None of us like change. I get it. Especially when there’s no need to change. After all, “if it ain’t broke don’t fix it”, right? But what if you learned it just may be broken? Long-time respected voice in the backflow industry USC's FCCCHR has written about vault flooding three times in their publication, Cross Talk. First in 2005, then in 2014 when they wrote,
"When a backflow preventer is installed below grade, the vault or pit in which an assembly is installed may fill up with water—possibly contaminated water. The water in the pit could create a cross-connection between the water in the pit and the backflow preventer through the test cocks. This may occur whether the test cocks are opened or closed."
Most recently they published on the topic in late 2016. The language says utility vaults may fill up with water. Well, you may be surprised at just how often vaults do fill up with water. Here is a video showing a compilation of some of the recent footage and photos sent to Safe-T-Cover by testers in the field.
As you can see from the video, this is a common problem. A Texas backflow tester has sent us many pictures and videos of flooded utility vaults over the years. We also interviewed a tester and instructor who works in Virginia on the subject, Chris Mayhew, to hear what he had to say about it. To save you the click, here was the most staggering thing he told us, "Except for brand new installations, 100% of vaults I've worked on have flooded at least once. " A cross connection control investigator in a large mid-western city told us from the thousands of vaults he opened over a 30 year career that about 1 vault out of 100 is dry. He also said that most of the time the backflow device was completely under water. If you watched the video, you'll have seen that in one instance a vault has been installed within a few feet of a roof drain. If it's only required to be tested once per year, imagine how often it's actually free of water.
We see this as a clear problem but know utility vaults have been the standard for backflow design for several decades. Yes, we know change in any industry can be hard. But we believe the protection of clean water, safety, and the owner’s best interest should be enough evidence that the best practice of using an above ground enclosure should replace the vault. It seems we aren't the only ones. See page five of this catalog from Zurn, a backflow preventer manufacturer, for examples of where they expect backflow devices to be installed. The civil engineering community has implemented many other changes through the years when a better design presented itself. Your next project is the time to make this change. Please call us if we can provide support or help you on your next project.