Loading...
HomeMy WebLinkAboutNCD003162542_Badin Business Park_Corrective Action_20210125Badin Business Park, LLC January 25, 2021 Ecological Risk Assessments • Former Ball Field Area • Alcoa/Badin Municipal Landfill Meeting Overview 2 Introductions: Alcoa Corporation Integral Consulting Inc. Civil & Environmental Consultants, Inc. Objective: Outline the process for completing the ecological risk assessment (ERA) for the Former Ball Field and the Alcoa/Badin Landfill Agenda: Former Ball Field Alcoa/Badin Landfill Review and Next Steps Discussion Former Ball Field Area Ecological Risk Assessment Discussion Overview/History 4 Overview/History 5 ERA Process Overview for Former Ball Field Area 6 Purpose: Is there ecology present, and what do the existing data say about potential for eco risk? Guided by: NCDEQ SLERA Guidance, Region IV Supplemental, USEPA ERA Ecological Setting 7 Source: Yadkin-Pee Dee River Basin Priority Watershed Atlas, NCDWQ (2010) Overview of Analytical Data – Former Ball Field Area 8 Surface soils ‒<2 feet ‒Driven from 2015 and 2018 investigations ‒Data Points (n = ~60) Organics few detections ‒PAHs: Detected in 29/59 samples (~0.1-12 mg/kg; R4 ESV = 1.1 mg/kg) ‒PCBs: Detected in 2/59 samples (max = 0.5 mg/kg; R4 ESV = 0.041 mg/kg) ‒SVOCs and VOCs: Detected at < 5% at very low concentrations Inorganics detected, but generally low concentrations (within background range) ‒Lead: arithmetic mean is 22 mg/kg (R4 ESV = 11 mg/kg), RFI background = 33 mg/kg ‒Cyanide: ND to < 0.6 mg/kg (R4 Soil = 0.1 mg/kg), RFI background max = 3.5 mg/kg ‒Fluoride: Detected in 1/51 samples at 42 mg/kg (R4 Soil = 32 mg/kg), RFI background max = 7.3 mg/kg Overview of Analytical Data – Former Ball Field Area cont., 9 Surface water −SW collection box (one sample) Most analytes not quantified or otherwise < 15A NCAC 02B .0211, .0212 (WS-I) Groundwater −Former Ball Field (3 samples) Most analytes not quantified or otherwise < 15A NCAC 02B .0211, .0212 (WS-I) Preliminary Ecological Conceptual Site Model 10 Summary for the Former Ball Field Area 11 ERA Big Picture −Lots of data – no data gaps −Overall low frequency of detection; low concentrations −Inorganics within background range One document submittal for the Former Ball Field −Steps 1 & 2 (SLERA + Checklist) + Step 3A −Clear articulation of process as invoked by Guidance −Completeness and technical rigor Example refinements (Step 3A) −Frequency of Detection (FOD) −Refined Ecological Screening Values and Toxicity Reference Values (receptor specific, range of NOAEL – LOAEL) −UCL Exposure Point Concentrations (EPC) −Background Example Drill-down case in point - PCBs 12 2/59 Detected −ABF-SB-006: Aroclor 1248 = 0.02(J) mg/kg −ABF-SB-053: Aroclor 1260 = 0.48 mg/kg −tPCBs = 0.0324 – 0.48 mg/kg Region 4 ESV = 0.041 mg/kg (tPCBs) −Los Alamos, robin (invert), Aroclor 1248 NOAEL TRV (lowest of all Aroclors) Step 3A Considerations −FOD < 5% −Aroclor-specific ESV – Ar1260 ESV = 0.88 mg/kg [NOAEL] > 0.48 mg/kg (ABF-SB-0513 Ar1260) −Total PCB LOAEL ESV = 0.41 mg/kg < Total PCBs = 0.48 mg/kg −Total PCB 95% UCL = 0.086 mg/kg (lower than LOEL ESV) −Los Alamos PRG, robin (invert) = 17 mg/kg – 54 mg/kg Preliminary finding – PCBs unlikely to present unacceptable ecological risk Recommended Path Forward - Former Ball Field Area 13 COPECs? (Max>ESV) Refinement of COPECs Unacceptable Screening Level Risk?Continue ERA Process No Risk Management/ NFA Implement ERA NCDEQ Guidance (Steps 1 & 2) No Yes No Yes Region 4, USEPA Step 3A ERA = ecological risk assessment COPEC = constituent of potential ecological concern ESV = ecological screening value NFA = no further action Alcoa/Badin Landfill Ecological Risk Assessment Discussion Overview/History 15 Overview/History 16 ERA Process Overview for the Alcoa Badin Landfill 17 Purpose: Is there ecology present, and what do the existing data say about potential for ecological risk? Guided by: NCDEQ SLERA Guidance, Region IV Supplemental, USEPA ERA Preliminary Ecological Setting 18 Other Considerations for Local Setting 19 Proposed Path Forward - Alcoa Badin Landfill 20 COPECs? (Max>ESV) Refinement of COPECs Unacceptable Screening Level Risk? Complete Detailed ERA No Risk Management Implement ERA No Yes No Yes? ERA = ecological risk assessment COPEC = constituent of potential ecological concern ESV = ecological screening value Data Gaps? Investigation Work Plan No Yes Continue with revised Corrective Measures Study Review – Next Steps Ecological Risk Assessment Discussion Review and Proposed Next Steps 22 Former Ball Field −Prepare Ecological Risk Assessment −Submit to NCDEQ Q2 2021 Alcoa/Badin Landfill −Complete data review and prepare investigative work plan −Submit to NCDEQ Q2 2021 −Implement investigative work plan in Q3 to Q4 2021 −Complete Ecological Risk Assessment target Q2 2022