As we have recently seen in the news, in New York there have been more 10 deaths with more than 100 people infected with Legionnaire’s disease. Even though most of the water treatment for cooling towers, fountains and potable water supplies are treated with certain biocides for legionella prevention, why do we still see roughly 24,000 cases of Legionnaire’s disease every year around the globe? The answer: Conventional water treatment solutions are not sufficient because they do not remove biofilm. Hence, inactivating Legionella is easy with Chlorine when it does not hide behind the biofilm. Meaning long term Legionella prevention is only possible with biofilm removal, water disinfection, and prevention of future biofilm growth.
Biofilm is a breeding ground for Legionella. Complete removal of biofilm and on-going treatment of legionella in water systems is the only way to eliminate the deadly bacteria.
Legionella is a ubiquitous aquatic organism that thrives in warm environments (32°C to 45°C) and causes more than 90% of Legionnaires disease cases. The Legionella pneumophilia organism hides beneath the polysaccharide biopolymer films that protected biofilm from many commonly used water disinfectants. As water circulates during normal operation, biofilm debris is eroded and dispersed throughout the system and aerosolized, increasing the risk of passerby inhaling a sufficient number of the airborne bacteria thatcauses Legionnaire’s’ disease.
There are a few good options for biofilm removal in cooling tower water treatment systems or potable water treatment systems including chlorine dioxide and Mixed Oxidant Solution.