Why must a backflow preventer be included in a sprinkler system?

A backflow preventer is a crucial component in a sprinkler system primarily to prevent contaminated water from entering the public water supply. It is designed to allow water to flow in one direction—into the system—while preventing any reverse flow that could occur due to backpressure or back siphonage. If a sprinkler system were to malfunction or have maintenance issues, there is a risk that water, which may be contaminated with chemicals or other pollutants, could flow back into the clean water supply. This measure protects public health and safety, ensuring that only clean, potable water is supplied to consumers.

The other options touch on aspects of a sprinkler system but do not reflect the primary function of a backflow preventer. For example, while system pressure is important, enhancing pressure is not the role of a backflow preventer; rather, that function relates more to pump systems or the design of sprinkler heads. Similarly, backflow preventers do not control the activation of sprinkler heads, which is determined by various factors including heat detection and zone control. Lastly, while reducing maintenance needs is always a goal in system design, backflow preventers are not primarily included for this purpose. Their main function is to safeguard the water supply from contamination, which is critical for public