ARCHIVED REPORTS_2010 ANNUAL REPORT

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Nestle USA, Inc., Ripon, California March 31, 2011 2010 Annual Report TCE • Concentrations of TCE above the laboratory reporting limit were present in 29 of 56 wells in 2010 (Table 3.1) ranging from 0.55 pg/L (well M-52B, January) to 340 pg/L (well M-10A, October). • The spatial distribution of TCE concentrations in the Upper Aquifer has remained consistent over the past five years, except for a slight increase in the extent of TCE to the northwest toward well M-1 OA in 2007, 2008, and 2010 (Figure 9). • An increase in TCE concentrations in well M-10A from 85 pg/L in the Second Quarter 2009 to 250 pg/L in the Third Quarter 2009 prompted a subsurface investigation to assess groundwater conditions and concentration trend S13,14 ECM concluded that a decline in groundwater extraction from the Industrial Avenue treatment system (extraction wells EI-1 and EW-1), and the influence of variations in the pumping at municipal well MW-4 most likely caused the increase in the concentration of TCE in M- 1 OA. • Stable TCE concentrations over time are observed in 27 Upper Aquifer monitoring wells. Occasional fluctuations observed in some wells are likely due to changes in groundwater flow direction. Most of these wells are located close to the WWTP (e.g. M-1 7A and M-44 A). • Decreasing TCE concentration trends are present in 24 monitoring wells. TCE concentrations in wells near the Site, such as M-1A and M-3A (Appendix C) showed significant decreases which are indicative of continued success of source mass removal by the On-Site extraction and treatment system. Cis-1,2-DCE • Concentrations of cis-1,2-DCE were present in 18 of the 56 Upper Aquifer wells monitored in 2010 ranging from 0.53 pg/L (well M-50A, April) to 36 pg/L (well M-9A, April). • Cis-1,2-DCE concentration trends in each well generally follow the TCE trend as summarized above, except M-1 B. • Relatively higher cis-1,2-DCE concentrations as compared to TCE concentrations were observed in wells located southwest of the Stockton Avenue extraction and treatment system and in the vicinity of the City of Ripon WWTP (Figure 6). The presence of higher cis-1,2-DCE concentrations infers continued intrinsic remediation through the reductive dechlorination process near the WWTP and other biodegradation processes in areas distal to the WWTP1e VC • Concentrations of VC were present in five of the 56 Upper Aquifer wells sampled in 2010, and ranged from 0.56 pg/L (M-32A, April) to 1.6 pg/L (M-23A, April). • The presence of VC in Upper Aquifer wells is limited to wells located near the City of Ripon WWTP, except well M-6A, demonstrating continued reductive dechlorination in the vicinity of WWTP. • The presence of VC in well M-6A is a result of the pumping histories of municipal well MW-6, which was screened across all three aquifers, and of the Regal Almond well, which was screened in the Upper Aquifer. 14