What is the recommended remediation method for a faucet found to have Legionella pneumophila without any disinfectant residual?

The recommended remediation method of installing a sub-micron filter while investigating other solutions is appropriate in this scenario because it addresses the immediate concern of Legionella pneumophila being present without relying on chemical disinfectants that may not be effective or feasible in all settings. Sub-micron filters are capable of removing bacteria, including Legionella, from the water supply. This method provides a viable short-term solution while allowing for further assessment and potential long-term remediation strategies to be developed.

Among the other choices, hyperchlorination may not be ideal due to potential risks of high chlorine levels and the requirement for monitoring chlorine residuals, as well as the possibility of recontamination after treatment. Replacing the entire faucet would be a more drastic and less practical measure, especially when filtration can serve as an effective immediate solution. Running hot water for a short duration may not be sufficient to eliminate the bacteria, particularly if the system lacks proper disinfectant residuals—this may allow for survival or regrowth once hot water flow ceases. Hence, installing a sub-micron filter serves both as a practical short-term fix and a step towards a comprehensive management plan.