PDFWAC 246-215-05220
Design, construction and installation—Backflow prevention device, design standard (FDA Food Code 5-202.14).
A backflow or backsiphonage prevention device installed on a water supply system must meet standards for construction, installation, maintenance, inspection, and testing for that specific application and type of device in accordance with WAC 246-290-490 and 51-56-0600.