Hard water in Eloy, AZ
Reported by Picacho Water Company · August 2025
- AZ typical
- 180 mg/L
- EPA health violations since 2016
- 3
- Softener for 3 people
- 32k grain
- Data
- Utility report
Eloy water measures 343 mg/L (20.1 gpg) of hardness, very hard by USGS standards. The number comes from Picacho Water Company, dated August 2025.
Eloy sits 163 mg/L above the typical Arizona figure of 180. None of the 10 nearest cities we track has harder water. The range nearby runs from 103 mg/L in Sun Lakes to 220 in Casa Grande.
What 343 mg/L means at home
Scale forms fast here. Kettles and coffee makers need regular descaling, and showerheads clog unless you clean them.
Tank water heaters collect mineral sediment that insulates the water from the burner, so flushing the tank matters more than usual.
Dishes and glass shower doors spot easily. Soap scum and a dull film on hair or laundry are common complaints.
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 343 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.
3 people × 75 gallons a day × 20.1 gpg = 4,513 grains a day. A 32,000-grain unit regenerates about every 7 days.
EPA record for Eloy's water system
3 health-based violations since 2016
Serves about 8,999 people from groundwater.
- Health-based
- 3
- Monitoring or reporting
- 33
- Open now
- 1
EPA lists Eloy City of as the system serving Eloy. The hardness figure above comes from a different system's report, which TapWaterData uses for Eloy.
| Contaminant or rule | Violations | Period | Status |
|---|---|---|---|
| Groundwater Ruletreatment of well water | 1 | 2026 | 1 open |
| Nitrateoften from fertilizer or septic systems | 2 | 2026 | Resolved |
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 Eloy water hard?
Yes. It measures about 343 mg/L (20.1 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Eloy in grains per gallon?
About 20.1 gpg. One grain per gallon equals 17.1 mg/L, so 343 mg/L divided by 17.1 gives 20.1.
What size water softener do I need in Eloy?
For 3 people using 75 gallons each per day, 20.1 gpg works out to about 4,513 grains a day. A 32,000-grain softener covers that with a regeneration about every 7 days.
Has the Eloy water system had EPA violations?
EPA records show 3 health-based violations for Eloy City of since 2016, involving Groundwater Rule, Nitrate. There were also 33 monitoring or reporting violations, which are about late or missing tests and notices.
Nearby cities
- Casa Grande220 mg/LVery hard
- Florence109 mg/LModerately hard
- San Tan Valley109 mg/LModerately hard
- Maricopa220 mg/LVery hard
- Queen Creek178 mg/LHard
- Sun Lakes103 mg/LModerately hard
- Gilbert168 mg/LHard
- Chandler139 mg/LHard
- Tucson Mountains180 mg/LHard
- Casas Adobes180 mg/LHard
Hardness data: TapWaterData US Water Hardness (utility report, August 18, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.