What is the possible consequence of backflow in a plumbing system?

Backflow in a plumbing system refers to the unwanted reverse flow of water, which can potentially lead to significant health and safety hazards. The primary concern with backflow is that it can cause the contamination of the water supply. When backflow occurs, it can draw pollutants, chemicals, or untreated water from various sources back into the potable water lines. This contamination can lead to serious health risks for anyone consuming the water.

Understanding this, "potential contamination of the water supply" is a correct consequence of backflow because it addresses the fundamental issue of ensuring that drinking water remains safe and clean. Proper backflow prevention measures are essential in plumbing systems to maintain water quality and guard against these hazards.