Describe how to prevent cross-connection and backflow when connecting to an outside water source.

• A. Use backflow preventer or check valves on inlet
• B. Ensure hoses are clean
• C. Maintain physical separation
• D. All of the above

Answer: (D)

Preventing cross-connection and backflow when tapping an outside water source means creating barriers that stop contaminated water from entering the potable system. The primary safeguard is a backflow preventer or inlet check valve, which blocks reverse flow if supply pressure changes. Keeping hoses clean is essential because dirty hoses can introduce debris or pathogens into the system, even if backflow is blocked. Maintaining physical separation—avoiding loops, staying clear of other water sources, and keeping the connection isolated—helps prevent unintended cross-connections and siphoning. Using all of these together provides robust protection: a mechanical barrier to backflow, cleanliness to prevent contamination, and proper layout to avoid cross-connections.