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The Dangers of Legionella: Assessing Safety Risks for Recently Opened Buildings

The NAR recently warned real estate agents about the risks of Legionella bacteria in recently-opened buildings. It’s a challenge that many property owners and real estate professionals haven’t had to face until this pandemic. But after being closed for many months as a result of COVID-19, some buildings are particularly vulnerable to this bacteria.

What is Legionella Bacteria and How is it Transmitted? 

Naturally, you’ll find Legionella in freshwater environments, such as lakes. But, it’s of grave concern if the bacteria starts to grow in man-made water systems, because it can be very dangerous to humans. Of particular concern are commercial buildings and buildings that use cooling towers and/or air conditioning units or heating units that use water. Legionella can also be found in hot tubs, showerheads, faucets, tanks, and other plumbing systems. 

Legionella can grow and multiply rapidly in a water system, and humans can become sick if they inhale droplets contaminated with the bacteria. It’s also possible, though somewhat rare, to get sick from drinking water which is contaminated with Legionella. There are two main illnesses arising from Legionella bacteria — Legionnaires’ Disease, a respiratory condition, and Pontiac Fever, which is a milder case of illness.  

Legionnaires’ disease presents in a similar way to pneumonia and typically requires hospitalization. Symptoms include shortness of breath, fever, dry cough, and muscle pain. It can be fatal, and the National Academies of Science, Engineering, and Medicine has stated the disease afflicts and kills more people in the US than any other reported waterborne disease. 

Pontiac Fever presents as a flu-like illness with symptoms such as headache, fever, and muscle aches. Most patients with Pontiac fever will recover with antibiotic medications. 

Cases of Legionnaires’ disease are generally found in industrialized settings. In New York, in 2015, there was a case where 138 cases of Legionnaires disease were traced back to a cooling tower in the Bronx. 

How Can it Be Avoided? 

Empty buildings, where water has been sitting stagnant for a long period of time, are a potential breeding ground for Legionella bacteria. 

The CDC (Centers for Disease Control and Prevention) issued guidance in September for reopening buildings after a prolonged shutdown or reduced operation as a result of COVID-19. To ensure the safety of building occupants, they advise building owners should:

  • Develop a comprehensive water management program for all water systems and devices
  • Ensure water heaters are properly maintained and temperatures are correctly set
  • Flush water systems
  • Clean any decorative water features 
  • Ensure hot tubs/spas are safe 
  • Ensure cooling towers are well-maintained and clean
  • Ensure any safety equipment such as sprinkler systems are well-maintained and clean
  • Maintain water systems

For further information and guidance from the CDC, visit

Additionally, Purdue University’s Center for Plumbing Safety recently conducted a study into the water quality of water in low occupancy and shut down buildings. The study looked into various preventative measures. It also recommended that any future guidelines allow for tailored plans and actions to be developed for buildings as site-specific variations need to be considered.

What to Watch Out For As a Real Estate Agent

As a real estate agent, you may be dealing with a commercial property that has been shut down or used less due to the COVID-19 pandemic. You may also be dealing with condos and apartment buildings for which construction or final finishing has ceased for a period of time because of the pandemic. 

In any case, you need to be alert and cautious when faced with properties that use cooling towers and/or HVAC systems that use water, if they’ve been vacant or uninhabited for a long period. 

If unsure, ask the building owner these questions:

  • What safety measures are in place to prevent waterborne diseases? 
  • Do you have a building water management program/plan for this building?
  • What safety measures and testing procedures are in place?
  • When was the water system last tested and was any waterborne disease found?

Upon reopening, building owners should carry out a comprehensive assessment of all water systems of their premises before anyone is allowed to re-enter the building. As a real estate agent, it’s reasonable to ask if this has been done. 

Managing Your Risk

Real estate professionals should do a risk assessment before entering any potentially contaminated properties. For your own safety and the safety of your clients and others, ensure you have sufficient answers to the questions above before thinking about entering an at-risk property. If property owners can’t answer these questions, you might suggest they consult with a specialist water treatment company before selling or leasing their property. 

To minimize your risk of illness, wear a mask to prevent the inhalation of droplets contaminated with Legionella bacteria. Keep in mind that people with compromised immune systems and older people are particularly vulnerable to Legionnaires’ disease. 

Legionnaires’ disease is a potentially lethal illness, and real estate agents need to be aware of the potential dangers. Besides the obvious moral concerns about contributing to another person’s illness, if you show a property and a potential buyer falls ill, you may also find yourself facing a lawsuit.

If you are aware of any water quality issues, including waterborne disease or test results, you must disclose this information to any potential buyers. Failure to do so may see you being sued for failure to disclose. Anything that materially affects the value and/or desirability of a property and may influence the decision whether or not to purchase must be disclosed. 

If you have concerns about a building’s water systems safety, you can contact your local health department who may do further investigations to ensure a property is safe. 

Real estate agents face an increasing number of risks in their everyday business. Ensure you have sufficient insurance protection in case a claim is made against you. Contact CRES at 800-880-2747 for a confidential discussion about your insurance needs today.

CRES specializes in real estate Errors and Omissions insurance and has a team of expert legal professionals available 7 days a week to help you prevent claims before they become lawsuits. We can find you the best property management E&O insurance as well.

As part of one of the largest insurance brokers in the world, we have access to more E&O options to find you the best coverage at the best price.

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