occur during dumping (Jones and Lee 1978). Brannon further recommends the 

 use of bioassessment techniques (including bioaccumulation assays, to deter- 

 mine both short- and long-term lethal and sublethal impacts to the biota. 

 Gambrell et al . (1978) discuss the relative environmental risks of different 

 disposal alternatives and the problems with different contaminants and dis- 

 posal methods. 



To the above recommendations we suggest adding the use of bulk sediment 

 analysis where the addition of contaminants to a water body could have long- 

 term significance. An example is San Francisco Bay. Pollutants enter the 

 Bay from various sources, including dredging. They are resuspended and trans- 

 ported within the aquatic system and eventually there is a loss of pollu- 

 tants from the Bay via the narrow mouth. If the input of pollutants is 

 greater than the outflow, long-term buildup of sediment pollutants may be 

 harmful to the biota (letter dated 28 April 1977 from Richard Kroger, FWS, 

 Sacramento, California). 



Potential for Productive Uses 



Contaminants and organic debris found in the material from many main- 

 tenance dredging sites limit the potential uses of the material. Often 

 contaminant levels are not environmentally acceptable. There is also often 

 too much organic matter for certain engineering uses. There are many situa- 

 tions, however, where maintenance material can be put to beneficial uses. 



Material from maintenance dredging, if not high in contaminants is often 

 excellent as a substrate for recreation areas, marsh establishment, or as a 

 soil additive. Sand and gravel may be useful for construction material, but 

 they are usually mixed with other materials in quantities that make separa- 

 tion necessary. The cost of separation is often greater than the market 

 value of the final product (Mai lory and Nawrocki 1974). 



Polluted material can sometimes be used as land fill for industrial 

 sites, depending on the contaminants present and the use of the land. A fre- 

 quent constraint on the use of maintenance material for construction sites is 

 that such land fills must be developed over short periods. Unfortunately, fill 

 from maintenance dredging usually becomes available over relatively long peri- 

 ods. Another constraint is the poor engineering properties of fine-grained 

 materials (Boyd et al . 1972) which often characterize fill from maintenance 

 dredging. 



There is some potential for filling mines and pits with dredged material. 

 Transport distance is the most critical variable. Long distance transport is 

 now feasible, although expensive (SCS Engineers 1977). The greatest potential 

 for disposal in mines and pits appears to be in the Great Lakes area and along 

 some of the Midwestern rivers. Extreme caution should be exercised in the 

 use of mines and pits for disposal of contaminated material, as ground water 

 contaminantion could occur in some instances (Gambrell et al . 1978). 



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