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Data for each well in this appendix begins with a listing of the water quality data collected during the past two years, followed by water level measurements and remarks explaining the sampling procedure. This is followed by a plot of TDS versus time for the entire period of record. The regression line on this plot is generated by a method known as LOWESS (LOCally WEighted Scatterplot Smoothing). A smoothness factor of 1.0 (on a scale of 0 to 1) was used, which results in maximum "smoothing". Finally, this plot is followed by a table listing historic TDS values and percent milliequivalents for major ions. - Alluvium. Well 32 is located furthest upstream on Little Grassy Creek. Review of the TDS plot indicates an increasing trend. This is due to the contribution of waters from Spoil Springs 3, 4, and 5. Further downstream, Well 6 has historically displayed an increasing TDS trend although recently TDS values have dropped. Furthest downstream on Little Grassy Creek and below NPDES 002, is Well 31A. It also displays an increasing TDS trend. Three wells are sampled in the Grassy Creek alluvium. Well 71 monitors the alluvium upstream of mining at Seneca II. It displays an increasing TDS trend. Well 33 monitors the Grassy Creek alluvium at the Little Grassy Creek confluence. It displays an increasing TDS trend. Well 70 monitors the alluvium below Seneca II and also downstream of the confluence with Scotchmans Gulch. It interestingly displays a decreasing TDS trend. In the Cow Camp Creek alluvium (below NPDES 004), water quality is measured at two wells. Well 46 displayed an increasing TDS trend until 1986/1987, then a decrease until 1991, an increase from 1991 to 1999, and finally a decrease since 1999. Well 69, located below 46, interestingly displays a decreasing TDS trend. Well 68, completed in the Bond Creek alluvium (below NPDES 008), was drilled along with Well 69 (see above) in 1988. It displays a slightly increasing TDS trend. 7