Does UPC 2015 allow hose connections below grade (e.g. in an underground valve box)? Is a regular vacuum breaker sufficient in this situation or is a double check valve needed (typical for sprinklers)?

603.5.17 Potable Water Outlets And Valves. Potable water outlets, freeze-proof yard hydrants, combination stop-and-waste valves, or other fixtures that incorporate a stop and waste feature that drains into the ground shall not be installed underground. A vacuum breaker is not considered a "stop and waste feature" correct?

Related question regarding yard hydrants, which would be an alternative if I can't put a hose connection under ground. Per Table 603.2 "Freeze resistant sanitary yard hydrants" "Such devices are not for use under continuous pressure conditions."

Does this mean a valve is required a before a yard hydrant? i.e. when you close the valve on a hose bib "hose connection vacuum breaker" is no longer subject to operating pressure, however the "freeze resistant sanitary yard hydrant" assembly as a whole technically remains under pressure when you shut off the yard hydrant.

  • What yard hydrant are you referring to? Commented Apr 22, 2020 at 20:39
  • This is a freeze resistant sanitary yard hydrant which doesn't have any openings underground. UPC 603.5.17 is prohibiting hydrants like these that have fitting at the bottom (below ground) which drains water out of the riser pipe to prevent freezing.
    – Serguei
    Commented Apr 22, 2020 at 22:52
  • I put in a couple low hose bibbs off the sprinkler system . They were inconvenient , I plugged one and raised the other to about one foot . above the ground. Commented May 26, 2020 at 2:19

1 Answer 1


You'd probably need a double check valve like a sprinkler system to put a garden hose connection underground.

For the yard hydrant: Your link says "Frost Proof" which is different than "Freeze resistant". Further your referenced code says " that incorporate a stop and waste feature that drains into the ground". The description for the yard hydrant you have linked says "Unlike conventional hydrants which drain the water into the ground, these use a reservoir below the frost line to contain the water".

I'd argue that either point makes this portion of the code inapplicable but certainly the 2nd portion where it doesn't drain into the ground at all.

  • Code uses the term "freeze resistant" and as far as I can tell "frost proof" and "freezeless" are colloquial terms for the same. Can you explain the difference? Also I updated the original question, I'm really asking two separate questions there.
    – Serguei
    Commented Apr 23, 2020 at 1:00
  • I'd disagree. There is a big difference between water resistant and water proof and a similar difference between freeze resistant and freeze proof. Commented Apr 23, 2020 at 2:43
  • Waterproof? Do you mean like ISO standards for watches? IP Codes for electrical equipment? Something else? With respect to yard hydrants "freeze resistant" is used consistently in Universal Plumbing Code and the underlying ASSE 1057 standard which describes different mechanisms for achieving "freeze resistance". Freeze proof/freezeless/etc. are just marketing terms applied liberally, I wouldn't try to extract fine details where none were put.
    – Serguei
    Commented Apr 23, 2020 at 3:51

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