9.4 Tier III Plant Bioaccumulation Test

prediction from the reference material, or there are COC for plant uptake

other than metals. Further evaluation in Tier III, or management actions

as an alternative to further evaluation, should be considered. A decision

to implement management actions for plant bioaccumulation by

interrupting complete exposure routes to ROC outside the CDF may

require more detailed information prior to design of such actions. If

management actions are selected, no further evaluation of plant

bioaccumulation is necessary.

9.4 Tier III Plant Bioaccumulation Test

The Tier III plant bioaccumulation procedure involves growing index plants

on the dredged material and reference soils and determining growth and

bioaccumulation of COC. A photo of the test setup is shown in Figure 9-2. Two

index plant species are available for use, depending on the dredged material and

habitat tested. The procedure determines both the potential plant growth and the

plant bioaccumulation of all COC. Plant growth is measured by the yield of

aboveground tissue. Bioaccumulation is measured by the translocation and

accumulation of COC into the aboveground tissues of the plant. The procedure

applies to both marine and freshwater dredged material in both wetland and

terrestrial habitat conditions. Detailed, step-by-step procedures are provided in

Appendix I.

Figure 9-2. Photo of the plant bioassay test setup

9-9

Chapter 9

Plant Bioaccumulation