A typical 500-megawatt coal-fired power plant draws about 2.2 billion gallons of water each year from nearby water bodies, such as lakes, rivers, or oceans, to create steam for turning its turbines. This is enough water to support a city of approximately 250,000 people.

When this water is drawn into the power plant, 21 million fish eggs, fish larvae, and juvenile fish may also come along with it -- and that's the average for a single species in just one year. In addition, EPA estimates that up to 1.5 million adult fish a year may become trapped against the intake structures. Many of these fish are injured or die in the process.