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Let’s Break it Down: Legionnaires, Legionella, Risks, Symptoms, Water Treatment, Disease, & Bacteria

Updated: Jul 3

Source: CDC (link)

Do the words Legionnaires or Legionella sound familiar? If you are a building operator, owner, or contractor that provides building maintenance, the looming risks are something you should familiarize yourself with, along with how to prevent or treat cooling towers and other breeding sources. Let’s walk you through what you need to know.

What is the difference between Legionnaires and Legionella?

Legionnaires Disease is a pneumonia-like illness (lung infection) caused by Legionella bacteria through droplets in the air or swallowing water containing Legionella. Legionella can also cause Pontiac Fever but is less severe than Legionnaires. The first recorded outbreak of Legionella was in 1976, and the latest figures show 10,000 cases reported in 2018 according to the CDC. The CDC also estimates that 1 in 10 people who get sick from Legionnaires will die. It does not tend to pass from person to person. Read more CDC Fast Facts here:

Legionella Threats in Buildings

For commercial buildings, cooling towers are your primary concern when it comes to Legionella bacteria in water or Legionella risk. Open vs closed loop piping systems can also play a role in Legionella risk. The CDC outlines a toolkit for you here:

Legionella Bacteria Prevention and Treatment

Regular monitoring and maintenance, especially during warmer months, is necessary to prevent Legionella bacteria from proliferating. Additionally, proper water treatment with the right balance of chemicals and cycling keeps water from stagnation and prevents hospitable breeding grounds for the bacteria. Proper system chemistry will also prevent problems such as scale, corrosion, and other harmful biological growths. Treatment will involve online remedial treatment, online disinfection, offline cleaning and disinfection, and emergency cleaning and disinfection. A regular maintenance agreement will check water levels to ensure the designed solution is effective and continues to perform accordingly.

Don’t risk it! Give us a call at (240) 306-3000 for a free on-site assessment and quote or complete the form below.


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