Which action leads to cross contamination of non-potable and potable water?

Which action leads to cross contamination of non-potable and potable water?

• A. Using a color-coded cutting board
• B. Storing chemicals away from food prep area
• C. Cleaning with sanitizer
• D. Leaving a hose submerged in mop bucket

Answer: (D)

Cross-contamination between potable and non-potable water occurs when a path allows dirty, non-potable water to flow back into the clean water supply. Leaving a hose submerged in the mop bucket creates exactly that risk: if water pressure drops or a siphon effect occurs, dirty mop water can be drawn back through the hose into the potable water system or faucet. This backflow can contaminate the water you use for rinsing, cooking, or drinking, which is why hoses should never sit submerged in buckets and should be equipped with backflow prevention or used with proper air gaps and elevated storage. The other practices address different safety goals. Using color-coded cutting boards helps prevent cross-contamination between raw and ready-to-eat foods, storing chemicals away from the prep area reduces chemical exposure risk, and cleaning with sanitizer reduces microbial contamination on surfaces—none of these introduce a backflow path into the drinking water.

Cross-contamination between potable and non-potable water occurs when a path allows dirty, non-potable water to flow back into the clean water supply. Leaving a hose submerged in the mop bucket creates exactly that risk: if water pressure drops or a siphon effect occurs, dirty mop water can be drawn back through the hose into the potable water system or faucet. This backflow can contaminate the water you use for rinsing, cooking, or drinking, which is why hoses should never sit submerged in buckets and should be equipped with backflow prevention or used with proper air gaps and elevated storage.

The other practices address different safety goals. Using color-coded cutting boards helps prevent cross-contamination between raw and ready-to-eat foods, storing chemicals away from the prep area reduces chemical exposure risk, and cleaning with sanitizer reduces microbial contamination on surfaces—none of these introduce a backflow path into the drinking water.