Legionella Bacteria Control and Management Plans for Workplace Safety

September 4, 2025

Legionella poses a significant risk to occupant and worker safety. Do you have a Legionella Bacteria Control and Management Plan in place to protect your buildings and their occupants?

In some jurisdictions, Legionella is already recognized as a specific workplace hazard and Legionella Bacteria Control and Management Plans (LBCMPs) or similar plans are required by Occupational Health and Safety regulations. In most parts of Canada, OHS regulations require employers to assess and control biological hazards, which include Legionella.

Legionella bacteria can result in Legionnaires Disease, a severe form of pneumonia that can result in multi-organ failure. Legionnaires Disease has a case fatality rate of 5%-10%, which increases to 25% to 40% in healthcare associated cases and in immunocompromised cases. Legionnaires Disease has an increased risk of infection for people over the age of 50, with a higher risk of sever outcomes for children, people over 70, and people with underlying conditions. Importantly, there is an occupational risk for operations and maintenance staff who work with cooling towers, industrial water systems, and pools and spas.

Employers can protect workers by assessing their water‐ and HVAC‐systems for potential Legionella risk as part of a broader biological-hazard assessment, controlling exposure through engineering and administrative measures, and documenting relevant inspections and corrective actions. Engineers with experience in and knowledge of ASHRAE Standard 188 and CSA Z816 can help employers and building owners apply these risk mitigation measures by developing a building-specific LBCMP. Healthcare facilities, long-term care facilities, and hotels are often at higher risks of Legionella bacteria contamination, but all building types and workplaces can take steps to protect occupants and staff from the associated health risks.

An LCBMP provides building owners and operators with documentation and tools to protect building staff and occupants from the effects of Legionella and a program to monitor and assess the risk of Legionella in building systems on an ongoing basis.

The Government of Canada Standard MD 15161 provides guidelines for developing LBCMPs. These guidelines are informed by ASHRAE Standard 188 and CSA Z816. Building Engineers can work with you to ensure that your standard operating procedures and OHS plans include an engineer-sealed LBCMP that meets these standards.

To develop an LBCMP, our Engineers will review all susceptible water systems in the building and document and inventory key water systems with greatest potential for Legionella amplification. These can include cooling towers, decorative fountains and waterfalls, humidifiers and misters, and domestic water systems. Once inventoried, the Engineer will develop a single line diagram, including water sampling locations, of each susceptible system.

The Engineer will compile or develop standard operating procedures, procedures and manuals for maintenance, protocols for maintenance and testing of water quality, maintenance logs and records, as well as all forms and information supplied by building staff.

LBCMPs need to be assessed and updated every five years, or if there is a major change in procedures or equipment, a change in procedures for maintaining water quality, or a need for decontamination when water quality reaches action levels.

Legionella can cause chronic and even fatal health issues, including respiratory failure, septic shock, and multi-organ dysfunction. Preventative maintenance in your building can protect occupants against these serious health risks.

 

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