COVID-19: Are you ready for the next normal?


Legionnaire’s Disease – Tools for Risk Mitigation

Legionnaire’s disease is a serious illness caused by the waterborne bacteria called Legionella. One way a person can become sick is by inhaling contaminated aerosolized water from improperly maintained building water systems.

In June 2015, ASHRAE published ASHRAE 188 – Legionellosis: Risk Management for Building Water Systems, which made Legionella water management programs a voluntary consensus standard for large buildings in the United States. According to the Centers for Disease Control and Prevention (CDC), to determine if your facility needs a water management program to reduce the risk of Legionella amplification and spread, answer the following questions:

  1. Is your building a healthcare facility where patients stay overnight or does your building house or treat people who have chronic and acute medical problems or weakened immune systems?
  2. Does your building primarily house people older than 65 years (like a retirement home or assisted living facility)?
  3. Does your building have multiple housing units and a centralized hot water system (like a hotel or high-rise apartment complex)?
  4. Does your building have more than 10 stores (including basement levels)?

If you answered “yes” to any of the questions above, the CDC recommends that you have a water management program for that building’s hot and cold water distribution systems.

Buildings with devices that can spread contaminated water droplets should have a water management program, even if the building itself does not. If you answered “no” to all of questions 1 – 4, but “yes” to any of questions 5 – 8, the CDC recommends that you have a Water Management Plan for that device.

  1. Does your building have a cooling tower?
  2. Does your building have a hot tub (also known as a spa) that is not drained between each use?
  3. Does your building have a decorative fountain?
  4. Does your building have a centrally-installed mister, atomizer, air washer, or humidifier?

If you answered “no” to questions 1 – 8, the CDC recommends that you should still maintain water systems according to manufacturer recommendations.

For more information about Legionella risk, creating or maintaining a Water Treatment Program, or other ways in order to reduce your risk of Legionella amplification in your building’s water systems, contact the experts at Cogency at