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TABLE OF CONTENTS <br /> EXECUTIVE SUMMARY .......................................................................................................ES-1 <br /> 1. INTRODUCTION....................................................................................................................I <br /> 1.1 Purpose of the RAP.........................................................................................................1 <br /> 1.2 Regulatory Framework....................................................................................................1 <br /> 1.3 Site Description...............................................................................................................2 <br /> 1.4 Site History......................................................................................................................3 <br /> 1.5 Site Characterization.......................................................................................................3 <br /> 1.6 Previous Removal Actions Taken...................................................................................4 <br /> 1.7 Site Geology and Hydrogeology.....................................................................................4 <br /> 1.7.1 Regional Geologic and Hydrogeologic Setting...................................................4 <br /> 1.7.2 Local Geology and Hydrology............................................................................4 <br /> 2. NATURE AND EXTENT OF CONTAMINATION...............................................................6 <br /> 2.1 Conceptual Site Model....................................................................................................6 <br /> 2.2 Nature and Extent of Soil and Sediment Contamination ................................................7 <br /> 2.3 Nature and Extent of Groundwater Contamination.........................................................7 <br /> 3. RISK EVALUATION AND REMEDIAL ACTION OBJECTIVES ......................................9 <br /> 3.1 Summary of Risk Assessment.........................................................................................9 <br /> 3.2 Remedial Action Objectives..........................................................................................10 <br /> 4. SUMMARY OF FEASIBILITY STUDY..............................................................................11 <br /> 4.1 Technology Screening...................................................................................................11 <br /> 4.2 Identification of Alternatives for Soil, and Sediment....................................................11 <br /> 4.2.1 Alternative 1 —No Action.................................................................................11 <br /> 4.2.2 Alternative 2—Existing Durable Cover, Fence, and Institutional Controls......11 <br /> 4.2.3 Alternative 3 —Excavation with On-Site Consolidation, Existing and New <br /> Durable Cover, and Institutional Controls ........................................................12 <br /> 4.2.4 Alternative 4—Excavation(to 2 feet) with Off-Site Disposal (Backfilled with <br /> Clean Fill), Existing Durable Cover, and Institutional Controls.......................12 <br /> 4.2.5 Alternative 5 —Expanded Excavation with On-Site Consolidation, Existing <br /> Durable Cover, Expanded New Durable Cover, and Institutional Controls.....12 <br /> 4.3 Evaluation of Alternatives.............................................................................................13 <br /> 4.4 Comparative Analysis ...................................................................................................14 <br /> 4.5 Description of Recommended Alternative—Expanded Excavation with On-Site <br /> Consolidation, Existing Durable Cover, Expanded New Durable Cover, and <br /> InstitutionalControls.....................................................................................................14 <br /> 4.6 Basis for Proposed Remedy ..........................................................................................17 <br /> Site 47 RAP for Soil i October 2023 <br />