El Mirage's cross-connection rules in City Code 14-10 make the customer responsible for testing and servicing backflow assemblies at least once a year, using a certified tester on the City's list, with repairs and replacement at the customer's expense. For a test or repair, call the number on this page to be connected with a local plumber in El Mirage.

Backflow in El Mirage
The City of El Mirage Water Services Division produces and distributes water for El Mirage and for the Original Town Site of Surprise, close to 40,000 people in all. Its cross-connection code puts the job on the customer: test and service each assembly at least once a year, pay for any repair or replacement, and use a certified tester from the list the City maintains. The tester sends the results and any repair records to the City. Customers in the Original Town Site of Surprise should ask El Mirage whether the same code covers their accounts.
What to do now
- Find your last test date on old paperwork or ask the City.
- Close the irrigation or main valve if the device is leaking hard.
- Book a tester from the City's list. Ask the plumber to confirm before the visit.
- Get a copy of the results after the tester sends them to the City.
- Ask about permits for new devices with Development Services, Building Safety.
Symptoms and likely causes
| Symptom | Likely cause |
|---|---|
| Water from the relief port | Worn or fouled check valve |
| Vent cap spitting when sprinklers start | Tired poppet seal |
| Weak sprinkler pressure | Debris lodged in the assembly |
| Split body after a cold night | Freeze damage |
El Mirage's water report lists hardness of 4 to 9 grains per gallon, averaging 7, which is softer than much of the Valley. Scale is less of a factor here than worn rubber parts baked by long summers. The city sits on the west bank of the Agua Fria River, and lots near Grand Avenue and Thunderbird Road share the same exposure to heat.
Cost factors
- Pass as found, or rebuild and retest
- Device type and size
- Replacement of cracked or discontinued units
- Permit for a new device
- How many assemblies the property has
- Access, if the device is hidden in plants or gravel
When you call through this page, say whether you're in El Mirage proper or the Original Town Site of Surprise, and what the device protects: irrigation, a pool, a business line or a fire sprinkler system. Ask the plumber to confirm they're on the City's tester list, and request a copy of the results they send in so you have your own record of the annual test.
Backflow Testing questions in El Mirage
How often does a backflow assembly have to be tested here?
Who is allowed to test my backflow assembly?
Who pays for testing, repairs and replacement?
Where should the assembly sit on my property?
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