Warm water systems

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Controlling Legionella in warm water systems

"Managing the risk of Legionnaires’ disease due to warm water systems."

A copy of this draft document is available on the link below. If you have any questions, please contact the Legionella Section at 1800 248 898 or lrmp@dhs.vic.gov.au. Please note that it is approximately 100 pages in length.

Please note that, at this stage, the document is in draft form. For advice regarding the current regulatory requirements for warm water systems, please refer to Part 3 of the Health (Legionella) Regulations 2001.

Background

The Department of Human Services has developed this document to provide guidance in relation to the management of the risks of Legionella in the warm water systems within facilities such as hospitals, nursing homes and aged care facilities, where overnight accommodation is provided. Other facilities with warm water systems can still benefit from the information in the document.

Legionella can grow in warm water and warm water systems commonly found in commercial and public buildings, and there is substantial evidence that this has been the cause of cases of Legionnaires’ disease in other countries. Victoria’s experience, however, has been that, although Legionella has been detected in warm water systems, there has been no clear evidence linking the presence of the bacteria with cases of the disease in hospitals or aged care facilities.

Recently, however, a car wash with a warm water system was linked to several cases of Legionnaires’ disease.
This document recognises the weight of international evidence but balances this against the lack of evidence in Victoria and Australia and, in doing so, discusses a graduated process to managing the risks of Legionnaires’ disease due to warm water systems.

Download document

Controlling Legionella in warm water systems 2007: A guide for Victorian hospitals and aged care facilities (358kb, pdf)

Approved alternative disinfection methods for warm water systems

The Health (Legionella) Regulations 2001, under Regulation 17, require

The responsible person to ensure that the warm water system is disinfected by one or more of the following methods –

1. at least once each month by heat or chlorination; or
2. continuously by means of automatic low level chlorination; or
3. continuously by means of ultra-violet light treatment; or
4. a method approved in writing by the Secretary.

Under Regulation 17(d), additional methods of disinfection of warm water systems may be approved by the Secretary (or a delegate of the Secretary).

On 30 May 2007, three additional methods of disinfection in warm water systems were approved. Warm water systems can now be disinfected using the following methods:

1. continuously by means of chlorine dioxide treatment; or
2. continuously by means of copper-silver ionisation; or
3. continuously by means of chloramination.

Further information about each method of disinfection is available in the Controlling Legionella in warm water systems guide. If you wish to disinfect your warm water system using a different method, then you should first contact the Legionella Team on 1800 248 898 or via email at lrmp@dhs.vic.gov.au.