The DCVA is a system used to prevent a cross-connection when the backflow would not be hazardous to one's health. The DCVA consists of a shut-off valve on either end and two check valves in the center. When water flows in the normal direction, the check valves are forced open by the flow of water.
The RPBA is more complex, adding a hydraulic spring-loaded pressure differential relief valve between the two check valves. This addition makes the RPBA suitable for cross-connection control where the backflow could create a danger to public health.
Washington State law requires backflow assemblies to be field tested annually to make sure the device is working properly. The District sends out notices to remind of upcoming reporting due in advance of due dates. Two documents, a form
Backflow Prevention Assembly Test Report (PDF) and document
Backflow Assembly Tester Resource List are provided in that notice. Should you have further questions or need additional information, please
Email Chris Zoepfl, Cross-Connection Control Program Manager or call (253) 946-5427.