Backflow & Cross Connection Control

Cross Connection control is a vital part of protecting our drinking water. As the water passes through the distribution system to all the buildings in the City, it is important to ensure its safe. A cross - connection, or the opportunity for substances other than drinking water to enter the plumbing, can threaten the quality of our drinking water in the distribution system. The City of Bainbridge Island requires that all cross-connections or potential cross-connections have a backflow preventer installed and tested annually.

General Information

Get information about what cross-connection and backflow is.

Backflow Preventor Choices & Requirements

Visit the Backflow Preventer Choices and Requirements page for information on types of backflow preventers and specific applications.

Regulations & Forms

State regulations, required permits, state certified testers, backflow assembly test report form.

View Permits, Regulations, and Forms page for:

  • COBI Backflow Assembly Test Report Form
  • Hold Harmless Agreement
  • Partial List of Local Certified BATs

City Hired Backflow Testing Program

Testing Questions & Answers

Check out frequently asked questions about cross connection control.

More Information

For answers to specific cross-connection control questions, contact the cross connection control specialists at the Operations Division of the Public Works Department via email or at 206-842-1212.