2025-07-29_HYDROLOGY - M2007044

• Permit No: M2007044
• IBM Index Class Name: Hydrology
• Doc Date: 7/29/2025
• Doc Name: Hydrology Report
• From: Energy Fuels Resources Inc
• To: DRMS
• Annual Report Year: 2025
• Report Quarter_Month: 2
• Permit Index Doc Type: Hydrology Report
• Email Name: ACY
• Email Name: THM
• Media Type: D
• Archive: No

WHIRLWIND MINE, PERMIT NO.M-2007-044
SECOND QUARTER 2025 HYDROLOGICAL REPORT
Attachment 4.DP Spring
Dissolved Specific Oxygen-
Monitoring Sampled Inflow Rate Field pH Temperature Oxygen Conductance Reduction Comments
Date (Y/N) (gpm) (s.u.) (deg. C)
(mg/L) (US/cm) Potential (mV)
9/8/2017 No 4 5 6.93 14.04 8.83 563.6 246
10/20/2017 No 4 5 6.25 9.31 &03 549.0 179.1
3/22/2018 No 63 7A7 6.08 1031 370.0 46.1
6/20/2018 Yes 6.0 7 14 10.25 1046 384.0 6.9
9/7/2018 NO 49 7.39 11 06 12.04 375.0 283.9
12/14/2018 No 4 5 6.83 602 *** 557.0 337
Q1 2019 No NM NM NM NM NM NM Inaccessible due to county road conditions
6/25/2019 Yes 60 7.17 10.05 9.13 550.0 210
9/13/2019 No 25 7.45 10.82 1&06 541.0 163
11/8/2019 No 4.3 7.65 8.59 11.52 563.8 275
3/27/2020 No 6.0 7 58 5.49 12.37 55&0 528
6/24/2020 Yes 4.0 689 1024 1082 500.0 196
9/11/2020 No 4.5 7.41 10.60 10.65 587 0 286
11/6/2020 No 5.0 745 8.81 15.70 519.0 89
Q1 2021 No NM NM NM NM NM NM Inaccessible due to county road conditions
6/18/2021 No 40 7.77 10.74 10.33 594.0 152A
7/13/2021 Yes 40 7.61 14.98 10.30 557.7 109.0
9/9/2021 No 40 6.18 11 49 9.97 618.0 246.9
11/9/2021 No 4.6 7.60 9.02 13.88 668.0 67.2
3/30/2022 Yes 5.7 712 5.80 12.88 565.0 60.6
6/23/2022 No 4.0 733 10.62 12.11 6350 233.3
8/1/2022 Yes 37 6.34 11 60 10.12 5585 528.0
11/16/2022 No 3.6 6.35 7 78 11.24 572.7 519.0
Q1 2023 No NM NM NM NM NM NM Inaccessible due to county road conditions
5/10/2023 No 4.6 7.41 813 8.51 424.0 3.5
7/25/2023 Yes 3.7 7.58 12.54 11.08 541.6 295.0
10/31/2023 No 3.5 714 6.47 14.42 534.0 43.2
Q1 2024 No NM NM NM NM NM NM Inaccessible due to county road conditions
5/1/2024 No 3.8 7.53 697 4.51 5480 33.9
9/11/2024 Yes 3.3 720 11.50 10 17 542.0 223.5
10/30/2024 Yes 3.8 7.54 8.06 1067 350.0 193.1
Q1 2025 No NM NM NM NM NM NM linaccessible due to county road conditions
5/28/2025 No 1 40 7.35 1 8.63 1 11.12 1 561.0 123.0
* ORP Probe broke during 4/18/11 Monitoring Event.
***- Meter malfunctioned during site visit-no measurements were taken.
NM = Not Measured