FIFTH FIVE-YEAR REVIEW REPORT FOR BRIO REFINING SUPERFUND SITE HARRIS COUNTY, TEXAS September 2018 Prepared by U.S. Environmental Protection Agency Region 6 1445 Ross Avenue Dallas, TX 75202-2733 I?IFTH FIVE-YEAR REVIEW REPORT BRIO REFINING SUPERFUND SITE EPA ID#: TXD980625453 BARRIS COUNTY, TEXAS This attached report documents the U.S. Environmental Protection Agency's performance, determinations, and approval of the Brio Refining Superfund Site (I3rio Site or Site) Fifth Five-Year Review under Section 121 (c) of the Comprehensive Environmental Response, Compensation, a.nd Liability Act, 42 U.S. Code Section 962l(c). Summary of the Fifth Five-Year Review Report The results of the Fifth Five-Year Review indicate that the remedy completed to date is currently protective of human health and the environment in the sh01t term. Overall, the remedial actions performed are functioning as designed, and the Site is being maintained appropriately. No deficiencies were noted that currently impact the short-term protectiveness of the remedy, although items were identified that require fmther action to ensure the continued long-term protectiveness of the remedy. Environmental Indicators Human Exposure Status: Current human exposures at the Site are under control Contaminated Groundwater Status: Groundwater migration is under control Site-Wide Ready for Reuse: Yes Actions Nccclccl The following actions must be taken for the remedy to be protective in the long-term : Further delineate affected groundwater in the Fifty Foot Sand Zone (FFSZ) and prepare a remediation action plan. Continue qua1terly sampling ofFFSZ groundwater until EPJ\ approves a return to annual sampling. Continue current pumping rate of the Pit J-Numerous Sand Channel Zone groundwater to maintain an upward gradient. Determination I have determined that the remedy for the Brio Refinery Superfund Site is currently protective of human health and the environment. This five-year review report specifies the actions that need to be taken to ensure the continued long-term protectiveness of the remedy. L i u.Jcf {j f/4,dYkg 'n d (' Carl E. Edlund, P.E. Date Director, Superfond Division U.S. Environmental Protection Agency Region 6 CONCURRENCES FIFTH FIVE-YEAR REVIEW REPORT BRIO REFINERY SUPER.FUND SITE EPA IJ)#: TXD980625453 HARRIS COUNTY, TEXAS Carlos A. Sanchez • Chief, Arkansas/Texas Section Anne Foster Date Attorney; Office of Regio_nal Counsel Date Chief, Supcrfund Branch, Office of Regional Counsel Date ISSUES/RECOMMENDATIONS FIFTH JIJVE-YEAR REVIEW REPORT BRIO REFINERY SUPERFUND SITE EPA ID#: TXD980625453 HARRIS COUNTY, TEXAS . Issues/Recomme11datio11s Operable Unit (OU) without Issues/Reconunendations Identified in the Five-Year Review: None Issues and Recommendations Identified in the Five-Y car Review: Source Control/ Issue Category: Monitoring Management of Migration OU Issue: Continued Operation Site constituents were detected at concentrations above their maximum contaminant levels (MCL) in the Fifty Foot Sand Zone (FFSZ) downgradient from the Site. Recommendation: Further delineate affected groundwater in the FFSZ and prepare a remediation action plan. Continue quarterly sampling of FFSZ groundwater until EPA approves to a return to annual sampling. Continue current pumping rate of the Pit J-Nmnerous Sand Channel Zone groundwater to maintain an upward gradient. Affect Current Affect Future Party Oversight Milestone Date Protectiveness Protectiveness Responsible Party No Yes PRP EPA March 31, 2021 1 Table of Contents LIST OF ABB.REVIATIONS & ACRONYMS ......................................................................................... 4 I. INTRODUCTION ................................................................................................................................... 5 Site Background ........................ ,........................................................................................................... 5 Physical Characteristics ........................................................................................................................ 5 Land and Resource Use ........................................................................................................................ 6 Five-Year Review Summary Form ....................................................................................................... 7 II. RESPONSE ACTION SUMMARY ...................................................................................................... 8 Basis for Taking Action ................................................................•....................................................... 8 Response Actions .................................................................................................................................. 8 Initial Response ..................................................................................................................................... 8 Remedial Actions .................................................................................................................................. 8 Remedial Action Objectives ................................................................................................................. 9 Remedy Selection ................................................................................................................................. 9 Status of Implementation .................................................................................................................... 12 Soil Bentonite Barrier Wall ................................................................................................................ 12 Sheet Pile Barrier Wall ....................................................................................................................... 12 Cover System ...................................................................................................................................... 12 Mud Gully Improvements ................................................................................................................... 13 Groundwater Control Systems ............................................................................................................ 13 Institutional Controls .......................................................... : ............................................................... 13 Systems Operations/Operation & Maintenance .................................................................................. 14 III. PROGRESS SINCE THE LAST REVIEW ............................................................................. ,......... 16 Status of Recommendations ................................................................................................................ 16 IV.FIVE-YEARREVIEWPROCESS .................................................................................................... 18 Community Notification, Involvement & Site Interviews .................................................................. 18 Data Review ........................................................................................................................................ 18 Gradient Monitoring ........................................................................................................................... 19 Groundwater Quality Monitoring ....................................................................................................... 19 Groundwater and DNAPL Recovery .................................................................................................. 20 Treated Groundwater Analysis ........................................................................................................... 20 Site Inspection ..................................................................................................................................... 20 V. TECHNICAL ASSESSMENT ............................................................................................................ 22 QUESTION A: .................................................................................................................................... 22 QUESTION B: ................................................................................................................................... 22 QUESTION C: .................................................................................................................................... 23 VI. ISSUES/RECOMMENDATIONS ..................................................................................................... 24 VII. PROTECTIVENESS STATEMENT ................................................................................................ 25 VIII. NEXT REVIEW ......................................................................................................................... 26 2 Tables Table I - Compliance/Performance Standards ....................................................................................................... I 0 Table 2 - Summary of Implemented Institutional Controls ......................................· .............................................. 14 Table 3 - Protectiveness Determinations/Statements from the Fomth Five-Year Review ..................................... 16 Table 4 - Status of Recommendations from the Fourth Five-Year Review ............................................................ 17 Table 5 - FFSZ Compliance/Performance Monitoring Wells ................................................................................