For many years electric power plants were allowed to be built which used vast amounts of water to cool the mechanisms driving the huge turbines generating power. One byproduct was heated water returned to a river, itself a regulated effluent becauses most fish don't tolerate such increases to water temperature. On the front end, the intake structures at some plants also consumed large amounts of larvae or juvenile fish unable to escape. The whole problem was regulated very poorly, basically by a single paragraph of the Clean Water Act. This presentation describes the problem of "cooling water intake structures" just as it was being reviewed by US EPA. Today such new structures are basically regulated out of existence in favor of larger cooling towers which act like radiators to cool and recirculate intake water.

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