Backflow Prevention

Backflow Prevention Assembly

Double Check Valve AssemblyBackflow prevention assemblies protect the drinking water supply from contamination by preventing the reverse flow of untreated liquids from the customer's property back into the public supply line.

Customers are required to install and properly maintain backflow prevention assemblies on their water service when additional water sources are present on their property, or if a specialized type of water use exists.

Additional water sources include wells or if you are in the Grants Pass Irrigation District. Examples of specialized water use are irrigation systems or fire sprinkler systems.

Reduced Pressure Backflow AssemblyAll backflow prevention assemblies are required to be tested at least annually to ensure they are functioning properly. Backflow assemblies that fail annual testing are required to be repaired or replaced.

Assembly Testing

Commercial, multiple-family and public customers are contacted each year by letter informing them it is time to test their assemblies. A letter will not be sent if the backflow test report has already been received with a passed test result for the year. These customers are responsible for obtaining a state certified backflow tester, having the test performed, and having a licensed plumber complete necessary assembly repairs.

View a list of certified backflow testers.

Assembly Fees

Single-family residential customers are billed a monthly fee of $2 per assembly. This fee is used to provide funding for a city-administered contract for the annual testing and minor repair of all single-family residential assemblies.  This fee does not cover replacement of an assembly if it is unable to be repaired.  

Contact Us

  1. Backflow Prevention Program

    Ph: 541-450-6115


    Monday - Friday
    8 a.m. - 4 p.m.