276 



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 abate- 

 ment facilites. 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 

 polluted by the municipal wastes of the Washington metropolitan 

 area. Nowhere is there such a clear example of the effects of massive 

 municipal waste discharges on an estuary. During the low flow periods 

 of the warm summer months, dissolved oxygen levels approach zero in 

 some reaches, being kept from total depletion by heavy production 

 from large algae growths. The effects of these waste discharges are 

 measurable along 20 miles of the river (IV-5-9). 



James River^ Va. 



Another example of sewage wastes in an estuarine system is the 

 James River in Virginia (figure IV.5.28) . The James River is the most 

 southerly major tributary of the Chesapeake Bay. It is approximately 

 400 miles in length and varies in width from 5 miles at the mouth to 

 less than 0.1 mile in its upper extremities. The river is tidal from its 

 mouth to the city of Richmond, a distance of 90 nautical miles. The 

 freshwater-saltwater interface migrates between river mile 24 and 60, 

 depending on tide and river flow conditions. 



Richmond, Va., is the major waste source on the upper James. 

 Wastes from this city have caused an over enrichment of the upper 

 river section which has resulted in nuisance growths of algae typical 

 of polluted water. The saline sections of the river have not reflected 

 hyperfertilization and are in the transitional stages. 



However, brief flareups of nuisance biological growths have oc- 

 curred and its appears that these nuisance conditions will remain for 

 longer periods of time until a noxious stability is reached (IV-5-10). 



Upper Bwcayne Bay^ Fla. 



This is one of the man bays on the Florida coast in which the shal- 

 low depths allow light penetration sufficient for the growth of sub- 

 merged vegetation (such as grasses) and algae. Among the impacts 

 of raw sewage discharges into such systems are the limitation of light 

 penetration due to suspended solids and the settling of organic mate- 

 rial to the bottom. Both of these impacts affect the submerged vegeta- 

 tion and algae. 



Upper Biscayne Bay is located between Miami and Miami Beach. 

 It is nonuniform in width (2 to 4 nautical miles) and is approximately 

 6 nautical miles in length. The Miami River enters the southwest 

 portion of the bay (fi^. IV.5.29). The total number sewage outfalls 

 entering upper Biscayne Bay was 70. The Miami River, carrying the 

 sewage from 29 outfalls, was the major pollutant source. It is estimated 

 that 30 to 50 million gallons per day raw sewage flows into the bay. 



Kinds of fixed vegetation divided the bay into two major zones. 



