Cross connection is the actual or potential connection between a potable and non-potable water supply. These types of connections constitute a serious public health hazard. Community water systems are required to have a cross-connection control program to prevent cross-connections and backflow to the potable water supply system.

• Drinking Water Cross-Connection Control Programs – Explains what a cross-connection is and advises water purveyors on measures that must be taken to protect their water systems against contamination and pollution from cross-connections.
• Drinking Water Cross-Connection Control – Frequently Asked Questions (April 2014) Provides answers to questions about cross-connection control, backflow, and community and noncommunity water system requirements.
• Idaho Rural Water Association Cross Connection Control