Hardness
Very Hard
380 PPM · 22.2 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 Canadian County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
380 PPM · 22.2 GPG
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0 mg/L
0% of action level
Utility match
1 system
Serves 7,542 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
380 PPM
Parts per million
380
mg/L as CaCO₃ equivalent
Grains per gallon
22.2
1 GPG ≈ 17.1 PPM
What this means at home
At 380 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
5
Nearest site
8.4 mi
Observation range
Jan 5, 2016–May 21, 2026
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: North Canadian River near Calumet, OK (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.
Piedmont median
380 PPM
About the same2 indexed ZIP readings · Range 380–380 PPM
Oklahoma median
226 PPM
154 PPM higher148 indexed ZIP readings · Range 7–610 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, 2023
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 PCI/L
Local 18
EPA limit 15
100% line = listed limit
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Gross Alpha, Excl. Radon and U | OK2000909 | Archived | Jul 1, 2025through Sep 30, 2025 |
| Combined Uranium | OK2000909 | Archived | Jul 1, 2025through Sep 30, 2025 |
| Combined Radium (-226 and -228) | OK2000909 | Archived | Jul 1, 2025through Sep 30, 2025 |
| Gross Beta Particle Activity | OK2000909 | Archived | Jul 1, 2025through Sep 30, 2025 |
| Gross Alpha, Excl. Radon and U | OK2000909 | Archived | Apr 1, 2025through Jun 30, 2025 |
| Combined Uranium | OK2000909 | Archived | Apr 1, 2025through Jun 30, 2025 |
| Combined Radium (-226 and -228) | OK2000909 | Archived | Apr 1, 2025through Jun 30, 2025 |
| Gross Beta Particle Activity | OK2000909 | Archived | Apr 1, 2025through Jun 30, 2025 |
| LEAD AND COPPER RULE REVISIONSHealth-based | OK2000909 | Resolved | Oct 17, 2024through Jul 15, 2025 |
| LEAD AND COPPER RULE REVISIONS | OK2000909 | Resolved | Oct 17, 2024through Jul 15, 2025 |
| Chlorine | OK2000909 | Resolved | Aug 1, 2024through Aug 31, 2024 |
| Revised Total Coliform Rule | OK2000909 | Resolved | Aug 1, 2024through Aug 31, 2024 |
| Glyphosate | OK2000909 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| 2,4-D | OK2000909 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| Simazine | OK2000909 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| Glyphosate | OK2000909 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| 2,4-D | OK2000909 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| Gross Alpha, Excl. Radon and UHealth-basedReported 18 PCI/L · MCL 15 | OK2000909 | Resolved | Jan 1, 2024through Mar 31, 2024 |
| Simazine | OK2000909 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| Revised Total Coliform Rule | OK2000909 | Resolved | Dec 1, 2023through Dec 31, 2023 |
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 Piedmont ZIP 73762 using 380 PPM nearby hardness and 2 reported measurement benchmarks.
Scale protection
380 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 systemsDrinking water protection
Gross Alpha, Excl. Radon and U has 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 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 380 PPM, or 22.2 grains per gallon, classified as very hard. This is not a household tap measurement.
At 380 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.