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Cripple Creek & Victor Gold Mining Company January I5, 2004 <br />Mr. Phil Bames -3- 043-2170 <br />The flow from the Phase IV PSSA LVSC system should not be considered as a unique occurrence. <br />Data records from both the Phase [and Phase II PSSA's show that pumping rates as high as <br />20 gallons per minute were attained from these LVSC systems during ore loading. The cyclic nature <br />of flow in the Phase IV PSSA LVSC system occurs because ore loading occurs over a large area <br />(over 400,000 square feet), resulting in a delay of the hydraulic response, as shown in Figure 1. <br />LVSC Sumu <br />When evaluating the hydraulic response of the LVSC risers, it is important to note the size of the <br />LVSC sump, as this has a direct influence on pumping rate, measured level or hydraulic head and <br />response of the riser pumps. The LVSC sump is a relatively small sump, and is significantly smaller <br />than the Phase 1 and Phase I[ LVSC sumps. The bottom area of [he sump is only 40 square feet and is <br />2 feet deep, and contains less than 700 gallons of pore water. Therefore, when the sump is full, the <br />only area that is exposed to 2 feet of hydraulic head is the 40 square foot sump, not the entire VLF <br />footprint. The area of the LVSC sump is less than 0.01 percent of the total wetted surface area of the <br />PSSA. <br />Future LVSC Flow <br />Based on observations and discussions presented on the LVSC data, further drainage from the <br />LVSCF is anticipated with additional ore loading within the PSSA. Based on the available data, peak <br />flow rates should develop approximately 20 to 30 days after loading starts, and may take 90 or more <br />days to decline to pre-ore loading flow rates. To-date, approximately 2.5 million gallons of water has <br />been pumped from the LVSC system, leaving approximately 2.5 million gallons of meteoric water <br />left within the LVSCF. <br />An estimate of the time frame and flow rates until full drainage of the LVSCF is achieved cannot be <br />made since it is dependent on the location, amount, and loading rate of the ore. Some case histories <br />from other leach pads and landfills with similar LVSC systems have indicated that periodic drainage <br />within the contained LVSC may continue for years. <br />CONCLUSIONS <br />Pumping of water from [he Phase IV PSSA LVSC system is not a unique occurrence and should be <br />expected to continue. Data records indicate that the LVSCF may contain approximately 5 million <br />gallons of meteoric water, of which approximately 2.5 million gallons have been pumped from the <br />sump. The daily pumpage records collected from the Phase IV PSSA LVSC system indicate a <br />correlation between the sump pumping rate and ore loading within the PSSA, therefore as the PSSA <br />is loaded with ore, more water will report to the LVSC sump. CC&V has appropriately installed a <br />larger capacity pump (approximately 35 gpm) in one caisson to assure timely evacuation of pore <br />water from the system. This pump is level controlled and also contains a transducer to obtain level <br />readings. The combination of the larger pump and the existing pump will provide flexibility in <br />handling both base flows and periodic higher flows resulting from ore loading. Based on the <br />available data, it is recommended that the system continue to be monitored for flow and water quality <br />in accordance with existing practice. <br />ewa~zmm~ioanuiiro.a~oo.ooss~pnrv.LVSCAoc Golder Associates <br />