At what elevation does a house require a backflow?

For a house to require a backflow prevention device, it is generally determined by the potential for backpressure or backsiphonage, which can occur when there is a significant drop in pressure in the supply system. The elevation at which backflow is a concern often relates to the height of the structure relative to the municipal water supply. Specifically, at an elevation of 50 feet, a significant drop in pressure may create conditions that allow contaminants to flow back into the water supply from higher elevation fixtures or systems, making it essential to install a backflow prevention device.

Backflow prevention devices are critical in safeguarding potable water supplies by preventing the reverse flow of water, which can introduce harmful contaminants. When structures exceed this elevation, the risk of backflow incidents increases, necessitating the installation of appropriate devices to ensure public health and safety. This is why the specified elevation of 50 feet is a key threshold in determining whether backflow prevention is required.