New South Wales and Victoria
Cooling towers and Legionella in NSW and Victoria
In New South Wales, the occupier of the premises gives notice that a cooling water system is installed, then has it risk-assessed and audited, and has its water sampled at least once a month and tested for Legionella. In Victoria, the owner of the land keeps the cooling tower system registered with the Secretary while it is in operation, and whoever owns, manages or controls it has a sample tested for Legionella at least once every 3 months.
General information, not legal advice. NSW: the Public Health Act 2010 and the Public Health Regulation 2022, in the versions current from 1 September and 1 August 2026. Victoria: the Public Health and Wellbeing Act 2008 (authorised version 071) and its Regulations of 2019 (authorised version 029). Only these two states are covered here, and the laws themselves are linked at the foot of the page.
In Victoria, the monthly sample is for the heterotrophic colony count; Legionella is tested at least once every 3 months.
Notified in one state, registered in the other
In New South Wales the word is notice. Section 31 of the Public Health Act says “The occupier of premises at which a cooling water system or warm-water system is installed must cause notice of that fact to be given”: within one month after becoming the occupier if the system was already there, or within one month after it is installed. The maximum penalty is 10 penalty units. The notice goes in writing, with the fee the local government authority (the council for the area) sets, to that authority, and any change to it is notified within 7 days.
In Victoria the word is registration, and it sits with the owner of the land. The system must be registered with the Secretary for as long as it is in operation, which lasts until it has been decommissioned or removed and the Secretary has been notified; the maximum penalty is 120 penalty units for a natural person and 600 for a body corporate. Each registration or renewal runs for no more than 3 years, and the fee is counted per tower: 7.5 fee units for one year, 14 for two and 20.5 for three, under regulation 64 as amended to 1 July 2026.
Who carries the duty
In NSW it is the occupier of the premises, for the notice, for installing, operating and maintaining the system to the prescribed requirements, and for the clocks below; the Act gives the occupier a defence where a duly qualified person was engaged to do the work.
Victoria splits it. The owner of the land must keep the system registered, and must take all reasonable steps to make sure its risk management plan exists, is reviewed and is audited by an approved auditor. The testing falls to the responsible person, meaning anyone who owns, manages or controls the system, so a manager can carry it while someone else owns the land.
The NSW calendar
| When | What falls due |
|---|---|
| Before it starts operating | The first risk assessment, by or under a competent person, rating the system low, medium or high risk; the council is told within 7 days after each assessment. |
| At least every 12 months, or every 5 years | A new risk assessment: every 12 months if high risk, every 5 years if low or medium risk, and within 30 days if there is reason to believe the latest is no longer valid. |
| At least once a month | Samples taken by a duly qualified person and tested for Legionella and heterotrophic colony count, an inspection and chemical analysis, and a report to the occupier. |
| Within 24 hours | Reportable test results go to the council after the occupier receives them. |
| Each 12-month audit period | An audit by an auditor the Secretary has approved, finished within 2 months after the period ends, and the council told within 7 days after. |
| Within 30 days of the council’s notice | The council’s identification number on a durable sign on each tower, at least 148mm by 210mm (A5 size). |
| Within 4 hours of a request | Records kept electronically, made available for an authorised officer to inspect, and contact details for each duly qualified person who installed, operated or maintained the system, and each competent person who provided services for it, in the last 5 years. The 4 hours is for electronic records; records kept on the premises are made available for inspection on an authorised officer’s request. |
Reportable results are Legionella “greater than or equal to 1,000 colony-forming units per millilitre”, or a heterotrophic colony count “greater than or equal to 5 million colony-forming units per millilitre”.
The Victorian calendar
| When | What falls due |
|---|---|
| At least once each month | A service to check it runs without defects, and a sample to a laboratory for the heterotrophic colony count. |
| At least once every 3 months | A sample to a laboratory to test for Legionella. |
| At most 6 months apart | A chlorine-compatible bio-dispersant added, the water disinfected, each tower cleaned inside, and the water disinfected again; also before first use and after a shutdown of over a month. |
| Within 24 hours | Once told of a Legionella detection by a laboratory report or the Secretary: the water disinfected, the water treatment, operation and maintenance programs reviewed, faults corrected and changes made to stop them happening again. Notice to the Secretary of a result above 1000 colony forming units per millilitre of Legionella, or of 3 detections in a row. |
| Each 12-month period, and annually | The owner of the land must take all reasonable steps to have the risk management plan reviewed, and updated if necessary, at least once in each 12-month period, and audited annually by an approved auditor. |
The Regulations’ maintenance and testing duties do not apply to a system that is shut down or otherwise not in use.
Two numbers that are easy to swap. In NSW, water is tested for Legionella every month. In Victoria, the monthly sample is for the heterotrophic colony count, and Legionella is tested at least once every 3 months. NSW reports 1,000 or more colony-forming units per millilitre to the council; Victoria’s notice to the Secretary starts above 1000.
One line on other systems: in NSW, warm-water systems are exempt from this part of the Act except in hospitals.