Prescott Hard Water Guide: Softeners, Wells, RO (2026)

Updated October 22, 2026. This guide is general information, not legal or engineering advice. Rules change, so confirm with the agency listed before you start work.

Quick reference

Topic	What to know	Source
Prescott hardness	Moderately hard: 75 to 130 ppm, or 4.3 to 7.6 grains per gallon	City of Prescott water quality report (2024)
Prescott source	Seven wells in the Prescott AMA, Little Chino Sub-Basin	City of Prescott water quality report
Sodium in city water	Prescott 14 ppm; Chino Valley 16 ppm	City of Prescott (2024); Town of Chino Valley (2025)
Softener sodium	About 7.9 mg/L added per grain per gallon removed	University of Arizona Extension (AZ1799)
RO wastewater	Roughly 3 to 8 gallons per gallon treated	University of Arizona Extension (AZ1799)
Private wells	Owner is responsible; no law requires testing	University of Arizona Extension
Contractor license	ROC Water Conditioning Equipment: R-54 (residential), C-54, CR-54	Arizona ROC
Handyman exemption	Under $1,000 total, minor work, no building permit needed	A.R.S. 32-1121(A)(14)

How hard is the water in Prescott?

The City of Prescott's annual water quality report for 2024 calls the city's water moderately hard, averaging 75 to 130 parts per million, which the city converts to 4.3 to 7.6 grains per gallon. Hardness is the dissolved calcium and magnesium in the water. The same report lists sodium at 14 ppm. If you're in Prescott Valley, Chino Valley, Dewey-Humboldt or on a private well, those numbers may not apply to you; check your own provider's report or test your water.

Where does the water come from?

Prescott produces its water from seven production wells in the Prescott Active Management Area, drilled into the confined deep Lower Volcanic Unit of the aquifer underlying the Little Chino Sub-Basin. The Town of Chino Valley's system also uses groundwater wells in the Little Chino Sub-Basin. Groundwater picks up minerals from the rock it passes through, which is where the hardness comes from.

What else is in the reports?

Both reports list arsenic, which comes mainly from erosion of natural deposits. Prescott's 2024 report shows a range of 1.8 to 8.0 parts per billion against a federal limit of 10, and the city manages it by blending water from different wells and treating one well with adsorptive media. Chino Valley's 2025 report shows a high of 7.5 ppb, with no violation. A softener doesn't treat arsenic. If you want to reduce it at the tap, ask a water treatment company which point-of-use systems are certified for it, and read your provider's latest report.

Do softeners add sodium?

Yes. University of Arizona Cooperative Extension says sodium-based softeners increase the sodium in your water, by roughly 7.9 mg/L for each grain per gallon of hardness removed, and that it's best to avoid drinking softened water. Common advice is to leave a cold-water tap unsoftened or add a reverse osmosis faucet for drinking and cooking.

What about reverse osmosis?

RO lowers dissolved solids, including sodium and hardness minerals. Extension notes that hard water fouls RO membranes, so RO often follows a softener, and that home RO units produce roughly 3 to 8 gallons of wastewater per gallon of treated water. For homes on septic, Extension suggests routing RO wastewater outside to irrigate salt-tolerant plants to lower the flow and salt load to the system.

I'm on a private well. What should I do?

Test it. University of Arizona Extension's well owner's guide says owners are responsible for the upkeep of their well and the quality of its water, and there are no federal or state laws requiring a private well to be tested. A lab test tells you whether hardness is the main issue or whether iron, sediment or other problems need treatment first.

Who can install a water softener in Arizona?

The Arizona Registrar of Contractors licenses this work. Its Water Conditioning Equipment classification (R-54 residential, C-54 commercial, CR-54 dual) covers installing and repairing water conditioning equipment and the piping, valves and indirect waste piping for brine and backwash. Plumbing classifications also cover some water conditioning work. Under A.R.S. 32-1121(A)(14), unlicensed work is allowed only for minor jobs where the total price, including labor and materials, is under $1,000 and no local building permit is required, and anyone advertising under that exemption must say "not a licensed contractor." Check a company's license on the ROC website, and ask your city or town whether your installation needs a permit.

Questions to ask a water treatment company

What ROC license do you hold, and can I see the number?
What hardness did you measure, and how did you size the unit?
Will outdoor and irrigation lines stay unsoftened?
Where will the regeneration and RO drain water go?
What maintenance does the system need, and what's warrantied?

Common questions

How hard is Prescott, AZ water?

The City of Prescott's 2024 report says it's moderately hard, averaging 75 to 130 ppm, or 4.3 to 7.6 grains per gallon.

What license does a water softener installer need in Arizona?

The Arizona Registrar of Contractors has a Water Conditioning Equipment classification (R-54, C-54 and CR-54). Plumbing licenses cover some of this work too.

Do I have to test my private well in Arizona?

No law requires it, but University of Arizona Extension says well owners are responsible for their water quality and recommends testing.

Prescott hard water guide (2026)