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Mr. Lucas J. West <br /> December 4,2025 <br /> Page 2 <br /> Table 2-Monthly Piezometer Elevations <br /> Monitoring Well Piezometer Depth Depth to Water Depth of Water <br /> Identification Observation Date (ft) p <br /> (ft) (ft) <br /> P6 11/26/2025 72.46 DRY N/A <br /> P7 11/26/2025 92.50 DRY N/A <br /> P8 11/26/2025 97.51 96.70 0.81 <br /> P9 11/26/2025 72.30 71.98 0.32 <br /> P10 11/26/2025 58.30 57.47 0.83 <br /> Pl l 11/26/2025 41.80 41.40 0.40 <br /> P12 11/26/2025 41.71 41.65 0.06 <br /> P13 11/26/2025 41.34 41.02 0.32 <br /> P14 11/26/2025 41.24 DRY N/A <br /> P15 11/26/2025 41.10 40.86 0.24 <br /> The leak detection system at the LTF Collection Pond was inspected November 24, 2025, and 990 gallons were <br /> evacuated from the leak detection system and pumped to the LTF. The LTF underdrain system was visually inspected <br /> November 24,2025,and the flow rate was measured to be approximately 26 gallons per minute(gpm). <br /> West Pit Waste Water Treatment Plant <br /> During the month of November 2025, the West Pit Waste Water Treatment Plant (WWTP) was operated <br /> intermittently(3 to 4 days per week)under Colorado Department of Public Health and Environment(CDPHE) CDPS <br /> Permit No. C00045675 for discharge into the Rito Seco alluvial aquifer. During the month, 4,889,400 gallons <br /> (15.01 acre-feet) of treated water was discharged to the Rito Seco and 459,900 gallons (1.41 acre-feet) of water was <br /> transferred from the West Pit to the Lined Tailing Facility (LTF). Additionally, no water was reinfiltrated into the <br /> West Pit in November. <br /> BMRI performed the monthly visual seepage expression inspections on November 26, 2025, in the historic seepage <br /> area identified in Figure 2 of the permit. No seepage expressions were observed in the historic seepage area. <br /> BMRI measured the monthly West Pit backfill, alluvial and monitoring wells as required under the QA/QC Plan. <br /> Measurements obtained for the monthly wells are shown in Table 3. <br /> Table 3-Monthly and Quarterly Groundwater Depth to Water <br /> Monitoring Well Identification Observation Date Depth to Water <br /> (ft) <br /> BF-4 11/26/2025 24.92 <br /> BF-5R 11/26/2025 30.81 <br /> BF-6 11/26/2025 30.96 <br /> M-6 11/26/2025 DRY <br /> M-7 11/26/2025 DRY <br /> M-8 11/26/2025 DRY <br /> M-9 11/26/2025 141.05 <br /> M-10 11/26/2025 23.80 <br /> M-11R 11/26/2025 37.70 <br /> M-12 11/26/2025 174.2 <br /> M-13R 11/26/2025 125.56 <br /> M-14 11/26/2025 130.44 <br /> M-16 11/26/2025 16.46 <br /> M-17 11/26/2025 16.22 <br />