Uncertainty (Text Version)

Scope and complexity depend on how much uncertainty the risk manager can live with. Court-ordered or legally mandated assessments are likely to be challenged, so strict attention to any uncertainties will ensure that the conclusion is defensible. The risk manager and risk assessor need to be clear with each other about where uncertainty exists, how much can be tolerated, and ways it can be reduced if needed.

You may find EPA's quality guidance documents at http://www.epa.gov/quality/qa_docs.html helpful to your planning.

This is another place where tiered assessments can help. Once the risk assessor understands the risk management needs, he or she can design explicit steps of increasing cost and complexity. This approach can increase understanding and reduce uncertainty throughout the assessment process.