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Water Hazards

Question #

W5.2 — Legionella Bacteria Control Management


Is a Legionella Bacteria Control Management Program in place at the building?


Applicable to all buildings (systems or equipment in the owner or landlord’s control)


Yes or No


Legionella risk management is important to provide a safe environment for employees and visitors to your facility and in preventing the bacteria that causes Legionnaires’ disease.


    1. Develop a building-specific Legionella Bacteria Control Management compliant with ASHRAE 188 “Legionellosis: Risk Management for Building Water Systems” and Public Works and Government Services Canada’s “Control of Legionella in Mechanical Systems”
    2. The program must cover the following:
      • Responsible parties, including the building team’s training Requirements
      • Analysis of building water systems and water system flow diagrams. The following systems must be considered for Legionella susceptibility, at a minimum:
        • Cooling towers and evaporative condensers
        • Aerosol-generating misters, atomizers, humidifiers
        • Hot and cold water systems
        • Domestic hot water storage tanks
        • Open-air systems (such as decorative fountains)
        • Whirlpool Spas
        • Building-specific water sampling protocol
        • Control measures, monitoring and corrective actions
    3. Demonstrate that the program was developed by a person competent in Legionella mitigation measures
    4. Program must be signed by building manager, dated within the past 12 months.


    5. The owner or landlord must provide information to the Tenant Representative(s) that manage(s) water use within the tenant space on how to implement a Legionella Bacteria Control Management Program


    • Building-Specific Legionella Bacteria Control Management Program OR evidence that Program was shared with Tenant Representative(s)

Adapted BB3 Question

Question 05.01.01 — Is a Legionella Bacteria Control Management Program in place at the building?

Suggested Lead

In-house, with third-party support




Other Notes

    • Only having a legionella management plan for a specific system (e.g. cooling towers) is not sufficient to meet Requirements. The plan should cover all applicable water-using systems in the building.
    • The building’s water systems should be described in the form of a flow diagram to assist in analyzing the areas of risk and determining sampling locations. Where necessary, control measures, such as preventative maintenance, inspections and water treatment should be implemented. These control measures must be monitored to ensure they are effective (for example, through routine sampling activities and checking temperatures of hot water once a month)
    • Risk analysis and monitoring of control measures must be documented and kept current. At a minimum, the program must be reviewed every 12 months to ensure risks associated with legionella susceptible systems are mitigated

Water treatment in HVAC equipment must, at all times, meet local provincial and/or federal guidelines and regulations.


5 Points