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

摘要

Recent changes in environmental regulations toprotect the water column have prohibited the open water disposalof dredged sediment from the New York Harbor. Theserestrictions have decreased the average amount of dredging by theNew York Port Authority by 70% for 1996. As a result, the NewYork Harbor will lose about a foot of depth each year if thecontaminated sediments are not dredged. Decreases in the depthwill have a severe economic impact, as larger cargo ships willdock in deeper ports.Because of the restrictions and perceived political problemswith dredging and open water disposal of the contaminatedmaterials, the New York Port Authority and the Corps ofEngineers are investigating the use of geosynthetic fabriccontainers (GFCs) to reduce the movement of contaminatedsediments outside the boundary of the disposal site and todecrease the impact of the sediment on the water column. Duringthe dredging operation, the barge will be lined with theappropriate GFC to filter the dredge sediments.This laboratory study investigates the migration of fines andcontaminants through GFCs. Contaminated dredges sedimentwas characterized for the physical and chemical properties. Benchscale filtration and barge simulation tests were conducted on thecontaminated sediment and GFC configurations to determine theamount of total suspended solids that would be released to the water column.