Ecological Risk Assessment: Site Conceptual Model | Region 8: Risk Assessment

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Site Conceptual Model

In this step, the risk assessor prepares a schematic diagram that:

identifies the primary source of contamination in the environment (e.g., acid drainage from a mine site, disposal of solid wastes to soil or streams, airborne releases from an industrial operation),
shows how chemicals at the original point of release might move in the environment (e.g., a chemical in soil might penetrate down into groundwater or might be taken up into plants),
identifies the different ecological receptors (e.g., birds, mammals, fish, plants) that might come into contact with contaminated media,
lists the potential exposure pathways (e.g., ingestion of contaminated water, ingestion of contaminants in soil or food, direct contact with contaminated soil or water) that may occur for each population.

This conceptual model is used to plan the risk assessment and associated data collection activities and is often revised periodically as data become available at a site. Examples of Region 8 ecological site conceptual model diagrams and other useful resources are provided below.

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Examples of Region 8 Site Conceptual Models

Site Conceptual Model, Example 1 (PDF) (1 pg, 13K)
Site Conceptual Model, Example 2 (PDF) (1 pg, 14K)

Resources

Guidance documents and other resources that may be helpful in preparing the ecological site conceptual model include the following:

Reuse Assessments: A Tool To Implement The Superfund Land Use Directive (PDF) (Memorandum, OSWER 9355.7-06P, June 2001) (24 pp, 83K)

Model Site Conceptual Model for RI/FS Baseline Risk Assessments of Human and Ecological Health (PDF) (Region 8 Superfund Technical Guidance RA-05, May 1995) (7 pp, 603K)

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