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Published byJayson Cummings Modified over 6 years ago
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Anniston PCB Site Review of Risk Assessments for OU-1/OU-2
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EPA’s Cleanup Process Data Collection From: -Site Discovery
-Preliminary Assessment -Site Inspection Source: -Risk Assessment Guidance for Superfund - Volume 1. Human Health Evaluation Manual. Part A, EPA/540/1-89/002 To: -Selection of Remedy -Remedial Design -Remedial Action Evaluation Toxicity Assessment Exposure Risk Characterization
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Site Assessment: Data Collection and Evaluation
Range of information helps identify what is needed to evaluate risks including: Types of chemicals Amount of chemicals Who might be contacting chemical (“exposure”)
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Map of Anniston PCB Site
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Type of Data Collected for the Anniston Area (OU-1/OU-2)
Soils Air Groundwater Surface water Land use information
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Human Health Risk Assessments
Protective NOT Predictive Meant to protect the public, not predict the occurrence of a disease (e.g., cancer) NOT a Health Assessment (like Anniston Community Health Study)
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What is a Risk Assessment?
Risk = Exposure (Dose) x Toxicity Exposure: How much is contacted Toxicity: How hazardous is the chemical
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Toxicity of a Chemical Based on studies in animals and humans
Safety Factors used to ensure protectiveness Example: Amount of PCBs without effect in animals divided by safety factors.
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How EPA Protects the Community from Cancer Risks
Risk of Cancer: 1 in 3 people in US will contract cancer Cleanup actions are required if the additional cancer risk exceeds 1 additional cancer in 10,000 people exposed to a particular chemical
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How EPA Protects the Community from Risk of Other Injury or Disease?
Risk of Other Injury or Disease Besides Cancer: Compare Estimated Exposure (Dose) in Community to “Safe” Dose Safe dose doesn’t cause effects in animals or humans, divided by safety factors If estimated Dose exceeds “acceptable” intake – cleanup actions are needed
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Human Health Risk Assessment Current and future land uses:
Residential (Adult, Child) Industrial/Commercial Worker (Adult) Construction Worker (Adult) Utility Worker (Adult) Commercial Visitors (Adult, Young Child) School/Daycare Occupants (Adult, Young Child) Recreational User (Young Child, Adolescent) Trespasser (Adolescent)
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Exposure Media: Soil Surface water Air Groundwater
incidental ingestion dermal contact inhalation of fugitive dust Surface water inhalation of volatiles Air inhalation Groundwater Ingestion of drinking water
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Human Health Risk Findings (2010)
Surface soil in residential and high activity areas was appropriately addressed through the early actions (NTCR) Surface soil in a limited number of nonresidential areas exceeds EPA risk levels Subsurface soil throughout the Anniston area do not present an elevated risk Groundwater EPA risk levels only exceeded in one isolated area located near the Facility Air levels of PCBs are low and similar to background conditions Surface water exposure in Snow Creek does not present a risk to the community
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Ecological Risk Assessment
Ecological risks were evaluated with EPA oversight (2013) Ecological risk evaluations focused on sediment and surface water of Snow Creek The floodplain was evaluated in a screening-level assessment that was focused on urbanized habitat
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Ecological Risk Findings
Risks to aquatic species associated with: PCBs Several metals (chromium, lead, manganese, mercury, nickel and vanadium) Risks are primarily present in sediment deposits located in Snow Creek upstream of Highway 202 Field studies of the floodplain areas confirmed the lack of quality and connected habitat and terrestrial ecological risks
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Next Steps Range of potential cleanup options are identified and evaluated in the Feasibility Study (FS) currently under EPA review. General FS steps include: Identify the areas to be addressed based on the risk assessments and government regulations Identify the type of cleanup actions that could be used to address the areas Evaluate the range of cleanup options using criteria developed by EPA Based on the FS, EPA issues a Proposed Plan for public comment describing their preferred cleanup option EPA issues a Record of Decision describing the final cleanup approach based on input from the community and the State
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Questions
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Locations with Surface Soils Exceeding PCB Nonresidential Risk Thresholds
Exposure Unit with PCBs Below EPA Risk Threshold Exposure Unit with PCBs Above EPA Risk Threshold Facility (OU-3)
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