extraction efficiency with hot hydrochloric acid, the various metals 

 studied (except lead), will not migrate easily from the waste deposits 

 to the overlying water. Lead and copper were found to be the most 

 useful elements for delineating the distribution of wastes. 



Limited surveys of heavy metals in sediment samples from the Bight 

 were also made by SHL (1972) in conjunction with zooplankton investi- 

 gations, but were later expanded. Heavy metal analyses were also made 

 on a few plankton and animal samples collected in and around the dis- 

 posal areas. 



The distribution of heavy metals in the sediments, such as copper, 

 chromium, lead, nickel and zinc, as determined by the SHL, covers an 

 area larger than the dumping grounds. (Fig. 28, 29, 30, 31, 32). Heavy 

 metal content of the sediments in and around the dumping grounds was 

 significantly increased as compared to nonpolluted sediments, and as 

 previously determined by the SUNY study (Gross, 1971). Discrepancies 

 in the ranges of heavy metal concentrations, as determined by SHL and 

 SUNY, even though within the same general area, are attributed primarily 

 to differences in points of sampling, which indicate geographic varia- 

 tion, and to a lesser extent to differences in analytical techniques. 

 High values of heavy metals in the sediments, (SHL, 1972) along the upper 

 part of the Hudson Canyon, south of the dumping grounds, indicate that a 

 transport mechanism is in operation. 



Analysis for heavy metals in organisms, by SHL, showed that some 

 specimens contained concentrations of lead, chromium and mercury that 

 were above the normal range for marine animals. These metals were also 

 found in the water in higher concentrations (SHL, 1972). 



e. Organic Fraction . Sewer sludges, from treatment plants in New 

 York City and New Jersey, dumped in the Bight, are rich in organic 

 material (Table 10) . Total loss-on-ignition ranges from about 46 to 

 80 percent of the dry weight of the material. Oxidizable carbon content 

 ranges from 18 to 26 percent. The remaining non-organic fraction of 

 the sludges is composed of aluminosilicate materials which are chemically 

 similar to shale (Gross, 1970). 



A large percentage of the organic fraction of sewage sludge dumped in 

 the N.Y. Bight is composed of water soluble acids and sugars. (Gluturic 

 acid, glycolic acid, lactic acid, citric acid, benzoic acid, phenyl 

 lactic, glucose, sucrose, lactose, etc.) (Walter, 1961). Another large 

 fraction of organic material is relatively insoluble, and will remain in 

 suspension or will be included in the bottom sediments until final de- 

 composition. This group may contain proteins, certain carbohydrates, 

 fats, esters, and unidentified organic components. The percent total 

 carbon composition of suspended solid material in sewage is shown in 

 Table 11. 



The material dredged from the New York harbor and disposed at the 

 dredge dumping grounds consists primarily of silicate material, and 



67 



