Laserfiche WebLink
® Climax Molybdenum <br />A Freeport- McMoRan Company <br />May 30, 2013 <br />Via UPS Tracking Number: 1Z 804 847 13 7727 4319 <br />Yr. Peter Hays <br />Division of Reclamation Mining and Safety <br />1313 Sherman St., Rm. 215 <br />Denver, CO 80203 <br />COLORADO OPERATIONS <br />Henderson Mine and Mill <br />P.O. Box 68 <br />Empire, CO 80438 <br />Phone (303) 569 -3221 <br />Fax (303) 569 -2830 <br />DIVISION OF RECLAMATION <br />MININGAND SAFETY <br />Re: Permit M -477 -342, Submittal of Annual Water Monitoring Report - Henderson Operations <br />Groundwater Management Plan <br />Dear Mr. Hays: <br />Climax Molybdenum Company (CMC) is submitting this Annual Water Monitoring Report (Report) <br />pursuant to the requirements in Section 7.1 of the Henderson Operations Groundwater Management Plan <br />(GWMP) approved on July 25, 2012 as Technical Revision 16 to Reclamation Permit No. M- 1977 -342. <br />Sampling was conducted at the required locations in accordance with the GWMP and each sample was <br />analyzed for the required parameters. A deviation from the numeric protection limit (NPL) of 6.5 -8.5 pH <br />was observed at the Mine point of compliance (POC) well MNGW -1 during the December 2012 <br />monitoring event, with a measured pH of 6.4. Henderson is carrying out follow -up monitoring at this <br />location and will present these results and further assessment of this data to the DRMS in the coming <br />weeks. <br />Additionally, the GWMP indicated that Henderson was in the process of conducting groundwater studies <br />at the Mill to determine: <br />The appropriateness of MLGW -7's current location and the rationale for or against a nested well <br />at this location; <br />The appropriateness and recommended location of a POC well below 3 -Dam and the rationale <br />for or against a nested well at this location; and <br />The appropriateness and recommended location of a POC well in the Potato Gulch drainage and <br />the rationale for or against a nested well at this location. <br />AJAX and Clear Creek Associates have developed a technical memorandum included as Attachment A to <br />this Report, which includes a summary of the groundwater studies completed at the Henderson Mill in <br />2012, a description of the geology and hydrogeology at the site and recommendations for POC locations. <br />Based on these recommendations, Henderson proposes to add MLGW -15 as a POC, which is a deeper <br />well nested with MLGW -7 downgradient of 1 -Dam. Additional POC wells below 3 -Dam and in the Potato <br />Gulch drainage are not proposed at this time pending additional sampling and hydrogeologic <br />characterizations, respectively. <br />Please contact me at (303) 569 -3221, ext. 1233 or Bryce Romig (ext. 1204) if you have any questions <br />regarding this submittal. <br />