material at long distances from the 

 dredging project; the use of dredged 

 material for land enhancement whether as 

 a landfill material or as a soil; the 

 development of products such as shrimp, 

 lawn sod, or horticultural crops grown 

 in dredged material; and, finally, with 

 the development of disposal areas into 

 recreational or commercial sites. 



A major effort in this project is 

 to identify, in a categorical sense, po- 

 tential disposal areas at remote inland 

 locations some distance from the dredg- 

 ing operations; to examine components of 

 an inland transport system; and to as- 

 sess environmental, technical, economic, 

 and institutional factors associated 

 with upland disposal. An example would 

 be the use of abandoned pits or quar- 

 ries, both as a disposal option and a 

 significant land use benefit. 



The concept of the beneficial use 

 of dredged material for land improve- 

 ment, especially in agriculture, appears 

 promising. Under this task the physical 

 and chemical qualities of dredged mate- 

 rial as a soil base or amendment will be 

 evaluated. Another potential use of 

 dredged material is for sanitary land- 

 fill cover. Presently sanitary landfill 

 cover can be purchased for up to $6.54/ 

 m •* ($5/yd 3 ). in some cases, the use of 

 dredged material would be economically 

 competitive. 



The Productive Uses Project is also 

 exploring possibilities of manufacturing 

 marketable products of commodities from 

 dredged material or using disposal sites 

 for similar activities. Products manu- 

 facture (e.g., ceramics or bricks) has 

 not proven feasible on a scale which 

 could significantly affect large quanti- 

 ties of dredged material. In some iso- 

 lated cases the manufacture of a syn- 

 thetic aggregate may be worthwhile. 



A recently completed study dealt 

 with the feasibility of using disposal 

 areas for growing land sod or horticul- 

 tural products. The study found that 

 there is a considerable demand for such 

 products, particularly near large urban 

 centers, and in some cases this may be a 

 feasible alternative. 



The potential for mariculture of 

 shrimp and other commercially valuable 

 species is being investigated by Dow 

 Chemical Company. Dredged material was 

 transferred to two 0.10-ha (0.25-acre) 



ponds located within Dow's facilities at 

 Freeport, Texas, and about 0.3 m (1 acre) 

 of material was placed in each pond. Two 

 similar ponds received no material and 

 were designated control ponds. After an 

 initial fertilization to stimulate algal 

 growth, about 10,000 juvenile shrimp 

 were placed in each of the four ponds. 

 No other food was added throughout the 

 experiment. Previous shrimp mariculture 

 work indicated that the survival rate 

 should be 50% or greater. All four ponds 

 were harvested after 3 mo. Over 75% of 

 the shrimp survived, and those raised on 

 dredged material were significantly 

 larger than those in the control ponds. 

 The disposal area land-use concepts 

 task is assessing the technical and eco- 

 nomic aspects of developing disposal 

 areas as landfill sites. We have also 

 included the development of recreational 

 areas and other public or private land- 

 use concepts. 



HABITAT DEVELOPMENT PROJECT 



The final project, the Habitat De- 

 velopment Project, is divided into five 

 tasks: (1) the effects of dredged mate- 

 rial disposal on marsh and terrestrial 

 habitat, (2) marsh development, (3) ter- 

 restrial habitat development, (4) aquat- 

 ic habitat development, and (5) island 

 habitat development. These tasks are 

 closely related and often grade natural- 

 ly into one another. 



The basic emphasis of these tasks 

 can be summarized in two main objec- 

 tives: to determine the environmental 

 impact of habitat development and to 

 evaluate habitat development as a dis- 

 posal alternative. 



Major emphasis is being placed on 

 the first task, determining the effects 

 of disposal in marsh and terrestrial 

 areas. To a larger extent, all of the 

 work in the Habitat Development Project 

 relates to this task. The environmental 

 impacts of dredged material disposal and 

 habitat creation at all of our field 

 sites are being carefully evaluated, and 

 this information will form the basis of 

 most of our findings and conclusions 

 relative to impact assessment. In addi- 

 tion to the field studies, much of the 

 ongoing work in impact assessment is 

 directly related to heavy metal and 



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