Hospital acquired Legionnaires’ disease appears to be increasing and the presence of Legionella in hospital drinking water is the main risk factor, known with certainty to be predictive of risk for contracting Legionnaires’ disease. To date the majority of health care facility Legionella cases have been linked back to the potable water supply, not cooling towers.

The national Guidelines for Legionella control in the operation and maintenance of water distribution systems in health and aged care facilities were released in late 2015. The 45-page document addresses the issue in detail. If you’re working in this area, there are a number of things you should know about how the guidelines change the previous approach:

1. The national guidelines were developed due to potable water having been found to be the environmental source of nearly all reported cases of hospital outbreaks of Legionnaires’ disease.


Hospital acquired Legionnaires’ disease has been reported from many hospitals since the first outbreak in 1976. Although cooling towers were linked to the cases of Legionnaires’ disease in the years after its discovery, potable water has been the environmental source for almost all reported hospital outbreaks of Legionnaires’ disease. Hospital acquired Legionellosis has a high mortality rate reported up to 40%.

2. The high profile Legionnaires’ outbreak caused by the plumbing system at Wesley hospital in 2013 was the final impetus for the development of the Australian national guidelines.

There are up to approximately 400-500 cases of Legionnaires’ disease reported each year in Australia. Confirmed nosocomial cases of Legionnaires’ from both hospitals and aged care facilities have occurred across all states. In Australia this has led to substantial litigation in some cases and disruption to the normal operations of these health facilities. The Wesley Hospital outbreak in 2013 resulted in the death of one 65-year-old patient and protracted intensive care for one 45-year-old patient. The hospital was closed to new admissions and was only fully opened four weeks later. The source of the Legionella was the potable cold water. It was recognised that there were no regulations or standards either in Queensland or nationally.

3. The national guidelines were developed to provide health and aged care CEOs, hospital engineers, infectious disease specialists and facility managers with best practice guidance on how to prevent and respond to this risk.

The guidelines are aimed at facility managers and teams assembled to manage Legionella risk to help them develop a risk management plan. Most states require a risk management plan be developed by health and aged care facilities to manage their Legionella risk.

4. The Guidelines were developed by the National Environmental Health Standing Committee (enHealth) and ratified by the Australian Health Protection Principal Committee.

Each state’s regulatory framework was enacted prior to the release of the national guidelines. The national guidelines sit over each state’s regulatory framework providing “best practice” non-prescriptive guidance. enHealth’s membership includes the Commonwealth, State and Territory health departments, New Zealand Ministry of Health and the National Health and Medical Research Council. The committee has consulted with experts in the field both internationally and from within Australia across government agencies and other stakeholders.

The Australian Health Protection Principal Committee coordinates the national approach to the prevention and response to communicable disease, public health emergencies and environmental threats to public health. It is chaired by the Australian Chief Medical Officer and each state’ and territories’ Chief Health Officer.

5. The guidelines apply to all water distribution systems in health and aged care facilities, with the exception of cooling towers.


The guidelines require not only warm water systems, but cold and hot water systems and all components of the system which can expose patients, be assessed and managed as a risk. Health and aged care facilities are high risk for Legionnaires’ disease. The clinical profile of patients and residents mean many are susceptible to contracting disease if exposed to Legionella, and water distribution systems provide ideal conditions for the growth of Legionella (variable incoming water quality, warm water, aging plumbing systems & water storage) in close proximity to these vulnerable patients.

6. Managers of facilities have a duty of care to develop a risk management plan that has detailed written procedures for controlling risk and monitoring programs.

Risks vary between locations and facilities, hence a systematic analysis of the site must be performed to develop a risk management plan with control measures that can be appropriately and effectively targeted.

7. You need a multidisciplinary team of suitably experienced and qualified people to develop a holistic, cohesive approach to managing your risk.

External expertise should be sought from water quality specialists, environmental health officers, infectious disease specialists, plumbers, and water treatment service providers.

8. You need to implement prevention strategies to reduce risk, rather than just testing for Legionella and taking remedial action to disinfect.

The guidelines stipulate a multi-barrier approach to the reduction of risk should be taken. A multi-barrier approach is a series of controls to reduce or remove the hazard or likelihood of a hazardous event. If one control fails (e.g. temperature) there will be another backup control to prevent the hazardous event of Legionella growth (e.g. residual disinfectant) or exposure (Point of Use filtration in high clinical risk settings).

9. Prevention strategies are more cost-effective in the long run for health facilities, rather than responding with remedial actions after positive Legionella detections.

The cornerstone to a multi-barrier approach is an effective residual disinfectant program designed with a series of controls such as flushing, temperature control, filtration and meticulous monitoring.

10. Want to know more? A complete summary of the guidelines can be downloaded below.

The 8 page PDF summarises the report allowing you to quickly understand the critical areas of the guideline that you must be aware of.

Words of advice


Many risk management plans provided by consultants only identify what the hazards and hazardous events are at a site and possible risk management measures. They do not provide a detailed site plan, with detailed procedures for operational controls.

Facilities vary in their size, the complexity of the water distribution network, and the risk to the occupants, so risk management plans must be tailored to the individual facility based on a thorough understanding of the site and the clinical profile of occupants.

HydroChem can assist you at all stages, assessing your risk and developing detailed procedures and implementing water treatment to mitigate your risk. We pride ourselves on providing practical solutions that are cost-effective and safe.

If you have any queries or require assistance in preventing Legionella outbreaks at your facility, contact Nick Duncan to find out how we can help with Legionella Detection and Risk Management.

Nick Duncan | Director
Mobile: 0411 121 848

  • Download our 8 page summary

    Access our free 8 page downloadable summary of the new guidelines for Legionella control