What does the Maximum Contaminant Level (MCL) represent?

The Maximum Contaminant Level (MCL) specifically represents the highest concentration of a contaminant that is permissible in a drinking water supply according to regulatory standards. This value is established to protect public health by ensuring that water systems do not allow contaminant levels that could pose a risk to individuals consuming the water. The MCL is based on scientific research and is designed to safeguard against various health hazards that might arise from exposure to these contaminants over time. Thus, choice B correctly identifies the MCL as a threshold meant to prevent excessive exposure to harmful substances in water, thereby promoting safety and health for the public.