8.4.2 Tier III - Animal Bioaccumulation Decision

Concentrations of COC in tissues of organisms in the dredged material are

statistically compared to the concentrations in tissues of organisms in the

reference material to determine whether there is an indication of greater

bioaccumulation from the dredged material than from the reference. See

Section 2.3.5 for additional details on selection of an appropriate reference

material.

8.4.2 Tier III - Animal Bioaccumulation Decision

After consideration of the Tier III animal bioaccumulation information in the

context of the conceptual site model and the complete exposure routes to ROC

populations outside the CDF, one of the following conclusions is reached.

1. Bioaccumulation from the dredged material is not statistically greater than

bioaccumulation from the reference material. No further evaluation of

animal bioaccumulation is necessary.

2. Bioaccumulation from the dredged material is statistically greater than

bioaccumulation from the reference material. Therefore the magnitude of

potential effects on ROC populations outside the CDF must be

considered, leading to a conclusion that either:

Figure 8-2. Photo of the animal uptake bioassay

setup

a. There is little potential for effects on ROC populations outside the

CDF. No further evaluation of animal bioaccumulation is necessary.

b. Effects on ROC populations outside the CDF are likely, and

management actions should be considered. A decision to implement

management actions for animal bioaccumulation by interrupting

8-13

Chapter 8

Animal Bioaccumulation