Rhode Island Journeyman Plumber Practice Exam

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

1. To enhance aesthetic appeal

2. To prevent contamination of the water supply

3. To manage costs associated with plumbing

4. To facilitate groundwater recharge

The correct answer is: To prevent contamination of the water supply

The purpose of an air gap in plumbing systems is to prevent contamination of the water supply. An air gap creates a physical separation between the water supply and any potential contaminants, such as wastewater or chemicals, ensuring that they cannot mix. This is crucial for maintaining the integrity of drinking water and complying with health standards. By having a defined space—often above the highest point of the waste outlet—it acts as a barrier that protects the potable water system from backflow, which can occur if there's a drop in water pressure, potentially allowing contaminated water to siphon back into the clean water supply. The air gap is a vital element in plumbing design that upholds public health and safety, demonstrating its importance far beyond aesthetic considerations, cost management, or environmental impacts like groundwater recharge.