What kind of water contamination can an air gap effectively prevent?

An air gap is an effective method for preventing contamination from dirty water sources. An air gap involves a physical separation between the nozzle of a water supply outlet and the flood level of the receiving vessel, which creates a barrier that prevents backflow. This design ensures that if there is a drop in pressure in the water supply system, dirty water, which may contain sediments, pollutants, or other harmful substances, cannot be siphoned back into the clean water supply. The air gap acts as a defense mechanism to maintain the integrity of the potable water supply by preventing any backflow from contaminated sources.

In contrasting contexts, contamination from chemical spills, air pollutants, or biological sources may involve different methods of prevention and control, but an air gap specifically addresses the risk associated with dirty or potentially polluted water being introduced into the clean water lines, thus highlighting its importance in plumbing and water safety standards.