Hardness
Very Hard
340.5 PPM · 19.9 GPG
Local water dashboard
Official source aggregationWater quality in Tombstone, AZ 85638
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Cochise County.
No active health-based violation reported
- Primary matched system
- Tombstone City Of
- Source water
- Surface water + Groundwater
- County
- Cochise County
- Profile updated
At a glance
What the current records say
EPA quarter 2026Q2
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0 mg/L
0% of action level
Utility match
3 systems
Serves 1,545 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
340.5 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
340.5
mg/L as CaCO₃ equivalent
Grains per gallon
19.9
1 GPG ≈ 17.1 PPM
What this means at home
At 340.5 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
6
Nearest site
24.7 mi
Observation range
Jan 22, 2020–Nov 2, 2022
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: UPPER CORO HEADQUARTERS WASH (Stream).USGS source documentation ↗
Regional context
Is 85638 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Tombstone median
341 PPM
About the same1 indexed ZIP readings · Range 340.5–340.5 PPM
Arizona median
241 PPM
100 PPM higher285 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 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
EPA limit 0.015
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 17
- Health-based
- 1
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Surface Water Treatment RuleHealth-based | AZ0402033 | Archived | Feb 1, 2026through Feb 28, 2026 |
| E. COLI | AZ0402018 | Resolved | Oct 27, 2025through Mar 5, 2026 |
| Consumer Confidence Rule | AZ0402033 | Resolved | Oct 2, 2025through Mar 26, 2026 |
| Lead and Copper Rule | AZ0402018 | Resolved | Oct 1, 2024through Oct 15, 2024 |
| Surface Water Treatment Rule | AZ0402033 | Resolved | Aug 1, 2023through Aug 31, 2023 |
| Interim Enhanced Surface Water Treatment Rule | AZ0402033 | Resolved | Aug 1, 2023through Aug 31, 2023 |
| E. COLI | AZ0402018 | Resolved | Jul 14, 2023through Aug 21, 2023 |
| E. COLI | AZ0402018 | Resolved | Jun 15, 2023through Jul 28, 2023 |
| Revised Total Coliform Rule | AZ0402018 | Resolved | Apr 1, 2023through May 16, 2023 |
| Consumer Confidence Rule | AZ0402018 | Resolved | Oct 2, 2022through Aug 15, 2023 |
| Consumer Confidence Rule | AZ0402018 | Resolved | Jul 1, 2022through Aug 15, 2023 |
| Surface Water Treatment Rule | AZ0402033 | Resolved | Apr 1, 2022through Apr 30, 2022 |
| Interim Enhanced Surface Water Treatment Rule | AZ0402033 | Resolved | Apr 1, 2022through Apr 30, 2022 |
| Chlorine | AZ0402013 | Resolved | Jan 1, 2022through Mar 31, 2022 |
| TTHM | AZ0402033 | Resolved | Aug 1, 2021through Jul 31, 2022 |
| Interim Enhanced Surface Water Treatment Rule | AZ0402033 | Resolved | Jul 1, 2021through Jul 31, 2021 |
| Interim Enhanced Surface Water Treatment Rule | AZ0402033 | Resolved | Jun 1, 2021through Jun 30, 2021 |
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 Tombstone ZIP 85638 using 340.5 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
340.5 PPM is 3× 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 Tombstone
Is tap water safe in Tombstone?+
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.
How hard is the water?+
Nearby USGS observations produce an estimate of 340.5 PPM, or 19.9 grains per gallon, classified as very hard. This is not a household tap measurement.
Do I need a water softener?+
At 340.5 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.