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current ground water monitoring program is presented in Table 15-8 of <br />the Yoast Mine PAP. <br />Ground Water Level Summary. This year, water levels at all wells fell <br />within their historic ranges, with the following exception. Wadge <br />overburden well YOV30 has experienced a general decline in water levels <br />since it was first monitored in 1991. <br />All alluvial wells are showing distinct seasonal water level <br />fluctuations in response to periods of precipitation recharge or the <br />lack of precipitation. Overburden and coal well water levels are <br />fluctuating in response to the precipitation recharge, induced ground <br />water flow to the reclaimed mine pits. Wells YOV29, YOV9 and YWU16 were <br />often dry. <br />Ground Water Quality. Table 4 shows the ground water parameter list <br />used for all well water samples. Appendix C provides all ground water <br />quality data collected during the past two years, along with sampling <br />remarks. This is followed by a plot of TDS versus time for the entire <br />period of record. The regression line on this plot is generated by a <br />method known as LOWESS (Locally Weighted Scatter plot Smoothing). Unless <br />otherwise noted, smoothness factor (SF) of 1 (on a scale of 0 to 1) was <br />used, which gives maximum smoothing. This plot is followed by a table <br />listing historic TDS values and percent milliequivalents for major ions. <br />Finally, a statistical report representing baseline (i.e., premining) <br />data for each well (when available) is presented in Appendix Cl. On this <br />statistics report, "censored data" refers to analytical values that were <br />below the detection limit, which were censored from the min/max/mean <br />calculations. The time frame for baseline conditions is listed under <br />"conditions specified" at the bottom of each page. <br />- Alluvium. One well, YAAL14, monitors water quality in the Annand Draw <br />alluvium. TDS values for this well display an increasing trend. <br />Two wells, YGAL15 and 16, monitor water quality in the Grassy Creek <br />alluvium. Well 15 is located on Grassy Creek below the confluence of the <br />3