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5.0 CONCLUSIONS AND 

 RECOMMENDATIONS 



The success of capped dredged 

 material mounds in Long Island Sound and 

 elsewhere was based on the initial 

 formation of a well-defined mound of 

 contaminated dredged material followed by 

 controlled placement of cap material to 

 cover the underlying material. These 

 capped sites were at a maximum water 

 depth of 60 m. The question of extending 

 capping operations to greater depths has 

 been addressed in the analysis of results 

 from disposal operations at sites in deeper 

 water, such as MBDS, Port Gardner, 

 Portland, and Elliott Bay. It has been 

 shown that controlled placement of 

 dredged material at these sites results in 

 well-defined dredged material mounds. 



The formation of a well-defined mound 

 at MBDS supports the use of capping as an 

 effective management option at this site to 

 deal with the volume and type of dredged 

 material resulting from proposed projects 

 in the Boston Harbor area. The depth at 

 MBDS is greater than the maximum depth 

 at other disposal sites in New England 

 where capping has been employed 

 successfully. However, this increase in 

 water depth has not hindered the formation 

 of a well-defined dredged material deposit, 

 nor is there any suggested effect on the 

 behavior of the dredged material. 

 Postdisposal monitoring by bathymetry and 

 REMOTS® is as effective in defining the 

 dredged material mound at this site as it 

 has proven to be in Long Island Sound. 



Deep Water Capping 



