An Assessment of the Environmental Effects of Dredged Material Disposal in Lake Superior. Volume 5. Trace Element Study: Duluth-Superior and Keweenaw Study Areas.

Abstract : Present procedures for evaluation of harbor sediments do not provide sufficient information to adequately assess alternatives for the disposal of dredged material. This is especially true for trace element evaluations. The elutriate test described later (also see Lee and Plumb, 1974) has been recently developed primarily to identify potential problems of water quality, although some information about sediment quality is also obtained. Existing knowledge of the relationship of trace elements in sediments to trace elements in organisms is too scarce to allow information from the elutriate test to predict the effect of dredged materials on the trace element concentrations in benthic organisms. The purpose of this part of the study is to develop a procedure to accurately assess the extent of trace element pollution of sediments. Such a procedure must provide information about sediment quality which supplements the results provided by the elutriate test. The information provided by this procedure, along with the concentrations of trace elements in organisms and the results of the bioassay experiment, is used to determine permissible concentrations of trace elements in sediments.