ARCHIVED REPORTS_2013 ANNUAL REPORT

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Nestl6 USA, Inc., Ripon, California March 26, 2014 2013 Annual Report The following are key observations regarding river stage and its influence on groundwater flow: • River stage follows the typical timing pattern for dam release flow. River stage during the spring release flow was relatively high, but occurred over a shorter duration than usual, likely related to extreme drought conditions in the region in 2013. • All four groundwater monitoring events occurred when the river was at or near normal low flow (elevation of approximately 40 feet). As reflected in the potentiometric surface maps for the Upper and Intermediate aquifers (Figure 3-1 through Figure 3-4, and Figure 4-1 through Figure 4-4), the regional groundwater flow direction appears to be towards the north-northwest and the horizontal gradient is relatively low, typical of low river stage conditions. 2.2.3 INFLUENCE OF PUMPING A pumping well causes localized depressions in the potentiometric surface of the aquifer penetrated by the well screen (or open interval). The most influential pumping wells on groundwater flow in the Study Area are the City of Ripon municipal supply wells. Table 2 presents a summary of monthly production volumes for the municipal wells. Although daily production in each municipal well typically varies in a given month, the amount of drawdown and the size of the cone of depression in the potentiometric surface are generally proportional to the monthly production volume for each well. The following is a summary of observations regarding the pumping wells in the Study Area affecting the Upper, Intermediate, and Lower aquifers (Figure 3-1 through Figure 5-4) during the 2013 monitoring period: • IRAP wells EI-1, EU-3, and EU-4 pumped continuously (with minor interruptions) in 2013, which resulted in a localized depression in the potentiometric surface in the Upper Aquifer at the Site (Figure 3-1 through Figure 3-4). • City of Ripon municipal wells operated with variable pumping schedules and pumping rates in 2013. MW-3 penetrates the Intermediate Aquifer; MW-5 penetrates the Upper, Intermediate, and Lower aquifers; and MW-10 penetrates the Intermediate and Lower aquifers. Localized lower water levels were observed during the 2013 Second, Third, and Fourth Quarter gauging events at well MW-5, and during the 2013 Third and Fourth Quarter gauging events at wells MW-3 and MW-10. Pumping rates for the City of Ripon Production wells for the day of water level monitoring are presented with the quarterly gauging data (Appendix E of this document and Appendix A of each of the quarterly Site Status reports). • The absence of depressed groundwater levels in First and Second Quarters 2013 at wells MW-3 and MW-10 and in First Quarter 2013 at well MW-5 indicates that the wells either did not pump at high enough rates or did not pump at all to influence the potentiometric surface at the time of the monitoring events. This absence of depressed groundwater levels is also the case for municipal wells MW-7, MW-9, and MW-11, since the pumping rates for these wells were zero or low throughout 2013 (Table 2). 6