Air toxics are those pollutants known or suspected of causing cancer or other serious health effects.
Industrial process cooling towers remove heat from chemical and industrial processes.
Specifically, water treatment chemicals, such as chromium, are added to cooling tower waters to protect equipment and piping from corrosion, and to control algae growth in the tower. Chromium emissions are released into the atmosphere from the cooling tower during the cooling process. The final rule will reduce emissions of chromium by approximately 25 tons annually, representing a 100 percent reduction from current levels. Hexavalent chromium is a potent human carcinogen and is known to cause lung cancer. Under the Clean Air Act Amendments of 1990, EPA is required to regulate emissions of 189 listed toxic air pollutants.