What component prevents back-siphonage of irrigation water into the potable water supply?

• A. Electric irrigation valves
• B. Backflow devices
• C. Irrigation controllers
• D. Water meters

Answer: (B)

Backflow devices are specifically designed to prevent back-siphonage, which is the unwanted reverse flow of water from a non-potable source back into the potable water supply system. These devices create a physical barrier that stops contaminated water from entering the clean water supply. They are critical in maintaining water quality and ensuring that drinking water remains safe from potential pollutants that may be present in irrigation systems.

Electric irrigation valves, irrigation controllers, and water meters perform important functions in irrigation systems but do not offer protection against back-siphonage. Electric valves control the flow of water in an irrigation system, irrigation controllers manage the timing and scheduling of irrigation, and water meters measure the volume of water used, but none provide the necessary safeguards to prevent contamination of drinking water. Thus, backflow devices are essential to protect public health by ensuring that water intended for drinking does not become contaminated by irrigation water.