Hardness
Very Hard
245 PPM · 14.3 GPG
Local water dashboard
Official source aggregationWater quality in Sonoita, AZ 85637
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Santa Cruz County.
1 active health-based violation
- Primary matched system
- Sonoita Valley (south) Water Company
- Source water
- Groundwater
- County
- Santa Cruz 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
0.008 mg/L
53% of action level
Utility match
3 systems
Serves 169 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
245 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
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
34.4 mi
Observation range
Jan 11, 2016–Mar 31, 2026
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: SWALLOW SPRING (Spring).USGS source documentation ↗
Regional context
Is 85637 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Sonoita median
245 PPM
About the same1 indexed ZIP readings · Range 245–245 PPM
Arizona median
241 PPM
About the same285 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)
0.008 mg/L
Reported Dec 31, 2024
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 0.008
EPA limit 0.015
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 30
- Health-based
- 4
- Active health-based
- 1
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Public Notice | AZ0412005 | Unaddressed | Oct 18, 2025 |
| Public Notice | AZ0412020 | Resolved | May 12, 2025through May 2, 2025 |
| Groundwater RuleHealth-based | AZ0412020 | Resolved | Mar 23, 2025through Jun 18, 2025 |
| Public Notice | AZ0412005 | Unaddressed | Dec 20, 2024 |
| Public Notice | AZ0412020 | Resolved | Dec 20, 2024through Jul 15, 2025 |
| LEAD AND COPPER RULE REVISIONS | AZ0412005 | Resolved | Oct 17, 2024through Dec 17, 2025 |
| LEAD AND COPPER RULE REVISIONSHealth-based | AZ0412005 | Resolved | Oct 17, 2024through Dec 17, 2025 |
| LEAD AND COPPER RULE REVISIONS | AZ0412020 | Resolved | Oct 17, 2024through Jan 27, 2025 |
| LEAD AND COPPER RULE REVISIONSHealth-based | AZ0412020 | Resolved | Oct 17, 2024through Jan 27, 2025 |
| Combined Uranium | AZ0412005 | Resolved | Oct 1, 2024through Dec 31, 2024 |
| Gross Alpha, Excl. Radon and U | AZ0412005 | Resolved | Oct 1, 2024through Dec 31, 2024 |
| Lead and Copper Rule | AZ0412020 | Resolved | Oct 1, 2024through Oct 15, 2024 |
| Public Notice | AZ0412005 | Resolved | Apr 28, 2024through Jun 28, 2024 |
| Public Notice | AZ0412005 | Resolved | Apr 28, 2024through Jun 28, 2024 |
| Public Notice | AZ0412005 | Resolved | May 18, 2023through Jun 30, 2023 |
| Public Notice | AZ0412005 | Resolved | May 18, 2023through Jun 30, 2023 |
| Combined Uranium | AZ0412005 | Resolved | Jan 1, 2023through Mar 31, 2023 |
| Gross Alpha, Excl. Radon and U | AZ0412005 | Resolved | Jan 1, 2023through Mar 31, 2023 |
| Revised Total Coliform Rule | AZ0412020 | Resolved | Dec 1, 2022through Jan 27, 2023 |
| Consumer Confidence Rule | AZ0412020 | Resolved | Oct 2, 2022through Oct 18, 2022 |
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 Sonoita ZIP 85637 using 245 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
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 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 Sonoita
Is tap water safe in Sonoita?+
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 245 PPM, or 14.3 grains per gallon, classified as very hard. This is not a household tap measurement.
Do I need a water softener?+
At 245 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.