A Great Tower Design is the Best Protection from Legionella

Legionella Cooling Towers

A deadly respiratory disease is on the rise again – and no, it isn’t COVID-19. In a study of Legionnaires’ Disease diagnoses from 1992 to 2018, released in February 2022, CDC researchers discovered that cases increased significantly in 2003 after about ten years of stable numbers. Researchers also found that cases in the past few years are increasing at alarming rates – hundreds of percent – and for unclear reasons.

Legionnaires’ Disease is a serious and often fatal form of pneumonia caused by Legionella bacteria. Early March 2022 saw 20 confirmed cases with 14 hospitalizations and two deaths from Legionnaires’ Disease in Riverside County, California, and Legionella was detected that same week at two Illinois Department of Corrections facilities. Legionella flourishes in standing, fresh water and is easily spread through micro-droplets of water – both common attributes of conventional cooling tower designs.

Tower Tech modular cooling towers are designed to counteract these two Legionella-fostering flaws in conventional towers. Keeping your facility and environment safer is just one of the many benefits of a Tower Tech tower.

Conventional Tower Design, Drift and Legionella

Standard cooling towers have a design that provides an ideal ‘breeding and feeding’ ground for Legionella in their sediment-forming basins. These cooling towers also commonly contain scale and algae as well as iron, zinc and potassium from corrosive metals. Add trapped dirt and dust to these and settle them at the bottom of a stagnant basin, and the first bout of warm weather can yield massive Legionella growth in just a few short weeks.

Hospital Medical Center


Standard cooling tower designs don’t just foster Legionella growth; they also contribute to its spread. Legionnaires’ Disease isn’t transmissible person-to-person. Instead, each infected individual will have had to inhale Legionella-containing water droplets. Induced draft cooling towers typically release 0.002% to 0.005% of their circulating water flow in the form of drift emissions – a mist a person could actually feel when walking near the cooling tower. Every inhalation of such a dense mist containing Legionella increases the chance of contracting Legionnaires’ Disease.

Mitigating bacteria growth with an anti-microbial agent is a correction after the fact. A Tower Tech modular cooling tower is designed to help stop the growth of Legionella before it starts, rather than killing the bacteria after it has grown in your system.

How Tower Tech Gives You the Edge aGAINST LEGIONELLA 

The revolutionary design of Tower Tech towers takes away Legionella’s two favorite things: an open, stagnant basin and high drift.

Tower Tech towers have a fully enclosed Flow-Thru Basin™ in lieu of an open basin or open louver that is exposed to the air and sunshine. This not only greatly reduces the amount of dust that can enter the system, but it also deters the photosynthesis needed to grow algae (Legionella’s superfood). Rapid system turnover also deters Legionella, as the water in the tower sits still for less time than in a conventional tower, giving the bacteria less time to snack on anything that can help them grow.


Tower Tech towers have also been designed to reduce drift from an industry standard of 0.005% to a best practice of 0.0004% – this is an 80-90% reduction in the droplets spread by conventional towers. Tower Tech’s high-efficiency drift eliminators, which use a three-pass, sinusoidal-shaped wave configuration, prevents water escape much better than traditional drift eliminators.

Stay Safest with the Best Design

Tower Tech cooling towers attack the sources of Legionella growth: a closed basin and rapid turnover to avoid algae growth and sediment buildup, and super-low drift rates. Don’t settle for addressing harmful bacteria after it’s already grown in your system. Let’s talk about how Tower Tech towers can keep your business from being another number in the rising Legionnaires’ Disease statistics.

Sustainable efficiency is our guiding purpose by saving valuable resources.