Hard water in Eagan, MN
Reported by Eagan · September 2025
- MN typical
- 160 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
The water in Eagan carries roughly 132 mg/L of dissolved calcium and magnesium, or 7.7 grains per gallon. That is hard water. The number comes from Eagan, dated September 2025.
At 132 mg/L, Eagan is 28 mg/L below the typical Minnesota figure of 160. Of the 10 nearest cities we track, 3 have softer water and 7 have harder. The range nearby runs from 82 mg/L in St. Paul to 310 in Savage.
What 132 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 132 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 × 7.7 gpg = 1,737 grains a day. A 24,000-grain unit regenerates about every 13 days.
EPA record for Eagan's water system
No health-based violations since 2016
Serves about 68,223 people from groundwater.
- Health-based
- 0
- Monitoring or reporting
- 1
- 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 Eagan water hard?
Yes. It measures about 132 mg/L (7.7 grains per gallon), which the USGS classes as hard.
What is the water hardness in Eagan in grains per gallon?
About 7.7 gpg. One grain per gallon equals 17.1 mg/L, so 132 mg/L divided by 17.1 gives 7.7.
What size water softener do I need in Eagan?
For 3 people using 75 gallons each per day, 7.7 gpg works out to about 1,737 grains a day. A 24,000-grain softener covers that with a regeneration about every 13 days.
Has the Eagan water system had EPA violations?
EPA records show no health-based violations for Eagan since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.
Nearby cities
- Inver Grove Heights270 mg/LVery hard
- Rosemount270 mg/LVery hard
- Burnsville193 mg/LVery hard
- Bloomington100 mg/LModerately hard
- St. Paul82 mg/LModerately hard
- Lakeville270 mg/LVery hard
- Savage310 mg/LVery hard
- Farmington270 mg/LVery hard
- Edina146 mg/LHard
- Minneapolis89 mg/LModerately hard
Hardness data: TapWaterData US Water Hardness (utility report, September 6, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.