Backflow Prevention: What It Is and Why It’s

Backflow prevention is a set of plumbing safeguards designed to keep contaminated water from moving in the reverse direction—back into a community or building’s potable (drinking) water supply. Without these controls, everyday conditions like pressure changes can allow pollutants to travel backward through pipes and fixtures.

When backflow happens, the danger is not theoretical. Chemicals, wastewater, fertilizers, pesticides, or other unsafe substances can be drawn into drinking lines through cross-connections, creating risks for residents, workers, and customers.