171 



Based upon roughly a decade of experience using undersea pics, it 

 appears that the distinction between sand caps and dredged material 

 can ce maintained physically and chemically. Despite the apparent 

 success associated with this technique, the siting of these pits 

 remains a contentious issue that has to be addressed when this 

 alternative is proposed. Another concern is sediment dispersal 

 during dredging and disposal operations. An initial loss of 3-5% 

 of the volume occurs in the water column during pit disposal. 

 Improvements in dredging procedures need to be considered. A more 

 comprehensive long-term monitoring program is needed to ensure that 

 pit stability is maintained and any long-term diffusion of 

 contaminants is detected. 



Beneficial Use 



In Glasgow, dredged material is applied to beneficial uses on land. 

 The areas where this might be applied are those places where a 

 heavy contaminant loading already exists in the soil. Several 

 sites exist in New Jersey wnere even a fairly significant 

 contaminant loading would be an improvement in the soils. It is 

 quite clear from the beneficial use in Glasgow that attractive 

 gardens can be developed on dredged material despite contaminant 

 loadings. Potential effects on groundwater need to be considered 

 however. This land application and soil development process needs 

 to be considered in the context of other approaches to 

 bioremediation . It has the advantage that port lands might be used 

 and the goals of the project could be very well defined. 



Recommendations 



The main impetus to clean up dredged material remains the dioxin 

 contamination in the Passaic River. This contaminant has 

 stimulated public interest in dredging activities and disposal 

 practices. One approach would be to combine a short-range strategy 

 to clean up the dioxin "hot spot" with intermediate and long-range 

 strategies that addresses the vast bulk of dredged material . 



Short-Range Strategy 



The Mud Dump site off Sandy Hook is reaching the end of its useful 

 life as a place to dispose of contaminated sediments. This does 

 not mean we hastily have to adopt an unproven alternative if risks 

 to marine life and human health continue to be within acceptable 

 limits . 



An orderly phase-out of current practice can be conducted as 

 alternate solutions are pursued and set in place. Several European 

 nations have adopted this approach to manage disposal of 

 contaminated sediments. In view of the current need to dredge Port 



5 



