According to the SDWA, what is the Maximum Contaminant Level Goal (MCLG) for Legionella?

The Maximum Contaminant Level Goal (MCLG) for Legionella is set at zero as per the Safe Drinking Water Act (SDWA). This means that there is no acceptable level of Legionella bacteria in drinking water because it poses a significant health risk, particularly to vulnerable populations such as the elderly and those with compromised immune systems.

Setting the MCLG for Legionella at zero reflects the intent to protect public health by preventing any potential exposure to this pathogen. Even minimal levels of Legionella can lead to serious diseases like Legionnaires' disease. Therefore, the goal of regulatory standards is to eliminate any possibility of contamination in drinking water supplies, ensuring that water is as safe as possible for consumption. This strict standard emphasizes the importance of stringent water quality management practices to prevent outbreaks and safeguard public health.

Other options, like one, five, or ten, would imply that a certain level of Legionella could be acceptable, which contradicts the health protective principle underlying MCLGs for contaminants that can cause significant disease.