cooling  tower

Water-cooling systems, air-handling systems, and hot and warm-water systems are known as "regulated systems" under the Public Health Act 2010 and Public Health Regulation 2012 legislation.

Regulated systems can provide an environment for Legionnaire’s disease and there are obligations that apply to building owners/occupiers and Council to prevent the spread of this disease in our community.

What is Legionnaires' disease?

Legionnaires' disease is a form of pneumonia and is a result of an infection of the lung caused by the Legionella bacteria. The disease is caused by breathing in aerosols which contain Legionella bacteria. This bacteria is present in low levels in the environment, but can grow rapidly to dangerous levels in cooling towers and in warm water systems.

Legionella growth can be controlled by proper water treatment procedures and regular cleaning.

Regulated system operation requirements

Building owners and occupiers are responsible for ensuring that the regulated system is installed, maintained and operated in accordance with legislation and Australian Standards AS/NZS 3666.2:2011 and AS/NZS 3666.3:2011 and Code of Practice. The system must also be registered with Council.

To safely maintain regulated systems, building owners or occupiers must arrange for a “duly qualified” person (who has expertise in the field, such as a tertiary qualified chemist, chemical engineer or microbiologist) to.

  • demonstrate the disinfection process used adequately controls microbial growth
  • inspect the system every month and clean it every 6 months
  • undertake regular microbiological water testing
  • ensure operation and maintenance manuals are on-hand including start-up and shut- down procedures, decontamination procedures and relevant contact persons
  • ensure a log book details all work carried out and includes details of checks and servicing performed
  • certify the system each year.

Only "duly qualified" contractors can be engaged to install, operate and maintain regulated systems. The Office of Fair Trading licenses contractors who undertake this work.

All regulated 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.

Building occupiers who fail to meet minimal requirements are liable to enforcement action and heavy fines.

Building occupiers also have a duty to ensure that access to the system for inspection and maintenance is safe and meets Safe Work Australia requirements. Should an inspection be unable to be undertaken by Council Officers due to unsafe access, inspection fees may still apply.

Visit the Safework website for more information.

Design and construction

Location of air intakes should be carefully planned. They should be placed well away from exhaust discharges and cooling-towers to avoid cross-contamination. They should also be away from pedestrian areas. All air intakes should be above the ground to make sure that dust, rain and small animals don't get into them.

Ductwork should be graded to prevent water collection and should be thoroughly cleaned before the system begins operating.

Installation of a water cooling system or hospital warm water system must be notified to local government authorities, so that a local register of systems can be kept up to date.

Regulated systems must be registered with Council

Use the below notification form to register and provide updates on your regulated system

Regulated Premises Registration form

There is no fee for notification in the Muswellbrook local government area.

Email the completed form to This email address is being protected from spambots. You need JavaScript enabled to view it. or drop it off at the Council Administration Centre during business hours.

Council inspections of regulated systems

Authorised officers conduct routine inspections on regulated systems from November to February each year to coincide with peak months of use. Investigative inspections may also be conducted outside of peak periods where required.

The purpose of the inspection is to ensure that all systems comply with legislative requirements under the Public Health Act 2010 and Public Health Regulation 2012 and do not cause a risk to public health.

Where non-compliance is found, appropriate enforcement action can be issued under the Public Health Act 2010.

The degree of the enforcement depends on the severity of the non-compliance.

An inspection fee as prescribed by Council’s adopted Fees and Charges and is applicable for each inspection undertaken. Additional sampling fees may also be incurred.

Legislation changes

NSW Health has been developing amendments to the Public Health Regulation 2012 in relation to the control of Legionnaires' disease in water-cooling systems. The amendments will be implemented in stages.

The first of two amendments to the Regulation commenced 01 January 2018.

NSW Health Legionella control regulatory changes related to monthly testing article

More information

NSW Health's Code of Practice for the Control of Legionnaires' Disease (currently under review)

NSW Health Legionella control

Australian Standard AS/NZS 3666 "Air Handling and Water Systems of Buildings - Microbial Control”

This standard is in three parts and is the main standard governing Legionella control. It is available from Standards Australia website, alternativley call 1300 65 46 46 or fax: 1300 65 49 49.

You can view a copy of this Standard at Muswellbrook Shire Council’s Administration Building however due to copyright laws, Council are unable to loan you the document.

In NSW call 1300 066 055 to talk to your local Public Health Unit.

Alternatively, you can contact Council’s Planning and Regulations team by calling 6549 3700 or by emailing This email address is being protected from spambots. You need JavaScript enabled to view it..

Sample Inspection Checklist

Cooling Tower and Warm-Water Systems Management Plan

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