Legionnaires’ disease is an extreme type of pneumonia caused by Legionella bacteria. Although typically found in natural water sources, Legionella can be found in purpose-built water systems. Legionella can make individuals sick when contaminated water from building water systems that are inadequately maintained is inhaled. In the United States, Legionnaires’ disease is rising.

Cooling towers are common areas where Legionella can grow and spread even if considered a cold water distribution system. Facility managers and building owners are responsible for ensuring their occupants’ safety, so a water management program is crucial.

Cooling tower drift is the tiny droplets of water carried out of the cooling tower with the exhaust air. The drift droplets can contain chemical additives, like corrosion inhibitors. While this is a natural process, excessive drift can cause more significant issues:

Water loss: Makeup water must be added back to bring the water levels up to the appropriate functioning level
Chemical Loss: Drift that contains beneficial chemicals must be added back so corrosion and bacteria don’t become an issue. Additionally, a chemical loss can have implications on the surrounding environment.
Health Concerns: Drift can contain a microorganism called Legionella. If inhaled, various health risks, like pneumonia, can occur.

This is just the water added back into the facility to compensate for any loss or water drift.