Prescribed Legionella water tests

Verification monitoring can take whatever form is required to verify that your water risk management plan (WRMP) is effectively managing the risks associated with the presence of Legionella within your water distribution system.

However, for the purpose of notification and reporting under the water risk management provisions of the Public Health Act 2005 (the Act), only Legionella tests that meet the requirements of a “prescribed test” are required to be notified and reported to the Department of Health. 

This is to ensure that only confirmed results of viable Legionella from a prescribed test are reported to the regulator.

Scope

Under section 61A of the Act, a prescribed test must be used to test for Legionella bacteria in water samples.

The term “prescribed test” is defined under section 2Y of the Public Health Regulation 2005 (PDF, 658KB) and is used in sections 61H and 61I of the Act.

Requirements of a prescribed test

A prescribed test must:

  • use culture-based analysis, to quantify the number of Legionella colony forming units in the sample tested
  • be performed by an accredited testing laboratory and
  • be a test that is identified within the scope of the testing laboratory’s accreditation.

Accredited testing laboratory

An accredited testing laboratory is one that is accredited as complying with ISO/IEC 17025: General requirements for the competence of testing and calibration authorities.

ISO/IEC 17025 is an accreditation that is given to the testing laboratory by either:

  • the National Association of Testing Authorities (NATA) Australia (ABN 59 004 379 748) or
  • another entity the chief executive is satisfied is appropriately qualified to accredit a testing laboratory as complying with ISO/IEC 17025.

Specific test methods for Legionella

Currently, Legionella test methods developed by Standards Australia and the International Organisation for Standardisation such as AS/NZS 3896 (Waters – Examination for Legionella spp. including Legionella pneumophila), AS5132 (Waters – Examination for Legionella spp. including Legionella pneumophila – using concentration) and ISO 11731 (Water Quality – Enumeration of Legionella) are the standard culture-based Legionella methodologies used in Queensland.

However, other in-house laboratory Legionella testing methods may be used provided the method:

  • uses culture-based analysis to quantify the number of Legionella colony forming units grown on microbiological media; and
  • the particular in-house Legionella testing method used is identified within the scope of testing laboratory’s accreditation.

Resources

  • AS/NZS 3896:2017 Waters – Examination for Legionella spp. including Legionella pneumophila.
  • AS/NZS 5132:2017 Waters – Examination for Legionella spp. including Legionella pneumophila – using concentration.
  • ISO 11731 Water quality – Detection and enumeration of Legionella.
  • ISO/IEC 17025 General requirements for the competence of testing and calibration authorities.

Last updated: 5 October 2017