What is the function of a backflow preventer in a water distribution system?

The function of a backflow preventer in a water distribution system is to prevent contaminants from entering the supply. Backflow can occur when there is a sudden drop in water pressure, which may allow water to flow backward into the distribution system. This backward flow can introduce harmful substances from adjacent systems, such as sewage or other pollutants, into the clean water supply.

Backflow preventers are designed to create a physical barrier that stops this reverse flow, ensuring that the drinking water remains safe and uncontaminated. They are critical in maintaining the overall health and safety of a water distribution system, protecting public health from potentially dangerous contaminants.

Other options, such as aerating the water, regulating temperature, or measuring water flow, do not address direct contamination issues and are not functions of a backflow preventer. Each of these other functions is managed by different components or systems within the water infrastructure.