ARCHIVED REPORTS_FIVE-YEAR WATER QUALITY REVIEW REPORT 11-17-2008

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Five-Year Water-Quality Report November 17,2008 Neenah Paper FR LLC Ripon Mill Page 18 of 19 For anions, bicarbonate, which is the dominant anion in undegraded water, increases then decreases relative to the other anions, until it is the subordinate anion in the effluent. In effluent, chloride and sulfate are elevated relative to bicarbonate. Figure 9 illustrates that there are more wells in the more-degraded categories in comparison with the 2002 observations, although in most categories,the patterns are smaller for 2007 than for 2002, implying better water quality. Figure 10 shows the Stiff patterns plotted on a site map. This map illustrates that the best water quality, in both the semiperched and upper/intermediate zones is in the southeastern part of the site. The good water quality in this area reflects the influence of the Stanislaus River and the application of the low-TDS water from SSJID. The most degraded water quality is in the northeastern part of the site. This water quality reflects the concentration of minerals in groundwater caused by evapotranspiration of the eucalyptus trees in the east orchard. The change in water quality from undegraded to effluent, as shown in the Stiff patterns, can be traced on trilinear diagrams, also (Figure 11). On a trilinear diagram,the triangle in the lower left represents the cation balance in the water sample and the triangle in the lower right shows the anion balance;the large diamond shows overall water quality for all water samples. The effluent sample, ASB-2, is shown on all three figures to compare with the water chemistry of the monitoring wells. The colors of the symbols on the diagrams correspond to quadrants of the site (pink=NW,blue= NE,yellow= SW, green= SE, and red=Mill/ASB ponds). On the trilinear diagrams the progression from undegraded groundwater(OB-17, PW-6)to degraded groundwater(OB-2, OB-4) is shown by an increase in the relative percent milliequivalents/liter of chloride and/or sulfate relative to bicarbonate. Changes in the cations (lower left triangle) from undegraded to degraded are shown by an increase in the relative percent milliequivalents/liter of calcium and/or magnesium relative to sodium. Trend Analyses Appendix B shows the results of trend analysis for pH, electrical conductance, chloride, sodium, sulfate, nitrate, and TDS. The Mann-Kendall test for trend was conducted for the period 2002 through 2007.5 Figure 12 shows a summary of the results of the trend analyses. Overall, most parameters (67%) show no trend, with about equal amounts of upward and downward trends (16%up and 17% down). Chloride, specific conductance, and sulfate show more downward than upward trends. Specific conductance shows the most downward trends, at 47% downward(9% upward). In the previous five-year review,trend analysis was conducted only for TDS, for the entire 5 Trend analysis was by the Mann-Kendall test which is a standard nonparametric test for trend,described in many statistics texts. The test compares the number of sequential increases or decreases of a variable ordered by time;if the number of increases is greater than the number of decreases and the test statistic is greater the tabled value,an increasing trend is indicated. For example,see Gilbert,R.O., 1987,Statistical Methods for Environmental Pollution Monitoring, Van Nostrand Reinhold.,pp.207-215. 003044.02 Lawrence&Associates W:UientslFoxRiver-NeenahU year review reports15 Year Review 20081Neenah_5YearReview Aug2008.doc