How hard is the water in Eau Claire, WI?

Tap water hardness
101mg/L
5.9gpg
Moderately hardReports range 65–101

Reported by Eau Claire Waterworks · September 2025

WI typical
170 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
Utility report

The water in Eau Claire carries roughly 101 mg/L of dissolved calcium and magnesium, or 5.9 grains per gallon. That is moderately hard water. The number comes from Eau Claire Waterworks, dated September 2025. Reports for this system disagree, with values from 65 to 101 mg/L.

Eau Claire on the hardness scale, with nearby cities
060120180240300360+WI typical 170Chippewa Falls: 49 mg/LChippewa Falls 49Lake Hallie: 61 mg/LLake Hallie 61Rice Lake: 96 mg/LRice Lake 96Altoona: 102 mg/LAltoona 102Menomonie: 150 mg/LMenomonie 150River Falls: 180 mg/LRiver Falls 180New Richmond: 194 mg/LNew Richmond 194Hudson: 210 mg/LHudson 210Holmen: 319 mg/LHolmen 319Onalaska: 337 mg/LOnalaska 337Eau Claire 101mg/L as calcium carbonate060120180240300360+WI 170Chippewa Falls: 49 mg/LChippewa F. 49Lake Hallie: 61 mg/LLake Hallie 61Rice Lake: 96 mg/LRice Lake 96Altoona: 102 mg/LAltoona 102Menomonie: 150 mg/LMenomonie 150River Falls: 180 mg/LRiver Falls 180101 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 101 mg/L, Eau Claire is 69 mg/L below the typical Wisconsin figure of 170. Of the 10 nearest cities we track, 3 have softer water and 7 have harder. The range nearby runs from 49 mg/L in Chippewa Falls to 337 in Onalaska.

What 101 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 Eau Claire

3 people × 75 gallons a day × 5.9 gpg = 1,325 grains a day. A 24,000-grain unit regenerates about every 18 days.

Size it for your household

EPA record for Eau Claire's water system

Eau Claire Waterworks · PWSID WI6180230

No health-based violations since 2016

Serves about 70,587 people from groundwater.

Health-based
0
Monitoring or reporting
0
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 Eau Claire water hard?

Somewhat. It measures about 101 mg/L (5.9 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Eau Claire in grains per gallon?

About 5.9 gpg. One grain per gallon equals 17.1 mg/L, so 101 mg/L divided by 17.1 gives 5.9.

What size water softener do I need in Eau Claire?

For 3 people using 75 gallons each per day, 5.9 gpg works out to about 1,325 grains a day. A 24,000-grain softener covers that with a regeneration about every 18 days.

Has the Eau Claire water system had EPA violations?

EPA records show no health-based violations for Eau Claire Waterworks since 2016.

Nearby cities

All 112 cities in Wisconsin

Hardness data: TapWaterData US Water Hardness (utility report, September 16, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.