What is Backflow?
Any time the expected or regular flow of the drinking water system is reversed, waste or application water from any commercial, institutional, or residential plumbing system is permitted to enter the clean water resource system. The used or abused water flows “back again,” instead of “out and about,” which could contaminate the water that is being drunk, used for bathing, or used for cleaning.
This flow may reverse if there is a large shift in water pressure, such as when the supply point’s water pressure is lower than the main point’s typical water pressure when the faucet is switched on. If this occurs, water is drawn back into the device from the usable point, which is normally where the faucet is turned on, and could contaminate the remaining water. If such issues are not resolved, the public water supply may eventually revert to something simpler.