Attempts to Develop Beneficial Uses for Milwaukee Harbor and Green Bay Harbor Dredged Material

Milwaukee Harbor and the Fox River/Green Bay Channel have been primary focus areas for the U.S. Army Corps of Engineers and the U.S. Environmental Protection Agency's Great Lakes National Program Office in attempts to develop beneficial uses for dredged material. Studies have focused on low-cost treatment alternatives that could be implemented at the dredged material disposal facilities to enhance the degradation of contaminants and produce a marketable product. The goal of the program is to convert dredged material confined disposal facilities to handling facilities where dredged material could be dewatered, screened, mixed with amendments, phytoremediated, composted, and stockpiled as necessary before eventually being moved off-site for beneficial uses. Pilot scale studies have included attempts to compost the dredged material and to evaluate its marketability as a topsoil or topsoil amendment. Mixtures from the composting study were tested in the greenhouse for comparison to commercial topsoil mixtures. A marketing study evaluated the potential demand for a treated dredged material product in the Milwaukee and Green Bay areas and identified several potential customers for the dredged material-derived topsoil. The results presented suggest that dredged material can be treated on confined disposal facilities and that topsoil created from dredged material could be a marketable product. Efforts to treat remaining PCBs in the dredged material have been more successful than the treatment of PAHs. Conclusions from this research and others suggest that the PAHs in the dredged material topsoil may not be bioavailable and therefore may not be a concern. This paper will discuss the lessons learned with these pilot scale efforts and will discuss concerns with the long-term management of dredged material.