Backflow Prevention Practice Exam

An air-gap separation is a critical requirement between the potable water supply and a sanitary sewer due to the risk of contamination. The purpose of an air gap is to provide a physical separation that prevents any backflow of potentially contaminated water from the sewer system into the drinking water supply. If water from the sanitary sewer were to backflow, it could carry pathogens, chemicals, and other harmful substances directly into the potable water, posing serious health risks to individuals using that supply.

In situations involving appliances or systems like a bakery dough mixer, an isolation assembly, or a pressure washer, while certain risks may exist, they do not require the same level of separation as that required between potable supplies and sanitary sewers. The focus is particularly on protecting the integrity of the drinking water supply from any sources of contamination that might arise in sanitation systems, which is why the air-gap separation is mandated specifically in this context.