300 



Chemical extraction is currently being used by the San Diego Unified Port 

 District to separate copper ore from bay sediments. During loading operations 

 at the National City Marine Terminal, copper ore was discharged into the bay. 

 Chemical extraction is used to break the surface tension binding a contaminant 

 to a sand particle. Extraction uses nitric acid heated by steam to 100T to 

 break the surface tension, separating the sand and contaminants. The sand is 

 rendered non-hazardous and can be used in many different beneficial ways. The 

 copper ore will be sent to a metal smelter in Arizona for processing. The 

 cost for chemical extraction is $75.00 to $100.00 per cubic yard. Processing 

 the copper at a metal smelter will help to recover some of the costs of 

 extraction. 



When material to be dredged is non-hazardous, disposal options are numerous 

 and inexpensive. If dredge material is hazardous, then the disposal costs 

 increase exponentially and disposal options decrease. More research needs to 

 be performed to discover disposal options for contaminated material that are 

 affordable and acceptable by all regulatory agencies. 



