Management of cooling water systems in NSW

Cooling water systems must be managed safely in order to prevent the growth and transmission of Legionella bacteria.

In NSW the Public Health Act 2010 and the Public Health Regulation 2022 outlines the legal requirements to ensure public safety through the effective management of cooling water systems.

The Public Health Regulation 2022 (the Regulation) requires all cooling water systems to be managed according to AS/NZS 3666:3:2011 Air-handling and water systems of buildings - Microbial control - Performance-based maintenance of cooling water systems. This risk management approach requires the individual characteristics and unique risks of each cooling water system to be assessed and controlled by the building occupier (the occupier) to prevent Legionnaire's disease.

Further information is available from the fact sheet New Requirements for Managing Cooling Water Systems at a Glance.

What is Legionnaires disease?

Legionnaires disease is an illness caused by the inhalation of Legionella. Legionella is found in moist environments and becomes a problem when dispersed into the air as an aerosol. Water cooling systems that are used to cool the air in large buildings a required to be monitored to control the risks poised by Legionella.

Management of Cooling Water Systems

The information below outlines the requirements for the installation, operation and decommissioning of cooling water systems.

The occupier is ultimately responsible for ensuring the cooling water system/s are managed in accordance with the Public Health Act 2010 and the Regulation.

Further information is available from NSW's Health fact sheet on Management of Cooling Water Systems Throughout Their Lifecycle.

The occupier must notify Council of the new installation within 1 month by completed and submitting Form 6 Notification of Installation or Change in Particulars together with a site plan showing the location of the new system.

A risk assessment must be completed before a newly installed system starts operating. Further information on risk assessments and risk management plans is found below.

Unique Identification Numbers (UID)

When Council's Environmental Health team are notified of a new cooling water system, a unique identification number will be provided for each tower on the system.

The Regulation requires the UID to be displayed on a sign affixed to all cooling towers. The sign must be:

  • Minimum size of 148mm by 210mm (A5 size);
  • Clearly visible to a person examining or inspecting the cooling water system; and
  • made of a durable material.

The Public Health Regulation 2022 requires that occupiers to ensure that:

  • A competent person undertakes a risk assessment of the cooling water system every five years (or more frequently if required);
  • A competent person documents to risk assessment in an RMP and prepares a certificate of RMP completion; and
  • The certificate of RMP completion is provided to Council within 7 days of completing the risk assessment.

The frequency that a new risk assessment is undertaken of a system is determined by the competent person.

Other instances in which a new risk assessment shall be completed are:

  • The risk of the system has changed and the previous risk assessment is no longer valid. If so, a new risk assessment must be completed within 30 days of identifying the change in risk; and
  • An authorised officer notifies the occupier to complete a risk assessment. If so, a new risk assessment must be completed within 30 days of the notice being given.

Occupiers are required to ensure all cooling water systems are sampled and tested on a monthly basis for Legionella and heterotropic colony count (HCC).

If a reportable test result of Legionella count is ≥1,000 colony forming units per mililitre (cfu/mL) or HCC ≥5,000,000 cfu/mL is obtained, the occupier is responsible for notifying Council within 24 hours of receiving the result. The results must be provided by completing Form 4 Notification of reportable test result.

Audits of the Risk Management Plans are to be conducted on an annual basis. The occupier must engage an independent auditor to audit compliance with the RMP and Regulation.

The audit must be conducted within two months after the end of the 12 month audit period. The audit will include review of the following documents:

  • Current valid RMP for the cooling water systems;
  • Monthly reports (Form 3) which are completed by a Duly Qualified Person;
  • Records of actions required to be completed by the RMP during this audit period;
  • Records of actions taken to address non-compliance identified by previous audit; and
  • Records any any notifications made to Council.

A list of approved auditors can be found on the list of NSW Health approved auditors of cooling systems.

The occupier must submit the Certificate of Audit Completion to Council within 7 days of the completion of the audit. Council's EHOs will review the certificate of audit completion and will investigate systems that do not comply with the RMP and Regulation.

The occupier must notify Council of the decommissioning of a cooling water system within 7 days by completing Form 6 Notification of installation or change in particulars.

The NSW Health Guidelines provides practical guidance on the legal requirements in the Public Health Act 2010 and the Public Health Regulation 2022 and outlines effective management of cooling water systems for all stakeholders. Read the full guidelines.