Objective:

The Department of Defense (DoD) is responsible for numerous dredging projects in bays and harbors throughout the United States. Many of these projects occur in locations associated with past and current military activities. One complication when dredging in these areas has been the discovery of Munitions and Explosives of Concern (MEC) within sediments. The presence of ordnance in dredged material presents a potential explosive hazard to dredging personnel and equipment. Any subsequent beneficial use of dredged material also must address the possibility of ordnance presence and/or removal. Dredged material containing MEC is not acceptable for preferred reuse options, including beach replenishment and most upland disposal scenarios, unless there is confidence that the ordnance has been removed. The main objective of this effort is to demonstrate a field-based technology that can separate ordnance from dredged material quickly and effectively in order to save costs via operations and disposal options.

Technology Description:

This project is composed of three phases. During Phase I, a survey will be conducted to determine the historical magnitude of the amount of dredged sediment impacted by ordnance and to identify potential demonstration/validation sites. A data inventory (i.e., database) will provide information on historical dredging projects that have encountered MEC and be made available via the internet. Field observations will be conducted on working dredges and screening operations in order to evaluate safety measures and develop specifications for a Phase II/III dredging and physical separation effort. To select the most appropriate technologies, potential dredge/separation systems will be ranked according to cost estimates, demonstration site, separation technologies, etc. Additionally, specific components and demonstration opportunities will be identified. During Phase II, one or a combination of dredging and separation technologies will be demonstrated at an appropriate site for their ability to systematically remove ordnance from dredged material quickly and effectively. The field-technology demonstration will be coordinated with ongoing and planned dredging operations. During Phase III, a draft technology assessment report, followed by a final report with cost metrics, will be prepared.

Expected Benefits:

Dredging will continue to be required for material that may not subsequently meet ocean disposal or land use requirements because of ordnance. With the trend towards upland disposal, beneficial reuse, and the difficulties in establishing ocean disposal sites, human exposure to dredged sediment will increase. Reuse options, such as creating land, beach replenishment, sediment capping, and near shore sediment replenishment, may become viable options for sediment containing MEC if ordnance items can be successfully removed to a high degree of verifiable certainty. Integrating modern dredging technologies with physical separation technologies provides an innovative tool, which can reduce the quantity of the dredged material requiring additional treatment. (Anticipated Project Completion - 2007)

Contact:

Mr. William Wild
SPAWAR Systems Center (PL-BS)
Marine Environmental Quality Branch (Code 2362)
53475 Strothe Road
San Diego, CA 92152
Telephone: (619) 553-2781
Fax: (619) 553-6305
E-mail: bill.wild@navy.mil