Hard water in Lake Mills, WI
Reported by Lake Mills Waterworks · August 2022
- WI typical
- 170 mg/L
- EPA health violations since 2016
- 6
- Softener for 3 people
- 32k grain
- Data
- Utility report
Tap water in Lake Mills has about 324 mg/L of hardness, which is 18.9 grains per gallon. On the USGS scale that counts as very hard. The number comes from Lake Mills Waterworks, dated August 2022.
Lake Mills sits 154 mg/L above the typical Wisconsin figure of 170. Of the 10 nearest cities we track, 7 have softer water and 3 have harder. The range nearby runs from 144 mg/L in Columbus to 364 in McFarland.
What 324 mg/L means at home
Scale forms fast here. Kettles and coffee makers need regular descaling, and showerheads clog unless you clean them.
Tank water heaters collect mineral sediment that insulates the water from the burner, so flushing the tank matters more than usual.
Dishes and glass shower doors spot easily. Soap scum and a dull film on hair or laundry are common complaints.
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 324 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 × 18.9 gpg = 4,264 grains a day. A 32,000-grain unit regenerates about every 7 days.
EPA record for Lake Mills's water system
6 health-based violations since 2016
Serves about 6,211 people from groundwater.
- Health-based
- 6
- Monitoring or reporting
- 19
- Open now
- 1
| Contaminant or rule | Violations | Period | Status |
|---|---|---|---|
| Lead and Copper Rulecorrosion control and lead sampling | 5 | 2016–2022 | Resolved |
| Combined radiumnaturally occurring radioactivity | 1 | 2017 | Resolved |
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 Lake Mills water hard?
Yes. It measures about 324 mg/L (18.9 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Lake Mills in grains per gallon?
About 18.9 gpg. One grain per gallon equals 17.1 mg/L, so 324 mg/L divided by 17.1 gives 18.9.
What size water softener do I need in Lake Mills?
For 3 people using 75 gallons each per day, 18.9 gpg works out to about 4,264 grains a day. A 32,000-grain softener covers that with a regeneration about every 7 days.
Has the Lake Mills water system had EPA violations?
EPA records show 6 health-based violations for Lake Mills Waterworks since 2016, involving Lead and Copper Rule, Combined radium. There were also 19 monitoring or reporting violations, which are about late or missing tests and notices.
Nearby cities
- Jefferson280 mg/LVery hard
- Fort Atkinson278 mg/LVery hard
- Watertown249 mg/LVery hard
- Cottage Grove347 mg/LVery hard
- Sun Prairie337 mg/LVery hard
- Edgerton291 mg/LVery hard
- Whitewater323 mg/LVery hard
- Columbus144 mg/LHard
- Stoughton312 mg/LVery hard
- McFarland364 mg/LVery hard
Hardness data: TapWaterData US Water Hardness (utility report, August 8, 2022), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.