Hard water in Gardner, KS
Reported by Water District 1 of Johnson CO · September 2025
- KS typical
- 138 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
The water in Gardner carries roughly 135 mg/L of dissolved calcium and magnesium, or 7.9 grains per gallon. That is hard water. The number comes from Water District 1 of Johnson CO, dated September 2025.
Gardner sits close to the typical Kansas figure of 138 mg/L. Of the 10 nearest cities we track, 2 have softer water and 2 have harder. The range nearby runs from 133 mg/L in Paola to 416 in Bonner Springs.
What 135 mg/L means at home
Expect white crust on faucets and showerheads, plus spots on dishes that come out of the dishwasher.
Kettles collect scale quickly. Water heaters build up sediment at the bottom of the tank, which makes them work harder over time.
Soap and detergent need a little more to lather, and soap scum shows up in the tub.
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 135 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 × 7.9 gpg = 1,782 grains a day. A 24,000-grain unit regenerates about every 13 days.
EPA record for Gardner's water system
No health-based violations since 2016
Serves about 23,942 people from surface water.
- Health-based
- 0
- Monitoring or reporting
- 1
- Open now
- 0
EPA lists Gardner, City of as the system serving Gardner. The hardness figure above comes from a different system's report, which TapWaterData uses for Gardner.
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 Gardner water hard?
Yes. It measures about 135 mg/L (7.9 grains per gallon), which the USGS classes as hard.
What is the water hardness in Gardner in grains per gallon?
About 7.9 gpg. One grain per gallon equals 17.1 mg/L, so 135 mg/L divided by 17.1 gives 7.9.
What size water softener do I need in Gardner?
For 3 people using 75 gallons each per day, 7.9 gpg works out to about 1,782 grains a day. A 24,000-grain softener covers that with a regeneration about every 13 days.
Has the Gardner water system had EPA violations?
EPA records show no health-based violations for Gardner, City of since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.
Nearby cities
- Spring Hill135 mg/LHard
- Olathe140 mg/LHard
- De Soto135 mg/LHard
- Lenexa135 mg/LHard
- Overland Park135 mg/LHard
- Shawnee135 mg/LHard
- Paola133 mg/LHard
- Leawood135 mg/LHard
- Louisburg133 mg/LHard
- Bonner Springs416 mg/LVery hard
Hardness data: TapWaterData US Water Hardness (utility report, September 8, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.