Water testing in Phoenix is the step that turns a guess into a choice. The City of Phoenix report gives ranges for its whole system; a test at your own tap shows where your home sits in them, and it is what any softener, filter or reverse osmosis system should be chosen from.
Water Treatment Phoenix is an independent referral service, not an installer, plumber or water utility. When you send the form, your details go to an independent local water treatment pro who can contact you and prepare a quote.
What the city’s report already tells you
For City of Phoenix customers, the 2025 water quality report gives total hardness of 172 to 302 ppm (10 to 17.6 grains per gallon) and total dissolved solids of 464 to 716 ppm. It says about 97 to 99% of the water came from the Salt, Verde and Colorado rivers and about 2% from about 20 city wells. It also says taste, odor and hardness are not regulated under drinking water health standards.
Those are ranges. Your tap is one point in them, and that point is what matters for sizing a softener or deciding whether reverse osmosis will make a difference.
What to test at your tap
| Test | Why it matters | Reference |
|---|---|---|
| Hardness | Sets the size and setting of a softener | USGS: over 180 mg/L is very hard |
| Total dissolved solids | Shows whether RO will change your drinking water | EPA secondary guideline 500 mg/L |
| Iron and manganese | Explains rusty or black staining | EPA 0.3 mg/L iron, 0.05 mg/L manganese |
| pH | A basic reading of the water | EPA secondary range 6.5 to 8.5 |
| Chloride | Explains a salty taste | EPA 250 mg/L |
EPA’s secondary standards are non-mandatory guidelines for taste, color and staining. They are useful reference points when you read results.
Start with a question
Good advice on home treatment begins with one question: what contaminant do you want to remove or reduce? Testing answers that. If the problem is scale, hardness is the figure you need. If it is staining, test for iron and manganese. If you have a specific concern, ask for that contaminant by name, and choose treatment certified to remove it.
Testing before and after
A test is also how you check that a system works. Ask for hardness to be measured before and after a softener, and dissolved solids at the RO faucet and at the main kitchen tap. Write the figures down and keep them with the equipment. If they drift later, ask the pro to check the system.
Private wells
If your home draws from a private well instead of a city system, different rules apply. EPA says private well owners are responsible for delivering safe drinking water to their households, and advises testing a private well every year for total coliform bacteria, nitrates, total dissolved solids and pH, using a laboratory certified for drinking water testing. Test right away if conditions near the well change, or after any part of the well is repaired or replaced.
Reading the results
Results come in different units. Reports give parts per million (ppm) or milligrams per liter (mg/L) for the same measure; the City of Phoenix report compares its ppm figures directly with EPA’s mg/L guidelines. Hardness may also be given in grains per gallon; one grain is about 17 mg/L. Compare each result with its reference: hardness against the USGS scale, where over 180 mg/L is very hard; dissolved solids against EPA’s 500 mg/L guideline; iron, manganese, chloride and pH against EPA’s secondary guidelines. EPA sets its secondary guidelines for aesthetic considerations such as taste, color and odor, and does not enforce them.
Not a City of Phoenix customer?
If your water comes from another Valley city or a private water company, the City of Phoenix figures are not yours. Find the provider’s name on your bill, read its annual water quality report, and then test your own tap. The areas page has notes for Gilbert, Chandler, Mesa, Scottsdale and Peoria.
Want a pro to test the water at your tap?
Asking a pro to test
When a water treatment pro tests your water, ask which tests are being done, what each result was, and how the results led to the system on the quote. A quote that names your hardness and dissolved solids is one you can check. Send the form with what you notice and an independent pro in the Valley can contact you about testing and treatment. Asking is free.
For what the figures mean, see the Phoenix water quality guide and the Phoenix hard water guide.
Ask a local pro