sediment laden water flows enter the river <br /> or any other natural waterway. <br /> Once surface water is collected within the mining pit, it will mingle with process water(dust <br /> control on the crusher), be collected in the pit floor perimeter ditches, and routed to the pit <br /> dewatering pump. For Area 2,the pit dewatering pump will then pump into a sediment pond on <br /> the southwest edge of the disturbance area. For Area 2,the pit dewatering pump will then pump <br /> into the pond on the Orchard Grove Industrial Pit to the south. These sediment ponds will allow <br /> suspended solids to further settle and clean water to discharge out via an approved discharge <br /> point into the Wilsea Drain and local groundwater. <br /> 7.1.1 Disturbed Area Runoff <br /> Two drainage basin collects all of the disturbed ground runoff within the 23 '/4 West Pit site and <br /> drains it towards the pit areas. These can be seen on Map G-1. Stormwater runoff calculations <br /> can all be found in Appendix G-1 in this exhibit. The results of those calculations can be seen on <br /> Map G-1. The peak runoff is generated following reclamation due to the presence of the lake. <br /> Mining and reclamation will not create additional drainage from the site. Baseline and mining <br /> drainage scenarios are shown on Map G-1 and delineated in Appendix G-1. <br /> Sediment discharge will be controlled during mining by the sediment pond and mining pit. <br /> Following mining,revegetation and the development of the lake will prevent the discharge of <br /> additional sediment from the site. <br /> 23 114 West <br /> July 2020 G-5 Gnf Leaie Ai and lnociale� I'LL(' <br />