ARCHIVED REPORTS_FIRST QUARTER 2008 GROUNDWATER MONITORING REPORT

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Neenah Paper,Inc. _First-quarter 2008 Groundwater-Monitoring Report Apri130,2008 Page 11?f 9 Introduction • This letter presents the results of first-quarter 2008 groundwater monitoring performed by Lawrence & Associates (L&A) between January 28 and 30, 2008, at Neenah Paper (NP), Inc.'s Ripon facility (Figure 1). The work described in this letter fulfills the monitoring and reporting requirements set forth in Waste Discharge Requirements, Order 5-01-148, dated 14 June 2001, issued by the California Regional Water Quality Control Board, Central Valley Region (CVRWQCB). Also per Order 5-01-148,L&A will prepare, on NP's behalf, a Five Year Water Quality Report which discusses (1) actions taken during the previous five years to reduce the total dissolved solids (TDS) levels in mill effluent and (2) a hydrogeologic analysis of the effects the reduction in TDS levels had on the groundwater quality in the semiperched, upper, and intermediate aquifers. The five year report will be submitted to the CVRWQCB by June 30, 2008. Figure 2 shows all monitoring well locations and identifies their respective aquifers. Corrective Action Evaluation and Implementation Schedule In order to meet the water-quality protection standards (WQPS) adopted by the CVRWQCB for the site (Table 1), NP chose to import low TDS South San Joaquin Irrigation District (SSJID) water as the preferred corrective action method for reducing TDS levels in Plant effluent water and groundwater beneath the site.1.2 The water was provided by the City of Ripon and piped from their holding pond located on the north side of their municipal waste water treatment facility (MWWTF)ponds. Groundwater-quality modeling predicted that the application of low (<150 mg/L) TDS water in the east percolation field would improve (lower) TDS levels by 100 • to 500 mg/L, depending on the location in the subsurface, over a five year time period. Between June 26 and August 16, 2007, approximately 135.6 acre feet(44 million gallons) of low(133 mg/L) TDS water were pumped into NP's east percolation field and allowed to infiltrate into the subsurface. The east percolation field is located between a high TDS plume originating from the bottom of ASB-2 and production wells PW-6 through PW-8. In addition to recharging the semiperched aquifer with low TDS water, the irrigation water had the additional benefit of reversing the groundwater gradient away from the field, essentially creating a hydrologic barrier between ASB-2's TDS plume and the production wells. Improving the quality of water in the vicinity of the production wells ultimately improves the quality of water discharged by the mill as effluent. According to the L&A's groundwater model,the infiltration of 67 acre feet of water annually to the east percolation field, over a five year period, will bring TDS levels in the semiperched and upper aquifers into compliance with the site's WQPS. Groundwater quality improved in the immediate vicinity of the east percolation field in the semiperched aquifer by 18 to 22%, in the upper aquifer by 23 to 35%, and in the intermediate aquifers by 19 to 34% following the application of SSJID water.3 If groundwater quality continues to respond as predicted by L&A's groundwater model, the continued application of low TDS SSJID water should bring the semiperched and upper aquifers ' L&A,June 15,2005,Amended Report of Waste Discharge For Disposal Of Plant Effluent Water. L&A,March 31,2006,Addendum To Amended Report of Waste Discharge For Disposal Of Plant Effluent Water. • 'L&A, February 8,2008, Combined 2007 Annual Summary Report, 4th-Quarter 2007 Groundwater-Monitoring Report,And Preliminary Corrective Action Evaluation Neenah Paper Company Ripon Calffornia 005194.01 Task 8 Lawrence&Associates W:IClientslFoxRiver-NeenahlOuarterlyMonitoringl200811st quarterll st O 2008 report.doc