Refinery / RFI and Risk Assessment

RCRA Facility Investigation (RFI) Final Report and Summary, Baseline Human Health Risk Assessments, and Screening Level Ecological Risk Assessment (SLERA)
Oklahoma Refinery SiteRefinery / RFI and Risk Assessment

StanTech was hired by the facility to complete the RCRA Facility Investigation (RFI) Final Report and Summary for the site.  The RFI Final Report and Summary included data collected from previous field investigation and sampling activities conducted to investigate potential impact from a total of 48 historical Solid Waste Management Units (SWMUs). The RFI Final Report and Summary included identification of the SWMUs, waste sources and potential migration pathways, action levels, actual or potential receptors, and interim measures taken during the RFI.  In addition, a baseline Human Health Risk Assessment (RA) and a Screening Level Ecological Risk Assessment (SLERA) were conducted for the purpose of evaluating the risk to human health and the environment posed by wastes and potential releases of hazardous constituents identified during completion of RFI activities.

Major activities completed by StanTech included:

  • Assimilation of all data into data tables and maps by environmental media type
  • Quality Assurance/Quality Control (QA/QC) review of data
  • Evaluation of extent of delineation by environmental media type
    • Surface and Subsurface Soils
    • Surface Water and Sediments
    • Groundwater
    • Air
  • Creek sampling and completion of a Screening Level Ecological Risk Assessment (SLERA)
  • Completion of a baseline Human Health Risk Assessment
    • Interim submittals to Oklahoma Department of Environmental Quality (ODEQ)
    • Data Evaluation/Identification of Chemicals of Potential Concern (COPC)
    • Exposure and Toxicity Assessments
    • Use of computer modeling software to characterize potential risks/hazards
    • Generation of over 450 data tables which included data screening tables, statistical analyses, and computer model output tables
  • Evaluation of Risk Assessment results
  • Generation of findings, conclusions, and recommendations

The baseline Human Health Risk Assessments were conducted by StanTech using methodology provided in USEPA’s Risk Assessment Guidance for Superfund (RAGS).  Risk assessments conducted included evaluation of potential industrial worker exposures; potential construction worker exposures; potential migration of contaminants to groundwater (leaching evaluations); and potential residential exposures.

StanTech continues to conduct RFI-related activities for the facility including field investigations of areas of concern or new SWMUs which may be discovered during occasional construction at the facility.  Additional tasks completed by StanTech after completion of the RFI Final Report and Summary include field investigations of area of concerns, identification of additional SWMUs, and preparation of RFI Work Plans for newly-identified SWMUs.



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