Evaporative cooling towers and condensers can present a significant Legionella risk because warm recirculating water, extensive wetted surfaces and aerosol generation can support growth and dissemination when controls fail. Subject to the definitions and exceptions in the Notification of Cooling Towers and Evaporative Condensers Regulations 1992, relevant installations must be notified to the local authority. HSG274 Part 1 provides technical guidance for managing the risk. An effective programme addresses microbiological control, scale, corrosion, fouling, safe operation and system cleanliness. Treatment should be selected for the system design, operating conditions, make-up water, construction materials and environmental constraints rather than copied from another site. The written scheme should define dosing, bleed control, monitoring, inspections, cleaning, shutdown, recommissioning and remedial actions. HSG274 Part 1 states that biocide effectiveness should be monitored weekly, conventionally by suitable microbial dip slides, and that specific Legionella sampling should be carried out at least quarterly, with more frequent checks where circumstances require them. Inspection and cleaning frequencies should follow the risk assessment, plant condition and current guidance. Records must be reviewed for trends and failures, not simply collected.