Water cooling systems, also known as cooling towers, are often found on the roof of buildings. They cool warm air from an air conditioner by passing the air through an aerated chamber. The warm air can create a favourable environment for the growth of Legionella and other bacteria.
Council regulates water cooling systems under the Public Health Act 1991 and the Public Health (Microbial Control) Regulation 2000. These systems must also comply with AS /NZS 3666.2: 1995 and AS /NZS 3666.3: 2000. Council does not regulate air conditioners and hot water cylinders under this legislation.
The owners of premises are required to notify Council within one month of the purchase of a premises which has one of these systems or within one month of the installation of one of these systems. The owner or occupier of the premises must ensure that regular maintenance is carried out and that records of such maintenance are kept on the premises. Owners/occupiers are required to provide certification that the cooling tower complies with the disinfection requirements of the Australian standards.
Cooling System FAQ
How do I know if I have a cooling tower or warm water system on my premises?
Ask the landlord or company that services the air system. Do not attempt to access the roof to identify your cooling system unless you are equipped to do so, as this may be dangerous. Identifying a system is not easy unless you are a specialist in this field.
What is Legionella?
Legionella is a bacteria, and there are several species of Legionella that can cause pneumonia. The bacteria Legionella pneumophila is known to exist in air cooling towers.
What is the source of infection of Legionella?
Infection may also be contracted from warm water systems, free standing room humidifiers and communal spas.
What are symptoms of the disease?
Symptoms of the disease include headache, fever, cough, chest pain, diarrhoea, breathlessness and disorientation.
How can Legionella be controlled?
Legionella bacteria multiply rapidly at their preferred temperatures of 20°C – 45°C, which means that warm water systems, cooling towers and air conditioners are favourable for the growth of these pathogens. The growth of legionella bacteria may be prevented by sufficient cleaning, disinfection and maintenance of such systems.
When choosing a cooling tower, consideration should be given to how easily it can be cleaned and maintained and whether it meets the requirements of the relevant Australian Standards.