How can cross-connections in a plumbing system impact water safety?

Cross-connections in a plumbing system are points where non-potable water can potentially mix with potable water. This creates a significant risk for contamination of the drinking water supply because it allows harmful substances, such as chemicals, pathogens, or other pollutants, to enter what should be a clean and safe source of water.

When pressure in the system drops or during unusual circumstances, non-potable water could be drawn back into the potable water system, leading to widespread health risks. This is why maintaining an awareness of cross-connections is critical in plumbing practices, and proper backflow prevention methods, such as installed backflow preventers, are required to protect the public water supply.

The other options do not accurately represent the consequences of cross-connections. They do not improve water pressure, nor do they have anything to do with water temperature or drainage efficiency. The primary concern surrounding cross-connections is indeed the potential for contamination.