2014-06-09_HYDROLOGY - M1977342

• Permit No: M1977342
• IBM Index Class Name: Hydrology
• Doc Date: 6/9/2014
• Doc Name: Submittal of Annual Water Monitoring Report
• From: Climax
• To: DRMS
• Permit Index Doc Type: Hydrology Report
• Email Name: PSH
• Media Type: D
• Archive: No

CMC—Henderson Operations
DRMS 2013 Annual Water Monitoring Report
' June 2014
' 1.0 Introduction
The GWMP establishes a plan for groundwater monitoring at the Henderson Mine and Mill for
the protection of groundwater quality pursuant to Rule 3.1.7(5) of the Mineral Rules and
Regulations of the Colorado Mined Land Reclamation Board for Hard Rock, Metal, and
Designated Mining Operations and the Colorado Water Quality Control Commission (WQCC)
standards. Henderson has prepared this report in accordance with the requirements of Section 7.1
' of the GWMP to summarize results of 2013 water monitoring activities.
2.0 Baseline Monitoring
' Baseline monitoring for groundwater wells MLGW-17, MLGW-15 (nested with POC well
MLGW-7) and the designated domestic water supply POC well MLGW-ACR have been
' completed. Pursuant to the GWMP, newly monitored or constructed groundwater monitoring
locations have been monitored for a minimum of five quarters for the baseline parameters
summarized in Section 4.2 of GWMP. Monitoring for these POC locations has been completed
t and a detailed 5-Quarter Water Quality Data and Baseline Parameters Report was recently
submitted to the DRMS.
3.0 Discussion of Annual Water Monitoring Data
This section provides a summary of the annual water monitoring data collected in 2013 in
accordance with the GWMP for each permit-identified POC well and non-POC long-term
surface water monitoring location at the Henderson Mine and Mill. Monitoring is conducted
three times per year as stipulated in the GWMP as follows:
• During the April through June spring run-off period;
• During the summer months of July and August; and
• During the September through December low-flow period.
tIt should be noted that upon NPL deviations in pH at POC wells MNGW-1 and MLGW-7
accelerated monthly monitoring was established to better assess data trends. This monitoring
began in August, 2013 at MNGW-1 and in September, 2013 at MLGW-7.
This report includes both 2012-2013 data from triannual DRMS monitoring and the 2013
monthly accelerated monitoring for MNGW-1 and MLGW-7. Data can be seen in trend
' evaluation graphs as well as the data tables. All monitoring locations are depicted in Figures 1
and 2.
' Outliers are identified, as needed, using either the Dixon's or Rosner's statistical method
depending on the available number of data points.
3.1 Henderson Mine
Henderson Mine monitoring locations include POC well MNGW-1 and surface water locations
BG-20, CC-10 and CC-30. Graphical trends are presented as Trend Evaluations 1-16 of this
' report. Note that for the purpose of trending the analytical data, results reported below the
laboratory detection limit were included as a value of zero.
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