This close to the ocean, brass assemblies age in dog years.
Imperial Beach knows this work by name, some of it literally, the backflow assemblies serving commercial properties here have been repaired and replaced by the contractors we send, including the kind of corroded, failing units that salt air specializes in creating. Because that's the beach's contribution to backflow, the devices live outdoors, the marine layer works on them year round, and assemblies that would age gracefully inland corrode ahead of schedule here, valves seizing, housings pitting, seals giving out early.
The device's job is worth respecting. Water flows one direction, in, and the preventer makes reversal mechanically impossible, protecting the shared supply from anything a pressure drop might otherwise pull backward from the property side. For commercial properties, restaurants, multi unit buildings, anything with fire systems or serious irrigation, the protection is typically required, tested on schedule, and documented with the water authority, and the notices arrive on the calendar whether the assembly is ready or not. On the coast, it often isn't, which is where the letter becomes a plumbing project.
The project gets handled, performed by or under a licensed contractor, testing through repair through full replacement of assemblies the salt air has finished, with the documentation completed and filed properly, because the paperwork is half the requirement. Businesses and property managers call about exactly this, and the coastal version gets handled with the coastal factor respected, materials and assemblies chosen for the environment they'll actually live in. The beach corrodes what it can reach. The response is maintenance that reaches back.
"Most failed tests here are just salt doing its work."
