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Cripple Creek & Victor Gold Mining Company Squaw Gulch Valley Leach Facility Design <br />the VLF to quantify the moisture delivered to the VLF. The anticipated annual ore <br />delivery schedule for the VLF is presented in the design criteria. <br />Make -up water is calculated based on maintaining solution application to the VLF. The <br />make -up water requirements vary month -to -month depending on climatic conditions <br />and ore placement. <br />7.2.2 System Outflow Evaluation <br />System outflow components include evaporative losses, the difference in ore moisture <br />between as- delivered moisture content and field capacity (moisture lock -up), and <br />solution delivered to the process plant. Evaporative losses were modeled using <br />historic climatological data collected at CC &V. Monthly evaporative losses were <br />estimated based on the areas under leach and inactive areas, which is realistic <br />because evaporation rates will vary monthly and vary for active and inactive leaching <br />areas. This same approach was also used for the approximate 8 -year post- mining <br />leaching operations period. <br />The field capacity moisture content of the ore was modeled at 7.5 percent of dry <br />weight, based on data provided by CC &V. Data pertaining to the ore field capacity are <br />presented in Appendix B.7. The moisture content of the ore during active leaching will <br />exceed the static field capacity. The leaching ore moisture content was modeled to <br />vary between 9.5 and 10 percent by dry weight. <br />An advantage of the dynamic water balance model is that it simulates solution flow <br />from the PSSA to the process plant. This provides an opportunity for the operation to <br />actively manage the solution levels and volumes within the PSSA, and to maintain <br />sufficient capacity for contingency inflows. For example, by pumping more solution <br />from the PSSA than is applied in leach solution, the level of the PSSA can be dropped, <br />thereby providing more storage volume. Using this methodology, the mine can <br />effectively manage the solution levels in the PSSA. <br />7.2.3 Contingency Inflows <br />As in previous Amendments, the water balance model includes contingency inflows. <br />These include 12 hours of draindown and the 100 year /24 -hour design storm event. <br />The draindown volume was calculated based on application rate for the PSSA during <br />operations. Inflow from the 100 year /24 -hour design storm event was calculated as <br />the storm depth (3.5 inches) applied to the lined area for the PSSA. The contingency <br />inflows are delayed reporting to the PSSA based on the average ore depth using the <br />delay function. <br />7.3 Discussion of Results <br />The results from the dynamic, probabilistic water balance model are summarized in <br />Figures 4 and 5. Additional model output is presented in Appendix G.1. <br />Project No.: 74201125G0 Page 38 <br />1 September 2011 <br />amec'3 <br />