QEHSHealth
Legionella Risk Assessment
Assessment and control of Legionella bacteria in water systems.
Legionella pneumophila thrives in water at 20–45 °C, especially in stagnant, scale-laden systems. Risk sites: cooling towers, hot water systems, decorative fountains, dental units. Control: maintain hot water >60 °C, cold <20 °C, regular disinfection, and routine sampling. In the UK, HSE ACoP L8 and HTM 04-01 are the standards. CDC MMWR guidance applies in the US.