Every year or so the Montgomery County (VA) Public Service Authority sends me a letter asking what sorts of things I’ve got hooked up to the water supply. Part of this is a request to describe “Existing backflow devices”, along with a threat to conduct an inspection and interview if the information isn’t provided. Backflow seems like a personal matter, not one that I wanted somebody inspecting and interviewing me about.

On the slim chance that somebody else stumbles across this page trying to figure out what the heck a backflow device is, here is a picture of mine:

It took a bit of crawling around, but the device wasn’t hard to find. It was located in the crawlspace, right at the point where the water line enters from outside. The make (Watts regulator), model (No. 7 – 7U2-2), ASSE # (1024), and size (3/4″ x 3/4″) were printed or stamped on the front of it. This information was also sufficient to find the device (or a slightly newer iteration thereof) in the manufacturer’s catalog.