2016-09-16_PERMIT FILE - M2016010

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A : Transit Mix Concrete Co. EXHIBIT G WATER INFORMATION 1. Introduction This exhibit summarizes the pre-mine water quality and flow conditions in Little Turkey Creek, the results of the permit-level hydrologic design for the proposed Hitch Rack Ranch quarry, and the groundwater conditions. The project includes three mining areas, an excess fines stockpile, and an access road. The plant, topsoil stockpile, and additional excess fines stockpiles will be located inside the disturbance areas. This report presents the drainage plan to address the requirements of both the Colorado Division of Reclamation, Mining, and Safety and El Paso County. To the extent possible, the more conservative design criteria were used to ensure that the minimum requirements of both agencies are addressed. Mitigation measures for sediment and erosion control form the major components of the plan. The water management plan includes a network of terrace and down drain ditches to divert runoff from disturbed areas to sediment ponds located in the pit areas. The plan includes water management structures for all disturbed areas at seven key phases during the life of the mine: start up, year 6, year 11, year 24, year 38, year 53 (end of mine), and closure. Structures were designed for each phase using the ultimate extents of the disturbance, and the most conservative values reported in this document so that the structures only need to be constructed once. Prior to re-sloping and revegetation on disturbed areas, bare cover material surfaces are potential sources of high sediment loads in the runoff water. As a result, sediment control measures constitute the major water management control measure for non-reclaimed areas: • Clean water diversion ditches will minimize contact water volumes. • Runoff of sediment-laden water from the disturbed areas is collected on terraces and routed to sediment ponds using down drain ditches. • Sediment detention basins with fore bays and sediment controlling outlets. • Best management practices (BMPs) for sediment control. Where possible, progressive reclamation will be employed to reduce the extent of non- reclaimed areas, thereby reducing erosion and sediment-laden water volumes. 2. Surface Water The Hitch Rack Ranch quarry is located along the Little Turkey Creek and an unnamed tributary to Little Fountain Creek waterways. The majority of the project area is located in the Little Turkey Creek watershed, and only the northeast corner of the proposed quarry is located in Hitch Rack Ranch Quarry Permit Application M-2016-010 September 15. 2016 G-2