What is the purpose of an air gap in plumbing systems?

The primary purpose of an air gap in plumbing systems is to prevent cross-contamination between potable and non-potable water supplies. This is achieved by creating a physical separation between the drinking water supply and potential contaminants, ensuring that contaminated water cannot siphon back into the clean water system.

The air gap serves as a critical safety feature, particularly in situations where there is a risk of backflow, such as in sinks, dishwashers, or other fixtures that may be connected to the wastewater system. For instance, if there is a sudden drop in water pressure or another situation that causes the potential for backflow, the air gap acts as a barrier, effectively safeguarding the drinking water supply.

This safeguard is essential in maintaining public health standards and ensuring that water quality is not compromised by contaminants that could lead to health issues.