EPA 542-R-18-002 May 2018 http://www.epa.gov/remedytech http://cluin.org Examples of Groundwater Remediation at NPL Sites Notice and Disclaimer Preparation of this report has been funded by the U.S. Environmental Protection Agency (EPA) Office of Superfund Remediation and Technology Innovation (OSRTI) under Contract Numbers EP-D-09-053 and EP-W-14-001. Information in this report is derived primarily from EPA sources, including personal communications with EPA staff familiar with the remedies discussed in this report. Some information was also obtained from state personnel and remediation contractors. This report is not intended, nor can it be relied upon, to create any rights enforceable by any party in litigation with the United States. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. A PDF version of Examples of Groundwater Remediation at NPL Sites is available for viewing or downloading from https://www.epa.gov/remedytech, or http://www.cluin.org. For questions concerning this document, contact Linda Fiedler at [email protected] or 703-603-7194. Acknowledgements Acknowledgment is given to the federal and state Remedial Project Managers and technical staff and other remediation professionals for providing information for this document. Their cooperation and willingness to share their expertise on Superfund remedies will help regulators and system operators make informed decisions that will promote progress towards remedial action objectives at NPL and other contaminated sites throughout the U.S. and other nations. Cover pictures from top, clockwise: Groundwater treatment facility at Pemaco Superfund Site; In situ thermal treatment at Fort Lewis Logistics Center Superfund Site; Treatment Plant #1 at Holingsworth Solderless Terminal Superfund Site; Treatment building and air stripper tower at Tabernacle Drum Dump Superfund Site. This Page Intentionally Left Blank Table of Contents Notice and Disclaimer ........................................................................................................................... i Acknowledgements............................................................................................................................... i List of Tables ....................................................................................................................................... iv List of Figures ...................................................................................................................................... iv List of Acronyms and Abbreviations ................................................................................................. v Executive Summary ........................................................................................................................... vii 1. Purpose and Scope .......................................................................................................................... 1 1.1 Remedial Action Objectives and Associated Cleanup Levels ................................................ 1 1.2 Site Selection Process ............................................................................................................ 2 2. Observations and Analysis of Cleanups ....................................................................................... 3 2.1 Technologies Applied to Restore Groundwater...................................................................... 7 2.2 Technologies Used at DNAPL Sites ..................................................................................... 11 2.3 Cleanup Magnitude ............................................................................................................... 12 2.4 Cleanup Time ........................................................................................................................ 14 3. Sites Returned to Use .................................................................................................................... 17 3.1 Industrial/Commercial Reuse................................................................................................ 17 3.2 Recreational Use .................................................................................................................. 17 3.3 Alternative Energy Development .......................................................................................... 17 3.4 Other Reuses ........................................................................................................................ 18 4. Conclusions .................................................................................................................................... 19 Appendix A: Site Information Summary Tables ........................................................................... A-1 Appendix B: Case Summaries ........................................................................................................ B-1 List of Tables Table 2.1 NPL Sites that Achieved Groundwater Restoration ............................................................ 3 Table 2.2 NPL Sites that Achieved Significant Progress towards Groundwater Restoration ............. 4 Table 2.3 Hydrogeologic Setting and Contaminant Phase ................................................................. 6 Table 2.4 Remedial Technologies Applied at DNAPL Sites ............................................................. 11 Table 3.1 Sites Returned to Use ....................................................................................................... 18 Table A.1 Location, Industry Type, Contaminant Group, and Remedial Technology for NPL Sites that Achieved Groundwater Restoration ................................................................ A-1 Table A.2 Location, Industry Type, Contaminant Group, and Remedial Technology for NPL Sites that Achieved Significant Progress towards Groundwater Restoration ................. A-2 Table A.3 Summary of Technologies Applied to Restore Groundwater .......................................... A-3 Table A.4 Time to Meet RAOs and Hydogeologic Complexity for Sites that Achieved Groundwater Restoration ................................................................................................ A-6 Table A.5 Time to Achieve Significant Progress and Complexity for Selected Sites that Achieved Significant Progress towards Groundwater Restoration ................................. A-9 Table A.6 Site Information Summary Table ................................................................................... A-10 List of Figures Figure 2.1 Frequency of Contaminant Classes at 30 NPL Sites .......................................................... 5 Figure 2.2 Remedial Technologies and Approaches Associated with 30 NPL Sites ........................... 7 Figure 2.3 Remediation Timeline for Gold Coast Oil Corporation ........................................................ 8 Figure 2.4 Number of Technologies used to Achieve Groundwater Restoration ................................. 9 Figure 2.5 Number of Technologies at Sites that Achieved Significant Progress towards Groundwater Restoration .................................................................................................. 10 Figure 2.6 Remediation Timeline for Southern California Edison Co., Visalia Pole Yard .................. 12 Figure 2.7 Magnitude of Contaminant Concentration Decreases at Sites that Achieved Groundwater Restoration .................................................................................................. 13 Figure 2.8 Magnitude of Contaminant Concentration Decreases at Sites that Achieved Significant Progress towards Groundwater Restoration ................................................... 14 Figure 2.9 Cleanup Time and Magnitude for Sites that Achieved Groundwater Restoration ............ 16 List of Acronyms and Abbreviations Bgs below ground surface RAO Remedial Action Objective CERCLA Comprehensive Environmental RCRA Resource Conservation and Response, Compensation and Recovery Act Liability Act ROD Record of Decision COC Contaminant of Concern RPM Remedial Project Manager DCE dichloroethene SVE Soil Vapor Extraction DNAPL Dense Non-aqueous Phase Liquid SVOC Semivolatile Organic Compound DUS Dynamic Underground Stripping SWRAU Sitewide Ready for Anticipated Use EPA U.S. Environmental Protection Agency TCE trichloroethene ERD Enhanced Reductive TSD Treatment, Storage and Disposal Dechlorination UST Underground Storage Tank ERH Electrical Resistance Heating UXO Unexploded Ordnance ESD Explanation of Significant Differences VEB Vertical Engineered Barrier VOC Volatile Organic Compound ISCO In Situ Chemical Oxidation ISCR In Situ Chemical Reduction ISTT In Situ Thermal Treatment LNAPL Light Non-aqueous Phase Liquid MCL Maximum Contaminant Level MNA Monitored Natural Attenuation NCP National Oil and Hazardous Substances Pollution Contingency Plan NPL National Priorities List OSRTI Office of Superfund Remediation and Technology Innovation OU Operable Unit PAH Polycyclic Aromatic Hydrocarbon PCB Polychlorinated Biphenyl PCE Tetrachlorothene ppm Parts per million This Page Intentionally Left Blank vi Executive Summary Executive Summary This report documents where innovative and established technologies have been used to restore groundwater to beneficial use. This report includes a select number of example National Priorities List (NPL) sites where the remedial action objective (RAO) and associated cleanup levels were to restore groundwater