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 17 of 19 Stiff Patterns &Trilinear Diagram of Water Quality Water-quality data from onsite wells (October 2007)were plotted as Stiff patterns to compare the general-mineral characteristics of different aquifers and different areas onsite. Appendix C shows all patterns; Figure 9 summarizes the patterns, and Figure 10 shows the patterns plotted on a site map. Stiff patterns of water quality graphically represent water quality at the site by plotting concentrations of anions and cations (in meq/L) on a horizontal axis and then connecting the dots to create a unique pattern for each well. The colors of the Stiff patterns in Appendix C correspond to quadrants of the site (cyan=NW,blue=NE,yellow= SW, green= SE, and red=Mill/ASB ponds; aquifer zones are noted beside each pattern). Figure 9 illustrates the progression from relatively undegraded water(derived, in part, from the Stanislaus River) to effluent from ASB-2. October 2002 and October 2007 data were used to represent the progression at the beginning and end of the current five-year periods. The individual wells grouped in each category are listed on the right showing whether there is an increasing trend, decreasing trend, or no trend for TDS concentrations. In Figure 9,the lowest category represents undegraded water in the semiperched zone,which is represented by OB-17 in 2002 and OB-16 in 2008. These wells are located adjacent to the Stanislaus River and groundwater samples are composed mainly of river water. The small size of this pattern (relative to most other wells) indicates that this water is less mineralized than that in other wells. The shape of the pattern is distinct for OB-16: On the cation side, sodium and potassium are highest relative to calcium and magnesium; on the anion side,bicarbonate is higher relative to chloride, sulfate, and nitrate. The second lowest category on Figure 9 represents slightly degraded water in the intermediate zone. The 2002 and 2007 diagrams for PW-6 are used to represent the general chemistry typical of water samples in this category. Its pattern is similar in shape to that for OB-17,but larger, reflecting increased mineralization in the intermediate aquifer. Higher mineralization in deeper groundwater than in river water or the semiperched zone would be expected, and is not necessarily wholly attributable to effluent discharge at the site. The 2007 pattern suggests more influence from surface water than in 2002, as the 2007 pattern is smaller and more similar in shape to OB-16. As discussed above,pumping in the intermediate zone induces some flow from higher zones into the intermediate zone. Downward migration of the high-quality SSJID irrigation water can explain the current patterns for the pumping wells. As groundwater quality changes beneath the site,presumably from effluent discharge,magnesium and calcium increase, and calcium becomes the dominant cation. As degradation continues, sodium once again becomes the dominant cation, and magnesium and calcium remain elevated relative to undegraded groundwater. 003044.02 Lawrence&Associates W.I Clients ToxRiver-NeenahU year review reportsU Year Review 2008Weenah_5YearReview Aug2008.doc