What is an air gap in plumbing designed to do?

An air gap is a crucial safety feature in plumbing systems designed specifically to prevent backflow of contaminated water. It creates a physical space between the end of a water supply line and the flood level of a fixture, such as a sink or bathtub. This gap ensures that there is no direct connection through which potentially contaminated water can siphon back into the clean water supply. By maintaining this separation, an air gap effectively acts as a barrier against the risk of pollutants and contaminants entering the potable water supply, thus safeguarding public health and ensuring compliance with plumbing codes.

The other potential choices relate to different aspects of plumbing but do not pertain to the primary function of an air gap. While increasing water pressure, decreasing water waste, and improving water taste are relevant in various contexts within plumbing maintenance and design, these factors do not accurately describe the specific purpose that an air gap serves.