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Meteorological Data <br />No meteorological data is collected at the Yoast Mine. Data from the <br />National Climatic Data Center's Hayden Station is used here to evaluate <br />the precipitation trend. These data are provided in Appendix Al. <br />Precipitation data is summarized on Table 2. For this year, 17.58 inches <br />of precipitation was measured, which is 0.95 inches (5 %) below the 1981- <br />2010 average, 18.53 inches. All months except December, April, August <br />and September were below average. Snowpack runoff, as estimated by <br />totaling November through March precipitation values, was 6.71 inches, <br />which was 0.80 inches (11 %) below the 1981 -2010 average, 7.51 inches. <br />Ground Water <br />Water Levels. 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 ten 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 />Ground Water Level Summary. This year, water levels at all wells fell <br />within their historic ranges, except for wells YSAL3 and YOV30. Sage <br />Creek Alluvial Well YSAL3 exhibited its highest water level ever this <br />year with a value of 2.56 feet. Overburden Well YOV30 exhibited its <br />lowest water level this year with a value of 128.10 feet. All alluvial <br />wells are showing distinct seasonal water level fluctuations in response <br />to periods of precipitation recharge or the lack of precipitation. <br />Overburden and coal well water levels are fluctuating in response to the <br />precipitation recharge, induced ground water flow to the reclaimed mine <br />pits. <br />2 <br />