Hardness
Very Hard
187.5 PPM · 11 GPG
Local water dashboard
Official source aggregationWater quality in Phoenix, AZ 85310
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Maricopa County.
1 active health-based violation
- Primary matched system
- Phoenix City Of
- Source water
- Surface water + Groundwater
- County
- Maricopa County
- Profile updated
At a glance
What the current records say
EPA quarter 2026Q2
Compliance screen
Review needed
1 active health-based record
Lead 90th percentile
0 mg/L
0% of action level
Utility match
9 systems
Serves 1,695,000 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
187.5 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
187.5
mg/L as CaCO₃ equivalent
Grains per gallon
11
1 GPG ≈ 17.1 PPM
What this means at home
At 187.5 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
26
Nearest site
4.9 mi
Observation range
Jan 4, 2016–May 29, 2026
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: CITRUS-GROVERS @ 71ST AVENUE (Stream).USGS source documentation ↗
Regional context
Is 85310 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Phoenix median
211 PPM
23 PPM lower47 indexed ZIP readings · Range 97–295 PPM
Arizona median
241 PPM
53 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 pass1 fail
Lead (PB90)
0 mg/L
Reported Dec 31, 2025
Copper (CU90)
Not available
No numerical 90th-percentile result
Numerical coverage
2 comparable results
Missing values remain blank; absence is not treated as a pass.
Lead (90th percentile)
Measured in mg/L
Local 0
EPA limit 0.015
Arsenic
Measured in MG/L
Local 0.011
EPA limit 0.01
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 60
- Health-based
- 9
- Active health-based
- 1
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Lead and Copper Rule | AZ0407307 | Unaddressed | Jan 1, 2026 |
| ArsenicHealth-basedReported 0.011 MG/L · MCL 0.01 | AZ0407682 | Archived | Jan 1, 2026through Mar 31, 2026 |
| Revised Total Coliform Rule | AZ0407700 | Archived | Dec 1, 2025through Dec 31, 2025 |
| Public Notice | AZ0407280 | Unaddressed | Nov 16, 2025 |
| Revised Total Coliform Rule | AZ0407621 | Resolved | Nov 1, 2025through Jan 20, 2026 |
| Groundwater RuleHealth-based | AZ0407280 | Unaddressed | Oct 29, 2025 |
| Consumer Confidence Rule | AZ0407682 | Resolved | Oct 2, 2025through Nov 17, 2025 |
| Consumer Confidence Rule | AZ0407280 | Resolved | Oct 2, 2025through Mar 31, 2026 |
| Chlorine | AZ0407700 | Archived | Oct 1, 2025through Oct 31, 2025 |
| Revised Total Coliform Rule | AZ0407621 | Resolved | Aug 1, 2025through Oct 20, 2025 |
| LEAD AND COPPER RULE REVISIONS | AZ0407621 | Unaddressed | Jul 2, 2025 |
| Consumer Confidence Rule | AZ0407280 | Resolved | Jul 1, 2025through Jul 1, 2025 |
| Revised Total Coliform Rule | AZ0407025 | Resolved | May 1, 2025through May 31, 2025 |
| Surface Water Treatment Rule | AZ0407025 | Archived | May 1, 2025through May 31, 2025 |
| Public Notice | AZ0407700 | Resolved | Dec 20, 2024through Feb 12, 2025 |
| Public Notice | AZ0407307 | Resolved | Dec 20, 2024through Feb 26, 2025 |
| Public Notice | AZ0407280 | Unaddressed | Dec 20, 2024 |
| LEAD AND COPPER RULE REVISIONS | AZ0407700 | Resolved | Oct 17, 2024through Apr 17, 2025 |
| LEAD AND COPPER RULE REVISIONSHealth-based | AZ0407700 | Resolved | Oct 17, 2024through Apr 17, 2025 |
| LEAD AND COPPER RULE REVISIONSHealth-based | AZ0407307 | Resolved | Oct 17, 2024through Feb 26, 2025 |
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 Phoenix ZIP 85310 using 187.5 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
187.5 PPM is 2× 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 systemsDrinking water protection
Under-Sink Reverse Osmosis System
Arsenic, Groundwater Rule have a measured benchmark flag or active health-based SDWIS record in this profile.
A certified multi-stage RO system targets a broader range of dissolved contaminants at the kitchen tap.
Explore under-sink filtrationAffiliate 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.
Nearby indexed reports
Compare ZIPs in Phoenix
Estimates can differ across a city because monitoring locations and associated systems differ.
Frequently asked
Water questions for Phoenix
Is tap water safe in Phoenix?+
EPA ECHO reports 1 active health-based violation among the associated community water systems. Review the affected utility's current notice and Consumer Confidence Report.
How hard is the water?+
Nearby USGS observations produce an estimate of 187.5 PPM, or 11 grains per gallon, classified as very hard. This is not a household tap measurement.
Do I need a water softener?+
At 187.5 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.