Figure 1. Risk-based decision framework for dredged material management. At the conclusion of each phase, the regulator advances to the next phase if insufficient information is available to reach a determination

Phase 1:

Determine whether there is reason to believe that sediments are

contaminated.

Phase 2:

Conduct a conservative screening-level analysis.

Identify exposure pathways

Compare measured or modeled exposure point concentrations

(EPC) to appropriate screening level effect values.

Phase 3:

Estimate the probability of adverse effects to individual species.

Estimate probabilities quantitatively where adequate data are

available or can be obtained.

Consider:

Site-specific exposure information

Centralized database of ecological effects (ERED, etc.)

Exposure models

Bioassay information

Uncertainty assessment

Phase 4:

Evaluate probability of ecological consequences, extrapolating

from individual-level to population-level adverse effects.

Estimate probabilities quantitatively where adequate data are

available or can be obtained.

Figure 1. Risk-based decision framework for dredged material management. At the conclusion of each

phase, the regulator advances to the next phase if insufficient information is available to reach

a determination

Chapter 4 Risk Characterization Workgroup Summary