Laserfiche WebLink
CMC—Henderson Operations <br /> DRMS 2021 Annual Water Monitoring Report <br /> May 2022 <br /> Executive Summary <br /> This report provides a summary of the 2021 water monitoring data collected pursuant to the Climax <br /> Molybdenum Company(CMC)—Henderson Operations(Henderson)Technical Revision 16(TR- <br /> 16) to Permit M-1977-342 Groundwater Management Plan (GWMP). The Division of <br /> Reclamation,Mining and Safety(DRMS)approved the Henderson GWMP in July 2012.The focus <br /> of this report is 2021 data; however, historical data is included from the 2017-2020 monitoring <br /> periods to allow for the assessment of trends over time. All sampling was conducted at the required <br /> locations in accordance with the GWMP and each sample was analyzed for the required <br /> parameters. <br /> In a memorandum dated April 14,2015,the DRMS preliminarily accepted new proposed Numeric <br /> Protection Limits (NPLs) for indicator parameters at Mill Point of Compliance (POC) locations. <br /> Given that the NPLs were only preliminarily accepted, the 2021 report will again be using the <br /> original NPLs of pH 6.5 to 8.5 until the new limits are formally accepted. Proposed POC wells <br /> MLGW-15 and MLGW-17 are also being monitored and results presented in this report. <br /> Mine Water Monitoring <br /> Henderson observed pH values during 2021 that were below the NPL limits at POC location <br /> MNGW-1.No deviations or anomalies were observed at non-POC locations at the Mine. <br /> Mine water monitoring data for POC well MNGW-1 and non-POC long-term surface water <br /> locations BG-20, CC-10 and CC-30 are included in this report and presented both in a table and <br /> trend evaluation graphs. <br /> Mill Water Monitoring <br /> No deviations from established NPLs were observed at Mill POC wells. <br /> Mill water monitoring data for POC wells MLGW-ACR and MLGW-7, proposed POC wells <br /> MLGW-15 and MLGW-17 and non-POC long-term surface water monitoring locations WFR-20 <br /> and WFR-40 are included in this report and presented both in a table and trend evaluation graphs. <br /> 3 of 8 <br />