Evaluate Physical Characteristics of Sediment

Framework for Dredged Material Management

May 2004

3.5.2 Evaluate Physical Characteristics of Sediment

Evaluation of the physical characteristics of sediments proposed for discharge is

necessary to determine potential environmental impacts of disposal, the need for

additional chemical or biological testing, as well as potential beneficial use of the

dredged material. If this information has not been gathered during the project evaluation

phase, it must be obtained at this point in the framework. The physical characteristics of

the dredged material include: particle-size distribution, water content or percent solids,

specific gravity of solids, and plasticity characteristics. The sediment physical

characteristics should also be evaluated from the standpoint of compatibility with

different kinds of biological communities likely to develop for the disposal environments

under consideration.

3.5.3 Conduct Initial Evaluation of Sediment Contamination

The initial screening for contamination is designed to determine, based on

available information, if the sediments to be dredged contain any contaminants in forms

and concentrations that are likely to cause unacceptable impacts to the environment.

During this screening procedure, specific contaminants of concern are identified in a site-

specific sediment, so that any subsequent evaluation is focused on the most pertinent

contaminants.

Initial considerations should include but are not limited to:

Potential routes by which contaminants could reasonably have been

introduced to the sediments.

Data from previous sediment chemical characterization and other tests of the

material or other similar material in the vicinity, provided the comparisons are

still appropriate.

Probability of contamination from agricultural and urban surface runoff.

Spills of contaminants in the area to be dredged.

Industrial and municipal waste discharges (past and present).

Source and prior use of dredged materials (e.g., beach nourishment).

Substantial natural deposits of minerals and other natural substances.

Under CWA, some materials may be excluded from testing as specified in 40

CFR 230.60. Under MPRSA, testing must be conducted unless the exclusions in 227.13

(b) are met.

If the material does not meet the exclusions, contaminants must be addressed with

respect to their potential for biological effects and/or release through applicable

pathways. If such potential exists, the specific tests and assessments for contaminant

pathways described in Section 3.5.4 will be required. If ocean-disposal alternatives are

being considered, particular attention must be given to the presence of certain prohibited

materials (40 CFR 227.6) other than as trace contaminants. Detailed guidance for

chemical testing and evaluation of sediments can be found in USEPA/USACE (1995).