276 



Further, it is certain that the establishment of such a 

 definition would be a complex policy process and that the 

 definition would be revised with evolving knowledge and changing 

 economic and social circumstances. 



Because the necessary endpoints have not been defined, and 

 because technical difficulties impede its assessment, 

 assimilative capacity is, at present, a concept with only 

 qualitative usefullness. Therefore, it is inappropriate to 

 speculate what rate of waste inputs may be judged as having 

 exceeded some presently undefined effect level. However, in the 

 future it is important to note that contaminant concentrations, 

 at least for metals, are known to be in an appropriate dynamic, 

 steady-state equilibrium between inputs ^nd removal. This ig^ 

 evidenced by the fact that trace metal distributions in 

 sediments of the New York Bight apex have not changed 

 significantly over a recent five year period (NOAA 1981) or for 

 over a decade based on early measurements (NYC 1983a). Further, 

 no accretion of sediments in the Bight apex, other than dredged 

 materials, has been observed after decades of ocean dumping and 

 discharge. Also, it should be noted that the quantities of 

 PCBs and trace metals introduced into the Bight apex in sewage 

 sludge appear to have decreased in recent years despite some 

 increase in the volumes of sludge ocean disposed. If the 

 present contaminant input rate continues, it is reasonable to 

 assume that this state of dynamic equilibrium will also continue 

 and the contaminant concentrations in the New York Bight apex 

 will not increase. 



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