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 Grady County.
At a glance
EPA quarter 2026Q2
Hardness
Very Hard
380 PPM · 22.2 GPG
Compliance screen
Review needed
1 active health-based record
Lead 90th percentile
0.0038 mg/L
25% of action level
Utility match
1 system
Serves 16,036 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
33.5 mi
Observation range
Jan 5, 2016–May 21, 2026
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: North Canadian River blw Lk Overholser nr OKC, 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.
Chickasha median
380 PPM
About the same1 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)
0.0038 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.
Measured in mg/L
Local 0.0038
EPA limit 0.015
100% line = listed limit
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| LEAD AND COPPER RULE REVISIONSHealth-based | OK1010821 | Addressed | Oct 17, 2024 |
| LEAD AND COPPER RULE REVISIONS | OK1010821 | Addressed | Oct 17, 2024 |
| Revised Total Coliform Rule | OK1010821 | Resolved | Mar 1, 2024through Mar 31, 2024 |
| Chlorine | OK1010821 | Resolved | Jan 1, 2024through Mar 31, 2024 |
| Consumer Confidence Rule | OK1010821 | Resolved | Oct 2, 2023through Feb 16, 2024 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1010821 | Archived | Sep 1, 2023through Sep 30, 2023 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1010821 | Archived | Sep 1, 2023through Sep 30, 2023 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1010821 | Archived | Aug 1, 2023through Aug 31, 2023 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1010821 | Archived | Aug 1, 2023through Aug 31, 2023 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1010821 | Resolved | Aug 1, 2022through Aug 31, 2022 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1010821 | Resolved | Sep 1, 2021through Sep 30, 2021 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1010821 | Resolved | Sep 1, 2021through Sep 30, 2021 |
| Surface Water Treatment RuleHealth-based | OK1010821 | Resolved | Sep 1, 2021through Sep 30, 2021 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1010821 | Resolved | Aug 1, 2021through Aug 31, 2021 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1010821 | Resolved | Aug 1, 2021through Aug 31, 2021 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1010821 | Resolved | Jul 1, 2021through Jul 31, 2021 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1010821 | Resolved | Jul 1, 2021through Jul 31, 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
Matched to Chickasha ZIP 73018 using 380 PPM nearby hardness and 1 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
LEAD AND COPPER RULE REVISIONS 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.
Frequently asked
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.
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.