What is an appropriate action to take for a decorative fountain that has shown consistent Legionella presence in quarterly tests?

Shutting down and draining the fountain for cleaning is the appropriate action to take when consistent Legionella presence has been detected in quarterly tests. Legionella bacteria thrive in warm, stagnant water, which can often be present in decorative fountains. By draining the fountain, you eliminate standing water, which is a primary environment for the growth of Legionella.

Cleaning the fountain thoroughly after draining is crucial to remove any biofilm, sediment, or other contaminants that may harbor bacteria. This process helps to significantly reduce the risk of Legionella proliferation in the future. Following the cleaning, it would also be essential to implement a monitoring plan to ensure that Legionella levels remain safe in subsequent tests.

While adding chlorine could be beneficial in some cases for disinfection, it may not be sufficient on its own to fully address the problem if the system has already shown persistent issues with Legionella. Similarly, simply changing lighting fixtures or increasing water circulation does not address the underlying bacteria presence and would not effectively mitigate the risk. Therefore, draining and cleaning the fountain allows for a thorough intervention aimed specifically at managing and reducing Legionella risks.