When connecting a public water supply to a potential contamination source, what size air gap is required?

The requirement for an air gap when connecting a public water supply to a potential contamination source is crucial for ensuring safe drinking water. An air gap acts as a physical barrier to prevent contaminants from entering the water supply. The correct standard is that the air gap should be at least two times the diameter of the inlet pipe. This twofold dimension provides sufficient space to prevent backflow, which could occur due to pressure changes or siphoning, ensuring that any contaminants from the potential source cannot reach the potable water supply.

This restriction helps maintain a safe and sanitary water distribution system by reducing the risk of pollution and ensuring compliance with health regulations. It is important to adhere to these guidelines strictly in public health areas to protect the community from any harmful substances that might infiltrate their drinking water.