FIFTH FIVE-YEAR REVlEW REPORT FOR SALTVILLE WASTE DISPOSAL PONDS SUPERFUND SITE SMYTH COUNTY, VlRGINIA SEPTEMBER 2017 Prepared by U.S. Environmental Protection Agency Region 3 Philadelphia, Pennsylvania SEP 2 6 2017 Karen Melvin, Director Date Hazardous Site Cleanup Division U.S. EPA, Region III Table of Contents LIST OF ABBREVIATIONS & ACRONYMS .........................................................................................................2 I. INTRODUCTION...................................................................................................................................................3 Site Background .....................................................................................................................................................3 FIVE-YEAR REVIEW SUMMARY FORM ........................................................................................................6 II. RESPONSE ACTION SUMMARY ......................................................................................................................6 Basis for Taking Action .........................................................................................................................................6 Response Actions ...................................................................................................................................................7 Status of Implementation .......................................................................................................................................8 Systems Operations/Operation & Maintenance ...................................................................................................12 III. PROGRESS SINCE THE PREVIOUS REVIEW ..............................................................................................13 IV. FIVE-YEAR REVIEW PROCESS ....................................................................................................................15 Community Notification, Involvement & Site Interviews ...................................................................................15 Data Review .........................................................................................................................................................16 Site Inspection ......................................................................................................................................................19 V. TECHNICAL ASSESSMENT ............................................................................................................................19 QUESTION A: Is the remedy functioning as intended by the decision documents? .........................................19 QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels and remedial action objectives (RAOs) used at the time of the remedy selection still valid? ...............................................................................20 QUESTION C: Has any other information come to light that could call into question the protectiveness of the remedy? ................................................................................................................................................................21 VI. ISSUES/RECOMMENDATIONS .....................................................................................................................21 OTHER FINDINGS .............................................................................................................................................22 VII. PROTECTIVENESS STATEMENT ................................................................................................................22 VIII. NEXT REVIEW ..............................................................................................................................................23 APPENDIX A – REFERENCE LIST ................................................................................................................... A-1 APPENDIX B – SITE CHRONOLOGY ...............................................................................................................B-1 APPENDIX C – SITE MAPS ................................................................................................................................C-1 APPENDIX D – SITE INSPECTION CHECKLIST ............................................................................................ D-1 APPENDIX E – PRESS NOTICE ......................................................................................................................... E-1 APPENDIX F – SITE INSPECTION PHOTOS .................................................................................................... F-1 APPENDIX G – SELECTED TABLES AND CHARTS FROM 2015 ANNUAL MONITORING REPORT ... G-1 APPENDIX H – INTERVIEW FORMS ............................................................................................................... H-1 APPENDIX I – SMYTH COUNTY PUBLIC WATER ORDINANCE ................................................................. I-1 1 LIST OF ABBREVIATIONS & ACRONYMS CERCLA Comprehensive Environmental Response, Compensation, and Liability Act CFR Code of Federal Regulations EPA United States Environmental Protection Agency FCPS Former Chlorine Plant Site FYR Five-Year Review IC Institutional Control LTMP Long-Term Monitoring Plan MCL Maximum Contaminant Level µg/L Micrograms per Liter mg/kg Milligrams per Kilogram ng/L Nanograms per Liter NCP National Contingency Plan NPL National Priorities List Olin Olin Corporation O&M Operation and Maintenance OU Operable Unit PRP Potentially Responsible Party RAO Remedial Action Objective RCRA Resource Conservation and Recovery Act RI/FS Remedial Investigation/Feasibility Study ROD Record of Decision RPM Remedial Project Manager TMDL Total Maximum Daily Load UU/UE Unlimited Use and Unrestricted Exposure VDEQ Virginia Department of Environmental Quality 2 I. INTRODUCTION The purpose of a five-year review (FYR) is to evaluate the implementation and performance of a remedy to determine if the remedy is and will continue to be protective of human health and the environment. The methods, findings and conclusions of reviews are documented in FYR Reports such as this one. In addition, FYR Reports identify issues found during the review, if any, and document recommendations to address them. The U.S. Environmental Protection Agency (EPA) is preparing this FYR pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Section 121, consistent with the National Contingency Plan (NCP) (40 CFR Section 300.430(f)(4)(ii)), and considering EPA policy. This is the fifth FYR for the Saltville Waste Disposal Ponds Superfund site (the Site). The triggering action for this statutory review is the completion date of the previous FYR. The FYR has been prepared because hazardous substances, pollutants or contaminants remain at the Site above levels that allow for unlimited use and unrestricted exposure (UU/UE). The Site consists of four operable units (OUs), three of which will be addressed in this FYR. OU1 addresses Pond 5 surface water diversion. OU2 addresses the wastewater treatment plant for Pond 5 leachate. OU3 addresses the Pond 5 cap, Pond 6 soil cover, collection and treatment of leachate-contaminated groundwater from Pond 6, additional engineering controls for diversion/management of clean stormwater and groundwater, institutional controls and long-term monitoring. OU4 addresses mercury impacts at the Former Chlorine Plant Site (FCPS) and mercury impacts on the North Fork Holston and Holston Rivers. OU4 is not addressed in this FYR because it is still in the remedial investigation phase. The FYR was led by EPA remedial project manager (RPM) Andrea Bain. Participants included EPA community involvement coordinators Vance Evans and Kimberly Scharl, EPA hydrogeologist Mindi Snoparsky, and William Lindsay from Virginia Department of Environmental Quality (VDEQ). The review began on 9/26/2016. Appendix A includes a list of documents reviewed for this FYR. Appendix B includes a site chronology. Site Background The 125-acre Site is located in Saltville, Virginia, along the north bank of the North Fork Holston River (Figure 1). Olin Corporation (Olin), the Site’s potentially responsible party (PRP), made various chemicals on site from about 1895 to 1972, including chlorine gas from 1950 to 1972. Mercury, lost during the production process of chlorine gas, was mixed with wastewater and conveyed to Pond 5 and, to a lesser extent, Pond 6. The solids settled in the disposal ponds and the remaining wastewater was discharged to the North Fork. During Olin’s operation the ponds were designed to percolate wastewater through the pond solids and thus allow mercury in the wastewater to adsorb onto the fine, alkaline particles of the ammonia soda ash waste. At this time, the contents of the ponds can be considered primarily solids which are still settling over time. Mercury was also released to soil, groundwater and surface water at the FCPS via spills and during routine facility washing operations. The Site includes the FCPS; two waste disposal ponds, Pond 5 and Pond 6; and the North Fork Holston and Holston rivers (Figure C-2). The waste disposal ponds were used primarily to settle alkaline solids from waste slurry generated by the soda ash (sodium carbonate) manufacturing process. The settled solids are referred to as ammonia soda ash waste. Pond 5 and its dike cover about 76 acres. Pond 6 is located immediately