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TECHNICAL MEMORANDUM <br /> To: Tim Cazier, Environmental Protection Specialist <br /> Colorado Division of Reclamation, Mining and Safety <br /> From: Timm Corner, Director of Environmental Services <br /> AngloGold Ashanti North America <br /> Subject: Cresson Project; DRMS File No. M-1980-244;AM-10(MLE2) <br /> Geochemistry and Groundwater Adequacy Review Responses <br /> Date: August 13, 2012 <br /> DRMS has performed an adequacy review of the Geochemistry and Groundwater portion of the Cresson <br /> Project; DRMS File No. M-1980-244; AM-10 (MLE2),which was issued on August 7, 2012.This technical <br /> memorandum contains the responses of Cripple Creek and Victor Gold Mining Company,through its <br /> managing partner AngloGold Ashanti North America, Inc. <br /> The responses are presented in the order that they appear in the adequacy review. <br /> Adequacy Issue#1:Source of Neutralization in ECOSA Overburden <br /> DRMS Adequacy Comment <br /> Where is the neutralization capacity in the [ECOSA] overburden coming from?Is Cripple Creek& Victor <br /> (CC&V) going to apply a buffering agent as part of the placement of the overburden in ECOSA?Please <br /> explain. <br /> CC&V Response <br /> The source of neutralization of the ECOSA overburden is naturally-occurring carbonates.The overburden <br /> that will be delivered to the ECOSA has been routinely tested using the LECO furnace method for total <br /> carbon,with the following result (ECOSA Evaluation, Table 4): <br /> Total Carbon Content=0.21% <br /> The equivalent total calcium carbonate content of the overburden is therefore: <br /> Equivalent Calcium Carbonate = MW(CaCO3)/MW(C) * Carbon = (100.1/12) *0.21%= 1.75% <br /> This has an acid neutralizing potential of: <br /> Acid neutralizing potential = 17.5 tons CaCO3 per kiloton of rock <br /> Some proportion of this ANP is available from the rock, and it is this neutralizing potential that is <br /> referred to in the MLE2 report. No neutralizing material is to be added to the ECOSA overburden. <br /> Adrian Brown Consultants, Inc. Page 1 of 8 <br />