The components of sewage effluents are, as always, -diverse in response to inputs. 

 Nutrients in many forms are present and so are trace metals, synthetic organic com- 

 pounds, chlorine, detergents, particulate materials, and unnumbered other minor 

 components. Washington, a residential and office-related city, produces at least 6 

 metric tons of phosphorus and 10 metric tons of nitrogen per day, but there are rela- 

 tively few metals or other constituents of industrial origin (Schubel, 1972). Baltimore 

 and the Norfolk area release larger relative quantities of nonnutrient chemicals. 



The effects and management alternatives for some of these materials have been 

 studied in the Chesapeake Bay region. Sewage sludges may not be deposited over- 

 board in the system, and the potential alternatives of landfill, incineration, spraying 

 for agricultural use, drying or composting with wood chips for land application, use 

 as fuel, and dumping at sea have all been explored. Some are used, but no economi- 

 cally accepted and environmentally satisfactory method or set of methods for 

 dealing with increasing quantities on a long-term basis has been found for the large 

 population centers. The effects of sewage sludges on estuarine and freshwater fish 

 have been summarized (Tsai, 1975). 



Bacteria and viruses are introduced from septic tank overflow, overloaded treat- 

 ment systems, and co-mingled sewage and surface water, usually during heavy rain- 

 fall. In the Chesapeake, the states maintain routine monitoring of shellfish beds, 

 swimming beaches, and other sites by standardized coliform-based techniques 

 supplemented by other testing. The area of shellfish beds closed because of exces- 

 sive coliform counts has declined from about 385,000 acres in 1970 to about 240,000 

 acres in 1980; Maryland reduced its closure areas from 320,000 acres to 70,000 acres 

 in that period (Garreis, 1980 and Wiley, 1980). Lowered numbers indicate both 

 improvement in preventing contamination and reduction in the impact on the 

 shellfish industry. The standard indicator techniques are recognized to be useful for 

 some purposes, although both scientists and health officials recognize their 

 substantial limitations (Colwell, 1977; Colwell and Kapper, 1978). 



Recent research has partially documented the presence of potential human patho- 

 gens in the estuary, apparently from sewage sources (Colwell, 1977). Fecal coliforms 

 can be very abundant, 24,000/ 100 ml of water, in Baltimore Harbor; Salmonella is 

 frequently associated with fecal coliform organisms and is widespread, especially 

 near cities. Clostridium botulinum, the agent of botulism, has been found at random 

 sites over the Bay in sediments. Enteroviruses have received attention, but their signi- 

 ficance in the Bay is not established. Many antibiotic-resistant bacteria have been 

 observed in samples from shellfish and water. Fish have yielded preliminary evidence 

 of contamination and possible infection by human pathogens near areas of sewer 

 outfalls (Janssen and Meyers, 1968). 



The principal impression from review is that, while efforts are made to protect 

 human health, understanding of bacteria and viruses in the Chesapeake Bay is primi- 

 tive and inadequate, both for those from sewage and those endemic to the system 

 that play extremely important roles in the processes of the Bay (Colwell, 1977; 

 Cronin et al., 1977). There are dangers in that situation. 



Nutrients 



The effects of nutrients on the Bay system and the costs of wise management of 

 them present some of the most pervasive, complex, and perplexing of pollution 

 problems. Nutrients arise from natural decay and runoff, from industrial activities, 

 from disturbed land used for agriculture or development, and from sewage treatment 

 plants. The present and potential effects of excessive enrichment have frequently 

 been cited as a "major" problem or "the most serious" problem threatening the 

 health and usefulness of the Bay system (Cronin, L., 1967; Cronin, L., et al., 1977; 

 Federal Water Pollution Control Administration, 1969; McKewen, 1972; Perkinson 

 et al., 1973; Pritchard, 1971; Schubel, 1972). 



The national and global literature on nutrients is vast, and a large number of 

 surveys, monitoring observations, research projects, and analyses have been 

 completed in the Chesapeake Bay region (Champ, 1977; Corps of Engineers, 1974; 



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