Which of the following is a recommended practice to mitigate Legionella risk in decorative fountains?

Regularly replacing the fountain water is a recommended practice to mitigate Legionella risk because it helps prevent the buildup of biofilm and stagnant water, both of which create a favorable environment for Legionella bacteria to thrive. Fresh water reduces the concentration of nutrients that support bacterial growth and helps maintain better water quality. Regular maintenance activities, including water changes, are crucial for minimizing the risk of Legionella exposure in decorative fountains, as they can harbor stagnant water and warmer temperatures, which are conducive to bacterial proliferation.

The other options, while they might seem beneficial at first glance, do not address the core issue of Legionella management as effectively as regular water replacement. Ensuring proper water quality and circulation through routine maintenance is fundamental for preventing the growth of harmful pathogens in these systems.