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