2015-01-20_HYDROLOGY - M1977342 - Laserfiche WebLink

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1/ Climax Molybdenum COLORADO OPERATIONS Henderson A Freeport-McMoRan Company 19302 County Road 3 Parshall, CO 80468 Phone(303)569-3221 RECENFI.I January 14, 2015 <JAN 2 0 2015 Via Email and UPS Priority Mail ExylsiON OF RWAyff 11 MINING AND SAFETY /Mr. Peter Hays Division of Reclamation, Mining and Safety 1313 Sherman St., Rm. 215 Denver, CO 80203 ✓ ✓ Re: Follow-up Notice for Mill Tailing Delivery Line, Droptower 1-7 Overflow, Permit No. M-1977- 342 Mr. Hays: Henderson Mill is providing this written follow-up notice to a phone call made to you on January 8, 2015 pursuant to Rule 8.1 and 8.2 of the DRMS Rules and Regulations. This notice is regarding process water which escaped from (primarily) droptower 5, but also from droptowers 1-4 and 6 & 7, to some extent. The Tailing Delivery Line (hereafter referred to as the TDL) is designated as an environmental protection facility in Henderson's Environmental Protection Plan. The overflow is believed to have begun just after 12:00 A.M. (midnight) the morning of January 8, 2015. It is believed to have lasted a very short period of time (-5 minutes), based on flow trending from mill operations. These trends also indicated that a spike in pressure and flow occurred just after midnight for a brief duration. We believe that approximately 9,000 gallons of tailing material was released during this event. This volume was factoring the tailing flow rate, the duration of the spike and assuming that approximately 10 percent of the total flow was released from the towers, while the remaining flow continued along its intended course, through the TDL. All material released from the TDL flowed along the alignment of the TDL to the No. 1 Cutout structure, located below the number 12 droptower. A fraction of the material, while flowing along this path also became entrained in snow. (a) After discovering the issue, Henderson employees began closely monitoring the situation to determine whether flow should be diverted. The flow had normalized following the short-lived event, so flow diversion to the Emergency Cut Out structure was not necessary. (b) Mill process water flow did not adversely impact human health, property or the environment. All material associated with this event flowed along the TDL alignment and access road. Any drainage from this area flows along a private Mill access road to a culvert, where it comingles with other process waters flowing into the tailing impoundment.