| Abstract: | Policies and pressures emanating from the 1972 Amendments to the Federal Water Pollution Control Act favor the installation of cooling towers, or closedcycle cooling systems, in power plants. An assessment of the relative risks of alternative cooling system designs indicates that, in general, adverse environmental effects associated with cooling towers are more certain, are of larger scale, and are more likely to be irreversible than impacts associated with once-through cooling systems and cooling reservoirs. Adverse environmental effects associated with once-through cooling and cooling reservoirs are largely amenable to mitigation in the context of resource management principles. These factors, together with the greater costs associated with cooling towers, indicate that wherever the feasibility is demonstrated and there is minimal risk to aquatic ecosystems, once-through cooling systems or cooling reservoirs should be preferred. |
