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of the alluvium at each well. • <br />A single monitor well (YAAL14) has been installed to monitor water levels in the alluvial <br />system within Annend Draw on the north end of the Yoast Mine. Exhibit 7-1 and 7-2 show <br />this monitoring well location and the potentiometric surface, respectively. <br />Vater level date for Vell YAAL14 has been collected since October, 1990. Monthly water <br />level data, including a hydrogreph is given in Appendix 7-2, and Appendix 7-1 contains the <br />well completion information for the Annend Drew alluvial well. <br />Ground water in Annend Draw occurs under unconfined conditions, with a mean water level of <br />10.25 feet end a mean saturated thickness of 12.05 feet (Table 7-4). Measurable seasonal <br />water level changes occur a[ this well cite, with the shallowest levels appearing during <br />the spring (average of 7.19 feet), and the deepest levels during the fall (average of <br />12.87 feet). Voter level fluctuations within each season are greatest in the spring (9.86 <br />feet), and least in the winter (2.17 feet). Table 7-4 shows the saturated thickness end <br />percent saturation of the alluvium et this well site. <br />Spring recharge in the form of snowmelt runoff and rainfall is the most significant period • <br />of recharge for the Annend Drew el luvial system, winter precipitation is the second most <br />important source of recharge to this system, end this may be due in pert to the relatively <br />low elevation of this monitoring site (well response to late February end early March <br />snowmelt runoff). <br />Four wells (YGAL15 to 18) have been installed to monitor water levels in the alluvial <br />system along the Grassy Creek side of the Yoest Mine. Exhibits 7-1 end 7-2 show the <br />alluvial monitor well locations and the potentiometric surface, respectively. Alluvial <br />Yells YGAL15 and YGAL16 ere located to monitor the downgredient portion of Grassy Creek <br />alluvium which may be effected by the proposed mining plan. The other two upgradient <br />wells will serve as background control points. <br />Vater level date for the Grassy Creek alluvial wells have been collected since September, <br />1990. Monthly water level date for Ch ese alluvial wells, including hydrogrephs, are <br />presented in Appendix 7-2. Appendix 7-1 contains well completion information. <br />Ground water in the Grassy Creek alluvial system occurs under unconfined conditions, • <br />although Yell YCAL15 exhibited a slight artesian condition in the spring of 1993. Moen <br />12 <br />