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The following discussion of the analytical data collected during the <br />reporting period is arranged by strata being monitored and coincides <br />with the format (by aquifer type) in which the analytical data are <br />presented in Appendix D. The following discussion of water quality will <br />limit itself to a description of total dissolved solids (TDS). A <br />separate section, Comparison of Ground Water Quality to Water Use <br />Standards, will list those samples that exceed water use standards. <br />Data for each well in Appendix D begins with a listing of the water <br />quality data collected during the past two years, followed by remarks <br />explaining the sampling procedure. This is followed by a plot of TDS <br />versus time for the entire period of record. The regression line on this <br />plot is generated by a method known as LOWESS (Locally Weighted Scatter <br />plot Smoothing). Unless otherwise noted, a smoothness factor (SF) of 1 <br />(on a scale of 0 to 1) was used, which gives maximum smoothing. A <br />statistical report representing baseline (i.e., premining) data for each <br />well (when available) is presented in Appendix D1 of the 2010 AHR. On <br />this statistics report, "censored data" refers to analytical values that <br />were below the detection limit, which were censored from the <br />min /max /mean calculations. The time frame for baseline conditions is <br />listed under "conditions specified" at the bottom of each page. <br />- Alluvium. One well currently monitors the Hubberson Gulch alluvium. <br />Well WHAL7 -2 exists on Hubberson Gulch downstream of mine discharges <br />from NPDES 006, 016 and 017. Its TDS plot shows a recent stable trend <br />(SF 0.5), with values generally decreasing since May 2005. A discussion <br />of water quality from Dry Creek Alluvial Well DCAL -02 will be found in <br />the follow Ground Water Point of Compliance Section. <br />- Wadge Overburden. Three wells monitor the Wadge overburden. North <br />area Well WOV14 exhibits an increasing TDS trend. Middle area Well WOV17 <br />overall exhibits a decreasing TDS trend, but with an unusually high <br />values in 2008, 2009 and 2011. South area Well WOV25 was drilled in <br />September 2004. It displays an increasing TDS trend. <br />4 <br />