Hardness
Very Hard
211 PPM · 12.3 GPG
Local water dashboard
Official source aggregationA 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.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
211 PPM · 12.3 GPG
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
Estimated local hardness
USGS hardness classification scale
211 PPM
Parts per million
211
mg/L as CaCO₃ equivalent
Grains per gallon
12.3
1 GPG ≈ 17.1 PPM
What this means at home
At 211 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
28
Nearest site
0.9 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: DUNLAP AND 7TH AVENUE @ PHOENIX, AZ (Stream).USGS source documentation ↗
Regional context
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
About the same47 indexed ZIP readings · Range 97–295 PPM
Arizona median
241 PPM
30 PPM lower285 indexed ZIP readings · Range 66.4–1250 PPM
EPA benchmark screen
Available numerical results from associated SDWIS community water systems, compared with the applicable action level or federal MCL. Federal measured-value coverage is incomplete.
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.
Measured in mg/L
Local 0
EPA limit 0.015
Measured in MG/L
Local 0.011
EPA limit 0.01
100% line = listed limit
| 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
Matched to Phoenix ZIP 85021 using 211 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
211 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
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
Estimates can differ across a city because monitoring locations and associated systems differ.
Frequently asked
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.
Nearby USGS observations produce an estimate of 211 PPM, or 12.3 grains per gallon, classified as very hard. This is not a household tap measurement.
At 211 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.