How hard is the water in Broken Arrow, OK?

Tap water hardness
92mg/L
5.4gpg
Moderately hard

Reported by Wagoner CO. RWD #4 · August 2025

OK typical
152 mg/L
EPA health violations since 2016
41
Softener for 3 people
24k grain
Data
Utility report

Tap water in Broken Arrow has about 92 mg/L of hardness, which is 5.4 grains per gallon. On the USGS scale that counts as moderately hard. The number comes from Wagoner CO. RWD #4, dated August 2025.

Broken Arrow on the hardness scale, with nearby cities
060120180240300360+OK typical 152Coweta: 92 mg/LCoweta 92Bixby: 92 mg/LBixby 92Catoosa: 92 mg/LCatoosa 92Tulsa: 110 mg/LTulsa 110Sapulpa: 111 mg/LSapulpa 111Sand Springs: 111 mg/LSand Springs 111Claremore: 131 mg/LClaremore 131Jenks: 148 mg/LJenks 148Owasso: 153 mg/LOwasso 153Skiatook: 153 mg/LSkiatook 153Broken Arrow 92mg/L as calcium carbonate060120180240300360+OK 152Coweta: 92 mg/LCoweta 92Bixby: 92 mg/LBixby 92Catoosa: 92 mg/LCatoosa 92Tulsa: 110 mg/LTulsa 110Jenks: 148 mg/LJenks 148Owasso: 153 mg/LOwasso 15392 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 92 mg/L, Broken Arrow is 60 mg/L below the typical Oklahoma figure of 152. None of the 10 nearest cities we track has softer water. The range nearby runs from 92 mg/L in Coweta to 153 in Owasso.

What 92 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 Broken Arrow

3 people × 75 gallons a day × 5.4 gpg = 1,213 grains a day. A 24,000-grain unit regenerates about every 19 days.

Size it for your household

EPA record for Broken Arrow's water system

Wagoner CO. RWD #4 · PWSID OK1021529

41 health-based violations since 2016

Serves about 37,658 people from surface water.

Health-based
41
Monitoring or reporting
5
Open now
0
20162017201820192020202120222023202420252026Surface Water Treatment Rule (LT2)Surface Water Treatment RuleTotal trihalomethanes (TTHM)'16'18'20'22'24'26Surface Water Treatment Rule (LT2)Surface Water Treatment RuleTotal trihalomethanes (TTHM)
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Surface Water Treatment Rule (LT2)filtration and disinfection252018–2025Resolved
Surface Water Treatment Rulefiltration and disinfection72021–2025Resolved
Total trihalomethanes (TTHM)a disinfection byproduct82021–2023Resolved

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 Broken Arrow water hard?

Somewhat. It measures about 92 mg/L (5.4 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Broken Arrow in grains per gallon?

About 5.4 gpg. One grain per gallon equals 17.1 mg/L, so 92 mg/L divided by 17.1 gives 5.4.

What size water softener do I need in Broken Arrow?

For 3 people using 75 gallons each per day, 5.4 gpg works out to about 1,213 grains a day. A 24,000-grain softener covers that with a regeneration about every 19 days.

Has the Broken Arrow water system had EPA violations?

EPA records show 41 health-based violations for Wagoner CO. RWD #4 since 2016, involving Surface Water Treatment Rule (LT2), Surface Water Treatment Rule, Total trihalomethanes (TTHM). There were also 5 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.