At least three years in Phoenix. City Code 37-143 counts from the date a copy went to the city, while the city's TRT 00636 guidance counts from the test date, so count from the later date. Arizona's state rule makes water systems keep their records three years. Mesa, Scottsdale and Tempe require records but set no period, so keep them for the assembly's life.
What Arizona and Valley cities require
Only two rules on the books give a number, and both say three years. The rest put a record duty on you without a clock.
| Who sets the rule | Who has to keep records | How long | What the rule says |
|---|---|---|---|
| Arizona (A.A.C. R18-4-215) | The public water system | At least three years | Records of installations and tests, plus an inventory of required assemblies |
| Phoenix (City Code 37-143) | The customer | At least three years; the code counts from the date the city got a copy, the city's guidance from the test date | Testing records, on the city's forms |
| Mesa (City Code 8-1-11) | The customer | No period stated | Each testing record goes to the city within seven calendar days or by the due date |
| Scottsdale (Revised Code 49-65) | The user | No period stated | Records of installation, testing, maintenance, repairs and replacements |
| Tempe (City Code 33-107) | The user | No period stated | Accurate records of tests and repairs, with parts used |
### The state rule is about the water system
The state rule, R18-4-215, puts the three-year duty on the utility. Arizona's backflow rule says "Records shall be retained by the public water system for at least three years and shall be made available for review by the Department upon request." Those backflow records must include, for each assembly, its identification number and description, location, test dates, repairs and repair recommendations, and "The tester's name and certificate number."
That's worth knowing for one reason. If your own copy goes missing, your water provider should have the last few years on file. Phoenix's code backs this up, too: the city "will keep adequate records of each test of an approved backflow prevention assembly and any subsequent maintenance or repair thereof." Call the provider's backflow office and ask for what they hold.
### Phoenix puts a clock on the customer
Phoenix goes further than the state. City Code 37-143 says "The customer shall submit copies of testing records pertaining to assemblies, on forms approved by the Planning and Development Director, by the date specified by the Planning and Development Director." Then comes the three-year retention line.
Notice where the clock starts, because Phoenix states it two ways. The code counts from the date a copy reached the city. The city's customer guidance, TRT 00636, says "The customer shall retain all records for a minimum of three years from the backflow assembly test date." The report always reaches the city after the test, so counting from the filing date meets both rules. A test done in late March and filed in early April is safe to discard in April three years on, not March.
The word customer is broad in Phoenix. The code defines a customer as "any person that has physical control, authority or responsibility for a water system that receives water service from the City public water system." So the duty can land on whoever runs the water system, including a manager or tenant with that control.
### Mesa, Scottsdale and Tempe: keep and send, no set period
Mesa's code is built around getting the record in on time. It says a testing record "must be submitted to the Department within seven calendar days after completion of the testing activity for which the record is made or by the compliance due date, whichever is sooner" (City Code 8-1-11). Late records bring a late fee. Mesa can also end water service if "any testing records have not been timely provided to the Department" (City Code 8-1-13).
Scottsdale's code says "The user shall maintain records, of the results of all installation, testing, maintenance, repairs, and replacements of the backflow prevention assemblies on forms approved by the Division" (Revised Code 49-65). Tempe's says "The user shall maintain accurate records of tests and repairs made to backflow prevention assemblies and provide the department with copies of such records" (City Code 33-107). Neither code sets an end date. Read literally, the duty to maintain records runs as long as you're the user.
Why three years is a floor
Three years is the legal minimum in Phoenix, and it's a thin one in practice. A few common situations call for records that go back further.
A notice says a report is missing. Phoenix can end water service to a customer who "Fails to timely submit records of tests and repairs of a backflow prevention assembly" (City Code 37-146). It can also add a civil penalty on water charges until the problem is fixed. Your copy, with the date it was sent, is the fastest way to show the report was filed.
The building changes hands. A buyer or a new property manager needs the assembly history to plan the next test and budget for repairs. Records that stop at three years leave gaps about when an assembly was installed or rebuilt.
An assembly keeps failing. Tempe requires records to "include the list of materials or replacement parts used." A long run of reports shows whether the same check valve fails every year. That history helps you decide between another repair and a replacement.
A brand-new assembly. Tempe won't issue a certificate of occupancy until the test results for a newly installed assembly are submitted with a request for inspection approval (City Code 33-107). That first report, with its permit number, is the start of the assembly's paper trail. Keep it for as long as the assembly is in the ground.
Fire systems. Records for fire sprinkler assemblies follow fire rules, too. Scottsdale requires annual inspection of certain fire system check valves "with records of the inspections provided to the fire department and the Division" (Revised Code 49-65). Those tests go to a fire-licensed contractor, but the owner should still keep the copies in the same file.
What your tester keeps, and why you should ask for it
Your tester has records of their own, and the one that matters most to you is the gauge calibration. A test reading is only as good as the gauge that took it.
Mesa requires recognized testers to calibrate their test equipment every year and send the city an accuracy report. Its code says "An equipment accuracy report dated more than one year old will be considered expired" (City Code 8-1-12). Phoenix's tester application records each test instrument's manufacturer, model and serial number, along with the calibration company and date.
Every Phoenix test report also carries the tester's certification number and test kit serial number. So ask for a copy of the calibration sheet that matches that serial number, and file it with the report. If a reading is ever questioned, you'll have both halves: the result and proof the gauge was in calibration that day.
For what each line of a report means and what to ask a tester before you hire one, see how to hire a backflow tester and what's on the report.
How to keep a backflow assembly file
Keep one file per assembly, named by its serial number. A building with an RP at the meter, a double check on the irrigation and a vacuum breaker on a boiler has three files, not one. Paper or digital works, as long as someone other than the tester can find it.
Put these in each file:
- 1The install record. Permit number, install date, make, model, size and serial number.
- 2Every test report. Initial, annual and after-repair tests, each with the tester's name, certificate number and test kit serial number.
- 3Proof of filing. The email, portal receipt or tester's written note showing the date the report went to the water provider. In Phoenix, count your three years from that date; it's later than the test date, so it covers both of the city's rules.
- 4Repair details. Parts replaced, with part numbers, and the date the assembly passed again.
- 5Calibration sheets. The tester's gauge calibration for each test date.
- 6Letters from the provider. Test notices, missing-report notices and any replies.
Set one reminder a month before each compliance date, and another a week after the test to confirm the report was received. That covers most of what goes wrong.
If you're not sure where reports go in your city, see where to send backflow test reports in the Phoenix area. If a notice already says you're late, read what happens when you miss a Phoenix backflow test deadline. And for the full annual cycle, see commercial backflow testing requirements in Arizona.
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