Sets out control strategies suitable for the management of legionnaires’ disease health risk from the cooling tower water systems of power stations connected to the national or regional grids used to supply electricity for public consumption.

This Standard sets out control strategies suitable for the management of legionnaires’ disease health risk from the cooling tower water systems of power stations connected to the national or regional grids used to supply electricity for public consumption. It applies to the cooling tower water systems associated with - (a) condensing systems of steam-driven turbines driving electricity generators; and(b) main power station auxiliary plant, such as coal pulverizing mills and turbine plant heat exchangers, where - (i) a chemical dosing regime is applied to maintain the cleanliness of those systems and is demonstrably effective in the control of concentrations of Legionella bacteria; and(ii) shutdown for cleaning of those systems would require total or partial shutdown of electricity generation by the power station, which may not be practicable.The approach to management of legionnaires’ disease health risk set out in this Standard is based on the principles and generic process set out in AS/NZS 4360. This approach involves setting the context, identifying risks, and then evaluating treating and monitoring risks, and ensuring that the information is communicated effectively.This Standard is not applicable to associated power station site services such as air-conditioning systems of buildings, or other relatively smaller cooling tower water systems in power stations that can be taken out of service without affecting electricity generation. The AS/NZS 3666 series of Standards applies to microbial control in these systems.NOTE: This Standard does not prohibit the operation of associated site services that use condenser water from a main power generation cooling tower.

First published as AS 5059-2003.Second edition 2006.Reconfirmed 2016. Originated as AS 5059-2003. Second edition 2006.