What is the required air gap distance for all potable water outlets?

The required air gap distance for all potable water outlets is determined by ensuring that there is adequate protection against backflow contamination. The standard practice is to maintain an air gap that is at least twice the diameter of the outlet drain pipe. This distance helps prevent any potential cross-connection between potable water and wastewater systems, which is crucial for maintaining water safety and public health.

By having an air gap of twice the diameter of the drain pipe, it allows for sufficient separation to mitigate risks that could arise from back-siphonage or backflow events, where contaminated water could flow back into the clean water supply. This measure is particularly important in locations where water supply could be impacted by external factors or backpressure from drain systems.

The other distances mentioned are insufficient for effectively protecting against contamination. A smaller air gap might not provide enough assurance of separation, potentially exposing the potable water supply to harmful substances. Thus, the requirement for an air gap that is double the diameter of the outlet drain pipe is not just a guideline but a critical safety measure in water systems.