Effective Legionella control is a total management system that includes, but is not limited to, management of biocide, water temperatures, environmental
conditions and regular maintenance and cleaning. Components and equipment that require maintenance and cleaning include basins, fill pack, drift
eliminators and side stream filters. Twenty risk factors associated with cooling towers are listed in Australian Standard AS 3666.3:2000 Air Handling and
Water Systems of Buildings – Microbial Control – Performance based maintenance of cooling water systems. The conductivity level (or increasing cycles
of concentration) is only one factor that can influence Legionella control. All 20 factors must be considered in a cooling water management program. The
recommendations about cycles of concentration in this guide do not compromise effective Legionella control but will improve the efficient use of water and
Refer to these downloadable documents for further information.