Back-siphoning is associated with cross-connection; the recommended approach is to prevent cross connections.

• A. True
• B. False
• C. Not related
• D. Only applicable to municipal supply

Answer: (A)

Back-siphonage occurs when pressure in the potable water system drops, creating a path from a non-potable source into the drinking-water supply through a cross-connection. A cross-connection is any link where a non-potable source could be connected to the potable supply, so a drop in pressure can pull contaminants back into the water you use for drinking, cooking, or irrigation. Because the problem relies on a pressure differential that allows reverse flow, the most effective defense is to prevent cross-connections from forming in the first place or to protect them with backflow prevention measures.

In pesticide practice, this is especially important. If a pesticide mixing area, storage container, or hose is connected in a way that could be drawn into the water system, backflow devices or an air gap should be used to block any reverse flow. This way, even if a drop in water pressure occurs, contaminated water cannot siphon back into the system. So the statement is correct: preventing cross-connections is the key approach to stop back-siphonage and protect the water supply.