What is the recommended air gap to prevent back siphonage?

To effectively prevent back siphonage, which can lead to contamination of the potable water supply, establishing an adequate air gap is crucial. The recommended distance for this air gap is at least twice the diameter of the water supply line. This distance ensures that any potential backflow of contaminated water is not able to reach the potable water source.

By maintaining an air gap of this size, the physical barrier created helps to impede the flow of any back-siphoning water, thereby reducing the risk of pollutants entering the drinking water supply. This guideline aligns with best practices in food safety and public health standards, as it effectively limits the possibility of cross-contamination from potential sources.

Greater gaps, while they would provide even more protection, may not be necessary and could pose practical challenges in space and plumbing design. Thus, the specified measurement of at least twice the pipe diameter strikes a balance between effective safety and practical implementation, making it the recommended standard in food safety protocols.