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Chavers Mining Resource <br /> Groundwater Monitoring and Mitigation Plan <br /> January 2024 <br /> Page 2 <br /> 2.1 MONITORING WELL NETWORK <br /> To monitor groundwater quantity and quality at the Site, ASCI utilizes a network of (5) <br /> groundwater wells that have been completed within the unconsolidated alluvial at the Site (i.e., <br /> MW-2 through MW-6). Borings were installed utilizing 4-1/4" ID hollow stem auger (HSA) <br /> drilling method from ground surface to the top of underlying bedrock. Monitoring wells were <br /> completed at a depth slightly above the top of bedrock encountered. Monitoring wells are <br /> constructed of two(2)-inch diameter Schedule 40 PVC with factory slotted 0.010"slot size for the <br /> screened portions. The filter packs consist of 10/20 silica sand and extend approximately two (2)- <br /> feet above the top of the well screen. A bentonite seal (chips) was installed from the top of the <br /> filter pack to ground surface. At the surface, concrete pads were installed along with a four (4)- <br /> inch square steel well cover with hinged locking cap to protect the above ground riser. Monitoring <br /> well construction details are presented in Table 1. Copies of the monitoring well construction logs <br /> are provided in Appendix A. <br /> 2.1.1 Groundwater Point of Compliance Wells <br /> Two (2) of the monitoring wells (MW-2 and MW-3) are located hydraulically up-gradient along <br /> the eastern boundary of the Site. Up-gradient monitoring wells MW-2 and MW-3 were installed <br /> in November 2016. Three (3) monitoring wells (MW-4, MW-5, and MW-6) are located <br /> hydraulically down-gradient along the western and northern permit boundaries of the Site. Down- <br /> gradient monitoring wells MW-4 through MW-6 were installed in June 2023.Down-gradient wells <br /> (MW-4 through MW-6) serve as the designated "Points of Compliance" (POC) wells in <br /> accordance with Rule 3.1.7(6)(b)(ii)(A). The locations of the monitoring wells are shown on <br /> Figure 2. <br /> 2.2 BASELINE GROUNDWATER QUANTITY <br /> Groundwater elevations collected from the monitoring wells at the Site between January 2022 <br /> through December 2023 are presented in Table 1. The maximum change in groundwater elevation <br /> for any well during the baseline collection period occurred in MW-3 at 5.57 feet and the minimum <br /> change occurred in MW-5 at 3.80 feet. The average change in groundwater elevation from all <br /> wells across the Site during the baseline collection period was 4.53 feet. A graph depicting the <br /> fluctuation in groundwater elevation for each well during the baseline monitoring period is <br /> presented in Figure 3.The groundwater high and low elevations identified for each well during the <br /> baseline collection period will be used as the basis for comparison for future groundwater <br /> measurements collected to demonstrate protection of groundwater quantity throughout the <br /> operational life of the mine until reclamation has been achieved (i.e.,when release of reclamation <br /> liability occurs). <br /> 2.2.1 Predicted Impacts to Hydrologic Balance <br /> Groundwater elevations at the Site prior to the start of mining are not available. To facilitate dry <br /> mining at the Site, groundwater has been pumped since 2016. Due to the influence of pumping <br /> the pit, the hydrologic balance within the alluvial aquifer at the Site is affected. However, as a <br /> result of the area-wide industrial development east of the South Platte River in the vicinity of the <br />