Evaluation of Closed Buckets for Remedial Dredging and Case Histories

This paper presents current practices and experience with closed buckets nationwide, discusses the feasibility of using a closed bucket for remedial dredging, and presents the results of using a closed bucket during Stage 1 of the East Waterway Deepening Project. Information on case histories nationwide for remedial dredging using a closed bucket will also be presented in this paper. The East Waterway is located at the mouth of the Duwamish River to the east of Harbor Island, Seattle, Washington. During permitting for Stage 1, local agencies expressed concern over the effect that resuspended unsuitable sediments from dredging operations may have on water quality in the East Waterway and points downstream. A closed bucket is a technology that was developed to help reduce sediment resuspension and sediment loss; the agencies requested that the Corps and the Port investigate using a closed bucket to dredge the East Waterway. Conclusions from the feasibility study prepared for the Corps and Port, and discussion of Stage 1 field operations and results will be presented.