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Cripple Creek & Victor Gold Mining Company January I5, 2004 Mr. Phil Bames -2- 043-2170 For comparison, the volume of LVSCF placed within the PSSA is approximately 3.5 million cubic feet. Using an average as-placed porosity of 42 percent (typical for uncompacted gravel), [he available pore volume in the LVSCF is approximately 1.5 million cubic feet, or about 10.8 million gallons. Therefore, the LVSCF had enough available pore volume to contain the precipitation that fell within the PSSA footprint. Evaluation of LVSC Records Data collected from the LVSC system between July 3 and December 31, 2003 are presented in Figures 1 through 3. Figure ]presents atime-series plot of daily water pumped from the LVSC (shading has been added to Figure 1 to denote the periods when ore loading occurred within the PSSA); Figure 2presents atime-series plot of pH from the water sampled from the LVSC; and Figure 3 presents a time series plot of Cyanide (WAD, Free, and Total) concentration from the water sampled from the LVSC. The data presented in Figure 1 show a cyclic increase and decrease in daily pumpage over the period of record. The cyclic nature of the daily pumpage can be correlated to ore loading in the PSSA. As shown in the pumping record, an increase in daily pumpage first occurs during the initial loading of the PSSA. The total ore tonnage placed during [his period was approximately 3 million tons. The daily pumpage peaked in mid-August, approximately one month after the initial loading, after which the daily pumpage decreases. Another period of ore loading (less than 800,000 tons) occurred in August/ September. Approximately one month later, there is a brief period of increased daily pumpage. At the end of September (approximately 90 days after the initial loading), the daily pumpage from the LVSC is at a minimum. In the middle of October, the daily pumpage rates begin to rise again. This rise in daily pumpage again correlates well with continued ore loading to the PSSA. The amount of ore placed during this period was approximately 2 million tons. The daily pumpage records shown in Figure I indicate that increases in daily pumpage may occur during or shortly after ore loading. This is due to the compression of the LVSCF, resulting in a decrease in pore water stored in the fill. According to mine records, the average ore thickness placed in the PSSA to-date is approximately 120 feet. Compression data from Drain Cover Fill (DCF) material (compression data for the LVSCF are not available, however this material is very similar in composition and size as DCF) indicate an approximate 9 percent decrease in porosity occurs with an equivalent ore load of 120 feet. Using an initial porosity value of 42 percent (uncompacted) and a final porosity value of 33 percent (a decrease of 9 percent), the decrease in pore volume in the LVSCF is approximately 312,000 cubic feet, or 2.3 million gallons. This result agrees well with the pumping records. According to the pumpage records, the total amount of water pumped from the LVSC system between July 3 and December 31, 2003 is approximately 2.5 million gallons. Figure 2 indicates that the water pH has generally remained neutral during the period of record, with periods of increasing and decreasing pH. Figure 3 shows that Free and WAD cyanide concentrations peaked in late-September at below 12 parts per million ppm. At the end of December, the cyanide concentrations dropped to around 6 ppm. It is important to note that pure process solutions within the PSSA would be characterized as having high pH (approximately 12.4 su) with higher cyanide concentrations (approximately 30 ppm). It is expected that the LVSC system contain some process solution, as the LVSC is designed to function as part of the overall containment system within the triple lined system. The water quality data indicate that the vast majority of the water removed from the LVSC is meteoric water related to construction. 1^0111)Ob~aaba331~0.0100.W551Phrv-LVSC.doc Golder Associates