43 



and despite the large extent of the deep ocean, pollutants have 

 been measured in all deep-sea sediments sampled to date. The pri- 

 mary source of these pollutants are atmospheric, but we need to be 

 concerned about any source that adds to the general level of con- 

 tamination. . 

 During the past year, the Institute of Marine and Coastal Sci- 

 ences at Rutgers has received funding from the Port Authority of 

 New York and New Jersey to assess sediment remediation technol- 

 ogy. This assessment included the organization of two major inter- 

 national conferences with some of the world's leading scientists 

 and engineers evaluating current research and demonstration pro- 

 grams in the U.S. and Europe. A broad range of remediation ap- 

 proaches were presented and evaluated, and a guidance document 

 was produced by a steering committee for each conference, copies 

 of which have been provided the committee staff for your informa- 

 tion. 



Considerable discussion at each conference centered on the lack 

 of an adequate characterization of sediment pollutant loads, distri- 

 bution and transport processes for New York Harbor. This is neces- 

 sary to determine which sediments and what quantity of dredged 

 material warrant remediation. Effective decisions concerning treat- 

 ment technology cannot be made without this information. A de- 

 tailed characterization of sediments is needed to focus treatment 

 alternatives on sediment sources and depositional areas in the estu- 

 ary. One useful technique for conducting this characterization is 

 sidescan sonar in conjunction with fine-grained sampling and study 

 of bottom boundary hydrodynamics. 



Bioremediation or the use of marine organisms to reduce con- 

 tamination was viewed by the participants as a viable strategy for 

 some sediments where they are contained and where there is a re- 

 stricted range of contaminants and the remediation processes have 

 a long time to work. 



Our second conference evaluated a range of technologies using 

 physical and chemical processes to remediate sediments. A wide 

 range of remediation projects are being conducted at the demon- 

 stration scale, and there is one full-scale separation treatment fa- 

 cility in Germany. Most of the U.S. remediation projects are being 

 sponsored by the Environmental Protection Agency through the 

 Assessment and Remediation of Contaminated Sediments or ARCS 

 program. This program involves bench-scale tests of solvent extrac- 

 tion, thermal desorption, and wet-air oxidation techniques with 

 contaminated sediments from Indiana Harbor, the Buffalo River, 

 and Saginaw Bay. These projects focus primarily on PAH's or po- 

 lynuclear aromatic hydrocarbons and PCB's, polychlorinated bi- 

 phenyls. 



Principal methods for remediation involve mechanical separation 

 to separate sand from silt. Other physical separation techniques 

 such as flotation may be effective and, along with heap-leaching 

 techniques, should be investigated further. One particularly inno- 

 vative program is being pursued in Great Britain where microorga- 

 nisms are used to immobilize and localize metal ions from solution 

 which are then separated with a high gradient magnetic separation 

 technique. This approach may also be effective with polar organic 

 compounds and is worthy of further exploration. 



