Legionella are rod-shaped bacteria that can cause legionellosis. The most common pathogen is Legionella pneumophila. Legionellosis includes Legionnaires’ disease, a severe sometimes life-threatening pneumonia, and Pontiac fever, a less severe infection without pneumonia.

As legionella naturally occur in freshwater habitats, they can easily enter potable water systems. Under favourable conditions, legionella can settle and propagate within biofilms in potable water tanks, pipes and installations. There is an increased risk for legionella propagation at water temperatures between 25 and 45 °C.

If legionella-containing warm water is nebulised and distributed via showers, air conditioning or cooling towers, there is an increased risk of infection for people inhaling the aerosols.

Conservative methods of eliminating legionella from potable water systems such as thermal disinfection and water or water/air flushing have shown to be ineffective because they do not reach and remove the biofilm in which legionella reside. The remaining organic material provides an optimal breeding ground for the re-growth of the remaining legionella after the measure.

Multi-step rinsing

To remove efficiently and sustainably legionella from potable water biofilms, we employ a tried and tested multi-step chemical cleaning method (multi-step rinsing) that we developed. Its efficacy has not only been tested and proven in practical experience but is also supported by current scientific evidence. This multi-step chemical cleaning method does not only remove legionella but also the biofilm itself. As a result, the potable water system is sustainably protected from legionella re-growth (if the system is operated according to technical standards and regulations).