Definitions
The terms and phrases listed below are defined in the context of their usage in this document. These definitions are to be considered regulatory in that they set important limits on actions associated with dredging and disposal projects.

Advance Maintenance Dredging - Dredging with the aim of providing year-round channel availability and to allow for an annual dredging cycle. Will not deepen the facility beyond its previously authorized depth.

Agitation Dredging - A sand bypasser dredge uses a propwash to stir up sediments. The current will then carry the sediments downstream away from the shoal area.

Aquatic area - The tidal waters and wetlands, and the land underlying these waters. The upper limit of aquatic areas is the upper limit of aquatic vegetation or, where such a line cannot be accurately determined, Mean Higher High Water.

Beach Nourishment - Deposition of sand material on actively eroding beach sites as a means of preventing further erosion of the bankline and to maintain the historic beach profile. Beach nourishment does not include creation of new upland area or beaches and must provide for the protection of estuarine resources (including habitat, nutrient, fish, wildlife, and aesthetic resources).

Beneficial Use - Placement or use of dredged material for some productive purpose. These uses may involve either the dredged material or the placement site as the integral component of the beneficial use.

Berm - A sloped wall or embankment used to prevent inflow or outflow of material and/or water into or from an area.

Clamshell Dredge - A mechanical cable excavator dredge that uses a single bucket attached to the dredge crane with cables. The dredge operates by lifting the bucket (the clamshell), dropping it into the bottom sediments, lifting the bucket and dredged material to the surface, and emptying the dredged material into a nearby disposal facility or barges for transportation to either an upland or in-water site disposal facility.

Confined Aquatic Disposal (CAD) - An in-water disposal location where dredged material is contained (see Confined Disposal Facility). Contaminated and capping material is placed in a natural or man-made bottom depression providing lateral support to the capped mound.

Confined Disposal Facility (CDF) - Include any disposal location where dredged material is contained, upland, in-water, or nearshore. Such disposal involves the controlled placement of the dredged material at a designated dredged material disposal site. Such a process may involve the construction of levees or other holding facilities as a means of containing the material.

Dredged material - Sediments, sand, gravel and other solids removed from an aquatic area.

Dredged material disposal - Deposition of dredged material in aquatic or upland areas.

Dredged Material Evaluation Framework (DMEF) - The DMEF provides a consistent technical framework to follow in identifying environmentally acceptable alternatives for the management of dredged material. This document represents the best available knowledge regarding dredged material assessment. As new information and technologies become available the document will be updated. The DMEF was prepared by a working group of the following agencies U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, Washington Department of Ecology, Washington Department of Natural Resources, and Oregon Department of Environmental Quality. This document is available online at http://www.nwp.usace.army.mil/ec/h/hr/Final/

Corps of Engineers Dredged Material Management Plan & Supplemental Environmental Impact Statement: Columbia and Lower Willamette River Federal Navigation Channel - Presents the findings of studies conducted to determine how to best maintain the existing 40-foot Columbia and Lower Willamette River navigation channel over the next 20 years using the criteria of least cost, environmental acceptability and technical feasibility. The potential impacts to physical, cultural and biological resources have been evaluated in accordance with the requirements of the National Environmental Policy Act (NEPA). The proposed actions are also evaluated in accordance with the requirements of the Clean Water Act (CWA), Endangered Species Act (ESA), Coastal Zone Management Act, Marine Protection Research and Sanctuaries Act, and other applicable environmental laws and Executive Orders.

Dredging - The removal of sediment or other material from an aquatic area for the purpose of deepening the area, obtaining fill material, or maintaining existing structures.

Dredging project proponent - The entity that is undertaking the dredging and dredged material disposal project.

Drift Right - A specific area or section of river bottom that has been cleared of snags and sunken debris and is shared and actively maintained by a group of fishermen as their fishing grounds.

Effluent - Water, including dissolved and suspended materials, which flows from a dredged material disposal site.

Estuarine Open-Water Disposal - All types of in-water dredged material disposal within the estuary which do not fall into the classifications of flow-lane disposal, beach nourishment, sump disposal, and disposal to provide fill material for an approved aquatic area fill project. Area D is the only such disposal site in the Estuary.

Flow-lane Disposal - In-water deposition of dredged material in or adjacent to the maintained navigation channel. Flow-lane disposal is allowed only in development management units between 20 and 65 feet below MLLW.

Hopper Dredge - A hopper dredge is a type of hydraulic dredging consisting of a propelled floating plant, capable of dredging material, storing it onboard, transporting it to the disposal area, and dumping it. Material from hopper dredges is disposed of in deep water in or alongside the navigation channel.

Inland Testing Manual (ITM) - Evaluation of Dredged Material Proposed for Discharge in Waters of the U.S. - Testing Manual (U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, Office of Water). The purpose of the ITM is to provide guidance regarding technical protocols under Section 404 of the Clean Water Act for evaluating proposed discharges of dredged material associated with navigational dredging projects into waters of the United States. This document can be found on-line at http://www.epa.gov/ost/itm/ITM/

In-water Disposal - Deposition of dredged material in a body of water. Methods include: beach nourishment, flow-lane disposal, estuarine open-water disposal, in-water sump disposal, agitation dredging and ocean disposal.

Levee - With regard to dredged material disposal, a structure consisting of sediments, rock, or other material designed to contain the dredged material and allow for settling of solids in a specific area while it is being deposited and after deposition has occurred. The term "levee" is also used in this plan to describe flood control structures. Flood control levees are sometimes repaired or reinforced with dredged material. (Note: referred to as a dike in the previous Plan).

Maintenance Dredging - Dredging of a channel, basin, or other water-dependent facility which has been dredged before and is currently in use or operation or has been in use of operation sometime during the past five years, provided that the dredging does not deepen the facility beyond its previously authorized or approved depth plus customary advanced maintenance dredging.

New Work Dredging - Dredging a channel, basin, or other water-dependent facility that has not been dredged before; deepening an existing dredged channel, basin, or other water-dependent facility beyond its previously authorized or approved depth; dredging a channel, basin, or other water-dependent facility that has not been in use of operation in the past five years.

Ocean Disposal - The deposition of dredged material in approved ocean disposal sites.

Ocean Testing Manual (Green Book) - Evaluation of Dredged Material Proposed for Ocean Disposal: Testing Manual (U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, Office of Water). The purpose of the Green Book is to provide technical guidance for determining the suitability of dredged material for ocean disposal through chemical, physical, and biological evaluations. The technical guidance is intended for use by dredging applicants, laboratory scientists, and regulators in evaluating dredged-material compliance with the United States Ocean Dumping Regulations. This document can be found on-line at http://www.epa.gov/OWOW/oceans/gbook/index.html

Pipeline Dredge - Pipeline dredges usually consist of a large centrifugal pump mounted on a non-propelled, specially designed barge. The bottom materials are then pumped up through a large diameter suction pipe to the barge, and then to the disposal area through a pipeline. The dredging end of the suction pipe is equipped with a revolving cutter-head that breaks up the bottom for easier transport.

Sump Disposal - Deposition of dredged materials in a temporary in-water disposal site. The material is subsequently rehandled to an upland disposal site.

Tidegate - A flood control structure designed to regulate tidal exchange between the ocean or estuary and inland sloughs.

Upland Disposal - Deposition of dredged material on uplands or shorelands, including on the top and landward sides of flood control levees. .