ARCHIVED REPORTS_2010 ANNUAL REPORT

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Nestle USA, Inc., Ripon, California March 31, 2011 2010 Annual Report equipment from damages, such as during power interruptions. The system was operational 95.9% of the time in 2010. The following is the breakdown of shutdown hours: • 108.5 hours due to high pressure at the City of Ripon NPS line; • 151.5 hours due to parts replacement (see description below); • 3 hours to replace a manufacturer's recalled part; • 3.5 hours for other repairs and maintenance; • 4 hours for system shut downs such as power failures due to weather. In addition to routine maintenance, the following activities were performed in 2010: • On March 4, 2010, the Stockton Avenue extraction and treatment system initiated a shut down due to flame loss. The system was non-operational between March 4 and March 10. ECM field technicians replaced a defective Veriflame controller that had been recalled. The Dungs gas solenoid valve failed due to water in the terminal box. ECM field technicians received a replacement part for the valve on March 10, 2010, installed the part and restarted the system to resolve the issue. The system operated without experiencing any similar events after the replacement. With approval from RWQCB, ECM stopped extraction from wells E-2 and E-6 and ceased system operation on October 1, 2010 (see Section 2.7). 4.2.2 PERFORMANCE MONITORING The Stockton Avenue extraction and treatment system featured two sampling points: • The influent to the air stripper (influent, combined flow from E-2 and E-6), • The effluent from the air stripper (discharge to the City of Ripon NPS). The influent to the Stockton Avenue extraction and treatment system included combined extracted groundwater from wells E-2 and E-6. COC concentrations for the combined influent to wells E-2 and E-6 decreased since 2004. TCE concentrations in the system influent declined to 16 pg/L, cis-1,2-DCE concentrations declined to 25 pg/L, and VC concentrations declined to 5.7 pg/L in 2010. The average mass removal rates of the Stockton Avenue extraction and treatment system have been declining, since extraction commenced in Upper Aquifer well E-2 in 2000, and in Intermediate Aquifer well E-6 in 2004. The rate of mass removal dropped from approximately 0.79 pounds per day during the First Quarter 2007 to 0.03 pounds per day during the Third Quarter 2010 due to reductions in E-6 flow rates and significant decrease in concentrations of COCs (Figure 12 and Figure 13). The reduced COC influent concentrations are consistent with a reduction in TCE concentrations in monitoring wells M-8A, M-8B and M-8C1 in this area (Appendix C). h The sustainable pumping rate for well E-6 dropped from an average of approximately 85 gpm during the First Quarter 2010 to 63 gpm during the Third Quarter 2010. Since September of 2006, the average annual sustainable pumping rate for E-6 decreased from 460 gpm to 76 gpm. 23