Closer Monitoring For Legionnaires Disease Cause
Building Industry Authority
4 July 2003
Closer Monitoring For Cause Of Legionnaires Disease
New rules for testing for the Legionella bacteria have been approved for all new commercial buildings by the Building Industry Authority (BIA), the body responsible for managing the New Zealand Building Code.
Legionella bacteria can be found in both water and soil in the New Zealand environment and is associated with two diseases, Legionnaires’ disease and Pontiac Fever. The Legionella bacteria can proliferate in man-made environments, in particular cooling towers. To prevent the growth of the organism, cooling tower water must be treated and tested regularly.
A new guidance document for territorial authorities changes the testing regime for cooling towers installed in air conditioning systems.
The new, more rigorous testing regime is based on the current Australian-New Zealand Standard, AS/NZS 3666.3. It expands on the current requirement of a monthly bacteriological testing of water in cooling towers, by also requiring a specific Legionella bacteria test each month. This was previously required six monthly.
The BIA will advise territorial authorities of the new compliance schedule shortly. It will come into force in the next few months and will apply to all new air conditioning systems. Although it is not a retrospective requirement, i.e. does not apply to existing buildings, the BIA is suggesting building owners and territorial authorities adopt the new testing regime for all cooling towers.
The Auckland City Council, which had a recent case of Legionnaires disease reported in its region, has welcomed the new rules. The Council's Principal Building Officer Bob de Leur said, “the new rules will provide a greater measure of protection associated with the air conditioning of buildings.”
“We see the increased testing requirement as another positive step to tighten up building controls to ensure the health and safety of building users,” he said. He stressed the need for building owners to recognize the importance of regular maintenance of all building features, not only air conditioning.