Legionnaires’ Disease Prevention Checklist

Legionnaires’ Disease Prevention Checklist

Building & Facility Management
• Develop a Water Management Plan (CDC/ASHRAE guidelines).
• Maintain hot water storage tanks ≥ 60 °C (140 °F). Deliver hot water to outlets ≥ 50 °C (122 °F).
• Prevent stagnation by flushing outlets, removing dead-end pipes, and draining storage tanks.
• Maintain adequate chlorine or other disinfection; test water regularly.

Cooling Towers & Large Water Systems
• Clean and disinfect cooling towers at least twice per year.
• Remove scale, biofilm, and sediment.
• Monitor pH, disinfectant residuals, and bacterial counts.
• Maintain drift eliminators to reduce aerosol spread.

Hot Tubs, Pools & Spas
• Maintain free chlorine at 2–4 ppm (CDC guidance).
• Monitor and adjust chemical balance daily.
• Operate spas at ≤ 40 °C (104 °F).
• Drain weekly; scrub surfaces to remove biofilm before refilling.

Homeowners
• Set water heaters to ≥ 60 °C (140 °F); flush annually to remove sediment.
• Flush infrequently used fixtures until hot.
• Clean showerheads and faucets regularly (vinegar or mild disinfectant).
• Empty, dry, and clean portable humidifiers daily; use distilled water.

Personal Risk Reduction
• High-risk individuals (older age, smokers, immunocompromised) should avoid:
• • Sitting close to decorative fountains or misters.
• • Using poorly maintained hot tubs.
• • Exposure to aerosolized water in questionable facilities.