Protecting And Eliminating Cross Connections
Drinking water flows from the source to your tap in pressurized water pipes. Normally it flows in one direction, although under certain circumstances it can flow in the opposite direction, or "backflow." When backflow occurs, water runs backwards through the water system. The water flowing backwards could contain something that might contaminate the drinking water supply. TVWD strives to maintain positive pressure in the system at all times, but events such as main breaks and fire fighting can contribute to backflow conditions.
A cross connection is any connection between piping that carries drinking water (also known as potable water) and the piping or fixtures that carry other types of water or substances that are not safe to drink or may impact the taste or odor of water (also known as non-potable water). Common cross connections include hot tubs, sprinkler and irrigation systems and auxiliary water systems (wells).
Per Oregon Administrative Rule (OAR) 333-061-070 and District Rules and Regulations, all approved backflow prevention assembly must be maintained and tested at least annually to protect the public water system.
TVWD's Cross Connection Program seeks to eliminate or protect all cross connections in the public water system and help customers comply with backflow prevention practices and regulations. All backflow assemblies must be inspected once a year by a certified backflow tester to ensure proper operation. If you have a backflow assembly that is required to be tested, you will receive a letter from TVWD with guidance about how to get this done. Failure to comply with required testing will result in the disconnection of your water service.
If you are unsure if your water-using fixture needs a backflow assembly or an annual backflow test, contact your plumber, landscaper or TVWD's Cross Connections Department.
There are approved circumstances where testing your backflow assembly is not required for underground lawn irrigation systems. These circumstances include when the irrigation system is shut off for the entire year or is disconnected permanently. To apply for this variance, complete the Backflow assembly Non-Use Certification Form (PDF) and return to TVWD.
For your convenience, TVWD has implemented an optional backflow assembly testing program for our residential customers. You may now choose to have TVWD make the arrangements to have your backflow assembly(s) tested annually by one of our contracted certified testers.
- TVWD will schedule your assembly(s) to be tested for a fee of $35 each.
- If repairs or replacement of the assembly are needed, we will assist by paying up to $50 towards the repair or replacement if completed by a TVWD contractor.
- The testing fee will be added to your water bill following the test.
- Available to TVWD and Valley View residential customers only.
Water Heater Thermal Expansion
Please note that you may need to protect your water heater from thermal expansion when you install a backflow prevention assembly at the water meter. This may be provided by the installation of a thermal expansion tank and a temperature and pressure relief valve. For more information, take a look at our Protect Your Water Heater From Thermal Expansion Brochure (PDF) or contact a licensed plumber.
More Backflow/Cross Connections Resources:
- Backflow Assembly Non-Use Certification Form (PDF)
- Residential Backflow Contract Testing Application (Gold Plan - PDF)
- Water System Standards (PDF) - contains backflow assembly specifications
- TVWD Rules and Regulations (PDF) - for TVWD's adopted Backflow and Cross Connection ordinances