Which statement correctly describes potable water, non-potable water, and a cross-connection risk?

• A. Potable water is non-drinkable under normal conditions.
• B. Potable water is safe to drink; non-potable water includes greywater or irrigation water; cross-connection risk includes a garden hose connected to a non-potable source to a faucet.
• C. Non-potable water is always safe for drinking.
• D. Cross-connections only occur in irrigation systems.

Answer: (B)

Understanding potable water, non-potable water, and cross-connection risk helps you see how contamination can move through a plumbing system. Potable water is the supply that's safe to drink and use for cooking. Non-potable water is water that isn’t safe for drinking, such as greywater or irrigation water, and it should stay separate from the drinking supply. A cross-connection is any link between a potable water line and a non-potable source, which becomes risky when pressure changes cause backflow, pulling non-potable water into the clean supply. The statement that best fits this is that potable water is safe to drink; non-potable water includes greywater or irrigation water; cross-connection risk includes a garden hose connected to a non-potable source to a faucet. This captures both what makes water potable versus non-potable and how a simple garden hose setup can create a backflow path into the drinking supply, highlighting why backflow prevention is important. The other statements misstate safety for potable versus non-potable or the places cross-connections can occur.