What is the primary function of the backflow preventer?

The primary function of the backflow preventer is to prevent water from flowing back into the city's water supply. This is crucial for ensuring the integrity and safety of the public water system. Backflow can occur when there is a change in pressure within the water system, which can cause contaminants from residential or commercial properties to flow backward into the clean water supply. By incorporating a backflow preventer, the risk of such contamination is significantly reduced, safeguarding public health and maintaining the quality of drinking water.

Maintaining a barrier against backflow helps to protect the entire water distribution system from pollutants and ensures that the water supplied to consumers remains safe and potable. The other options, such as increasing water pressure, regulating water temperature, or removing impurities from water, pertain to different processes and devices that do not relate to the core function of a backflow preventer.