In a scenario where a building has two water heaters and one is under repair, what is the risk of Legionella if managed improperly?

The choice that states risk exists for any building with biofilms present is correct because biofilms create an ideal environment for Legionella bacteria to thrive. These biofilms can form on various surfaces within plumbing systems, especially in water heaters, pipes, and fixtures where water stagnation may occur. When a water heater is under repair, the disruption in regular water flow can lead to stagnant water, which further promotes the growth of biofilms and increases the likelihood of Legionella proliferation.

Legionella can be present in any building that has plumbing systems, regardless of its height or whether it is residential or commercial. Factors such as temperature, water stagnation, and biofilm presence are critical in determining the risk, rather than the type or height of the building. Understanding the role of biofilms is essential for effective risk management and preventing outbreaks associated with Legionella.