Re-Opening Buildings And The Increased Risk Of Legionnaires’ Disease

Experts are warning of a new threat related to the Covid-19 outbreak that directly affects building owners and puts building occupants at further risk. Buildings that have been left empty or sat vacant are at an increased risk for one of the deadliest waterborne diseases in America, legionnaires’ disease. 

Legionnaires’ disease is a respiratory illness caused by the inhalation of water droplets containing bacteria. Experts warn that water which has sat in pipes for 21 days or longer is at an increased risk for the bacterial growth that causes this disease. 

Water and Disinfectants

Water delivered from a municipality will typically have small amounts of a disinfectant (usually chlorine) which protects the water from bacteria growth. Unfortunately, these disinfectants wear off over time as water sits in pipes unused.  With no disinfectant in the water, this creates a prime environment for bacterial growth that can have some serious consequences. 

Prevention of this disease is almost always tied to good maintenance of water systems. As a building owner or maintenance manager it is more important now than ever to take precautions to protect the health of your building occupants. 

What is Legionnaires’ Disease?

Legionnaires’ disease is a severe form of pneumonia and has a death rate of 1 in 10 according to the cdc. The disease is most commonly spreads through cooling towers, hot tubs, showers, faucets and water features.  Adults over the age of 50 and people with chronic lung conditions or a weakened immune system are most vulnerable to this disease. 

Sound familiar? 

Legionnaires’ Disease and Covid-19

The other scary part about this disease is that the symptoms are very similar to Covid-19. The most common symptoms of Legionnaires’ disease are: 


-Shortness Of Breath

-Muscle Aches


-High Fever

Because of how similar the symptoms are compared to Covid-19 this can create confusion and may result in an incorrect diagnosis.  That is why it is even more important to ensure building owners are doing safety checks before opening again. 

What Steps Should You Take? 

Before you resume operation, you will want to be sure to test the disinfect level in the water to ensure they are within acceptable ranges.

Note: There may be additional disinfecting steps that need to be evaluated by an expert if the water tested is not within acceptable ranges.

If you are close to 21 days of inactivity, you may also want to consider flushing any pipes that  have old stagnant water and cleaning cooling towers with disinfectants. Because this is spread through water droplets, it is important to wear a mask and gloves while performing these duties. Here is an example of measures taken to prevent stagnation in an unoccupied floor published by the CDC:  

CDC Example

For the complete guide on how to prevent this disease check out the CDC’s Toolkit on how to prevent the spread in buildings here. 

Need Help?

The CDC recommends that you work with health, academic and industry partners to develop and evaluate guidelines and standards to prevent this disease. Be careful when reopening your buildings and take precautions to ensure you and your tenants are safe. If there is anything we can do to help don’t hesitate to reach out by calling 1-800-237-3141 or by contacting us on our website