Hard water in Guadalupe, AZ

Tap water hardness
172mg/L
10.1gpg
Hard

Reported by Phoenix City of · October 2025

AZ typical
180 mg/L
EPA health violations since 2016
1
Softener for 3 people
24k grain
Data
Utility report

The water in Guadalupe carries roughly 172 mg/L of dissolved calcium and magnesium, or 10.1 grains per gallon. That is hard water. The number comes from Phoenix City of, dated October 2025.

Guadalupe on the hardness scale, with nearby cities
060120180240300360+AZ typical 180Sun Lakes: 103 mg/LSun Lakes 103Avondale: 105 mg/LAvondale 105Chandler: 139 mg/LChandler 139Gilbert: 168 mg/LGilbert 168Glendale: 168 mg/LGlendale 168Paradise Valley: 171 mg/LParadise Valley 171Queen Creek: 178 mg/LQueen Creek 178Tempe: 180 mg/LTempe 180Maricopa: 220 mg/LMaricopa 220Phoenix: 237 mg/LPhoenix 237Guadalupe 172mg/L as calcium carbonate060120180240300360+AZ 180Sun Lakes: 103 mg/LSun Lakes 103Chandler: 139 mg/LChandler 139Gilbert: 168 mg/LGilbert 168Paradise Valley: 171 mg/LParadise V. 171Tempe: 180 mg/LTempe 180Phoenix: 237 mg/LPhoenix 237172 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Guadalupe sits close to the typical Arizona figure of 180 mg/L. Of the 10 nearest cities we track, 6 have softer water and 4 have harder. The range nearby runs from 103 mg/L in Sun Lakes to 237 in Phoenix.

What 172 mg/L means at home

Expect white crust on faucets and showerheads, plus spots on dishes that come out of the dishwasher.

Kettles collect scale quickly. Water heaters build up sediment at the bottom of the tank, which makes them work harder over time.

Soap and detergent need a little more to lather, and soap scum shows up in the tub.

Hardness is not a health problem, and EPA sets no limit for it. It is a matter of scale and soap.

What to do about it

At 172 mg/L most of the trouble is scale, and only a few things deal with it.

Ion-exchange water softener

The standard whole-house fix. It swaps calcium and magnesium for sodium or potassium and needs salt plus a drain. Size it with the calculator below.

Salt-free conditioner

No salt and no drain line. It changes how minerals form scale instead of removing them, so water still tests hard.

Reverse osmosis or carbon filter

Under-sink reverse osmosis removes minerals from drinking water only. Plain carbon filters improve taste but do not soften.

Softener size for Guadalupe

3 people × 75 gallons a day × 10.1 gpg = 2,261 grains a day. A 24,000-grain unit regenerates about every 10 days.

Size it for your household

EPA record for Guadalupe's water system

Phoenix City of · PWSID AZ0407025

1 health-based violation since 2016

Serves about 1,695,000 people from surface water.

Health-based
1
Monitoring or reporting
3
Open now
0

TapWaterData ties Guadalupe to this system. EPA's service-area records do not name Guadalupe, so check the utility printed on your water bill.

20162017201820192020202120222023202420252026Surface Water Treatment Rule'16'18'20'22'24'26Surface Water Treatment Rule
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Surface Water Treatment Rulefiltration and disinfection12021Resolved

Health-based means a contaminant above its legal limit or a missed treatment step. Monitoring and reporting violations are late or missing tests and notices. Source: EPA ECHO, 2026Q3 export, violations with periods starting 2016 or later. Full EPA record.

Questions

Is Guadalupe water hard?

Yes. It measures about 172 mg/L (10.1 grains per gallon), which the USGS classes as hard.

What is the water hardness in Guadalupe in grains per gallon?

About 10.1 gpg. One grain per gallon equals 17.1 mg/L, so 172 mg/L divided by 17.1 gives 10.1.

What size water softener do I need in Guadalupe?

For 3 people using 75 gallons each per day, 10.1 gpg works out to about 2,261 grains a day. A 24,000-grain softener covers that with a regeneration about every 10 days.

Has the Guadalupe water system had EPA violations?

EPA records show 1 health-based violation for Phoenix City of since 2016, involving Surface Water Treatment Rule. There were also 3 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 42 cities in Arizona

Hardness data: TapWaterData US Water Hardness (utility report, October 5, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.