Introduction - trdoer10016

Introduction

Background

The U.S. Army Corps of Engineers (USACE) and the U.S. Environ-

mental Protection Agency (EPA) have statutory responsibilities with re-

gard to the management of dredged material placement in both ocean and

inland and nearshore waters. When dredged materials proposed for open-

water placement are found to require isolation from the benthic environ-

ment, capping may be appropriate for consideration as a management

action. The report herein is intended to provide technical guidance for

evaluation of capping projects.

This is one of a series of guidance reports pertaining to dredged mate-

rial management. This series includes a document entitled "Evaluating

Environmental Effects of Dredged Material Management Alternatives - A

Technical Framework" (Framework Document - USACE/EPA 1992). The

Framework Document articulates those factors to be considered in identi-

fying the environmental effects of dredged material management alterna-

tives on a continuum of discharge sites from uplands to the oceans

(management alternatives include open-water, confined, and beneficial-

use situations) that meet the substantive and procedural requirements of

the National Environmental Policy Act (NEPA), The Federal Water Pollu-

tion Control Act of 1972, Public Law 92-500, as amended by the Clean

Water Act of 1977 (CWA), and the Marine Protection, Research, and Sanc-

tuaries Act (MPRSA). Application of the technical guidance in this report

will allow for consistency in decision making with respect to capping

within the Technical Framework.

Potential for water column and benthic effects related to sediment con-

tamination must be evaluated when considering open-water placement of

dredged material. Management options aimed at reducing the release of

contaminants to the water column during placement and/or subsequent iso-

lation of the material from benthic organisms may be considered to con-

trol potential contaminant effects. Such options include operational

modifications, use of subaqueous discharge points, diffusers, subaqueous

lateral confinement of material, or capping of contaminated material with

suitable material (Francingues et al. 1985; USACE/EPA 1992).

Subaqueous dredged material capping is the controlled, accurate place-

ment of contaminated dredged material at an appropriately selected open-

water placement site, followed by a covering or cap of suitable isolating

Chapter 1 Introduction