The effect of natural water temperature variation on the monitoring and regulation of thermal discharge impacts : the role of predictive natural temperature models

Pollution control policies have been an outgrowth of increased awareness that measures must be taken to handle the increasing amounts of wastes and by-products of human activity. A particular problem in the policies is how to address wastes that have large natural variations due to natural sources and changing environmental conditions. This is especially true for the control of thermal discharges from steam-electric generating facilities into large bodies of water also influenced by solar heating and inflows of water from natural sources. The basis for most pollution control policies in the United States is the set of regulations specifying ambient and effluent standards. A major problem with ambient temperature standards indicated by two case studies of large thermal discharges, is the variability in induced and natural conditions which affect facility siting, design, and operation, and verification of compliance.