Engineering & Environmental Services

1 1682 Novato Boulevard Suite 100 Novato, California 94947-7021 Tel (415) 899-1600 Fax (415) 899-1601 PES Environmental , & Environmental Services A Report Prepared For: California Regional Water Quality Control Board San Francisco Bay Region 1515 Clay Street, Suite 1400 Oakland, California 94612 Attention: Mr. Alec W. Naugle, SUMMARY OF REMEDIAL INVESTIGATIONS, FEASIBILITY STUDY AND REMEDIAL ACTION PLAN NAPA PIPE FACILITY 1025 kaiser ROAD NAPA, CALIFORNIA _____ VOLUME 2 SITE 2/3 - EXTERNAL COATING BUILDING AREA _____ JUNE 7, 2007 By: D R A F T _____ Gary Thomas Senior Geologist, D R A F T _____ Robert S. Creps, Principal Engineer D R A F T _____ Carl J.

2 Michelsen, , Principal Geochemist PES Environmental , Inc. ii D R A F T TABLE OF CONTENTS LIST OF TABLES .. vii LIST OF viii INTRODUCTION ..1 Regulatory Context and Cleanup Level Selection ..2 Objectives of RI/FS/RAP ..4 SITE BACKGROUND ..5 Site Site Geology and Hydrogeology ..6 Facility-Wide 7 Younger Alluvium .. 7 Older Alluvium .. 7 Bedrock 7 Site-Specific Geology and Hydrogeology ..7 Fill Unit .. 8 Silty Clay Unit .. 8 Cemented Clayey Silt 9 Groundwater Flow Directions and Gradients ..9 Aquifer Testing 10 Tidal Influence .. 11 Summary of Previous Investigations.

3 11 Soil and Groundwater Testing at the kaiser steel Corporation Pipe Mill and Fabrication Facility in Napa California (1987) ..12 Site Investigation Report for the Napa Pipe Corporation Facility (1990) .. 12 June and July 1990 14 Site 2/3 Characterization, Groundwater Modeling, and Extraction Scenario Development (MW, 1993) ..15 Phase II Site Investigation (Shaw Environmental Inc., 2005).. 16 Facility-Wide Groundwater Monitoring 16 Summary of Interim Groundwater Remedial 17 SUPPLEMENTAL REMEDIAL INVESTIGATION .. 18 Field Activities and 18 Pre-Field Activities .. 19 Sampling Methods ..19 Analytical Methods ..20 Analytical Results.

4 21 Soil Results .. 21 PES Environmental , Inc. iii D R A F T TABLE OF CONTENTS (Continued) Groundwater Results .. 22 NATURE AND EXTENT OF CONTAMINATION .. 23 Nature and Extent of Contamination in 24 Petroleum 24 Volatile Organic 26 Nature and Extent of Contamination in Groundwater .. 26 Petroleum 26 Separate-Phase Floating 27 Dissolved-Phase Petroleum Hydrocarbons ..28 Volatile Organic 29 Conceptual Site Model .. 30 CONTAMINANT FATE AND 31 CHEMICALS OF CONCERN AND REMEDIATION 32 Chemicals of Concern .. 33 Soil .. 33 34 Summary of Chemicals of Concern .. 35 Cleanup Levels for Chemicals of Concern.

5 35 Areas Requiring Remediation .. 36 Areas and Volumes of Soil Exceeding Cleanup Levels .. 36 Areas and Volumes of Groundwater Exceeding Cleanup 37 FEASIBILITY STUDY SCOPING .. 37 Scope of the Feasibility 37 Applicable or Relevant and Appropriate Requirements and To Be Considered Factors for Impacted Soil and 38 Potential Chemical-Specific ARARs and TBCs .. 39 Potential Location-Specific ARARs and TBCs .. 39 Potential Action-Specific ARARs and 39 Additional Factors for Remedial Action Objective 40 Remedial Action Objectives .. 41 RAOs for Soil .. 41 RAOs for Groundwater .. 41 General Response 42 IDENTIFICATION AND SCREENING OF REMEDIAL TECHNOLOGIES.

6 42 Preliminary Technology Identification and Screening .. 43 Technology Identification .. 43 Technology Screening .. 43 Soil Treatment Technologies .. 44 Excavation .. 44 PES Environmental , Inc. iv D R A F T TABLE OF CONTENTS (Continued) Ex Situ Low Temperature Thermal Desorption .. 45 46 Landfarming .. 47 In Situ Chemical Oxidation .. 47 Off-Site 48 Groundwater Treatment 48 In Situ Enhanced Bioremediation .. 49 In Situ Chemical Oxidation .. 50 Saturated Soil Excavation .. 51 Existing Wastewater Treatment 51 Summary of Retained Remedial Technologies .. 51 DEVELOPMENT OF REMEDIAL ALTERNATIVES .. 52 Approach to Developing Remedial Alternatives.

7 53 General Remediation 53 In Situ Tool Box .. 54 Ex Situ Tool Box and Soil Management Protocol .. 55 Alternative 1 No Action .. 56 Alternative Description .. 56 Cost .. 56 Alternative 2 Maintain Existing Remedial Actions .. 57 Alternative Description .. 57 Cost .. 57 Alternative 3 Ex Situ Source Area Soil and Groundwater Treatment and In situ Groundwater Plume Remediation .. 57 Alternative 3 Description .. 57 Cost .. 60 Alternative 4 Ex Situ Soil and Groundwater Remediation .. 60 Alternative Description .. 60 Cost .. 61 EVALUATION OF REMEDIAL 62 Criteria for Evaluation .. 62 Threshold 62 Balancing Criteria.

8 63 Modifying Criteria .. 63 Detailed Evaluation of Alternatives .. 64 Alternative 1 No Action .. 64 Alternative 2 Maintain Existing Remedial Actions .. 64 Alternative 3 Ex Situ Source Area Soil and Groundwater Treatment and In Situ Groundwater Remediation .. 64 Alternative 4 Ex Situ Soil and Groundwater Remediation .. 65 PES Environmental , Inc. v D R A F T TABLE OF CONTENTS (Continued) Summary of Comparison of Remedial Alternatives .. 65 Recommended Remedial Alternative .. 65 REMEDIAL ACTION PLAN IMPLEMENTATION .. 65 Conceptual Remedial Design .. 66 Remediation Procedures and the Soil Management Protocol .. 66 Permitting and Contractor Health and Safety.

9 66 Site Preparation .. 67 Verification Sampling .. 68 Dust and Odor Control .. 68 68 Excavation 69 Schedule of Remedial Action Implementation and 69 Performance Criteria .. 69 69 70 TABLES ILLUSTRATIONS APPENDICES A Supplemental Remedial Investigation Lithologic Logs B Geologic Cross Sections Prepared by Montgomery Watson C Previous Investigation Lithologic Logs and Monitoring Well Completion Diagrams D Tables, Laboratory Reports, and Plates for 1987 Soil and Groundwater Testing by James M. Montgomery, Consulting Engineers, Inc. E Tables and Plates for 1989 Soil and Groundwater Investigation by James M.

10 Montgomery, Consulting Engineers, Inc. F Tables and Plates for 1990 Soil Investigation by James M. Montgomery, Consulting Engineers, Inc. G Tables and Plates from the 1993 Site 2/3 Characterization, Groundwater Modeling, and Extraction Scenario Development Report by Montgomery Watson PES Environmental , Inc. vi D R A F T TABLE OF CONTENTS (Continued) H Chemical Fate and Transport From Montgomery Watson s 1993 Site 2/3 Report I Tables and Plates for December 2005 Phase II Site Investigation by Shaw Environmental Inc. J Laboratory Analytical Reports and Chain of Custody Forms DISTRIBUTION PES Environmental , Inc. vii D R A F T LIST OF TABLES Table 1 Environmental Screening Levels Table 2 Water Level Survey Data May 16, 2006, Site 2/3, Second Quarter 2006 Monitoring Event Table 3 Water Level Survey Data October 3, 2006, Site 2/3, Fourth Quarter 2006 Monitoring Event Table 4 TPH as Diesel and TPH as Motor Oil in Groundwater Monitoring Wells, Site 2/3, Second and Fourth Quarter 2006 Monitoring Events Table 5 Volatile Organic Compounds in Groundwater Monitoring Wells, Site 2/3, Second and Fourth Quarter 2006 Monitoring Events Table 6 Summary of Analyses Performed on Soil and Groundwater Samples.