Backflow Protection for Reclaimed and Canal Water Sites

The city can only vouch for water it delivers. Once a property also has reclaimed water in purple pipe, a canal turnout, a well or a lake fill line, there's a path for that water to reach the drinking water side through one mistake: a hose run between two bibs, a jumper during a repair, a swapped valve. Mesa's code counts exactly those things as cross-connections: "bypass arrangements, jumper connections, removable sections, swivel or change-over devices."

So the state rule, A.A.C. R18-4-215(B)(2), requires an assembly wherever a water source the system hasn't accepted exists on the premises. The Valley cities then pick the top levels of protection for it: an RP, or an air gap.

Mesa's program page casts the net wide. Its list of auxiliary water includes reclaimed water, well water, impoundments, another provider's water, grey water and recycled rain water, and it says such customers need an RP on all potable connections.

Two details catch owners off guard. First, Mesa's definitions say an air gap is the method required for backflow protection of sewage or reclaimed water, which matters where potable water tops off a reclaimed system or pond. Second, Gilbert's rule applies to every potable meter on the property, not just the one near the landscape.

The assembly on your drinking water service is tested at least once a year by a certified tester, like any other required assembly. Chandler draws one line worth knowing: devices installed on reclaimed water services are exempt from its annual testing requirement, while the assemblies protecting city potable water are not. Chandler also handles one case itself. Under City Code 52-34.3, when new homes use reclaimed water, the city installs an RP in the right-of-way at the homebuilder's expense and tests and maintains it.

For commercial, HOA and school campuses, the potable-side RP is yours. It's tested on the same notice cycle as any other assembly. See commercial backflow testing for filing by city.

The assembly is the last line, not the only one. Day to day, the risk is people. Here's the play:

• Label and color. Reclaimed piping is typically purple and marked, so keep it that way after repairs. Our FAQ on what purple pipe means explains the color code.
• No shared hoses. A hose that moves between a reclaimed bib and a potable bib is a cross-connection waiting to happen.
• Watch repairs. A landscaper who ties a broken reclaimed lateral into a nearby potable line has created the exact hazard the RP exists for.
• Know your assemblies. Phoenix's report form records whether an assembly protects a fire system, landscaping or potable water. Keep a list so each one gets its test.

If your irrigation runs on city water through its own meter and there's no other source on site, the ordinary landscape rules apply. A PVB may be allowed. See commercial irrigation backflow testing. Fire service protection on reclaimed sites (Gilbert's rule names fire services too) goes to a fire protection contractor. Fire backflow assemblies and fire sprinkler work are outside what HQ does.

HQ tests, repairs and replaces the domestic RPs that protect the drinking water service on reclaimed, canal and well water sites, and files the results with the city. We don't work on the reclaimed system's pumps or controls. If an RP is dumping water or failed its test, we rebuild it and retest it on the same visit when we have the parts. You get an upfront price before work starts and free estimates for replacements. Related: HOA plumbing, school plumbing, backflow assembly repair and leak detection.