2023-06-05_HYDROLOGY - M1977342

• Permit No: M1977342
• IBM Index Class Name: Hydrology
• Doc Date: 6/5/2023
• Doc Name: Water Monitoring - Groundwater
• From: Clmax Molydenum
• To: DRMS
• Email Name: PSH
• Email Name: JLE
• Media Type: D
• Archive: No

CMC—Henderson Operations
DRMS 2022 Annual Water Monitoring Report
May 2023
Table of Contents
ExecutiveSummary............................................................................................................ 3
Introduction.........................................................................................................................4
1.0 Discussion of Annual Water Monitoring Data........................................................4
2.1 Henderson Mine...................................................................................................4
2.1.1 Point of Compliance Sampling Location: MNGW-I ...................................4
2.1.2 Surface Water Sampling Location: BG-20................................................... 5
2.1.3 Surface Water Sampling Location: CC-10................................................... 5
2.1.4 Surface Water Sampling Location: CC-30................................................... 5
2.2 Henderson Mill..................................................................................................... 5
2.2.1 Point of Compliance Sampling Location: MLGW-7.................................... 5
2.2.2 Proposed Point of Compliance Sampling Location: MLGW-15..................6
2.2.3 Proposed Point of Compliance Sampling Location: MLGW-17..................6
2.2.4 Proposed Point of Compliance Sampling Location: MLGW-ACR.............. 6
2.2.5 Surface Water Sampling Location: WFR-20................................................ 6
2.2.6 Surface Water Sampling Location: WFR-40................................................ 7
3.0 Conclusion............................................................................................................... 7
4.0 References................................................................................................................ 8
Figures
Figure 1, Monitoring Locations, Henderson Mine
Figure 2, Monitoring Locations, Henderson Mill
Tables
Table 1,Annual Water Monitoring Data, Henderson Mine
Table 2, Annual Water Monitoring Data, Henderson Mill
Trend Evaluation
Trend Evaluation 1, MNGW-1: Fe, Mn, Se, and Zn
Trend Evaluation 2, MNGW-1: Specific Conductivity
Trend Evaluation 3,MNGW-1: pH
Trend Evaluation 4, MNGW-1: Sulfate
Trend Evaluation 5, BG-20: Fe, Mn, Se, and Zn
Trend Evaluation 6, BG-20: Specific Conductivity
Trend Evaluation 7, BG-20: pH
Trend Evaluation 8, BG-20: Sulfate
Trend Evaluation 9, CC-10: Fe,Mn, Se, and Zn
Trend Evaluation 10, CC-10: Specific Conductivity
Trend Evaluation 11, CC-10: pH
Trend Evaluation 12, CC-10: Sulfate
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