Lake shore management and dredging waste disposal.

The disposal of dredged materials in the United States is a problem of major concern. Due to the fear of undesirable environmental consequences, the open water disposal of polluted dredgings is currently subject to rather severe constraints. Within the last decade extensive studies have been conducted on various aspects of the dredging and disposal process to identify alternate methods of disposal. As a result, the deposition of polluted dredge spoil in diked containment area (landfill or lakefill) has been found to offer the only feasible alternative at the moment, but the associated costs are usually very high. Accordingly, many current research efforts are being directed toward evaluating the potential benefts that may be realized by the use of dredged materials in various multipurpose schemes. If the drying process of the deposited materials can be accelerated, the resulting landfill can be used for harbour development, and part of the costs of the dredging and disposal operation may be offset by the increased land value. Recently, the idea has been advanced to create a chain of islands (archipelago) near the lake shore ; in addition to serving as long-term disposal sites, these islands may be used for recreational purposes and would enhance shore protection. The feasibility of combining this concept with an underground pumped storage facility is discussed, and certain advantages and disadvantages are pointed out. (A)