What does the term "backflow" refer to in water systems?

The term "backflow" specifically refers to the reverse flow of water in a plumbing system, which can lead to contaminants entering the drinking water supply. This situation typically occurs when there is a sudden drop in water pressure, causing water from polluted sources to flow backward into clean water lines. Backflow can happen through various means, such as cross-connections between potable water and non-potable sources, which poses a significant risk to public health, as it can introduce harmful pathogens and chemicals into the water supply.

Preventing backflow is critical in maintaining the integrity of drinking water systems, which involves employing devices like backflow preventers to ensure that water flows in one direction only. Understanding backflow is essential for anyone involved in the operation and maintenance of water systems, as it directly relates to water safety and public health.