New Cooling Tower Management Regulations for NSW

October 5, 2018

Significant new requirements for the management of cooling towers are now in place in NSW. The amended Public Health Regulation requires a performance-based risk management approach to managing cooling water systems. This approach allows each system to be managed according to its risk of Legionella contamination.

From 10 August 2018, building occupiers are required to ensure that there are six key safeguards in place for their cooling water systems:

1. Risk assessment of Legionella contamination, documented in a Risk Management Plan (RMP) – every five years (or more frequently if required)

2. Independent auditing of compliance with the RMP and Regulation – every year

3. Providing certificates of RMP completion and audit completion to the local government authority

4. Sampling and testing for Legionella and heterotrophic colony count – every month

5. Notifying reportable laboratory test results (Legionella count ≥1000 CFU/mL or heterotrophic colony count ≥5,000,000 CFU/mL) to the local government authority

6. Displaying unique identification numbers on all cooling towers.

The requirements for building occupiers to test for Legionella bacteria on a monthly basis and notify high ‘reportable test results’ to their local government authority commenced on January 1, 2018.

The Occupier is defined in the NSW Public Health Act 2010 as:

  • The owner of the premises that contains the water-cooling system or
  • The person entitled to occupy the premises (such as a leaseholder) or
  • The owner’s corporation under a strata scheme.

For each water-cooling system it is important that the Occupier be clearly identified and understand the new responsibilities.


The test sampling must be carried out by a Duly Qualified Person. This is a person who might reasonably be expected to be competent to install, operate or maintain a water-cooling system and can include people who work for water treatment companies, mechanical services companies, and other industry organisations that manage water-cooling systems on a day to day basis.

Samples must be tested by a laboratory accredited by the National Association of Testing Authorities (NATA). Test results can be provided to the Duly Qualified Person on behalf of the Occupier, to the Occupier, or the local government authority depending on contractual arrangements.

High HCC and or Legionella Test Results

The Regulation requires the water-cooling system to be operated to ensure Legionella counts and HCC remain below threshold levels.

  • Legionellafor results greater than 10 CFU/mL a remedial action must be taken as soon as practicable.
  • HCC – for results greater than 100,000 CFU/mL a remedial action must be taken as soon as practicable.

A Legionella count greater than 1000 CFU/mL and a HCC greater than 5,000,000 CFU/mL must be notified to the local government authority for that area within 24 hours.

Risk Management Plans

The Regulation requires a Competent Person to undertake an effective risk assessment, to identify and document in a Risk Management Plan measures to limit the growth and transmission of Legionella bacteria. The assessment should:

  • Assess the five risk categories and underlying risk factors for Legionella growth and transmission
  • Assign an overall risk rating of low, medium, or high risk to the system
  • Set requirements for system management based on the identified risks.

The first risk assessments under the amended Regulation will be completed in phases. Local government authorities will allocate systems in their area to a due date of 30 November 2018, 31 March 2019, or 30 June 2019.

The Occupier must ensure that an audit is carried out by an Independent Auditor for each 12-month period, with no gaps between periods.

For further information go to the NSW Department of Health website.

For advice or assistance, please contact
Gary Whatling
Manager (NSW/ACT), A.G. Coombs Advisory
P: +61 3 9248 2700  |  E.

download pdf

For more information

Contact Us

Loading ratings...

Latest Advisory Notes

July 27, 2021 in Advisory Notes

Operational Analytics and Facility Outcomes

Over the last 10 years we have seen the emergence of automated analytics in just about every aspect of our daily lives. This includes the use of analy...