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In preparing estimates of current PCB inputs to the apex, the 

 City's consultant reviewed and evaluated the Bopp et al . (1981) 

 paper and the data presented by Swanson et al . (1982) which was 

 attributed to O'Connor et al . (in press). Bopp et al . (1981) 

 did not prepare a mass balance of PCB inputs from all sources to 

 the New Yor)^ Bight, as might be implied by Swanson et al . 

 (1982). Most notably, they did not prepare an estimate of PCB 

 inputs from the Hudson River discharge. Rather, they prepared 

 an estimate of PCB loadings from the disposal of "recent fine 

 grained sediments" dredged from the harbor annually (which is 

 only a small fraction of the total annual dredged material load) 

 as part of a sediment PCB budget for the entire Hudson River. 

 Bopp et al. (1981) estimated an annual . transport of 1,860 kg_Df 

 PCBs to the New York Bight from dredged material dumping, 

 assuming that 0.62 million metric tons of fine-grained sediments 

 are dredged annually (Gross 1974) at an average concentration of 

 3 ppm PCBs. The City's consultant estimates that an average of 

 4.6 million metric tons/year of dredged material (including the 

 recent fine-grained sediments) are currently dumped in the New 

 York Bight apex, at an average concentration of 1 ppm PCBs. 

 This yields an estimated dredged material input of 4,600 kg 

 PCBs/year to the apex. The sources of the data forming the 

 basis for these estimates are detailed in Chapter 6 of New York 

 City's report supporting site designation dated March 9, 1983. 



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