What is back siphonage?

Back siphonage refers to the flow of contaminated water back into a potable water supply due to negative pressure created in the system. This typically occurs when there is a disruption in the water supply, such as during a sudden drop in pressure from a break in the main water line or when a nearby fire hydrant is opened for use. Such conditions can create a vacuum that pulls non-potable water—potentially contaminated—back into the clean water supply.

Understanding back siphonage is crucial for maintaining the integrity of a potable water system and preventing contamination. It's an important concept in plumbing design and public health standards, as proper backflow prevention measures must be implemented to safeguard drinking water supplies.