Hardness
Very Hard
209.5 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 Pima County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
209.5 PPM · 12.3 GPG
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0 mg/L
0% of action level
Utility match
5 systems
Serves 310 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
209.5 PPM
Parts per million
209.5
mg/L as CaCO₃ equivalent
Grains per gallon
12.3
1 GPG ≈ 17.1 PPM
What this means at home
At 209.5 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
8
Nearest site
19.8 mi
Observation range
Jan 11, 2016–Aug 16, 2016
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: D-13-12 09AAA1 (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.
Three Points median
227 PPM
17 PPM lower2 indexed ZIP readings · Range 209.5–244 PPM
Arizona median
241 PPM
31 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
1 comparable result
Missing values remain blank; absence is not treated as a pass.
Measured in mg/L
Local 0
EPA limit 0.015
100% line = listed limit
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Revised Total Coliform Rule | AZ0410132 | Unaddressed | Mar 1, 2026 |
| LEAD AND COPPER RULE REVISIONS | AZ0410132 | Unaddressed | Jul 2, 2025 |
| Total Haloacetic Acids (HAA5) | AZ0410206 | Archived | Jan 1, 2025through Dec 31, 2025 |
| TTHM | AZ0410206 | Archived | Jan 1, 2025through Dec 31, 2025 |
| Lead and Copper Rule | AZ0410132 | Resolved | Oct 1, 2024through Oct 15, 2025 |
| Lead and Copper Rule | AZ0410265 | Resolved | Jan 1, 2024through Jan 17, 2024 |
| Public Notice | AZ0410132 | Resolved | Jan 1, 2024through Sep 23, 2025 |
| Revised Total Coliform Rule | AZ0410132 | Resolved | Jan 1, 2024through Mar 5, 2024 |
| Nitrate | AZ0410132 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| E. COLI | AZ0410132 | Resolved | Aug 8, 2023through Sep 22, 2023 |
| Chlorine | AZ0410317 | Resolved | Oct 1, 2022through Dec 31, 2022 |
| Lead and Copper Rule | AZ0410132 | Resolved | Oct 1, 2022through Oct 18, 2023 |
| Revised Total Coliform Rule | AZ0410132 | Resolved | Dec 1, 2021through Jan 21, 2022 |
| Public Notice | AZ0410132 | Resolved | Oct 2, 2021through Dec 8, 2021 |
| Consumer Confidence Rule | AZ0410132 | Resolved | Oct 2, 2021through Nov 8, 2021 |
| Chlorine | AZ0410132 | Resolved | Oct 1, 2021through Dec 31, 2021 |
| Consumer Confidence Rule | AZ0410317 | Unaddressed | Jul 1, 2002 |
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 Three Points ZIP 85735 using 209.5 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
209.5 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 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.
Nearby indexed reports
Estimates can differ across a city because monitoring locations and associated systems differ.
Frequently asked
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.
Nearby USGS observations produce an estimate of 209.5 PPM, or 12.3 grains per gallon, classified as very hard. This is not a household tap measurement.
At 209.5 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.