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 7 of 19 10. July 2007 data for City of Ripon municipal well MW-4 shows a nitrate concentration of 9.2 mg/L(the June 2002 concentration was 38 mg/L), characteristic of local water quality (Appendix A). Ripon municipal well MW-9, located immediately east of the NP site was nondetect for nitrate in July 2007 (June 2002 showed nitrate concentration of 6.2 mg/L). GROUNDWATER MOVEMENT 11. In the semiperched zone during the period 2002 through 2007, the direction of the groundwater gradient varied on a seasonal basis, similar to historic patterns. In the first and third quarters, the gradient in the southeast part of the site(near the Stanislaus River) generally is from the site towards the river(to the south-southeast). In the second quarter, the gradient in the southeast part of the site (near the Stanislaus River) generally is from the river towards the site(to the north-northwest). In the fourth quarter, the gradient is often more or less parallel to the river in the southeast part of the site. In the northern and western parts of the site,the gradient generally is away from the site,ranging from northwest to west (Figure 3). 12. In the upper aquifer during the period 2002 through 2007,the groundwater gradient generally was always away from the central part of the site(to the southwest in the southwestern corner of the site,to the southeast or east along the eastern part of the site, to the northeast in the northeast part of the site, and to the northeast in the northwestern part of the site; Figure 4). 13. In the intermediate zone during the period 2002 through 2007,the groundwater gradient was similar to that in the upper zone, generally moving away from the site to the northwest and southeast(Figure 5). 14. Percolation of effluent in fields causes groundwater mounding in the semiperched zone to vary in location beneath the percolation areas. 15. Groundwater mounding in the semiperched zone is reflected,but muted, in the upper and intermediate zones. GROUNDWATER QUALITY 16. In the semiperched zone, areas of elevated TDS are associated with areas of groundwater mounding (high groundwater). The highest TDS generally is found in the vicinity of ASB-2 and in the northeast corner of the site (Figure 6). Elevated TDS beneath ASB-2 reflects percolation of effluent downward from the pond. Elevated TDS in the northeastern part of the site reflects concentration of constituents from evapotranspiration by the eucalyptus trees in this area. 17. In the upper zone, TDS concentrations are higher in areas of elevated groundwater. The highest concentrations are observed in the southwestern and northeastern corners of the site; concentration decreases to the southeast(Figure 7). The pattern of TDS in the upper aquifer reflects downward migration of applied effluent and clean irrigation water drawn towards the southeast by the active production wells there. 003044.02 Lawrence&Associates W.•IClientslFoxRiver-NeenahU year review reports Year Review 2008Weenah_5YearReview Aug2008.doc