How hard is the water in Carpentersville, IL?

Tap water hardness
67mg/L
3.9gpg
Moderately hard

Calculated from the utility's calcium and magnesium results · June 2025

IL typical
139 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
Calculated from utility data

Carpentersville water measures 67 mg/L (3.9 gpg) of hardness, moderately hard by USGS standards. TapWaterData worked it out from the calcium and magnesium levels the local utility reports (June 2025).

Carpentersville on the hardness scale, with nearby cities
060120180240300360+IL typical 139West Dundee: 14 mg/LWest Dundee 14Huntley: 31 mg/LHuntley 31Pingree Grove: 65 mg/LPingree Grove 65Elgin: 111 mg/LElgin 111Hoffman Estates: 229 mg/LHoffman Estates 229Lake in the Hills: 283 mg/LLake in the Hills 283Gilberts: 328 mg/LGilberts 328Algonquin: 378 mg/LAlgonquin 378Cary: 378 mg/LCary 378Crystal Lake: 388 mg/LCrystal Lake 388Carpentersville 67mg/L as calcium carbonate060120180240300360+IL 139West Dundee: 14 mg/LWest Dundee 14Elgin: 111 mg/LElgin 111Lake in the Hills: 283 mg/LLake in th. 283Gilberts: 328 mg/LGilberts 328Algonquin: 378 mg/LAlgonquin 378Cary: 378 mg/LCary 37867 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Carpentersville sits 72 mg/L below the typical Illinois figure of 139. Of the 10 nearest cities we track, 3 have softer water and 7 have harder. The range nearby runs from 14 mg/L in West Dundee to 388 in Crystal Lake.

What 67 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 Carpentersville

3 people × 75 gallons a day × 3.9 gpg = 886 grains a day. A 24,000-grain unit regenerates about every 27 days.

Size it for your household

EPA record for Carpentersville's water system

Carpentersville · PWSID IL0890200

No health-based violations since 2016

Serves about 37,983 people from groundwater.

Health-based
0
Monitoring or reporting
1
Open now
0

EPA lists this system as serving Carpentersville.

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 Carpentersville water hard?

Somewhat. It measures about 67 mg/L (3.9 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Carpentersville in grains per gallon?

About 3.9 gpg. One grain per gallon equals 17.1 mg/L, so 67 mg/L divided by 17.1 gives 3.9.

What size water softener do I need in Carpentersville?

For 3 people using 75 gallons each per day, 3.9 gpg works out to about 886 grains a day. A 24,000-grain softener covers that with a regeneration about every 27 days.

Has the Carpentersville water system had EPA violations?

EPA records show no health-based violations for Carpentersville since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.

Nearby cities

All 192 cities in Illinois

Hardness data: TapWaterData US Water Hardness (calculated from utility data, June 5, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.