Backflow / Cross-Connection Control Program

If you haven’t filled out the 2023 Cross Connection survey, please complete it ASAP! Download it here.

The Corbett Water District spends thousands of dollars each year to ensure the safety of our drinking water. A vital link in this effort is the Corbett Water District’s Cross-Connection and Backflow Prevention programs.

Water distribution systems are designed so that water flows in one direction from the treatment plant to the customer. Sometimes, a loss of pressure in the main system may draw water from customer pipes. A backflow device makes it so water can only flow in one direction, which prevents drinking water from being contaminated by other sources.

List of state backflow testers

Only OHA-certified Testers are allowed to provide testing services in Oregon.

Backflow Assembly Testers who provide their testing services for a fee are required to be licensed through the Construction Contractors Board (CCB) or the Landscape Contractors Board (LCB). Testers on the following list have provided information to DWS that they, or the company they work for, have either a CCB or LCB license; however, this information has not been verified. To verify licensing, you can look up CCB licenses or LCB licenses.

More about Backflow and Cross-Connections

Cross-Connections are any unprotected actual or potential connection or structural arrangement between a public or a consumer’s potable water system and any other source or system through which it is possible to introduce, into any part of the potable system, any used water or substance other than the intended potable water. Bypass arrangements, jumper connections or any other temporary or permanent connections through which backflow can occur are considered to be cross-connections.

Backflow is the undesirable reversal of flow of water or mixtures of water and other liquids or substances into the distribution pipes of the potable supply of water from any source or sources.

Federal and State laws require Water Purveyors to protect their system from cross-connections and backflow. To do this, we work closely with consumers, architects, contractors, and engineers to ensure that all those who are required to, comply with cross-connection control and/or backflow prevention requirements. If you have been contacted by the Corbett Water District and know you need a backflow prevention assembly installed or tested, see the Oregon State of approved backflow testers website at, for a list of certified testers.

It is suggested to contact the City of Gresham permit department at 503-618-2891 to discuss permit requirements.

For questions regarding this program please contact the District office at 503-695-2284 or via email by selecting here.