BC Update: No.28 - Legionella outbreak - information for building owners and managers
31 Aug 2005: Following the recent outbreak of legionellosis in Christchurch, the Department of Building and Housing reminds building owners and managers of their responsibilities under the Building Act in erms of maintaining a healthy and safe building.
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 breed in built environments, such as cooling towers. To prevent the growth of the bacteria, cooling towers must be treated and tested regularly. Legionnaires’ disease is not contagious and outbreaks are localised.
There are a number of formal mechanisms to ensure testing for legionella bacteria takes place on a regular basis.
The Building Act requires building owners with mechanical ventilation systems to have a compliance schedule issued by the territorial authority. The compliance schedule requires specific inspection, testing and reporting on mechanical ventilation systems, which includes air-conditioning cooling towers.
The model compliance schedule, published in the New Zealand Building Code Handbook as amended in April 2004, requires monthly testing for the presence of total bacteria and legionella bacteria. Legionella tests with results greater than or equal to 1000 cfu/ml should be notified within 48 hours to the local Medical Officer of Health at the Public Health Service of the District Health Board.
Territorial authorities are able to amend compliance schedules under the provision contained in the Building Act s107. For example, territorial authorities could now require all compliance schedules to include the current testing requirements for legionella contained in the Handbook.
A building warrant of fitness is supplied by the building owner to the council confirming that the mechanical ventilation systems have been maintained and checked in accordance with the compliance schedule, along with copies of inspection forms and any recommendations made by the inspecting IQP (independent qualified person).
If building owners do not comply with a notice to fix from the territorial authority to comply with the inspection, maintenance and reporting procedures stated in their compliance schedule, they could be fined up to $200,000. In the case of a continuing offence, a further fine not exceeding $20,000 exists for each day or part day during which the offence is continued.
Cooling towers outside of the building warrant of fitness, such as those associated with a manufacturing process, are covered under the Health and Safety in Employment Act 1992 administered by the Department of Labour and are expected to comply with AS/NZS 3666 Parts 1, 2 and 3.
An information sheet containing more information can be found on the Department’s website.