Hardness
Soft
39.6 PPM · 2.3 GPG
Local water dashboard
Official source aggregationWater quality in Smithville, OK 74957
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Le Flore County.
1 reported benchmark flag
- Primary matched system
- Mccurtain Co. Rwd #6 (kiamichi)
- Source water
- Surface water
- County
- Le Flore 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
0.0016 mg/L
10% of action level
Utility match
1 system
Serves 600 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
39.6 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
39.6
mg/L as CaCO₃ equivalent
Grains per gallon
2.3
1 GPG ≈ 17.1 PPM
What this means at home
At 39.6 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
25.8 mi
Observation range
Mar 3, 2016–May 25, 2023
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: Cossatot River near Vandervoort, AR (Stream).USGS source documentation ↗
Regional context
Is 74957 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Smithville median
40 PPM
About the same1 indexed ZIP readings · Range 39.6–39.6 PPM
Oklahoma median
226 PPM
186 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)
0.0016 mg/L
Reported Dec 31, 2025
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 0.0016
EPA limit 0.015
Total Haloacetic Acids (HAA5)
Measured in MG/L
Local 0.065
EPA limit 0.06
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 6
- Health-based
- 3
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| LEAD AND COPPER RULE REVISIONS | OK3004817 | Resolved | Oct 17, 2024through Jul 15, 2025 |
| LEAD AND COPPER RULE REVISIONSHealth-based | OK3004817 | Resolved | Oct 17, 2024through Jul 15, 2025 |
| Total Haloacetic Acids (HAA5) | OK3004817 | Resolved | Apr 1, 2021through Mar 29, 2021 |
| TTHM | OK3004817 | Resolved | Apr 1, 2021through Mar 29, 2021 |
| Total Haloacetic Acids (HAA5)Health-basedReported 0.065 MG/L · MCL 0.06 | OK3004817 | Resolved | Jan 1, 2021through Mar 31, 2021 |
| Total Haloacetic Acids (HAA5)Health-basedReported 0.068 MG/L · MCL 0.06 | OK3004817 | Resolved | Jan 1, 2021through Mar 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 Smithville ZIP 74957 using 39.6 PPM nearby hardness and 2 reported measurement benchmarks.
Drinking water protection
Under-Sink Reverse Osmosis System
Total Haloacetic Acids (HAA5) 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 Smithville
Is tap water safe in Smithville?+
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 39.6 PPM, or 2.3 grains per gallon, classified as soft. 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.