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Information for Property Owners and Facility Maintenance Operators

What causes Legionellosis?

Poorly maintained water systems such as the following have been linked to outbreaks of illness caused by Legionella bacteria:

  • Cooling towers
  • Hot water systems
  • Showers
  • Spas such as hydro-massage tubs
  • Fountains
  • Waterfall systems

During the summer of 2012, there was an increase in the number of Legionella related illnesses in Ontario

Maintain Your Water Systems

In the interest of preventing the spread of Legionella bacteria, please ensure the following recommendations are incorporated into your regular maintenance schedule for the water systems in your building/facility:

  • Follow equipment manufacturer maintenance instructions for the operation of atmospheric cooling towers, hot water systems and hydro-massage tubs
  • Use precaution when shutting down to ensure safeguards are in place
  • Ensure proper cleaning of the equipment prior to re-start
  • Respond to adverse situations such as: 
    • Changes in the functioning of the equipment
    • BuildingExternal influences such as nearby construction and high dust occurrences with cooling towers

Industry Standards

Regular maintenance of water systems in accordance with industry standards can prevent outbreaks of disease caused by Legionella bacteria. The ASHRAE and CTI documents below provide information and guidance to property owners and facility maintenance operators to reduce the risk of Legionella contamination in building water systems: