Hard water in Durant, OK
County estimate from 647 water samples in Bryan County · July 2026
- OK typical
- 152 mg/L
- EPA health violations since 2016
- 2
- Softener for 3 people
- 24k grain
- Data
- County estimate
Water samples from around Durant put hardness at about 235 mg/L (13.7 gpg), which would be very hard on the USGS scale. Treat this as a rough guide: it is the median of 647 samples taken across Bryan County, mostly wells and streams, not a test of Durant's treated tap water. One more reason for caution: EPA lists Durant's water system as using surface water, which is often softer than the wells behind the county figure.
At 235 mg/L, Durant is 83 mg/L above the typical Oklahoma figure of 152. Of the 10 nearest cities we track, 7 have softer water and 3 have harder. The range nearby runs from 46 mg/L in Poteau to 463 in Mustang.
What 235 mg/L means at home
Scale forms fast here. Kettles and coffee makers need regular descaling, and showerheads clog unless you clean them.
Tank water heaters collect mineral sediment that insulates the water from the burner, so flushing the tank matters more than usual.
Dishes and glass shower doors spot easily. Soap scum and a dull film on hair or laundry are common complaints.
Hardness is not a health problem, and EPA sets no limit for it. It is a matter of scale and soap.
What to do about it
At 235 mg/L most of the trouble is scale, and only a few things deal with it.
Ion-exchange water softener
The standard whole-house fix. It swaps calcium and magnesium for sodium or potassium and needs salt plus a drain. Size it with the calculator below.
Salt-free conditioner
No salt and no drain line. It changes how minerals form scale instead of removing them, so water still tests hard.
Reverse osmosis or carbon filter
Under-sink reverse osmosis removes minerals from drinking water only. Plain carbon filters improve taste but do not soften.
3 people × 75 gallons a day × 13.7 gpg = 3,092 grains a day. A 24,000-grain unit regenerates about every 7 days.
EPA record for Durant's water system
2 health-based violations since 2016
Serves about 15,545 people from surface water.
- Health-based
- 2
- Monitoring or reporting
- 0
- Open now
- 0
EPA lists this system as serving Durant.
| Contaminant or rule | Violations | Period | Status |
|---|---|---|---|
| Haloacetic acids (HAA5)a disinfection byproduct | 2 | 2024 | Resolved |
Health-based means a contaminant above its legal limit or a missed treatment step. Monitoring and reporting violations are late or missing tests and notices. Source: EPA ECHO, 2026Q3 export, violations with periods starting 2016 or later. Full EPA record.
Questions
Is Durant water hard?
Yes. It measures about 235 mg/L (13.7 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Durant in grains per gallon?
About 13.7 gpg. One grain per gallon equals 17.1 mg/L, so 235 mg/L divided by 17.1 gives 13.7.
What size water softener do I need in Durant?
For 3 people using 75 gallons each per day, 13.7 gpg works out to about 3,092 grains a day. A 24,000-grain softener covers that with a regeneration about every 7 days.
Has the Durant water system had EPA violations?
EPA records show 2 health-based violations for Durant Utilities Authority since 2016, involving Haloacetic acids (HAA5).
Nearby cities
- Ardmore242 mg/LVery hard
- Duncan290 mg/LVery hard
- Shawnee140 mg/LHard
- Norman148 mg/LHard
- Newcastle157 mg/LHard
- Moore94 mg/LModerately hard
- Oklahoma City157 mg/LHard
- Mustang463 mg/LVery hard
- Lawton152 mg/LHard
- Poteau46 mg/LSoft
Hardness data: TapWaterData US Water Hardness (county estimate, July 4, 2026), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.