What is "backflow" in a water distribution system?

Backflow refers specifically to the unwanted reverse flow of water in a water distribution system. This condition occurs when the hydraulic pressure within the system changes, causing water that has already flowed through the piping to flow backward, potentially bringing contaminants into the clean water supply. Backflow can happen due to various circumstances, such as a sudden drop in pressure or the creation of a vacuum in the system, and it poses significant risks to public health and safety by allowing impurities, chemicals, or pathogens to re-enter the drinking water supply.

The importance of understanding backflow lies in the need for effective backflow prevention devices and protocols, which are designed to safeguard potable water by ensuring that water flows in the intended direction only. Knowing how to identify and mitigate backflow incidents is crucial for maintaining water quality within a distribution system.