Register your cooling towers or warm-water systems

Building owners or occupiers must notify us of this equipment installed and operated.


Project Status: When you need to do this

What you need to do

Regulated water system registration applicationPDF · 93.78 KB · Last modified

Before you start

  1. For information on the NSW Health requirements or to access standard forms, templates and fact sheets, please visit NSW Health: Legionella control.
  2. Attend one of our free workshops if you operate a water-cooling system in the local area. The course is an excellent resource on controlling Legionella in cooling towers and how to maintain cooling tower systems. It also covers complying with the regulation requirements and preventing the spread of Legionella. Contact us for upcoming event dates.

Other information


  1. If we identify non-compliance with the requirements for regulated systems under the Public Health Act 2010, our authorised officers can order building occupiers/owners to comply with the requirements.
  2. Our officers can also conduct inspections of premises on which regulated systems are located and charge fees.
  3. Failure to comply with the requirements under the act can result in legal notices, orders, penalty infringements (fines), and/or legal proceedings against a building occupier or owner.

Regulatory changes to the management of water-cooling systems

The requirements to install, operate and maintain cooling water systems in NSW are found in:

  • Public Health Act 2010
  • Public Health Regulation 2012 (as amended)
  • Australian Standard AS/NSZ 3666 – 2011 Air-handling and water systems of buildings – Microbial control. The regulation was amended on 10 August 2018 to provide a performance-based, risk management approach to prevent Legionella bacteria in water cooling systems.

From 10 August 2018, building owners and occupiers must ensure the following requirements are complied with:

  1. A competent person (defined in Public Health Regulation 2012) must undertake a risk assessment of the cooling water system and document it in a risk management plan, at least every 5 years (more frequently if required, or for higher risk systems).
  2. A competent person prepares a certificate confirming the risk management plan has been completed, which must be submitted to the City of Sydney within 7 days of completing the risk assessment.
  3. Compliance with the risk management plan and Public Health Regulation 2012 must be independently audited and documented in an audit certificate, which is to be submitted to the City of Sydney every year.
  4. Monthly sampling and testing of the system for Legionella and heterotrophic colony count must be undertaken.
  5. High test results for Legionella (≥1000 cfu/mL) and heterotrophic colony count (≥5,000,000 cfu/mL) must be reported to the City of Sydney within 24 hours of receiving the results.
  6. Unique identification numbers for cooling towers must be displayed on all cooling towers. Please note, while the City of Sydney allocates the unique identification numbers, we do not specify which tower these are to be placed on. This is for the competent person to decide and advise on behalf of the owner/occupier and document it in the risk management plan.