emplaced upon the bottom at selected 

 sites and how the data compare with 

 mathematical simulation outputs from the 

 model . 



Short-term, high-intensity labora- 

 tory elevations have been completed to 

 determine the effects of contaminated 

 dredged materials on the water column. 

 Results of these laboratory studies show 

 that acute chemical effects on the water 

 column range from insignificant to com- 

 pletely nonexistent. Much of the con- 

 troversy associated with mobilization of 

 a wide range of contaminants is unfound- 

 ed and was not shown to occur in a broad 

 range of sediment and water conditions. 

 Only ammonium, iron, and manganese were 

 shown to be released to the water column 

 in quantities significantly greater than 

 background. These findings are being 

 tested in the field investigations which 

 I previously mentioned. 



Laboratory tests on the chemical 

 stability of sediment water systems can- 

 not be directly related to the response 

 of organisms. In studying the response 

 of selected organisms to the physio- 

 chemical conditions, we have found that 

 many of the projected impacts associated 

 with open water disposal were unfounded 

 fears. However, this task has delineat- 

 ed certain areas of significant ecologi- 

 cal concern. 



Vertical migration investigations 

 have shown that representative bottom- 

 dwelling organisms have a significant 

 ability to migrate upward through cover- 

 ings of various depths of dredged mate- 

 rial. Those organisms most severely 

 impacted are sand-dwelling organisms 

 that have a clay-like sediment deposited 

 on them, and mud-dwelling organisms 

 covered with sandy dredged material. 

 This indicates the desirability of 

 choosing a disposal site. 



Heavy metals availability to ben- 

 thic organisms from the solid phase por- 

 tion of dredged material is currently 

 under study. Preliminary results using 

 grossly contaminated Houston Ship Chan- 

 nel sediments indicate a general toxic- 

 ity of the sediments, but uptake of a 

 wide selection of heavy metals was not 

 occurring. 



The final task area that I am going 

 to mention in this project is concerned 

 with the environmental impact created by 

 placing dredged material in containment 



areas, as well as sanitary landfills and 

 quarries that could be disposal areas 

 under some of the various beneficial use 

 concepts being explored. The main goal 

 is to determine if contaminations intro- 

 duced into these confined areas through 

 dredging and disposal will be immobi- 

 lized, with negligible long-term re- 

 lease, or be discharged in environmen- 

 tally unacceptable quantities with the 

 effluent or leachate. Effluent is re- 

 leased almost continuously for several 

 weeks during the filling of most dispos- 

 al areas. This effluent could result in 

 chronic discharge problems in confined 

 bodies of water. Following filling of a 

 land disposal area, short- or long-term 

 leaching could potentially mobilize 

 chemical constituents from the dredged 

 material and threaten surface and 

 groundwater quality. 



DISPOSAL OPERATIONS PROJECT 



Most of our engineering or opera- 

 tions research effort is being conducted 

 by the second project, the Disposal 

 Operations Project. This project is pri- 

 marily concerned with improving the ef- 

 ficiency of dredged material disposal. 

 Several aspects of this project include 

 dike design and improvement of dewater- 

 ing techniques, landscaping of disposal 

 sites, silt curtain performance, and 

 treatment of contaminated, dredged mate- 

 rial. Because participants interests at 

 this workshop are primarily biological, 

 I have elected to devote little time to 

 •_ project. 



PRODUCTIVE USES PROJECT 



The basic philosophy for the third 

 project of the DMRP, the Productive Uses 

 Project, is to develop new or innovative 

 disposal methods, primarily on land, to 

 provide disposal alternatives which de- 

 rive maximum value from the resource 

 potential of dredged material. To pro- 

 vide the information necessary, the Pro- 

 ductive Uses Project is responsible for 

 investigating viable productive uses of 

 dredged material, or where environmental 

 considerations preclude its use, the 

 evaluating of new concepts for disposal 

 in upland areas. Specifically, the pro- 

 ject is divided into the four tasks. The 

 tasks are upland disposal of dredged 



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