Hardness
Very Hard
245 PPM · 14.3 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 Pima County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
245 PPM · 14.3 GPG
Compliance screen
Review needed
6 active health-based records
Lead 90th percentile
0 mg/L
0% of action level
Utility match
10 systems
Serves 732,906 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
245 PPM
Parts per million
245
mg/L as CaCO₃ equivalent
Grains per gallon
14.3
1 GPG ≈ 17.1 PPM
What this means at home
At 245 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
27
Nearest site
11.2 mi
Observation range
Jan 11, 2016–Mar 31, 2026
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: D-13-12 10DDA1 (Well).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.
Tucson median
245 PPM
About the same23 indexed ZIP readings · Range 209.5–245.5 PPM
Arizona median
241 PPM
About the same285 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, 2027
Copper (CU90)
Not available
No numerical 90th-percentile result
Numerical coverage
3 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 UG/L
Local 56
EPA limit 0.01
Measured in MG/L
Local 4.2
EPA limit 4
100% line = listed limit
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Revised Total Coliform Rule | AZ0410074 | Unaddressed | Mar 1, 2026 |
| Revised Total Coliform Rule | AZ0410435 | Unaddressed | Mar 1, 2026 |
| Revised Total Coliform Rule | AZ0410051 | Unaddressed | Feb 1, 2026 |
| Revised Total Coliform Rule | AZ0410435 | Unaddressed | Feb 1, 2026 |
| Ethylbenzene | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| trans-1,2-Dichloroethylene | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| 1,1,1-Trichloroethane | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| Toluene | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| Radium-228 | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| Vinyl chloride | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| Carbon tetrachloride | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| Combined Radium (-226 and -228) | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| Tetrachloroethylene | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| 1,1,2-Trichloroethane | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| 1,1-Dichloroethylene | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| 1,2-Dichloropropane | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| p-Dichlorobenzene | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| 1,2-Dichloroethane | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| Styrene | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
| Radium-226 | AZ0410112 | Archived | Jan 1, 2026through Mar 31, 2026 |
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 Tucson ZIP 85716 using 245 PPM nearby hardness and 3 reported measurement benchmarks.
Scale protection
245 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, Fluoride 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 6 active health-based violations among the associated community water systems. Review the affected utility's current notice and Consumer Confidence Report.
Nearby USGS observations produce an estimate of 245 PPM, or 14.3 grains per gallon, classified as very hard. This is not a household tap measurement.
At 245 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.