US Army Corps of Engineers
Baltimore District

Frequently Asked Questions (FAQs)

A dredged material management plan (DMMP) is a comprehensive, long-term plan for management of dredged material removed from channels and berths to provide safe navigation. A DMMP involves scheduling and budgeting of sediment management for dredging projects including material handling, processing and storage/placement of dredged material. Some DMMPs include the recycling or beneficial use of dredged material. DMMPs are used by both public and private maritime facilities and can range in size and scope from the dredging and placement of sediment from one small berthing facility to a port-wide or regional plan coordinating the interests of port authorities, the Corps, and private berthing facilities.

An EIS is a comprehensive document that is prepared to describe and evaluate the effects from a proposed action on the environment. The National Environmental Policy Act of 1969 (NEPA) requires the Federal government to provide a detailed statement of impacts (known as an EIS) resulting from any major Federal action that has the potential to significantly affect the environment. A "Federal action" is an activity that is entirely or partly financed, assisted, conducted or approved by a Federal agency. The "environment" is defined as the natural and physical environment and the relationship of people with that environment. A change in consequence, resulting from the action(s) is considered an "impact". Impacts can be positive or negative or both. An EIS describes all impacts to the affected environment, including effects to the land, water, air, living organisms, as well as social, cultural, and economic aspects. NEPA requires an analysis of alternatives. An EIS also evaluates impacts resulting from any reasonable alternatives to the proposed action. It is a decision-making document in that it selects the preferred alternative after thoroughly evaluating these impacts.

Although NEPA applies to all actions carried out, assisted, or licensed by the Federal government, the act specifies when an EIS must be prepared and the Council for Environmental Quality (CEQ) regulations provide the recommended format and content. In accordance with the CEQ regulations, Section 1502.1, the EIS "shall provide full and fair discussion of significant environmental impacts and shall inform decision makers and the public of the reasonable alternatives which would avoid or minimize adverse impacts or enhance the quality of the human environment".

A tiered EIS is prepared when there is a need to have subsequent NEPA documents (either an EIS or an Environmental Assessment) after an initial EIS. For example, another NEPA document might be needed to address impacts that may result from a follow-on, site-specific action that is included in the overall program. The tiered EIS is prepared to eliminate repetitive analysis of the same issues. During a tiered EIS process, the subsequent document will concentrate on discussions and analysis specific to the follow-on action, but will only summarize and reference issues discussed in the original, broader document.

Most U.S. ports are located on rivers or in estuaries that have natural water depths less than required for the larger vessels commonly used in domestic and international shipping. Terrestrial surface water runoff, wave action, and tidal currents carry sediments from the erosion of rock and soil and deposit this material in downstream areas of the rivers and estuaries including navigation channels and ship berths in ports. This erosion and deposition cycle is a natural process, which has been enhanced by increased land development.

Today's modern ships require deeper drafts to move goods more economically. Removal of the sediment material from the navigation channels and berths by dredging allows more fully loaded ships safe passage into and out of berthing facilities. Shallow draft clearances (shallow depths) in navigation channels and berthing facilities forces shippers to carry less cargo increasing the effective shipping cost of the delivery. In the case of tanker ships carrying petroleum products, costly and environmentally hazardous lightering may be required before the tanker can enter the shallow port. Lightering involves the open water transfer of fuel from the tankers to several smaller vessels to distribute the load and reduce the draft of the tanker to an allowable entry depth.

In general, dredged material is sediment that has been removed with an underwater excavating machine called a dredge. Dredging may be conducted either mechanically or hydraulically. Dredged material removed from waterways is categorized into two general types: maintenance material and new work material.

Maintenance material is material that has been removed from areas that have been dredged previously to similar depths. Maintenance material consists of recently deposited sediment material that originated as eroded soil carried to the riverbed or estuary bottom by rainfall runoff, wave action, or tidal currents. This typically uncontaminated sediment is removed as part of regular maintenance dredging programs. New work material is material taken from depths not previously dredged.

The Port of Baltimore's annual maintenance need of 4.4 million cubic yards (mcy) and the proposed new work projects result in a 20-year dredging need of just over 111 mcy.

The dredged material will be transferred via barge, hopper dredge, or hydraulically pumped via pipeline directly to a storage facility specifically designed to manage and store the dredged material, or placed in the open water (such as, the Pooles Island site or in the Atlantic Ocean). A confined disposal facility (CDF) is an open area surrounded by dikes which contain the material. While in the CDF, the dredged material will be decanted to remove excess water and dried by stacking or trenching the material or the addition of dewatering agents such as lime or fly ash.

A confined disposal facility is designed to contain all solid material but releases the water entrained in the dredged material upon its arrival to the CDF. The water decanted from the material will be returned to the waterway.

Beneficial use options will also be given full consideration. A beneficial use option is one which uses dredged material as a resource in a productive way. The DMMP shall include a detailed assessment of all feasible beneficial use alternatives, which may include agricultural use (topsoil), shoreline protection, wetland restoration, or creating wildlife habitats.

The DMMP will be developed by the Baltimore District, Corps in response to the growing need to have a cost effective long-term plan for the management of dredged material for the Port of Baltimore. The Baltimore District will work with regulatory and resource agencies, State and local officials, the maritime industry and the public to address the concerns of all parties who have a vested interest in the resources that the Port provides.
The Corps will fund the development of the DMMP/EIS. Study costs associated with activities related to dredged material management, but not required for the construction or maintenance of Federal channels, should be funded by non-Federal sources, or other Federal agencies having programmatic responsibilities for these activities.

The State, through its Maryland Port Administration, is preparing a Dredged Material Management Program for the Port of Baltimore. The program will develop a long-term dredging and dredged material placement plan for the Port, including the identification of potential new placement sites. The State's DMMP incorporates input from various stakeholders and the process is organized around an Executive Committee, a Management Committee, a Citizens Committee and numerous ad hoc working groups. The working groups will continuously identify, study, review and prioritize potential sites.

Both programs have similar goals and will address the dredging and material placement needs of the Federal channels and the non-Federal state and local channels. The plan is intended to ensure that the Port's Federal navigation projects continue to be completed in an environmentally acceptable and cost-effective manner, thereby justifying an ongoing investment of Federal funds.

Since, the Baltimore District, Corps has representatives on the State's Executive, Management, and ad hoc working group committees, the USACE is an integral player in the State's program. Dredging and dredged material management should be a cooperative process that benefits from the involvement of the key government and non-government stakeholders. The Baltimore District will continue to work closely with the State to share information and prevent the duplication of effort. This close coordination is essential in developing a comprehensive program for the Port of Baltimore that will increase economic growth and protect, conserve, and restore coastal resources.

The Corps shares with a local sponsor the responsibility of maintenance dredging and dredged material placement for Federal channels. Private industry and port authorities fund maintenance dredging and placement of material from their own facilities.

Contaminated sediment is deposited soil material that contains chemicals, at concentrations that are hazardous to human or ecological health. In general, the state environmental agency establishes the concentration limits of hazardous chemicals typically found in marine sediments using U.S Environmental Protection Agency (USEPA) guidelines. USEPA guidelines are established by modeling the effects on human health and the environment using conservative estimates of anticipated exposure limits and uptake.

Some marine sediments found in our industrial ports contain some elevated levels of contaminants but usually they exist at concentrations below the hazardous range and are therefore not a threat to human health or the environment. Before dredging occurs, the proposed dredged material may be sampled to determine if the sediment material contains contaminants above hazardous limits. If the material were determined to be contaminated, the regulatory agencies would require dredging and placement to be conducted in such a manner as to prevent human or ecological exposure to the contaminants.

Beneficial use of dredged material is recycling of dredged material for use as a product that has value. Dredged material has historically been considered a waste product and managed by creating facilities for permanent placement. Recently, the USACE and other technical experts in the maritime industry and material recycling field have found alternatives involving the use of dredged material for beneficial use. Examples of beneficial use of dredged material include beach replenishment, shoreline restoration, island restoration, manufactured topsoil, construction fill, landfill, abandoned mine and brownfield cover, and habitat restoration. Dredged material can also be heat treated and formed into lightweight aggregate and building blocks.

Storage capacity is limited within existing confined disposal facilities (CDFs) and diminishing each year. With increased quantities of dredged material to be managed and the high cost and space limitations involved in creating new CDFs, beneficial use is rapidly becoming a necessary facet of dredged material management. Recent characterization efforts conducted on dredged material in existing CDFs and recently dredged maintenance material has found sediments to be non-contaminated or minimally contaminated, making the material more likely to be beneficially reused.

An innovative use is using new technologies to improve the dredged material management process by implementing techniques that ensure an efficient and cost effective approach of using dredged material as a resource.