ARCHIVED REPORTS_2010 ANNUAL REPORT

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Nestle USA, Inc., Ripon, California March 31, 2011 2010 Annual Report Cis-1,2-DCE • Concentrations of cis-1,2-DCE were present in groundwater in seven of 19 Nestle monitoring wells, ranging from 0.61 pg/L (well M-21 D, July) to 25 pg/L (well M-61D, January). • Cis-1,2-DCE is found together with TCE in the same monitoring wells, with the exception of well M-21 D, which contains cis-1,2-DCE at concentrations of approximately 1 pg/L but no TCE (Figure 8, Table 3.3). VC • VC has not appeared in the Lower Aquifer wells except at M-20D, near the City of Ripon WWTP. • The VC concentration in well M-20D has decreased since reaching a maximum of 21 pg/L in October 2007, and has dropped 1.0 pg/L in October 2010, likely due to the closure of wells TH-8 and TH-10. 3.4 CITY OF RIPON MUNICIPAL WELLS The City of Ripon used 10 municipal supply wells to meet potable and non-potables water demand in 2010, pumping 1.75 billion gallons of groundwater (Table 8). The majority of these municipal supply wells are screened across multiple aquifers (Table 1); primarily in the Intermediate and Lower aquifers. Potable water withdrawal by the City of Ripon decreased by 6.6% from 2009 to 2010. Non-potable water withdrawal, which comprised 17% of the total production in 2010, increased by 7.7% most likely due to reduction in and cessation of pumping form well E-6 at Stockton Avenue. Combined potable and non-potable water withdrawal decreased 4.7% in 2010 over the previous year probably due to lower demand as a result of higher precipitation. The water consumption rate during 2010 averaged approximately 4.79 million gallons per day. City of Ripon Municipal Well Pumping over Time 0 2,500 C 0 2,000 E Q�500 E o a 1000 L yr 3 500 c 0 0 0 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 Municipal Well Pumping Municipal Well Pumping Trend 9 Municipal wells MW-5, MW-11, and MW-16 were used to meet the non-potable water needs. 17