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Peak Ranch Resource <br /> August 5, 2020 <br /> 7.1 Baseline Data <br /> Peak Materials has gathered surface water quality data from the Blue River both upstream and downstream of <br /> the Peak Ranch Resource site. This information is used to establish the baseline water quality of the river <br /> through this area and to determine if mining operations are impacting the river by comparing the upstream <br /> and downstream results. The surface water sampling locations along the Blue River are shown on Figure 1 in <br /> Appendix G-1. It should be noted that this baseline is influenced and affected by several man-made activities <br /> occurring along the river including, but not limited to agricultural irrigation runoff, sewage and septic system <br /> discharges, releases from upstream reservoirs, and runoff from roadways and other impermeable surfaces. <br /> 7.2 Surface Water Handling — Mining <br /> Surface water runoff will be handled the same way in all phases of the Peak Ranch Resource's mine life; <br /> water from all mining disturbance areas will drain into the active mining area. During Phase 1,this area will be <br /> the mine floor that sits two feet above the groundwater table. During Phase 2, said surface water runoff will <br /> drain to the exposed groundwater within the mining cell. Stormwater runoff related to non-mining disturbance <br /> areas includes the site road and berms. The site road will be graded to drain into the mine cell. Berms will <br /> drain to windrows that are installed at the base of each berm. These windrows will be built during berm <br /> construction to contain runoff following initial construction. The berms will be vegetated following construction <br /> with the permanent seed mix and will reduce the risk of sediment laden discharge. <br /> Grading of the site to drain internally, along with the buffers of undisturbed ground between the mine cell and <br /> the Blue River,will ensure that no sediment laden water flows enter the river or any other natural waterway. <br /> 7.2.1 Disturbed Area Runoff <br /> A roughly 54-acre area drainage basin collects all the disturbed ground runoff within the Peak Ranch <br /> Resource site and drains it towards the mining cells. It can be seen in the Stormwater Detail on Map C-2C. <br /> The mining cell, in terms of drainage areas, is roughly separated by the drainage easement that bisects the <br /> property. Therefore,there will be two drainage basins and there is adequate capacity to store all stormwater <br /> runoff from the mining cell and associated disturbance areas within the mining cells. The underlying material <br /> is permeable alluvium which will facilitate prompt infiltration of stormwater. <br /> 8.0 GROUNDWATER <br /> A comprehensive groundwater report is attached to this exhibit that describes the baseline groundwater <br /> regime on the property. <br /> 8.1 Groundwater— Mining <br /> Phase 1 mining will stay at least two feet above the local groundwater table. This will prevent the exposure of <br /> groundwater to evaporation. Samples and water level measurements will continue to be taken from the wells <br /> on a quarterly basis to ensure that mining activities are not negatively affecting the prevailing hydrologic <br /> balance of the groundwater. An approved SWSP will be in place to cover depletions associated water use for <br /> dust suppression in Phase 1, as described in more detail below in section 9 of this Exhibit. <br /> Phase 2 mining will expose groundwater to evaporative losses.A Water Court approved augmentation plan or <br /> other DRMS approved approach to ensure that long-term depletions from mining and reclamation activities, <br /> including groundwater evaporation,will be replaced to prevent injury to other water rights will be in place prior <br /> to commencement of Phase 2. Monitoring wells will be sampled quarterly throughout the life of the mine to <br /> continue to ensure that mining activities are not negatively affecting the prevailing hydrologic balance. <br /> 8.2 Groundwater— Reclamation <br /> Once mining of Phase 2 is complete, the site will enter final reclamation. The groundwater lake will be <br /> permanent and will remain following reclamation. The Water Court-approved augmentation plan will be in <br /> place and operational at this point to cover the long-term evaporative depletions associated with the <br /> Gmg 1�Kki and Aswi t ,rl.u' G-3 <br />