Dredging: Contaminated Sediments

U.S. Army Corps of Engineers Research Report Summary, June 1998

Dredging Operations and Environmental Research Program

Dredging:

Contaminated Sediments

Guidance for Subaqueous Dredged Material Capping (TR DOER-1)

ISSUE: Potential for water column and benthic

q Define capping project site selection consid-

effects related to sediment contamination must

erations.

be evaluated when considering open-water

q Develop guidelines for cap monitoring.

placement. Management options aimed at re-

SUMMARY: The research resulted in techni-

ducing the release of contaminants to the water

cal guidance for evaluation of subaqueous

column during placement and/or subsequent

dredged material capping. Guidance includes

isolation of the material from benthic organisms

level-bottom capping, contained aquatic dis-

may control potential contaminant effects.

posal, design requirements, a design sequence,

Subaqueous capping is the controlled, accurate

site selection, equipment and placement tech-

placement of contaminated dredged material at

niques, geotechnical considerations, mixing and

an appropriately selected open-water placement

dispersion during placement, required capping

site, followed by a covering (cap) of suitable

sediment thickness, material spread and mound-

isolating material. Although conventional

ing during placement, cap stability, and moni-

placement equipment and techniques may be

toring plans. This guidance is applicable to

used for a capping project, these practices must

dredged material capping projects in ocean wa-

be more precisely controlled in this application.

ters as well as inland and near-coastal waters.

RESEARCH: The objective was to develop a

AVAILABILITY OF REPORT: The report is

comprehensive approach for evaluation of sub-

available in .pdf format on the World Wide Web

aqueous capping projects, including these goals:

at http://www.wes.army.mil/el/dots and through

q Refine and adapt numerical models, labora-

Interlibrary Loan Service from the U.S. Army

tory testing procedures, and engineering de-

Engineer Waterways Experiment Station

sign approaches for capping evaluations.

(WES) Library, telephone (601) 634-2355. To

q Develop design requirements and a design

purchase a copy of the report, call NTIS at (703)

487-4780.

sequence for capping.

q Document equipment and placement tech-

niques for contaminated material and cap-

ping material placement.

About the Authors: Dr. Michael R. Palermo, Messrs. Tommy E. Myers, James E. Clausner,

Gregory L. Williams, and Dr. Marian E. Rollings perform research at WES; contract support

was provided by Dr. Robert E. Randall, Civil Engineering Department, Texas A&M Univer-

sity; and Dr. Thomas J. Fredette, the U.S. Army Engineer District, New England. Point of

Contact: Dr. Palermo, Principal Investigator, telephone (601) 634-3753 or e-mail

palermm@ex1.wes.army.mil.

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