IV-415 



contamination with human wastes, and the nutrient materials con- 

 tributed by municipal sewage systems have been sufficient to upset 

 the ecological balance in the system. 



In some portions of Arthur Kill and the Raritan River dissolved 

 oxygen values reach zero in summer conditions, and the western part 

 of Raritan Bay also has depleted dissolved oxygen. High photo- 

 synthetic production by algae counteract these effects in the larger 

 part of the Bay itself. 



Col i form bacteria counts are high throughout much of the Bay and 

 have forced the closing of some public bathing beaches; dye tracer 

 studies showed that unchlorinated human waste discharges from the 

 Upper Bay (New York Harbor) reached beaches on Staten Island within 

 six hours. In 1961 an outbreak of infectious hepatitis was traced 

 to raw shellfish taken from Raritan Bay in the areas within influence 

 of these human wastes. 



The investigations of the Raritan system have been in progress for 

 a sufficient length of time to document both the polluted conditions 

 and the beginning of recovery due to the construction of pollution 

 abatement facilities. Bacterial contamination still exists but the 

 biological community is recovering to form a more diversified and 

 stable aquatic population (IV-5-8). 



Potomac River, D. C, Md., Va. 



The head of the Potomac estuary near Washington, D. C, is severely 



