Water cooling systems, also known as cooling towers, are often found on the roofs 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.
What is Council’s obligation with water cooling towers
Council regulates water cooling systems under the Public Health Act 1991 and the Public Health (Microbial Control) Regulation 2000. Water cooling systems must also comply with AS /NZS 3666.2: 1995 and AS /NZS 3666.3: 2000, which can be obtained from the Australian Standards. Council is required to keep a register of all water-cooling and warm-water systems installed on premises in the Council area.
What does Council require from premises with water cooling towers
All water cooling systems are required to be equipped with an operating and maintenance manual. The manuals must include all details of inspections and servicing performed. Manuals and records must be kept on site. Council will inspect the operating and maintenance manuals as part of the annual inspection program.
It is your responsibility to ensure that council is provided with the necessary information.
What is Legionella
Legionella is a bacterium, and there are several species of Legionella that can cause pneumonia. The bacteria Legionella Pneumophila is known to exist in water cooling towers.
How can Legionella be controlled
Legionella bacteria multiply rapidly at their preferred temperatures of 20°C – 45°C, which means that 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.
What should I do if I own premises with a water cooling tower on the roof
The owners of premises are required to notify Council:
- within one month of the purchase of premises which has one of these systems
- within one month of the installation of one of these systems
The owner or occupier of the premises must also ensure:
- that regular maintenance is carried out and that records of such maintenance are kept on the premises
- certification is provided stating that the cooling tower complies with the disinfection requirements of the Australian Standards
How do I know if I have a water cooling tower on my premises
Ask the landlord or company that services the air conditioning 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.
Where can I get further information
Regulations and standards that apply can be found at NSW Department of Health or Standards Australia. General information regarding Legionella can be found at NSW Department of Health or by contacting Council’s Environmental Health Officers on (02) 6767 5555.