PASSIVE DEWATERING IN A DREDGE MATERIAL REHANDLING FACILITY

摘要

An innovative dredge material rehandling facility (DMRF) has been constructed for the passive dewatering of sediments slightly contaminated with polychlorinated hydrocarbons. The facility utilizes gravity and evapotransporation to dewater dredge material prior to moving the sediments to an onsite storage area. The dewatered sediments, which resemble topsoil, are available for beneficial reuse projects. The DMRF is located near the mouth of the Fox River at Green Bay, Wisconsin, USA. The facility has the potential capacity to store up to 7.4 million cubic yards (5.6 million cubic meters) of sediment in 110 acres (44.5 hectares) at a capital cost of approximately $2,000,000. The annual operating and maintenance (O&M) costs are estimated at $770,000. The combined capital and O&M costs results in a unit cost of less than $6.00/cubic yard ($4.58/cubic meter) of wet sediment. Once dewatered, the soil is available for beneficial reuse projects. The technology incorporated in the Brown County DMRF can be used at any upland confined disposal facility (CDF) and at an in-water CDF if the construction of the CDF allows for suitable subsurface drainage.