Legionella is a type of bacteria that causes a type of pneumonia called Legionellosis, also known as Legionnaires' disease. Legionella are sometimes found in cooling water systems and warm water systems. These systems are at optimum temperatures for the bacteria to reproduce, between from 20-45ºC.

Legionella is transmitted by inhaling mist from these systems. It is not spread through person-to-person contact. Owners and operators of high risk manufactured water systems are responsible for the control of Legionella.

Controlling Legionella

Microbiological water testing can determine the presence of Legionella.

You must notify Council if your test results in:

• 1000 or more colony forming units of Legionella per millilitre of water in their cooling tower and/or
• 10 or more colony forming units of Legionella per millilitre of water in their warm water system

Complete the Notification of Legionella in Water Sample form within 24 hours of receipt of your results.

An Environmental Health Officer will contact you with next steps.

Guidelines for water systems

Cooling water systems and warm water systems must be operated and maintained in accordance with:

• South Australian Public Health (Legionella) Regulations 2013
• Guidelines for the Control of Legionella
• Australian and New Zealand Standards (AS/NZS 3666)

Following these guidelines is essential in maintaining:

• correct commissioning/decommissioning procedures
• decontamination procedures
• setup, plans, manuals, maintenance, log books and record keeping

Building owners are also required to register all high risk manufactured water systems with Council and renew them annually.

Register Cool Water/Warm Water Systems
Register Decomissioning or Removal of High Risk Water Systems

More information 

Read the South Australian Public Health (Legionella) Regulations 2013.

Department of Health
Environmental Services Branch
8226 7100