ARCHIVED REPORTS_2011 REVISED FEASABILITY STUDY

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Nestle USA, Inc.—Ripon, CA January 28, 2011 2011 Revised Feasibility Study Initial capital cost is moderate but acceptable. The majority of spending will be during any chemical injection or subsurface barrier installations. The remediation impact and the shortened life of the project make this alternative cost-efficient (see Appendix D). 11 Comparative Analysis of Alternatives In this section, comparative analysis is conducted to evaluate the relative performance of the four alternatives based upon the evaluation criteria listed in Section 9. The purpose of this comparative analysis is to identify advantages and disadvantages of each alternative relative to one another. Table 3 summarizes this comparative analysis. 11.1 Overall Protection of Human Health and the Environment Alternative 1 does not adequately protect human health or the environment. Alternatives 2, 3 and 4 offer protection of human health and the environment, however, time requirements to achieve significant reduction of CDCs varies. Each of these alternatives protects municipal and private wells from plume migration. 11.2 Compliance with State and Federal Regulations Alternative 1 requires 75 years to achieve the ARARs. In Alternative 2, ARARs are achieved in 30 years. In Alternatives 3 and 4, time required to achieve the ARARs is significantly shortened, to 12 and 15 years, respectively. 11.3 Long-Term Effectiveness and Permanence Long-term effectiveness is very low for Alternative 1. While Alternatives 2 and 3 are more effective at containing the plume than Alternative 1, long-term O&M costs make those alternatives much less effective than Alternative 4. Alternative 4 is the alternative that is least dependent upon pump-and-treat technology. The largest factor in decreasing long-term effectiveness in Alternatives 2 and 3 is their significant dependence upon pump-and-treat technology. 11.4 Reduction in Toxicity, Mobility, and Volume Alternative 1 only reduces toxicity, mobility and volume of COCs by natural dispersion and biodegradation. These natural processes work slowly relative to active remediation technologies. Alternative 2 reduces dissolved phase concentrations by pumping and treating groundwater. This technology transfers toxicity to another medium, it does not reduce or eliminate toxicity completely. Alternatives 3 and 4 reduce toxicity and volume more effectively than Alternatives 1 or 2 by using in-situ chemical treatment. In-situ chemical treatment significantly decreases COC concentrations in the highest concentration areas, permanently reducing or oxidizing COCs to inert compounds. However, Alternative 3 depends solely upon the success of widespread pump-and-treat technology across the Study Area. 45