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10. Uncontrolled seepage from the. VLF ~ <br />The VLF is monitored several times each week at underdrains, leak detection systems, and low <br />volume solution collection systems. If seepage should occur, there should be sufficient warning <br />through these monitoring systems for early identification and subsequent modification of VLF <br />solution management to minimize uncontrolled seepage. Should seepage occur, the pump back <br />system below the Phase II toe berm would be used to capture and return seepage at that location; <br />to the VLF. The pump back system is designed to manage up to SOO gpm and return it to the I <br />VLF. The pump back is located in the thalweg of the primary drainage in which the VLF is <br />constructed and uncontrolled seepage reasonably would be expected to report to that location. ' <br />Should seepage occur at other locations, portable pumps and excavated sumps would be used to <br />contain and return solution to the VLF. Such pumps maybe gasoline, diesel, or electric powered <br />by portable generators. This equipment is on-site and can be deployed readily, as needed. Larger <br />rental pumps and additional generators are also available in Colorado Springs and Denver. <br />11. Failure of the emer~encv cvanide treatment svstem for the External Storage Pond <br />Failure of the emergency cyanide. treatment system for the external pond is possible. Should <br />failure occur and solution needed to be moved into the. pond at cyanide levels greater than 40 <br />ppm, the cyanide solution would be moved into the pond and the pond treated as a batch with <br />hydrogen peroxide or calcium hypochlorite. <br />The pond is outfitted with a bird hazing device which would be activated to minimize potential <br />for wildlife exposure.. Additional hazing techniques, including stationing personnel at the pond to <br />• haze birds until levels were .reduced below the 40 ppm, can be implemented readily. <br />12. Structural failure of the'VLF <br />Major structural failure of the VLF could occur but is highly unlikely. The Phase II toe berm is ~; <br />an engineered structure certified by a competent third-party engineer. It is reviewed routinely by <br />operating staff in the area and formally reviewed annually through AngloGold Ashanti's <br />geotechnical inspection program. The site is in a low seismic region and the VLF has been <br />designed taking into account such potential seismic activity. <br />Movement of ore material off liner could occur through slope failure since ore is stacked at the <br />angle of repose between catch benches. Ore could also move off liner due to a break in a barren <br />pipeline on the VLF, resulting in open flow sufficient to move stacked ore. Catch benches <br />provide some containment for such an occurrence. Portions of the VLF also have a small catch ' <br />area between the liner edge berm and the stacked material. This particular type of event is ' <br />recognized as an operational risk and is controlled by use of steel barren headers when headers <br />are near the liners edge, through the automatic shut down system, through monitoring of the pad; <br />by process operations and by implementing a stacking plan assuring proper operational slopes, <br />benches and setbacks from the liner edge. <br />. Cyanide Emergency Response Plan September 25, 2006 <br />EMS: AGANA/CCV Doc.# E-012 <br />S:\4010-00055 CC & V 112(d) Permit Application\ERP, SPCC, FMP\Cyanide Emergency Response Plan.doc Revision 03 <br />6- <br />