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2002 AHR McClane & Munger Canyon Mines Page 4 <br />PRECIPITATION <br />Based upon Bureau of Land Management records from a rain gage in Ashford Canyon, <br />the 2002 water year experienced 9.74 inches of precipitation compared to average <br />precipitation of 18.05 inches. The rain gage is not located at the mine but about 3.5 <br />miles north at an elevation of 5895 feet compared with 5610 at the portals. The daily <br />rainfall record is detailed on Table 2. The greatest 24 hour precipitation event during <br />the year, 0.62 inches, occurred on October 8`h. Figure 2 presents a graphical <br />comparison of the 2002 total monthly precipitation and the average monthly <br />precipitation for the period 1977 through 2002. <br />EFFECT OF THE MINES ON THE EAST SALT CREEK REGIME <br />Surface Water <br />Due to the limited disturbance of the mines there is little chance any significant effect on <br />the quantity or quality of the surface waters near either mine sites has occurred. As the <br />Division notes in its approval package for the Munger Canyon Mine, the total area that <br />will be disturbed by both mine sites amounts to 0.12 percent of the area of the East Salt <br />Creek drainage basin above the mines. <br />Surface water samples from East Salt Creek were obtained for two quarters during the <br />• 2002 water year. East Salt Creek was dry during the 2nd and 3rd quarter 2002 <br />monitoring events. Results from all water samples collected in 2002 are presented in <br />Table 4. The results from the samples collected from East Salt Creek above and <br />below the mine site are generally the same for all parameters. <br />Table 6 presents a full suite analysis of the mine water. The mine water has a TDS <br />value of 1810 mg/I compared to 3,000 to 4,000 mg/I for east salt creek. Therefore, <br />mine water discharge will supplement and improve the water quality in East Salt Creek. <br />The sample sites on McClane Creek were dry all four quarters. <br />Groundwater <br />Table 5 shows the results of groundwater sampling during 2002. The average static <br />water level for the baseline years of 1981 and 1986 is also shown. Results of quality <br />sampling are consistent with the results from previous years. Water depths were a little <br />lower than baseline values. GW-4 in close proximity to a hay field that is irrigated <br />during dry periods and in danger of being eroded with an oxbow, has been replaced <br />with GW-3. GW-3 is located adjacent to the road south of GW-4 and should be outside <br />of the influence of the irrigation of the hay field. Refer to Figure 4.2-2 of the McClane <br />Canyon Permit. The Division of Minerals & Geology has approved this substitution. <br />r~ <br />U <br />