What does a backflow device protect against?

A backflow device is specifically designed to prevent the backflow of contaminants into the potable water supply. This device ensures that water flows in the intended direction and protects the drinking water from potential pollutants that could enter the system due to pressure changes or other factors.

Backflow occurs when there is a reversal of flow, which can lead to contamination from various sources, including wastewater, chemicals, or other harmful substances that could compromise water quality. By installing a backflow device, water utilities can effectively safeguard public health and maintain the integrity of water supplies.

The other options relate to different concerns: excess pressure is managed through pressure regulation devices, voltage spikes pertain to electrical systems, and water shortages deal with supply and demand issues, but none of these directly relate to the purpose of a backflow device.