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water levels for these wells range from 1.09 to 20.51 feet below ground surface. Mean saturated thicknesses in the portions of the elluvisl system monitored range from 11.41 feet et TGAL15 (the most downgradient well), to 28.09 feet et YGAL18 (the most upg radiant well, Table 7.4). Slight, but measurable seasonal tlifferences in water levels have been noted in this alluvial system. In ell cases, spring appears to be the dominant season for recharge to these wells. Winter rainfall end late-season snowmelt runoff is the second most signiftcent source of recharge at all wells except YGAL16, where summer precipitation is more important. Fell mean water levels appear to be the deepest, except et Well TGAL15, where summer levels are the deepest. For ell wells, the deepest mean water levels range from 1.47 feet et Yell YGAl15, to 21.27 feet at Yell TGAL18. Water IeveL fluctuations et individual wells ere moderat e~, ranging from 2.83 feet et Well TGAL15 to 6.35 feet at Yell Y GAL16. Table 7.4 shows the saturated thickness and percent saturation of the alluvium et each of these wells. Lennox Overburden end Coal Water Levels. Four monitor wells were installed by the USGS in • the fall of 7980 to monitor water levels in the Lennox Overburden (YLOV3, YLOV4) and Lennox Coal (YLS, YLb). Exhibit 7.1 shows the locations of these monitor wells. Water level tlata for these wells were collected from October, 1980 through July, 1981. Monthly we ter level data for these wells are presented in Appendix 7-2, and well completion information is given in Appendix 7.1 and summarized in Table 7-2. Owing to the flowing nature of these weL[s, little useful water level information was obtained in 1980-81 (Table 7-3). In 1994, all four wells were capped end pressure Beuges installed. Preliminary pressure-heed levels range from +5.8 feet at YLOV3 to +26.2 feet et YL6. These wells lie in a tributary of Sage Creek which will be subject to mining activity by the year 2000. A sediment pond (Pond 012) is slated for construction to control sediment runoff from this area of the mine, and at that time the four Lennox overburden end toaL monitor wells will be abandoned according to accepted abandonment procedures. • Wadae Overburden Water Levels. Thirteen monitor wells (YOV1, 8, 9, 10, 15, 19, 20, 22, 25, 27, 28, 29, and 30) have been installed to monitor water levels in the Wedge overburden geologic unit et Yoast. Exhibits 7-1 end 7-2 show the overburden monitor yell 13 Revised 03/01/95