Cooling towers are one of the highest-risk water systems for Legionella bacteria in the UK. They have been linked to some of the country's most serious Legionnaires' disease outbreaks and remain a primary focus for the Health and Safety Executive (HSE). If you operate, manage, or are responsible for a cooling tower, understanding your legal duties is not optional, it is a matter of public safety.

This guide covers the key questions operators ask: how cooling towers cause Legionella, what the testing requirements are, what the relevant guidelines say, and what the data tells us about the scale of the risk.