The migration of contaminants through geosynthetic fabric containers utilized in dredging operations

Recent changes in environmental regulations to protect the water column hav e prohibited the open water disposal of dredged sediment from the New York Harbor. These restrictions have decreased the average amount of dredging by the New York Port Authority by 70% for 1996. As a result, the New York Har bor will lose about a foot of depth each year if the contaminated sediments are not dl:edged. Decreases in the depth will have a severe economic impac t, as larger cargo ships will dock in deeper ports. Because of the restrictions and perceived political problems with dredging and open water disposal of the contaminated materials, the New York Port Au thority and the Corps of Engineers are investigating the use of geosyntheti c fabric containers (GFCs) to reduce the movement of contaminated sediments outside the boundary of the disposal site and to decrease the impact of th e sediment on the water column. During the dredging operation, the barge wi ll be lined with the appropriate GFC to filter the dredge sediments. This laboratory study investigates the migration of fines and contaminants through GFCs. Contaminated dredges sediment was characterized for the physi cal and chemical properties. Bench scale filtration and barge simulation te sts were conducted on the contaminated sediment and GFC configurations to d etermine the amount of total suspended solids that would be released to the water column. (C) 1999 Elsevier Science B.V. All rights reserved.