How hard is the water in Tulsa, OK?

Tap water hardness
110mg/L
6.4gpg
Moderately hard

Reported by Tulsa · August 2025

OK typical
152 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
Utility report

The water in Tulsa carries roughly 110 mg/L of dissolved calcium and magnesium, or 6.4 grains per gallon. That is moderately hard water. The number comes from Tulsa, dated August 2025.

Tulsa on the hardness scale, with nearby cities
060120180240300360+OK typical 152Catoosa: 92 mg/LCatoosa 92Broken Arrow: 92 mg/LBroken Arrow 92Bixby: 92 mg/LBixby 92Coweta: 92 mg/LCoweta 92Sand Springs: 111 mg/LSand Springs 111Sapulpa: 111 mg/LSapulpa 111Jenks: 148 mg/LJenks 148Owasso: 153 mg/LOwasso 153Skiatook: 153 mg/LSkiatook 153Collinsville: 153 mg/LCollinsville 153Tulsa 110mg/L as calcium carbonate060120180240300360+OK 152Catoosa: 92 mg/LCatoosa 92Broken Arrow: 92 mg/LBroken Arr. 92Bixby: 92 mg/LBixby 92Sand Springs: 111 mg/LSand Sprin. 111Jenks: 148 mg/LJenks 148Owasso: 153 mg/LOwasso 153110 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Tulsa sits 42 mg/L below the typical Oklahoma figure of 152. Of the 10 nearest cities we track, 4 have softer water and 6 have harder. The range nearby runs from 92 mg/L in Catoosa to 153 in Owasso.

What 110 mg/L means at home

You may see faint white spots on glasses and shower doors after the water dries.

Scale builds up slowly. A kettle or coffee maker needs descaling now and then, maybe every few months.

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

Optional. Plenty of households at this level live with it and descale the kettle now and then.

Water softener

Worth a look if spots on glass bother you, or if your tankless water heater manual asks for softer water.

Carbon filter

Improves taste and removes chlorine. It leaves calcium and magnesium in place.

Softener size for Tulsa

3 people × 75 gallons a day × 6.4 gpg = 1,447 grains a day. A 24,000-grain unit regenerates about every 16 days.

Size it for your household

EPA record for Tulsa's water system

Tulsa · PWSID OK1020418

No health-based violations since 2016

Serves about 413,000 people from surface water.

Health-based
0
Monitoring or reporting
23
Open now
0

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 Tulsa water hard?

Somewhat. It measures about 110 mg/L (6.4 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Tulsa in grains per gallon?

About 6.4 gpg. One grain per gallon equals 17.1 mg/L, so 110 mg/L divided by 17.1 gives 6.4.

What size water softener do I need in Tulsa?

For 3 people using 75 gallons each per day, 6.4 gpg works out to about 1,447 grains a day. A 24,000-grain softener covers that with a regeneration about every 16 days.

Has the Tulsa water system had EPA violations?

EPA records show no health-based violations for Tulsa since 2016. There were also 23 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 34 cities in Oklahoma

Hardness data: TapWaterData US Water Hardness (utility report, August 18, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.