How hard is the water in Sapulpa, OK?

Tap water hardness
111mg/L
6.5gpg
Moderately hard

Reported by Sapulpa Rural Water Company · December 2024

OK typical
152 mg/L
EPA health violations since 2016
2
Softener for 3 people
24k grain
Data
Utility report

Tap water in Sapulpa has about 111 mg/L of hardness, which is 6.5 grains per gallon. On the USGS scale that counts as moderately hard. The number comes from Sapulpa Rural Water Company, dated December 2024.

Sapulpa on the hardness scale, with nearby cities
060120180240300360+OK typical 152Bixby: 92 mg/LBixby 92Broken Arrow: 92 mg/LBroken Arrow 92Catoosa: 92 mg/LCatoosa 92Coweta: 92 mg/LCoweta 92Tulsa: 110 mg/LTulsa 110Sand Springs: 111 mg/LSand Springs 111Jenks: 148 mg/LJenks 148Owasso: 153 mg/LOwasso 153Skiatook: 153 mg/LSkiatook 153Collinsville: 153 mg/LCollinsville 153Sapulpa 111mg/L as calcium carbonate060120180240300360+OK 152Bixby: 92 mg/LBixby 92Broken Arrow: 92 mg/LBroken Arr. 92Catoosa: 92 mg/LCatoosa 92Tulsa: 110 mg/LTulsa 110Sand Springs: 111 mg/LSand Sprin. 111Jenks: 148 mg/LJenks 148111 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Sapulpa sits 41 mg/L below the typical Oklahoma figure of 152. Of the 10 nearest cities we track, 5 have softer water and 4 have harder. The range nearby runs from 92 mg/L in Bixby to 153 in Owasso.

What 111 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 Sapulpa

3 people × 75 gallons a day × 6.5 gpg = 1,460 grains a day. A 24,000-grain unit regenerates about every 16 days.

Size it for your household

EPA record for Sapulpa's water system

Sapulpa Rural Water Company · PWSID OK3001904

2 health-based violations since 2016

Serves about 5,810 people from surface water.

Health-based
2
Monitoring or reporting
1
Open now
1
20162017201820192020202120222023202420252026Total trihalomethanes (TTHM)'16'18'20'22'24'26Total trihalomethanes (TTHM)
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Total trihalomethanes (TTHM)a disinfection byproduct22022Resolved

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 Sapulpa water hard?

Somewhat. It measures about 111 mg/L (6.5 grains per gallon), which the USGS classes as moderately hard.

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

About 6.5 gpg. One grain per gallon equals 17.1 mg/L, so 111 mg/L divided by 17.1 gives 6.5.

What size water softener do I need in Sapulpa?

For 3 people using 75 gallons each per day, 6.5 gpg works out to about 1,460 grains a day. A 24,000-grain softener covers that with a regeneration about every 16 days.

Has the Sapulpa water system had EPA violations?

EPA records show 2 health-based violations for Sapulpa Rural Water Company since 2016, involving Total trihalomethanes (TTHM). There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.

Nearby cities

All 34 cities in Oklahoma

Hardness data: TapWaterData US Water Hardness (utility report, December 12, 2024), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.