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<br />Ground Water <br />Water Levels <br />Table 3 provides a summary of ground water monitoring <br />sites at the Yoast Mine. Water level data are provided in Appendix B. <br />Water level reports for the past five years are presented immediately <br />after the water level hydrograph of all data since 1991. Water level <br />measurements are collected with an electrical water level indicator or a <br />steel tape. Pressure readings (in psi) obtained from flowing wells with <br />pressure gages are multiplied by 2.31 to obtain head in feet. The <br />current ground water monitoring program is presented in Table 15-8 of <br />the Yoast Mine PAP. <br />- Alluvium. One well, YAAL14, monitors the Annand Draw alluvium. Two <br />wells, YGAL15 and 16, monitor the Grassy Creek alluvium. Eight wells; <br />YSAL1 to 6, 8 and 12; monitor the Sage Creek alluvium. Most well water <br />levels exhibit the typical seasonal fluctuation, increasing water levels <br />in the spring Followed by decreasing water levels in the summer and <br />• fall. Beaver dams may affect water levels in the alluvium. Most wells <br />exhibited water levels this year within their historic ranges. Wells <br />YGAL16, YSAL3, 4 and 5 all exhibited the lowest water levels on record. <br />Several other wells exhibited the lowest water levels since 1994. Well <br />YSAL10 was abandoned in October 2002 (see Technical Revision 16 in last <br />year's AHR introduction). <br />- Wadge Overburden. Four wells; YOV9, 28, 29 and 30; monitor the Wadge <br />overburden. We11 YOV28 exists in the Annand Draw basin, all others exist <br />in the Sage Creek basin. Most wells exhibit typical seasonal <br />fluctuations, and water levels this year within their historic ranges, <br />although some lag time for the spring recharge is observed. Well YOV28 <br />(downgradient of the 1996/99 mine pit in Annand Draw) has experienced a <br />decrease in water levels since August 1996. Well YOV29 has experienced a <br />decrease in water levels since October 1998 .and has been dry since May <br />2000. Well YOV30 has also experienced a decline in water levels until <br />2000, but have increased since then. <br />3 <br />