Hardness
Moderately Hard
114.5 PPM · 6.7 GPG
Local water dashboard
Official source aggregationWater quality in Blackwell, OK 74631
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Kay County.
1 reported benchmark flag
- Primary matched system
- Blackwell Municipal Authority
- Source water
- Surface water
- County
- Kay 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
1 system
Serves 7,668 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
114.5 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
114.5
mg/L as CaCO₃ equivalent
Grains per gallon
6.7
1 GPG ≈ 17.1 PPM
What this means at home
At 114.5 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
4
Nearest site
55.3 mi
Observation range
Feb 17, 2016–May 19, 2026
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: McConnell C at Oliver St, Wichita, KS (Stream).USGS source documentation ↗
Regional context
Is 74631 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Blackwell median
115 PPM
About the same1 indexed ZIP readings · Range 114.5–114.5 PPM
Oklahoma median
226 PPM
111 PPM lower148 indexed ZIP readings · Range 7–610 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 pass1 fail
Lead (PB90)
0 mg/L
Reported Dec 31, 2024
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.
Lead (90th percentile)
Measured in mg/L
Local 0
EPA limit 0.015
TTHM
Measured in MG/L
Local 0.085
EPA limit 0.08
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 13
- Health-based
- 10
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1021101 | Resolved | Jul 1, 2025through Jul 31, 2025 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1021101 | Resolved | Jun 1, 2025through Jun 30, 2025 |
| Interim Enhanced Surface Water Treatment Rule | OK1021101 | Resolved | May 1, 2025through May 31, 2025 |
| Chlorine dioxide | OK1021101 | Resolved | May 1, 2025through May 31, 2025 |
| TTHM | OK1021101 | Resolved | Apr 1, 2025through May 6, 2025 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1021101 | Resolved | Jan 1, 2025through Jan 31, 2025 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1021101 | Resolved | Jun 1, 2024through Jun 30, 2024 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1021101 | Resolved | Mar 1, 2024through Mar 31, 2024 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1021101 | Resolved | Mar 1, 2024through Mar 31, 2024 |
| TTHMHealth-basedReported 0.085 MG/L · MCL 0.08 | OK1021101 | Resolved | Jan 1, 2023through Mar 31, 2023 |
| TTHMHealth-basedReported 0.082 MG/L · MCL 0.08 | OK1021101 | Resolved | Oct 1, 2022through Dec 31, 2022 |
| Surface Water Treatment RuleHealth-based | OK1021101 | Resolved | Sep 1, 2022through Sep 30, 2022 |
| Interim Enhanced Surface Water Treatment RuleHealth-based | OK1021101 | Resolved | May 1, 2021through May 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
Your personalized water action plan
Matched to Blackwell ZIP 74631 using 114.5 PPM nearby hardness and 2 reported measurement benchmarks.
Drinking water protection
Under-Sink Reverse Osmosis System
TTHM 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
Water questions for Blackwell
Is tap water safe in Blackwell?+
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 114.5 PPM, or 6.7 grains per gallon, classified as moderately hard. This is not a household tap measurement.
Do I need a water softener?+
There is no high-hardness trigger in this profile. Confirm with a tap test before buying equipment.