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Legionellosis and the role of agencies

12 August 2005: The information on legionellosis below was jointly developed by the Department of Building and Housing, Department of Labour and the Ministry of Health.

Legionella bacteria can be found in both water and soil in the New Zealand environment and are associated with two diseases, Legionnaires Disease and Pontiac Fever. Legionella bacteria can proliferate in man-made environments, including cooling towers. It is not contagious and outbreaks are localised. To prevent the growth of the organism, cooling towers must be treated and tested regularly.

There are a number of formal mechanisms to ensure that testing for legionella bacteria takes place on a regular basis. Some are governed by the Building Act, others by the Health Act. This information sheet provides background on testing for legionella bacteria under the Building Act and the roles of a number of agencies.

Department of Building and Housing

The Department of Building and Housing has a regulatory role in ensuring that buildings are safe and healthy under the Building Act. The Building Act sets the framework to ensure this. For buildings with cooling towers, provisions include:

  • building warrant of fitness regime
  • offence provisions
  • local authorities setting policies on dangerous and insanitary buildings.
  • The New Zealand Building Code Handbook requires monthly testing for legionella bacteria in water cooling towers.

Department of Labour

The role of the Department of Labour is to assess a workplace’s ability to understand and manage hazards which may arise in their day-to-day work. The Department works with businesses to promote compliance with health and safety legislation, establish health and safety controls around work processes, and educate on managing hazards. In the event of an outbreak of legionnaires disease, the lead agency in charge of the investigation is Public Health.

If a workplace is identified as being a possible source of legionella bacteria, the Department of Labour will work with Public Health and other agencies such as territorial local authorities to investigate specific risks in the workplace which may have contributed to the growth of the bacteria.

In serious cases, action may be taken under the Health and Safety in Employment Act to improve the health and safety of the workplace, prohibit dangerous activities or to prosecute.

Ministry of Health and Public Health Services

In New Zealand, legionellosis is a notifiable disease. A doctor is required to notify the Medical Officer of Health at the Public Health Service if he/she suspects a patient suffers from, or is diagnosed with legionellosis.

The Public Health Service will investigate by interviewing the patient and/ or their relatives to find out any risk features or exposures the patient has had. For a single case, such exposures may include exposure to soil or potting mix, or the hot water system in the person's home. When there is more than one case in an area, the Public Health Service will look for their exposures in common, such as visiting a building with cooling towers or visiting areas where there have been earth works.

The Public Health Service will take samples to test for legionella bacteria in these sources and may make recommedations if there are any health risks identified. The Ministry of Health will assist the Public Health Service by providing technical advice, if necessary.

Standards New Zealand

In April 2004 a more rigorous testing regime for cooling towers was introduced (NZS 3666.3). It increased the frequency of testing for legionella bacteria from six-monthly to monthly tests. This assists building owners to demonstrate their buildings’ compliance to the New Zealand Building Code and to demonstrate their ongoing compliance to councils.

Territorial authorities (councils)

Councils are required to follow the regulations established under the Building Act to ensure buildings are safe and healthy. They administer and enforce the building warrant of fitness regime. This identifies safety systems and features present in a building (such as sprinkler systems, lifts or cooling towers), the performance standards for those systems, and how they will be monitored and maintained to ensure they continue to function safely.

Building owners

Building owners are responsible for ensuring their buildings are properly maintained to comply with the building warrant of fitness. A building warrant of fitness is a statement supplied by the building owner to the council confirming that safety systems have been maintained and checked in accordance with requirements issued by the territorial authority.

Building owners must provide their building warrant of fitness annually to the council along with copies of inspection forms and any recommendations made by the inspecting ‘IQP’ (an independent qualified person) approved by the territorial authority.

If building owners do not comply with a notice from the territorial authority to comply with their building warrant of fitness, they could be fined up to $200,000 and in the case of a continuing offence, a further fine not exceeding $20,000 for day or part day during which the offence is continued.