Environmental Legionella Control

The Public Health Act 2010 and the Public Health (Microbial Control) Regulation 2012 govern man made environments and systems which are conducive to the growth of Legionella organisms and which are capable, under the right conditions, of transmitting Legionella infections.

These regulated systems include:

  • cooling systems
  • hot water systems
  • warm water systems, and
  • air handling systems.

The Public Health Amendment (Legionella) Control) Regulation 2018 was introduced to strengthen the laws to require a performance based (or risk management) approach to managing cooling water systems.

The Regulation requires all cooling water systems to be managed according to Australian/New Zealand Standard (AS/NZS) 3666 Part 3 (2011 edition). This risk management approach requires the individual characteristics and unique risks of each cooling water system to be assessed and controlled.

The Regulation sets out six key requirements or “safeguards” as part of the risk management approach:

  1. assessing risk of Legionella contamination and preparing a Risk Management Plan (RMP) – every 5 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 ≥1,000 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.

Legionella infection and control (Pontiac Fever and Legionnaires disease)

Legionellosis results from infection by a group of bacteria named Legionella.  Many different species of Legionella are commonly found in the environment, some of which are known to cause illness in people.

Legionella pneumophila is commonly found in water and has been isolated from regulated systems such as hot water systems, water cooling towers, warm and cold water taps and showers.  The bacteria must be inhaled to cause disease.  Legionnaires’ disease occurs most commonly in warmer months.  Cigarette smoking, heavy alcohol use or stress increase an individual’s risk of contracting the disease.

On the North Coast, Environmental Health Officers (EHOs) undertake a program of sampling and monitoring these regulated systems that have the potential to harbour Legionella bacteria. EHOs also investigate cases in people who have contracted the disease and attempt to identify and rectify the likely source.

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