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For comparison with their sediment budget, Bopp et al . (1981) 

 calculated an input of PCBs to the Bight from sewage sludge 

 dumping. Assuming an ar .1 input of approximately 0.2 million 

 metric tons of sludge solids per year, at an average dry weight 

 concentration of 3.5 ppm (from a single sample collected from 

 New York City's Wards Island plant around 1976 or 1977), Bopp et 

 al. (1981) calculated an annual input of 700 kg of PCBs/year. 

 The City's consultant used the best data available in mid-1982 

 to estimate that New York City disposes approximately 91,000 

 metric tons of sludge solids per year ( it was later determined 

 to be 84,140 metric tons in 1982). At dry weight concentrations 

 ranging from 0.556 ppm to 2.82 ppm at the City's 12 treatment 

 plants, the total PCB load from the twelve plants was estimated 

 to be 140 kg/year. Due to a lack of PCB data from the other 

 municipal permittees using the 12-Mile Site, it was assumed that 

 the average concentration of PCBs in sludges from other 

 permittees using the site was the same as the average for New 

 York City's plants, and, therefore, it was estimated that the 

 total PCB load from the other permittees was 167 kg/year. The 

 cumulative PCB load from all current 12-Mile Site permittees is, 

 accordingly, estimated to be 307 kg/year. This cumulative load 

 is based on a total solids load of 199,000 metric tons/year (or 

 approximately 0.2 million metric tons/year). Therefore, only 

 the PCB concentrations used by the City's consultant differ 

 significantly from the estimates used by Bopp et al . (1981). 

 As would be expected with the rapid decline in the use of PCBs 



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