Hardness
Hard
150 PPM · 8.8 GPG
Local water dashboard
Official source aggregationWater quality in Ajo, AZ 85321
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Pima County.
No active health-based violation reported
- Primary matched system
- Ajo Improvement Company
- Source water
- Groundwater
- County
- Pima County
- Profile updated
At a glance
What the current records say
EPA quarter 2026Q2
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0 mg/L
0% of action level
Utility match
3 systems
Serves 2,654 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
150 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
150
mg/L as CaCO₃ equivalent
Grains per gallon
8.8
1 GPG ≈ 17.1 PPM
What this means at home
At 150 PPM, mineral scale can build up on fixtures and heating elements, reduce soap lather, and leave visible spotting. Hardness is primarily an aesthetic and appliance concern—not itself a tap-water safety rating.
USGS sites used
22
Nearest site
29.5 mi
Observation range
Mar 27, 2018–Dec 18, 2024
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: C-16-06 21BAC (Spring).USGS source documentation ↗
Regional context
Is 85321 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Ajo median
150 PPM
About the same1 indexed ZIP readings · Range 150–150 PPM
Arizona median
241 PPM
91 PPM lower285 indexed ZIP readings · Range 66.4–1250 PPM
EPA benchmark screen
Contaminant snapshot
Available numerical results from associated SDWIS community water systems, compared with the applicable action level or federal MCL. Federal measured-value coverage is incomplete.
1 pass
Lead (PB90)
0 mg/L
Reported Dec 31, 2026
Copper (CU90)
Not available
No numerical 90th-percentile result
Numerical coverage
1 comparable result
Missing values remain blank; absence is not treated as a pass.
Lead (90th percentile)
Measured in mg/L
Local 0
EPA limit 0.015
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 14
- Health-based
- 0
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Lead and Copper Rule | AZ0410003 | Unaddressed | Jan 1, 2026 |
| Revised Total Coliform Rule | AZ0410001 | Resolved | Nov 1, 2024through Dec 30, 2024 |
| Revised Total Coliform Rule | AZ0410001 | Resolved | Oct 1, 2024through Dec 5, 2024 |
| Revised Total Coliform Rule | AZ0410001 | Resolved | Sep 1, 2024through Oct 11, 2024 |
| Revised Total Coliform Rule | AZ0410153 | Resolved | Sep 1, 2024through Oct 11, 2024 |
| TTHM | AZ0410001 | Resolved | Jul 1, 2024through Sep 30, 2024 |
| Total Haloacetic Acids (HAA5) | AZ0410001 | Resolved | Jul 1, 2024through Sep 30, 2024 |
| Total Haloacetic Acids (HAA5) | AZ0410153 | Resolved | Jan 1, 2024through Dec 5, 2024 |
| TTHM | AZ0410153 | Resolved | Jan 1, 2024through Dec 5, 2024 |
| TTHM | AZ0410001 | Resolved | Oct 1, 2023through Dec 31, 2023 |
| Total Haloacetic Acids (HAA5) | AZ0410001 | Resolved | Oct 1, 2023through Dec 31, 2023 |
| Arsenic | AZ0410001 | Resolved | Apr 1, 2023through Jun 30, 2023 |
| Arsenic | AZ0410001 | Resolved | Jan 1, 2022through Mar 31, 2022 |
| Arsenic | AZ0410001 | Resolved | Jul 1, 2021through Sep 30, 2021 |
No reported violation does not prove that every contaminant was tested or absent; SDWIS measured values are incomplete and lag state records.
Solutions matcher
Your personalized water action plan
Matched to Ajo ZIP 85321 using 150 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
150 PPM is 1× the high-hardness trigger used by this matcher.
Designed to reduce scale on fixtures, water heaters, glassware, and plumbing throughout the home.
Compare whole-house systemsAffiliate disclosure: we may earn a commission from qualifying purchases, at no added cost to you. Product matching is educational and does not replace certified water testing.
Frequently asked
Water questions for Ajo
Is tap water safe in Ajo?+
EPA ECHO shows no active health-based violation for the associated systems in this reporting snapshot. This does not prove every contaminant is absent; federal records can lag and household plumbing can change tap conditions.
How hard is the water?+
Nearby USGS observations produce an estimate of 150 PPM, or 8.8 grains per gallon, classified as hard. This is not a household tap measurement.
Do I need a water softener?+
At 150 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.