Hard water in Lawrence, KS
Reported by Lawrence, City of · April 2025
- KS typical
- 138 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
Tap water in Lawrence has about 142 mg/L of hardness, which is 8.3 grains per gallon. On the USGS scale that counts as hard. The number comes from Lawrence, City of, dated April 2025.
Lawrence sits close to the typical Kansas figure of 138 mg/L. Of the 10 nearest cities we track, 6 have softer water and 4 have harder. The range nearby runs from 135 mg/L in De Soto to 416 in Bonner Springs.
What 142 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 142 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 × 8.3 gpg = 1,863 grains a day. A 24,000-grain unit regenerates about every 12 days.
EPA record for Lawrence's water system
No health-based violations since 2016
Serves about 95,256 people from surface water.
- Health-based
- 0
- Monitoring or reporting
- 2
- 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 Lawrence water hard?
Yes. It measures about 142 mg/L (8.3 grains per gallon), which the USGS classes as hard.
What is the water hardness in Lawrence in grains per gallon?
About 8.3 gpg. One grain per gallon equals 17.1 mg/L, so 142 mg/L divided by 17.1 gives 8.3.
What size water softener do I need in Lawrence?
For 3 people using 75 gallons each per day, 8.3 gpg works out to about 1,863 grains a day. A 24,000-grain softener covers that with a regeneration about every 12 days.
Has the Lawrence water system had EPA violations?
EPA records show no health-based violations for Lawrence, City of since 2016. There were also 2 monitoring or reporting violations, which are about late or missing tests and notices.
Nearby cities
- Tonganoxie215 mg/LVery hard
- De Soto135 mg/LHard
- Gardner135 mg/LHard
- Bonner Springs416 mg/LVery hard
- Topeka145 mg/LHard
- Olathe140 mg/LHard
- Lenexa135 mg/LHard
- Ottawa144 mg/LHard
- Shawnee135 mg/LHard
- Spring Hill135 mg/LHard
Hardness data: TapWaterData US Water Hardness (utility report, April 23, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.