If Legionella was found only in pre-flush samples at 220 and 140 CFU/mL from water heaters, what should be allowed as a reasonable response?

The most appropriate response when Legionella is detected in pre-flush samples from water heaters is to drain and clean the water heaters. This action helps to mitigate the risk of potential Legionella growth and transmission. Legionella thrives in warm water environments, particularly in places like water heaters where conditions may promote its proliferation. By draining and cleaning the water heaters, you can remove sediment and biofilm that may harbor bacteria, which is a critical step in controlling and preventing any further bacterial growth.

Regular maintenance and cleaning of water heaters are essential preventative measures within a plumbing system. This action aligns with established guidelines for managing Legionella, focusing on reducing the potential sources of contamination as a proactive approach to water safety.

Ignoring the results would leave the potential health risks unaddressed, while drilling holes in the water heaters may lead to unnecessary damage and would not address the underlying issue. Running tests infrequently neglects the need for regular monitoring and proactive management, which is crucial in ensuring the safety of the water supply. Therefore, the correct management response emphasizes the importance of cleaning and maintaining the water heaters to prevent Legionella growth effectively.