Figure 4-1. Contaminant Pathways for Open-water Disposal

Framework for Dredged Material Management

May 2004

4.3 Evaluation of Contaminant Pathways of Concern

The main emphasis of contaminant pathway testing for open-water disposal is

aimed at determining if a given dredged material is acceptable for open-water disposal

from the standpoint of contamination. If dredged material is found to be environmentally

unacceptable for disposal in the ocean, it also would probably be environmentally

unacceptable for disposal in Section 404 waters.

As shown in Figure 4-1, the potential contaminant pathways for open-water

disposal are water column and benthic. Water-column contaminant impacts must be

considered from the standpoint of water quality (chemical) and toxicity (biological).

Benthic impacts must be considered from the standpoint of toxicity and bioaccumulation.

A tiered approach to contaminant testing and assessments is described in detail in the

dredged material testing manuals for MPRSA and CWA (USEPA/USACE 1991;

USEPA/USACE 1998; USACE 2003).

Figure 4-1. Contaminant Pathways for Open-water Disposal