Factors affecting disposal and reuse of contaminated dredged material
Type:
Presented during:
WODCON XVII: "Dredging in a Sensitive Environment" - 2004, Hamburg, Germany
Authors:
Mark Otten, P.E.
Abstract: Disposal or beneficial use of contaminated dredged material has become more expensive than dredging. There is a wide range in disposal costs for contaminated dredging projects, which makes it difficult to predict future costs. This paper will evaluate and describe the factors that affect disposal costs and provide a method to make more accurate estimates of disposal costs.
This paper is based on the author's experience on several projects in the United States including: (a) New Bedford Harbor in New Bedford, Massachusetts, (b) Ward Cove in Ketchikan, Alaska, (c) Thea Foss Waterway in Tacoma, Washington, (d) Bremerton Naval Complex in Bremerton, Washington, (e) Harbor Point in Utica, New York State and (f) brown-field redevelopment sites in New Jersey. The evaluation will also consider projects in the Fox River in Wisconsin and Commencement Bay in Tacoma, Washington.
This paper will evaluate dredged material processing and disposal technologies including: capping, near-shore confined disposal facilities, confined aquatic disposal, upland landfills, gravity settling, air-drying, stabilization/solidification, sand separation, and mechanical dewatering. Factors that have a significant impact on dredged material processing and disposal include: (a) sediment physical properties (solids content, particle size, organic content), (b) chemical concentrations and separate-phase oil, (c) regulatory classification (hazardous or non-hazardous waste), (d) quantity and type of debris, (e) volume of material to be dredged, (f) schedule, (g) project funding limitation, (h) site access and upland support area, (i) public opinion and concerns, (j) type of dredging, (k) rate of dredging, and (l) allowable working hours. This paper will describe how each of these factors impact disposal costs, so that readers will be able to make more accurate construction cost estimates.
Keywords: cost, estimate, contaminated dredged material, disposal