Cooling towers are used in many commercial buildings and factories for the purpose of comfort cooling and industrial process cooling. During the operation of a cooling tower, water aerosols are emitted from the top of the cooling tower, along with the exhaust air. These aerosols may contain biocides and other chemicals added to the cooling tower, as well as Legionella bacteria if the water in the cooling tower is not adequately maintained and disinfected. Similarly, water fountains could also generate water aerosols with undesirable chemicals and Legionella bacteria. With such contaminated water aerosols potentially coming into contact with the general public, they could possibly cause serious health issues such as Legionellosis infection.

Regulations and Code of Practice

Currently, the National Environment Agency (NEA) regulates the quality of water used in cooling towers and water fountains in Singapore, under the provisions of Environmental Public Health (Cooling Towers and Water Fountains) Regulations. These Regulations also outline certain preventive measures that are required to be put in place, such as cleaning, disinfection and regular testing of water in the cooling towers and water fountains.

Owners of cooling towers and occupiers of the premises where cooling towers are installed, are also advised to refer to the Code of Practice for the Control of Legionella Bacteria in Cooling Towers, which provides a set of guidelines for best practices in the design, location, maintenance and operation of cooling towers.