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Cripple Creek&Victor Phone(719)689-2977 <br /> Gold Mining Company Fax(719)689-3254 <br /> PO Box 191 <br /> 100 N Yd <br /> ANGLOGOLD AsHANTI victor,CO80860-0191 <br /> ANGLOGOLD ASHANTI (COLORADO) CORP. <br /> Hydro-Jex Project Monitoring Program (March 10, 2010) <br /> CC&V is planning to install nine injection wells to test the utility of the Hydro-Jex (Hi) system in enhancing <br /> recovery from the VLF in April 2010. There are several reports demonstrating the solutions can be injected into <br /> leach pads with relatively little risk to the heap. CC&V is committed to ensuring that the integrity of the VLF is <br /> preserved and that the project proceeds with the utmost levels of safety. The discussion below details a <br /> comprehensive plan for monitoring the area of the VLF impacted during the HJ project.The plan features a four- <br /> pronged approach that is designed to monitor all aspects of the project that could impact not only the stability, <br /> but also the operational balances of the VLF and is explicitly designed to ensure that the recommendations put <br /> forward in the letter from AMEC(RE: Hydro-Jex Program Review—10 December 2009) <br /> 1. Real-Time Monitoring of Injection Parameters <br /> The first level of monitoring during the HJ project will be at the point of injection. The HJ rig is outfitted with <br /> instruments and data loggers capable of continually measuring and recording pressure and flow rate at the point <br /> of injection. Previous studies have shown that during injection the flow of solution is initially limited by the <br /> porosity of the heap, but when the pump's pressure exceeds the rock pressure in the targeted depth, <br /> breakdown occurs and solution is pushed laterally into the heap. (Seal 2007; Seal and Fink 2008)The pressure at <br /> which breakdown occurs is a function of the bulk density of the ore, residual moisture level, and the injection <br /> depth. Assuming a residual moisture level of 9%, the breakdown pressures will range from 25 to over 400 psi, <br /> depending on the injection depth, and solution will spread approximately 80 feet laterally from the point of <br /> injection. Figures 1 and 2 show the estimated area affected during the HJ project. <br /> Metal Recovery Solutions, LLC (MRS) operators are experienced, having developed and used the HJ process at <br /> Newmont properties in Nevada, and will be able to use their knowledge in conjunction with the real-time <br /> pressure and flow rate data to ensure that the maximum pressures put forward by AMEC, i.e. the overburden <br /> pressure or fraction thereof, are not exceeded. Moreover, the real-time pressure and flow rate data will alert <br /> the operators to any possible local instability allowing them to take appropriate actions immediately. Because <br /> the pressure and flow rate monitors are an integral part of the Hydro-Jex rig this data will be available during all <br /> injection events. <br /> 2. Stability Monitoring and Factor of Safety <br /> AMEC Earth and Environmental (AMEC) has prepared this plan for the Cripple Creek & Victor Gold Mining <br /> Company (CC&V) presenting the recommended locations for surface survey monitoring during the upcoming <br /> Hydro-jex injection program. Based on the position of the Hydro-jex injection wells, the following anchor trench <br /> locations should be monitored via surface surveying: <br /> • Point 1: N 51792.95 E 35030.00 <br /> • Point 2: N 51145.47 E 34763.23 <br /> • Point 3: N 50543.38 E 34693.89 <br /> Please note these locations may need to be adjusted to suit field conditions and access, but should be located at <br /> the anchor trench. It is recommended that these locations be surveyed prior to initiating injection, and once a <br />