What does the term “backflow” mean in the context of water systems?

The term “backflow” refers specifically to the reverse flow of water from a non-potable source back into the potable water supply. This phenomenon poses significant risks to water quality, as contaminants from non-potable sources can re-enter the drinking water system, leading to potential health hazards. Backflow can occur due to changes in pressure within the water distribution system, causing water to flow in the opposite direction than intended. To prevent backflow, various systems, like backpressure preventers or vacuum breakers, are often implemented, ensuring that safe drinking water remains uncontaminated.

In contrast, other options describe different concepts related to water systems or treatment processes. For instance, the addition of chemicals to improve water quality is a standard practice but does not relate to backflow. The standard flow of water denotes how water is intended to move through the system under regular conditions, and dosing disinfectants pertains to a method employed during treatment rather than addressing the issue of backflow. These distinctions highlight why backflow specifically connects to the concern of contamination from non-potable sources into the drinking water supply.