2017-08-22_REPORT - M1980244 (2)

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(‘CC. J NEWMONT Newmont Mining Corporation Crpple Creek&Victor Gcla Mine 100 Nort'n 3" Street P 0 Box 191 T 719-689-4049 F 719-689-3264 www newmorl corn SENT CERTIFIED,RETURN RECEIPT REQUESTED 7015 1660 0000 0779 9598 C, AED 1111 August 24, 2017 b 7,011 Mr.Timothy Cazier,P.E. '600314 r, fai Environmental Protection Specialist ASla °F 1Nb pada Colorado Department of Natural Resources ,MIFI Division of Reclamation,Mining and Safety Office of Mined Land Reclamation 1313 Sherman Street,Room 215 Denver,Colorado 80203 Re: Permit No.M-1980-244; Cripple Creek&Victor Gold Mining Company("CC&V"); Cresson Project —Written Spill Notification additional information—Processed Ore Thickener Overflow Tank Spill— August 10,2017 Dear Mr. Cazier: Cripple Creek and Victor Gold Mining Company (CC&V) hereby provides a response to the Division of Reclamation, Mining and Safety (Division) August 18, 2017, inquire into the August 10th, 2017 Neutral pH spill that occurred at the Processed Ore Thickener Overflow Tank at the High Grade Mill(HGM). 1) Cleanup Response. Rule 8.2.3(a) requires a summary of "actions taken to respond and correct" the condition. The report provided a summary of what equipment/systems actions were taken to stop the spill, but no discussion was provided on the cleanup of the spill and how that was verified. Please provide a summary of the cleanup and how adequate cleanup was assured. CC&V Response: The neutral pH water that was spilled contains a dilute mixture of; potassium amyl xanthate (PAX), Dithiothreitol, and Frother F-501. The reagents are generally mixed at the following rates into the ball mill and float circuit; PAX 2,280 cc/min, Dithiothreitol 76 cc/min, F-501 12.8 cc/min, thus yielding concentrations in the neutral pH water that are not hazardous to human health and the environment. The HGM feed is roughly 250 tons an hour. The PAX, Dithiothreitol are water soluble and have an affinity to the ore, the reagents are primarily mixed into the ball mill and quickly react with the ore, leaving trace concentrations of the reagents in the neutral pH water. The frothing agent is a lighter than aqueous phase solution (LNAPL). The frother bonds with the gold ore, floats to the top and is skimmed off into to the float concentrate circuit in the HGM. In general the reagents are quickly consumed in the process; bonding with the ore and float to the top to be separated off into the float concentrate circuit in the HGM. The spill occurred over the HGM liner, preventing any spilled water from being released into the environments. Once the solution infiltrates into the HGM liner sump, the solution can be recovered and recycled in the mill. L7