This chapter summarizes the technical framework and regulatory background,
which define the open-water disposal option. As indicated in Chapter 1, this
report focuses on uncertainty within that option only.
Technical Framework Summary
USACE has developed a technical framework to determine the environmental
acceptability of various alternatives for disposing of dredged material
(USEPA/USACE 1992). Possible alternatives include the following:
a. Open-water disposal is the placement of dredged material in rivers,
lakes, estuaries, or oceans via pipeline or release from hopper dredges or
barges. Such disposal may also involve appropriate management actions
such as capping in a confined aqueous disposal (CAD) pit.
b. Confined disposal is placement of dredged material within diked
nearshore or upland confined disposal facilities (CDFs) via pipeline or
other means. The confinement dikes or structures in a CDF enclose the
disposal area above any adjacent water surface, isolating the dredged
material from adjacent waters during placement. CDFs may be
constructed as upland sites, nearshore sites with one or more sides in
water, or as island containment areas. If a hydraulic dredge is used to
place material in the CDF, excess water is normally discharged from the
CDF during filling operations. If CDFs are filled by mechanical
rehandling of dredged material, less effluent is released.
c. Beneficial use includes a variety of options utilizing the material for
some productive use. Examples of beneficial uses include beach
nourishment, strip mine reclamation, shoreline stabilization, erosion
control, and use in construction and industry.
The framework for selecting environmentally acceptable alternatives for the
management of dredged material consists of the following five steps:
a. Evaluation of dredging project requirements.
b. Identification of alternatives.
c. Initial screening of alternatives.
Chapter 3 Regulatory Background