133 



megawatt range, with a combined capacity of nearly 35,000 megawatts 

 of electrical power. While the bulk of these will be in the cooler parts 

 of the Nation, 12 will be in the South Atlantic, Gulf, and Caribbean 

 regions. In these regions water temperatures are high, greater volumes 

 must be used to achieve proper cooling, and the increase in water 

 temperature through the powerplant may be sufficient to cause en- 

 vironmental damage. 



In addition to water temperature, there are other environmental re- 

 quirements and problems associated with the use of estuarine waters 

 for cooling. The potential user must have access to the water, and the 

 water ideally should have a low suspended load to reduce maintenance 

 on the cooling system. A major problem is that use of the brackish 

 waters can be accompanied by large growth of mollusks and other 

 clogging organisms which can result in costly maintenance and repairs. 



WATER POWER GENERATION 



Many schemes have been promulgated to harness the energy of the 

 tides for the generation of electric power. In the Passamaquoddy arm 

 of the Bay of Fundy and in some parts of Cook Inlet, Alaska, the tide 

 range is in excess of 25 feet. If the vast amount of energy involved in 

 the water movement could be harnessed, a tremendous power source 

 would become available. Unfortunately, tidal electric plants cannot 

 compete economically with the fossil -fueled or nuclear thermoelectric 

 plants. Even more important, power generation peaks would vary with 

 tide fluctations, not consumer demands. It appears there is very little 

 potential for economic development of tidal power. 



WASTE DISPOSAL 



The concentration of population and industrial development in the 

 estuarine zone has led naturally to the use of estuarine waters for re- 

 moval of the waste materials of man's oi\dlization from his immediate 

 vicinity. It is unlikely that cities were built on the coastline with any 

 conscious consideration of the use of the estuarine environment for 

 waste disposal, yet it has happened that this use has become one of the 

 major uses of estuarine waters and the associated land. Virtually all 

 of the cities and industries in the coastal counties dispose of wastes 

 either directly or indirectly into the estuarine zone. 



Liquid waste discharges to estuarine systems include domestic waste 

 products, industrial waste materials of all degrees of chemical complex- 

 ity and sophistication, used cooling water with its thermal load, and 

 storm runoff. These wastes affect the estuarine environment in different 

 ways and can eliminate other benefical uses (fig. IV.2.20). 



Liquid wastes are not the only concern. The use of the estuarine 

 shoreline for refuse dumps and land fills results in considerable debris 

 getting into the water (fig. IV.2.21). Water leaching through these 

 dumps has a pollutional impact on the estuarine water. Spoil disposal 

 from dredging activities is another form of solid waste material that 

 contributes to estuarine degradation (fi^. IV.2.22). Solid materials 

 entering the estuary in the form of debris from storm runoff can be 

 significant in terms of damaging beneficial uses. 



The impact of waste disposal on the estuarine environment will be 



