Backflow happens when water flows in the wrong direction — from dirty pipes back into your clean supply lines. This reverse flow can carry bacteria, chemicals, or waste from irrigation systems, industrial lines, or other sources into your building’s drinking water. It often occurs due to pressure drops in the system, such as when there’s a water main break or heavy demand on the public line. Without a proper backflow prevention device, contaminants can quickly spread through faucets, hoses, and fixtures. Example: We recently helped a small restaurant in Gilbert after a backflow valve failed on its sink connection. Cleaning chemicals had begun leaking into the fresh water line. Our team replaced the faulty valve, flushed the system, and tested it to confirm the water was safe again. A simple test and timely repair can make all the difference between a small fix and a major health risk.