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Missouri Waste Control
Coalition Corrective Action Seminar
Venessa Madden U.S. EPA Region 7
Ecological Risk Assessment
• Regulatory Basis • Federal
Ø Superfund • Na>onal Con>ngency Plan
Ø RCRA • Correc>ve Ac>on – Determining the need for cleanup ac>ons and seFng clean-‐up goals.
• Eminent and Substan>al Endangerment (Sec. 7003)
RCRA Risk Assessment Paradigm
3
Guidance Documents • 1992 Framework for Ecological Risk Assessment. Risk Assessment Forum. EPA/630/R-‐92/001.
• 1997 Ecological Risk Assessment Guidance for Superfund, Process for Designing and Conduc>ng Ecological Risk Assessments, Interim Final. EPA 540-‐R-‐97-‐006, OSWER Direc>ve # 9285.7-‐25. www.epa.gov/superfund/programs/risk/ecorisk/ ecorisk.htm
• 1998 Guidelines for Ecological Risk Assessment, Final. Risk Assessment Forum EPA/630/R-‐95/002F. www.epa.gov/ncea/ecorsk.htm
• Eco-‐Updates -‐ h]p://www.epa.gov/oswer/riskassessment/ecoup/
EPA Superfund Guidance for ERA – Eight Step Process (U.S. EPA, 1997)
Scientific/ Management
Decision Point
STEP 8: Risk Management SMDP
Step 1: Screening Level Assessment • Problem formulation • Site visit • Toxicity evaluation
Step 2: Screening Level Assessment • Exposure estimate • Risk Calculation
Step 3: Problem Formulation • Assessment endpoints • Conceptual model • Exposure pathways • Questions/Hypotheses SMDP
Step 4: Study Design/DQOs • Lines of evidence • Measurement endpoints • Work Plan/Sampling Plan SMDP
Step 7: Risk Characterization
Step 5: Verification of Field Sampling Design SMDP
Step 6: Site Investigation and Data Analysis SMDP
Step 1 - Preliminary Problem Formulation
• Environmental Setting • Contaminants of Concern • Receptors • Contaminant Fate and Transport • Complete Exposure Pathways • Ecotoxicity
Step 2 - Screening Level Exposure Estimate
• Conserva>ve Parameters • Area use factor • Normalized Food Inges>on Rates (maximum es>mates (juveniles for example))
• Dietary composi>on (most contaminated food types) • Life stage sensi>vity (juvenile for example) • Bioavailability (100 percent)
Ecological Effects/Toxicity Evaluation
Screening Ecotoxicity Values • Chemical exposure levels that represent conserva>ve thresholds for adverse effects
• Benchmarks • Literature search
Eco-‐SSLs for Soil h]p://www.epa.gov/oswer/riskassessment/ecorisk/ecossl.htm
NAWQC h]p://water.epa.gov/scitech/swguidance/standards/criteria/current/index.cfm
Threshold Effect Concentra>ons (TECs) (MacDonald et al. 2000).
HQ = MAXIMUM DOSE
BENCHMARK HQ>1 Unacceptable HQ<1 Acceptable
Preliminary Risk Calculation
EPA Superfund Guidance for ERA – Eight Step Process (U.S. EPA, 1997)
Scientific/ Management
Decision Point
STEP 8: Risk Management SMDP
Step 1: Screening Level Assessment • Problem formulation • Site visit • Toxicity evaluation
Step 2: Screening Level Assessment • Exposure estimate • Risk Calculation
Step 3: Problem Formulation • Assessment endpoints • Conceptual model • Exposure pathways • Questions/Hypotheses SMDP
Step 4: Study Design/DQOs • Lines of evidence • Measurement endpoints • Work Plan/Sampling Plan SMDP
Step 7: Risk Characterization
Step 5: Verification of Field Sampling Design SMDP
Step 6: Site Investigation and Data Analysis SMDP
Step 3 - Baseline Problem Formulation
• Refinement of Preliminary Contaminants of Concern • Background • Frequency of detec>on and • Essen>al nutrients.
• Site specific Assessment Endpoints • Survival, growth, and reproduc>on of piscivores • Aqua>c community structure • Survival, growth, and reproduc>on of fish, invertebrates, and aqua>c plants
• Conceptual Site Model • Risk Ques>ons
Conceptual Site Model
12
Fish Benthic
Organisms PlantsSoil
Organisms
Inhalation X
Direct Contact X
Ingestion X •Direct Contact • • X
uptake into tissues Ingestion •
Ingestion •Direct Contact • • X
uptake into tissues Ingestion o o •
Ingestion X X •Direct Contact X • X
Pathway is not complete, no evaluation requiredX Pathway is complete but probably cannot be evaluated quantitatively
• Pathway is complete and significant, quantitative evaluationo Pathway is complete, limited quantitative evaluation may be possible
Exposure RoutePotentially Impacted Environmental MediaRelease Mechanism
Sediment
Historic Rail Lines
Source
Conceptual Site Model
Dust in Air
Surface Soil
Terrestrial Food Items (Plants, Mammals,
Invertebrates)
Surface Water
Aquatic Food Items (Fish, Aquatic
Invertebrates, Plants)
Aquatic ReceptorsTerrestrial Receptors (Plants, Invertebrates)
Chat on Ballasts
Wildlife Receptors (Birds, Mammals)
Emissions from Rail Cars
Step 4 - Study Design
• Select measurement endpoints • Structure of fish community • Survival and growth of invertebrates
• Select specific inves>ga>on methodology • Fish shocking/siening • Toxicity Tes>ng • Benthic Macroinvertebrate Surveys
• Select data interpreta>on methods • Develop Work Plan and Sampling Analysis Plan
How you accomplish this = DQO process
Work Plan and Sampling Analysis Plan • Work Plan
• Document the decisions made during problem formula>on • Iden>fy addi>onal inves>ga>ve tasks needed: data gaps
• Sampling Analysis Plan • Field Sampling Plan
• Sample types, loca>ons, frequency, equipment, procedures, handling and analysis
Step 5 - Field Verification of Sampling Design
Verify that endpoints, exposure pathways, and study design from steps 3 + 4 are appropriate and implementable
Step 6 - Site Investigation and Analysis Straight forward implementation of the studies designed in Step 4 and verified in Step 5.
Step 7 - Risk Characterization
• Risk Descrip>on • Key outputs of the risk characteriza>on step are contaminant concentra>ons in each environmental medium that bound the threshold for es>mated adverse ecological effects.
• Uncertainty Analysis • Conceptual model uncertain>es; • Natural varia>on and parameter error; • Model error.
STEP 8
Risk Management
Take Home Points • 8 – Step Process
• Technically Defensible
• Decision Oriented
• Mul;disciplinary
