A Legionella Risk Assessment, also known as LRA, is a random audit carried out to evaluate the potential threat of Legionella infection being present in a commercial property. This is one of the most reliable tests available and involves thorough assessment procedures, the main one being thorough fluid sampling from the area of possible contamination. A sample is taken from the interior of a structure, usually a building or a site with water pipes, and the fluid is decanted offsite for analysis. As a preliminary step, a visual observation is made of any changes in color or texture in the sample. Special cameras equipped with special lenses are then used to observe the resulting areas of contamination. Based on this initial information, the final Legionella Risk Assessment is carried out and the likely locations of the bacteria are pinpointed.
The primary purpose of a legionella risk assessment is to identify the likely sources of contamination, particularly if the facility has not been declared safe by the local health authorities. It is done so that the competent person can carry out relevant disinfection procedures as well as make recommendations about limiting potential risks. In addition, the competent person will also consider the likelihood of infestation by airborne species, which include the possible route of contact between people and water coming from a contaminated body of water. In this case, a separate assessment is carried out by another team of professionals to identify the specific sources of contamination.
The study results and recommendations from the legionella risk assessment will be communicated directly to the responsible authority and the professional tasked with implementing the controlling measures. Usually, the first contact with legionella or its product is through a surface water system that transports water in a public area or commercial building. Such cases may require the establishment of a specific control measure, which should be implemented as soon as the problem has been identified. This way, the number of people exposed to the bacteria and its products can be minimized, preventing an even higher risk of disease from occurring.