What is a cross-connection in water systems?

A cross-connection refers to a direct connection between a potable (drinkable) water source and a non-potable water source. This is significant because it poses a risk of contamination to the safe drinking water supply. If pressure changes occur in the water system, there is potential for non-potable water to siphon into the potable supply, leading to health hazards from pollutants, chemicals, or pathogens.

The purpose of identifying and managing cross-connections is to protect public health and ensure that the water supplied for consumption remains safe. Cross-connections are commonly found in situations like irrigation systems accessing well water, or plumbing fixtures that may allow contaminated water to backflow into clean water lines.

In contrast, other options mention aspects of water systems that do not directly relate to the dangerous interaction of potable and non-potable sources. For example, a union between two water treatment facilities and methods of pipeline maintenance do not involve the concept of safety regarding water quality in the way that cross-connections do. Similarly, a type of water filtration system does not pertain to the definition or implications of cross-connections in water systems.