What is the primary purpose of a backflow preventer?

The primary purpose of a backflow preventer is to prevent contamination of potable water. Backflow occurs when water in a plumbing system flows in the reverse direction, potentially allowing harmful contaminants from non-potable sources to enter clean drinking water. By employing a backflow preventer, any potential backflow is blocked, ensuring that the potable water supply remains safe and uncontaminated. This is particularly critical in systems where hazardous materials might be used or where there is a risk of pressure changes that could lead to backflow. Thus, a backflow preventer is an essential component in protecting public health and maintaining the integrity of water quality.