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estuarine system and result in gradual undesirable changes in the 

 ecosystem in addition to direct habitat damage. 



Sources of Pollution 



Nearly all of man's activities can result in environmental degrada- 

 tion. Pollutants and polluting conditions are very rarely unique to 

 a particular use or specific activity, but may result from man's 

 existence in the estuarine zone as well as his use of it. The major 

 sources of pollution are these: 



(1) Those sources associated with the extent of development 

 of the estuarine zone, including waste discharges from 

 municipalities and industries, and land runoff from these 



as well as agriculture; 



(2) Those sources associated with particular activities of 

 great pollutional significance, specifically dredging and 

 filling, watercraft operation, underwater mining, and heated 

 effluent discharges; 



(3) External sources having impact derived through flow 

 regulation and upstream water quality. 



Over eight billion gallons of municipal wastes are discharged daily 

 into the waters of the estuarine zone. While most of this volume is 

 domestic sewage, many municipal waste discharges also contain signif- 

 icant amounts of industrial wastes, which may add to the variability 

 and complexity of the wastes discharged. Municipal waste discharges 



