Routine Monitoring for <i>Legionella pneumophila</i> in Drinking Water Distribution Systems

Key Takeaways Legionella pneumophila presents a latent public health risk for public water systems; however, well‐run systems can maintain a baseline level in drinking water below a level of concern. Routine monitoring can establish a water utility's baseline Legionella pneumophila frequency of occurrence and concentration (MPN/100 mL). A routine monitoring program can follow the Revised Total Coliform Rule, which makes it reasonable for water utilities to implement.