Cross connection happens when a hose or pipe creates an unintended link between your home’s plumbing and a possible source of contamination — and it can let contaminated water flow backward into the public drinking water supply. The two guides below explain the risk and how to prevent it.
Theory of Backflow (PDF)
A short consumer guide explaining what backflow is, how it can contaminate drinking water through something as simple as a garden hose, and how to prevent it at home.
Methods and Devices (PDF)
Explains what a cross connection is and practical ways to avoid one, including keeping a 2-inch air gap between a hose and anything it’s filling.