U.S. Department of Energy - Energy Efficiency and Renewable Energy

Federal Energy Management Program – Operations and Maintenance

Cooling Tower Safety Issues

Warm water in the cooling system is a natural habitat and breeding grounds for microorganisms. Chemical treatment is required to eliminate this biological growth. Several acceptable biocides are available from water treatment companies for this purpose. Cooling towers must be thoroughly cleaned on a periodic basis to minimize bacterial growth. Unclean cooling towers promote growth of potentially infectious bacteria, including Legionella Pneumophilia. This bacteria produces the deadly Legionnaire's disease. Legionella may be found in water droplets from cooling towers, which may become airborne and become a serious health hazard if inhaled by a human. The lung is a warm and moist environment, which presents perfect conditions for the growth of such a disease. Common symptoms on patients with legionnaires disease are cough, chills, and fever. In addition, muscle aches, headache, tiredness, loss of appetite, and, occasionally, diarrhea can also be present. Laboratory tests may show decreased function of the kidneys. Chest X-rays often show pneumonia.