Backflow prevention in potable water servicing is intended to prevent what?

• A. It increases the rate of water flow.
• B. It reduces the need for hose connections.
• C. It prevents backflow contamination from wastewater into the potable water supply.
• D. It has no effect on safety.

Answer: (C)

Backflow prevention protects the drinking water supply by stopping reverse flow from non-potable sources back into the potable system. If pressure in the system fluctuates or a connected device creates higher pressure, water could be drawn backward through cross-connections. That backflow can bring contaminants, including wastewater or polluted water, into the clean supply. Devices and methods like backflow preventers, air gaps, or anti-siphon valves act as one-way barriers, ensuring water only flows away from the public supply. In practice, this is why hoses and other connections are kept clear of potential contaminants and why anti-siphon measures are used on fittings and fixtures.