Evaluation of Direct Physical Effects and Site Capacity

Framework for Dredged Material Management

May 2004

There are also special concerns if the site is a special aquatic site (e.g., a wetland)

as defined in Section 404 (40 CFR 230 Subpart E). For example, if the proposed disposal

site is a special aquatic site and the activity for which disposal is required is not water-

dependent, the Guidelines presume that nonaquatic alternatives are available [40 CFR

230.10 (a) (3)].

Physical compatibility between the characteristics of the dredged material and

proposed disposal site is not the sole factor to be used in determining compliance with the

Guidelines. Other requirements of the Guidelines, specifically Section 230.10, must also

be considered in the evaluation of dredged materials. In addition, under Section

230.11(g), the Guidelines require that the cumulative impact of the individual discharges

of dredged material on the aquatic ecosystem be included in the evaluation of individual

permits. Therefore, dredged material disposal, like all other discharges of dredged or fill

material into waters of the United States, cannot be permitted unless it has been

demonstrated to comply with all requirements of the CWA Section 404(b)(1) Guidelines.

The USACE and USEPA may jointly identify, in advance, sites generally suitable

or unsuitable for discharge of dredged material (40 CFR 230.80). The advanced

identification of sites does not permit or prohibit the discharge of dredged or fill material,

but does facilitate individual or general permit application and processing. Under the

authority of Section 404(c), however, USEPA may prohibit, withdraw, or restrict the

discharge of dredged or fill material if it determines that the discharge would have

unacceptable adverse effects. As mentioned previously, procedures for application of risk

assessment to the aquatic environment can also be found in Cura et al. (2001).

4.1.3 Site Monitoring

Site monitoring may be a requirement resulting from the site

designation/specification process, or may be required as a part of an established site

management plan. Detailed guidance on site-monitoring equipment and techniques and

on development of monitoring plans is available (Marine Board 1990; Pequegnat,

Gallaway, and Wright 1990; Fredette et al. 1990a, 1990b).

4.2 Evaluation of Direct Physical Effects and Site Capacity

An evaluation of direct physical impacts and site capacity should precede any

evaluations of potential contaminant impacts, since elimination of alternatives or sites

based on unacceptable physical impacts or inadequate site capacity is needed prior to

testing for contaminant effects.

4.2.1 Direct Physical Impacts

Direct physical impacts will almost always result from the disposal of dredged

material. Benthic organisms at the disposal site may be buried and may not be able to

migrate through the material. If the substrate is changed from what was previously