Cooling Water Systems

What is a cooling water system?

A cooling water system is a device that lowers the temperature of the water or other liquids by the process of evaporative cooling or an evaporative condenser that has an incorporated device containing either a refrigerant or heat exchanger.

Legionaries Disease can be associated with contaminated water including cooling tower water systems and spas, with most of Australia's outbreaks being linked to cooling towers.

Due to this link, water cooling towers need to be equipped with a disinfection process that aims to control the microbial growth of Legionnaire's disease. The disinfection processes must:

  • Be in operation at all times
  • Be certified by a qualified person annually as being an effective disinfection process
  • Be running in an effective manner to ensure that no test sample is taken from the tower that produces a test result with a Legionella count of more than 10 colony-forming units per millilitre, or a heterotrophic plate count of more than 100,000 colony-forming units per millilitre.

Along with the disinfection process, each tower needs to have an up to date manual. Each manual needs to include:

  • Physical details of the tower, equipment and systems
  • Information on maintenance and water treatment management
  • Cleaning, disinfection and emergency decontamination procedures
  • Operation and start up / shut down procedures
  • Details and dates of cleaning, services and microbial test conducted on the tower, and
  • Date, item of plant, equipment or system and nature of service performed including details on defects found or procedures undertaken

Under the Public Health Act 2010 and the Public Health Regulation 2012, we maintain a register of water cooling systems within the Local Government Area.

The owner of a property where a new cooling tower device is installed, is required to notify and provide information to Council on the device and install the device according to the AS/NZS 3666.1 1995. You must complete the Cooling Water Systems registration form(PDF, 169KB)

Guidelines on Legionella control

NSW Health has provided a document called NSW Guidelines for Legionella Control in Cooling Water Systems

The NSW Guidelines for Legionella Control in Cooling Water Systems provide guidance on the safe and effective management of cooling water systems for all stakeholders. The Guidelines provide practical guidance on the legal requirements in the Public Health Act 2010 and the Public Health Regulation 2012.

Download the Guidelines.

Warm Water System

Warm water systems, including thermostatic mixing valves (TMVs), may allow the growth and transmission of Legionella bacteria and are a regulated system under the Public Health Regulation 2012.

The NSW Health Policy Directive: Water - Requirements for the provision of cold and heated water [PD2015_008]  contains requirements for the provision of cold and heated water to be observed by care facilities, as defined in the Public Health Act 2010, to manage the risk of Legionella and to prevent scalding.

Occupiers are responsible for ensuring that their local government authority is notified of an installation or change in particulars of a warm water system. You must complete a Warm Water System registration form(PDF, 109KB) .

For more information contact Council's Environmental Health on (02) 9839 6055 or