Hard water in North Chicago, IL
Reported by Great Lakes Naval Training Station · April 2024
- IL typical
- 139 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
North Chicago water measures 136 mg/L (8.0 gpg) of hardness, hard by USGS standards. The number comes from Great Lakes Naval Training Station, dated April 2024.
At 136 mg/L, North Chicago is close to the typical Illinois figure of 139 mg/L. Of the 10 nearest cities we track, 3 have softer water and 7 have harder. The range nearby runs from 119 mg/L in Waukegan to 380 in Lincolnshire.
What 136 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 136 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 × 8.0 gpg = 1,791 grains a day. A 24,000-grain unit regenerates about every 13 days.
EPA record for North Chicago's water system
No health-based violations since 2016
Serves about 23,000 people from surface water.
- 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 North Chicago water hard?
Yes. It measures about 136 mg/L (8.0 grains per gallon), which the USGS classes as hard.
What is the water hardness in North Chicago in grains per gallon?
About 8.0 gpg. One grain per gallon equals 17.1 mg/L, so 136 mg/L divided by 17.1 gives 8.0.
What size water softener do I need in North Chicago?
For 3 people using 75 gallons each per day, 8.0 gpg works out to about 1,791 grains a day. A 24,000-grain softener covers that with a regeneration about every 13 days.
Has the North Chicago water system had EPA violations?
EPA records show no health-based violations for Great Lakes Naval Training Station since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.
Nearby cities
- Lake Bluff128 mg/LHard
- Waukegan119 mg/LModerately hard
- Gurnee250 mg/LVery hard
- Libertyville250 mg/LVery hard
- Vernon Hills250 mg/LVery hard
- Highwood120 mg/LModerately hard
- Mundelein250 mg/LVery hard
- Lincolnshire380 mg/LVery hard
- Grayslake250 mg/LVery hard
- Zion250 mg/LVery hard
Hardness data: TapWaterData US Water Hardness (utility report, April 22, 2024), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.